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Emad Shahmansouri, Zahra Abbasi,
Volume 10, Issue 1 (9-2023)
Volume 10, Issue 1 (9-2023)
Abstract
Extended Abstract
Introduction: The selection of optimum planting date for every climate and mother bulb size are important factors affecting the quantity and quality of seed production in different cultivars. This study was performed in Isfahan province, Frieden, during two growing years 2016-2017 to determine the effect of planting time and mother bulb size on the quantity and quality of short-day onion seed varieties Texas Early Grano 502
Materials and Methods: A split-plot experiment was performed in a randomized complete block design with four replications. The main factor was cultivation dates at four levels: the end of August, the first of September, the end of September and the first of October and mother bulb size at three levels with 3.55, 5.5-7, and 7.5-9cm diameters were assigned as sub-plots. The measured traits were number of umbel per unit area, the number of fertilized capsules in umbel, the number of seeds per capsule, 1000 seed weight, seed yield and germination rate.
Results: The results of combined analysis of variance showed that effect of year was only significant on the number of capsules per umbel at p<0.01. The interactions of year× mother bulb diameter and year× planting date× mother bulb diameter were not significant for any of the traits. The traits were not affected by the year. The results showed that the planting date had a significant effect on all traits except for 1000 seed weight, and the first planting date (the end of August) had the highest values in all traits. The highest germination percentage (89.83%) and the highest germination rate (12.8) were obtained on the first planting date, which showed a statistically significant difference with the subsequent planting dates. However, these two traits were not affected by mother bulb diameter treatment. The highest seed yield for onion diameter factor (505.65 kg h-1in the first year and 465.78 kg h-1 in the second year) was associated with mother bulb size of 7.5-9 cm.
Conclusions: The overall result showed that to obtain the highest and most desirable quality of onion seeds of Texas Early Grano 502 cultivar in Friedan of Isfahan, the planting date of the first of September and the size of the mother bulb “between” 7 to 9 cm is recommended.
Highlights:
1- Early planting time (the first of September) increased germination rate.
2- Increasing the mother bulb size increased the onion yield.
Introduction: The selection of optimum planting date for every climate and mother bulb size are important factors affecting the quantity and quality of seed production in different cultivars. This study was performed in Isfahan province, Frieden, during two growing years 2016-2017 to determine the effect of planting time and mother bulb size on the quantity and quality of short-day onion seed varieties Texas Early Grano 502
Materials and Methods: A split-plot experiment was performed in a randomized complete block design with four replications. The main factor was cultivation dates at four levels: the end of August, the first of September, the end of September and the first of October and mother bulb size at three levels with 3.55, 5.5-7, and 7.5-9cm diameters were assigned as sub-plots. The measured traits were number of umbel per unit area, the number of fertilized capsules in umbel, the number of seeds per capsule, 1000 seed weight, seed yield and germination rate.
Results: The results of combined analysis of variance showed that effect of year was only significant on the number of capsules per umbel at p<0.01. The interactions of year× mother bulb diameter and year× planting date× mother bulb diameter were not significant for any of the traits. The traits were not affected by the year. The results showed that the planting date had a significant effect on all traits except for 1000 seed weight, and the first planting date (the end of August) had the highest values in all traits. The highest germination percentage (89.83%) and the highest germination rate (12.8) were obtained on the first planting date, which showed a statistically significant difference with the subsequent planting dates. However, these two traits were not affected by mother bulb diameter treatment. The highest seed yield for onion diameter factor (505.65 kg h-1in the first year and 465.78 kg h-1 in the second year) was associated with mother bulb size of 7.5-9 cm.
Conclusions: The overall result showed that to obtain the highest and most desirable quality of onion seeds of Texas Early Grano 502 cultivar in Friedan of Isfahan, the planting date of the first of September and the size of the mother bulb “between” 7 to 9 cm is recommended.
Highlights:
1- Early planting time (the first of September) increased germination rate.
2- Increasing the mother bulb size increased the onion yield.
Ladan Zinati, Asieh Siahmarguee, Farshid Ghaderi-Far, Masomeh Yones-Abadi, Bhagirath Singh Chauhan,
Volume 10, Issue 1 (9-2023)
Volume 10, Issue 1 (9-2023)
Abstract
Extended Abstract
Introduction: The different species of Amaranthus species are among the most important damaging weeds in the world. Due to the importance of studying the effect of management factors on seed dynamics of different weed species, this experiment aimed to investigate the effect of burial depth and high temperatures on the seed dynamic of different species of Amaranthus in Golestan province including white pigweed (A. albus), prostrate pigweed (A. belitoides), hybrid Amaranthus (A. chlorostachys), redroot pigweed (A. retrofelexus) and green Amaranthus (A. viridis) were performed.
Materials and Methods: This research was conducted on five amaranthus species of white pigweed, prostrate pigweed, hybrid Amaranthus, redroot pigweed, and green Amaranthus at the seed laboratory and greenhouse of Gorgan University of Agricultural Sciences and Natural Resources. In the first experiment, seed emergence of different species of Amaranthus was studied in eight burial depths including 0, 1, 2, 3, 4, 5, 7, and 10 cm. In the second experiment, seeds were exposed to 50, 60, 70, 80, 90, 100, and 110 °C temperatures for 5, 10, and 15 minutes
Results: All seeds of A. blitoides and A. viridis germinated in the topsoil (zero depth); But, in A. albus, A. retroflexus, A. chlorostachys, 93%, 83%, and 3% of the seeds were emergence at the soil surface, respectively. By increasing the burial depth to one centimeter, the percentage of seeds emergence in different species of Amaranthus decreased significantly and was negligible at ≥ 2 cm depth. Germination test performed on retrieved seeds showed that zero to 16% of the seeds were able to germinate in petri dish, and most of the non-germinated seeds were viable. In all species except for A. chlorostachys high temperatures reduced the germination percentage.
Conclusion: Due to the reduction of seed germination percentage of different species of Amaranthus from a depth of more than one centimeter of soil, it seems that the use of conservation and conventional tillage methods has a good potential to reduce infestation of fields by these weeds. Also, although high temperatures reduce weed infestation in fields, they do not have a significant effect on depleting the seed bank of these species.
Highlights:
1- Seed dynamics of different species of Amaranthus were affected by burial depth and high temperature
2- Deep burial of seeds of different species of Amaranthus causes the stability of their seeds in the soil seed bank.
Introduction: The different species of Amaranthus species are among the most important damaging weeds in the world. Due to the importance of studying the effect of management factors on seed dynamics of different weed species, this experiment aimed to investigate the effect of burial depth and high temperatures on the seed dynamic of different species of Amaranthus in Golestan province including white pigweed (A. albus), prostrate pigweed (A. belitoides), hybrid Amaranthus (A. chlorostachys), redroot pigweed (A. retrofelexus) and green Amaranthus (A. viridis) were performed.
Materials and Methods: This research was conducted on five amaranthus species of white pigweed, prostrate pigweed, hybrid Amaranthus, redroot pigweed, and green Amaranthus at the seed laboratory and greenhouse of Gorgan University of Agricultural Sciences and Natural Resources. In the first experiment, seed emergence of different species of Amaranthus was studied in eight burial depths including 0, 1, 2, 3, 4, 5, 7, and 10 cm. In the second experiment, seeds were exposed to 50, 60, 70, 80, 90, 100, and 110 °C temperatures for 5, 10, and 15 minutes
Results: All seeds of A. blitoides and A. viridis germinated in the topsoil (zero depth); But, in A. albus, A. retroflexus, A. chlorostachys, 93%, 83%, and 3% of the seeds were emergence at the soil surface, respectively. By increasing the burial depth to one centimeter, the percentage of seeds emergence in different species of Amaranthus decreased significantly and was negligible at ≥ 2 cm depth. Germination test performed on retrieved seeds showed that zero to 16% of the seeds were able to germinate in petri dish, and most of the non-germinated seeds were viable. In all species except for A. chlorostachys high temperatures reduced the germination percentage.
Conclusion: Due to the reduction of seed germination percentage of different species of Amaranthus from a depth of more than one centimeter of soil, it seems that the use of conservation and conventional tillage methods has a good potential to reduce infestation of fields by these weeds. Also, although high temperatures reduce weed infestation in fields, they do not have a significant effect on depleting the seed bank of these species.
Highlights:
1- Seed dynamics of different species of Amaranthus were affected by burial depth and high temperature
2- Deep burial of seeds of different species of Amaranthus causes the stability of their seeds in the soil seed bank.
Fatemeh Ghorbannezhad, Mohsen Zavareh, Farzad Sharifzadeh,
Volume 10, Issue 1 (9-2023)
Volume 10, Issue 1 (9-2023)
Abstract
Extended abstract
Introduction: Linseed (Linum usitatissimum L.) is a multipurpose crop and is cultivated to obtain oil, fiber, and seeds. Under optimal moisture conditions, the temperature is considered an environmental factor affecting the germination of this crop. Hence, knowing the cardinal temperatures can help farmers to predict the successful germination, emergence, and even yield of linseed and help scientists to develop new cultivars that are more tolerant to high temperatures. Therefore, this study was performed to determine the temperature range and the cardinal temperatures of germination in two linseed genotypes.
Material and methods: The germination response of two linseed genotypes (Golchin genotype and Line 286) to nine temperatures (3, 5, 10, 15, 20, 25, 30, 35, and 40 Celsius degrees) was quantified in a CRD based split-plot experiment with four replications. For this purpose, three nonlinear regression models (beta, segmented, and dent-like) were used to fit to the data and select the superior model. The superior model was selected using the Akaike information index (AIC), the modified Akaike index (AICc), and ∆i.
Results: Findings showed that the beta model had the best performance in estimating the line 286 cardinal temperatures according to its lower AIC (-3.96), AICc (-89.61), and ∆i (0). Accordingly, the base, optimum, and maximum temperature as well as the number of biological hours estimated by this model for Line 286 were 7.18, 24.22, 40.16 Celsius degrees, and 19.25 hours, respectively. In the Golchin genotype, the beta model with the lowest AIC=-3.89 and AICc= -89.083 fitted better compared with the other models. Nonetheless, considering ∆i for beta which was respectively 0, 1.61, and 4.49 for beta, segmented, and dent-like models, Beta and segmented models had a similar accuracy in estimation of cardinal temperatures for Golchin genotype. These findings represent that the suitable temperature range for germination of the Golchin genotype is 3.8- 23.85 Celsius degrees and the range of biological hours to 50% of germination varied from 16.42 to 19.77 hours.
Conclusion: Overall, according to the results of this study, it is possible to predict the time to germination under optimal moisture conditions using the beta model for Line 286 and one of the two beta and segmented models for the Golchin genotype.
Highlights:
1. A suitable model was developed for a suitable prediction of the seed germination percentage of two linseed genotypes (Golchin genotype and Line 286).
2. The cardinal temperatures for two linseed genotypes (Golchin genotype and Line 286) were determined.
Introduction: Linseed (Linum usitatissimum L.) is a multipurpose crop and is cultivated to obtain oil, fiber, and seeds. Under optimal moisture conditions, the temperature is considered an environmental factor affecting the germination of this crop. Hence, knowing the cardinal temperatures can help farmers to predict the successful germination, emergence, and even yield of linseed and help scientists to develop new cultivars that are more tolerant to high temperatures. Therefore, this study was performed to determine the temperature range and the cardinal temperatures of germination in two linseed genotypes.
Material and methods: The germination response of two linseed genotypes (Golchin genotype and Line 286) to nine temperatures (3, 5, 10, 15, 20, 25, 30, 35, and 40 Celsius degrees) was quantified in a CRD based split-plot experiment with four replications. For this purpose, three nonlinear regression models (beta, segmented, and dent-like) were used to fit to the data and select the superior model. The superior model was selected using the Akaike information index (AIC), the modified Akaike index (AICc), and ∆i.
Results: Findings showed that the beta model had the best performance in estimating the line 286 cardinal temperatures according to its lower AIC (-3.96), AICc (-89.61), and ∆i (0). Accordingly, the base, optimum, and maximum temperature as well as the number of biological hours estimated by this model for Line 286 were 7.18, 24.22, 40.16 Celsius degrees, and 19.25 hours, respectively. In the Golchin genotype, the beta model with the lowest AIC=-3.89 and AICc= -89.083 fitted better compared with the other models. Nonetheless, considering ∆i for beta which was respectively 0, 1.61, and 4.49 for beta, segmented, and dent-like models, Beta and segmented models had a similar accuracy in estimation of cardinal temperatures for Golchin genotype. These findings represent that the suitable temperature range for germination of the Golchin genotype is 3.8- 23.85 Celsius degrees and the range of biological hours to 50% of germination varied from 16.42 to 19.77 hours.
Conclusion: Overall, according to the results of this study, it is possible to predict the time to germination under optimal moisture conditions using the beta model for Line 286 and one of the two beta and segmented models for the Golchin genotype.
Highlights:
1. A suitable model was developed for a suitable prediction of the seed germination percentage of two linseed genotypes (Golchin genotype and Line 286).
2. The cardinal temperatures for two linseed genotypes (Golchin genotype and Line 286) were determined.
Farzaneh Amirikia, Majid Nabipour, Masoumeh Farzaneh,
Volume 10, Issue 1 (9-2023)
Volume 10, Issue 1 (9-2023)
Abstract
Extended Abstract
Introduction: The use of seed priming technology to accelerate the germination and seedling emergence of multi-purpose plants such as halophytes (Alhagi) with the ability to produce medicine and forage under environmental stress conditions or use of saline water (such as seawater of Persian Gulf) has received much attention today. Therefore, the present study was conducted to investigate seed priming methods and different salinity levels on germination, seedling emergence, and some growth responses of Alhagi plant.
Material and Methods: Two separate split-factorial experiments were conducted based on a randomized complete block design with four replications as a petri dish culture (first experiment) and a pot experiment in the field was performed in the Department of Plant Production and Genetics, Faculty of Agriculture, Shahid Chamran University (Ahwaz, Iran) during 2020-21. In both experiments, different levels of salinity (municipal water source with EC=0.96 dS.m-1, 8 and 16 dS.m-1 using seawater of Persian Gulf) were assigned as the main plot, and different methods of seed priming (non-priming, hydro priming, hormonal priming with 50 ppm gibberellin and hydro priming+hormonal priming with 50 ppm gibberellin) and species (A. maurorum and A. graecorum) were assigned as sub-factors.
Results: The results showed the significance of salinity × species × priming interaction on all studied traits. According to the mean comparison results, the highest values of germination percentage, seed vigor index, seedling emergence, plant height, number of branches, total dry matter and stomatal conductance were obtained from a municipal water source with EC=0.96 dS.m-1 and hydro priming+hormonal priming with 50 ppm gibberellin for A. graecorum (29.1, 90.2, 24.0, 32.3, 52.5, 52.1 and 32.4% increase compared to non-priming and control salinity stress on this species, respectively). The output of the fitted logistic model to seedling emergence percentage showed that this model well explained the relationship between seedling emergence of two Alhagi species in responses to salinity and seed priming (R2 adj≥0.98 and RMSE≤3.38). Therefore, in both studied species, the decline in seedling emergence started from the 8 dS/m salinity level. However, at the 16 dS/m salinity level, the slope of increase in seedling emergence percentage was slower per time unit.
Conclusion: To cultivate and exploit the saline coastal lands and also to restore the pastures in the country, A. graecorum species under the combined treatment of hydro priming + hormonal priming with 50 ppm gibberellin are recommended in comparison with other treatment levels.
Highlights:
1- Germination and growth responses of two Iranian Alhagi species and the possibility of production by irrigation of seawater of Persian Gulf were investigated.
2- Seed priming technique was used to accelerate seedling emergence and improve some traits in two Alhagi species.
Introduction: The use of seed priming technology to accelerate the germination and seedling emergence of multi-purpose plants such as halophytes (Alhagi) with the ability to produce medicine and forage under environmental stress conditions or use of saline water (such as seawater of Persian Gulf) has received much attention today. Therefore, the present study was conducted to investigate seed priming methods and different salinity levels on germination, seedling emergence, and some growth responses of Alhagi plant.
Material and Methods: Two separate split-factorial experiments were conducted based on a randomized complete block design with four replications as a petri dish culture (first experiment) and a pot experiment in the field was performed in the Department of Plant Production and Genetics, Faculty of Agriculture, Shahid Chamran University (Ahwaz, Iran) during 2020-21. In both experiments, different levels of salinity (municipal water source with EC=0.96 dS.m-1, 8 and 16 dS.m-1 using seawater of Persian Gulf) were assigned as the main plot, and different methods of seed priming (non-priming, hydro priming, hormonal priming with 50 ppm gibberellin and hydro priming+hormonal priming with 50 ppm gibberellin) and species (A. maurorum and A. graecorum) were assigned as sub-factors.
Results: The results showed the significance of salinity × species × priming interaction on all studied traits. According to the mean comparison results, the highest values of germination percentage, seed vigor index, seedling emergence, plant height, number of branches, total dry matter and stomatal conductance were obtained from a municipal water source with EC=0.96 dS.m-1 and hydro priming+hormonal priming with 50 ppm gibberellin for A. graecorum (29.1, 90.2, 24.0, 32.3, 52.5, 52.1 and 32.4% increase compared to non-priming and control salinity stress on this species, respectively). The output of the fitted logistic model to seedling emergence percentage showed that this model well explained the relationship between seedling emergence of two Alhagi species in responses to salinity and seed priming (R2 adj≥0.98 and RMSE≤3.38). Therefore, in both studied species, the decline in seedling emergence started from the 8 dS/m salinity level. However, at the 16 dS/m salinity level, the slope of increase in seedling emergence percentage was slower per time unit.
Conclusion: To cultivate and exploit the saline coastal lands and also to restore the pastures in the country, A. graecorum species under the combined treatment of hydro priming + hormonal priming with 50 ppm gibberellin are recommended in comparison with other treatment levels.
Highlights:
1- Germination and growth responses of two Iranian Alhagi species and the possibility of production by irrigation of seawater of Persian Gulf were investigated.
2- Seed priming technique was used to accelerate seedling emergence and improve some traits in two Alhagi species.
Mahnaz Kandi, Asa Ebrahimi, Marjan Diyanat, Hamid Saeidian,
Volume 10, Issue 1 (9-2023)
Volume 10, Issue 1 (9-2023)
Abstract
Extended Abstract
Introduction: Weeds are one of the most important problems in agriculture and cause a lot of damage to crops. Overconsumption of herbicides in recent decades has led to harmful impacts on the environment and living organisms, including humans. In order to deal with these problems today, efforts are being made to reduce reliance on artificial herbicides and change direction towards sustainable agriculture as a part of integrated weed management. Among natural compounds, essential oils, which are components of aromatic and medicinal plants, were investigated to discover new herbicides.
Material and Methods: In order to investigate the effects of yarrow essential oil (Achillea wilhelmsii C. Koch) on the germination and growth of purslane (Portulaca oleracea L.) and rye (Secale cereale L.) seedlings, two factorial experiments were conducted in the form of a completely randomized design in three replicates at Islamic Azad University, Science and Research Branch. The first factor was the type of essential oil in two levels (normal and nanoemulsion) and the second factor was the concentration of essential oil in six levels (0, 100, 200, 400, 800, and 1000 µl L-1).
Results and Discussion: Scanning electron microscopy images showed the particles were relatively sperhical and their size varied from 1 to 100 nm. The zeta potential of the nanoparticles was -13.8 mV, indicating particle stability. Both type of essential oils reduced germination percentage, germination rate, plumule length, radicel length and seedling dry weight of both weeds and germination percentage decreased significantly with increasing concentration. At a concentration of 200 µl L-1, purslane treated with essential oil germinated 55.25%, but at the same concentration, the germination percentage of seeds treated with nanoemulsion of essential oil was 30.50%. Nanoemulsion of essential oil at concentration of 800 µl L-1 was able to completely prevent the germination and growth of purslane seedlings. Nanoemulsion of essential oil at a concentration of 1000 µl L-1 completely prevented rye seed germination. Germination rate decreased under treatment of yarrow essential oil and there was no difference between two types of essential oils at concentration of 200 µl L-1, but at a concentration of 800 µl, the germination rate of rye seeds treated with nanoemulsion of essential oil and ordinary essential oil reached to 1.40 and 0.32, respectively which was a significant difference.
Conclusions: The inhibition percentage of the studied traits in both weed species showed that the essential oil nanoemulsion was more effective than the normal essential oil. Yarrow essential oil was more effective on purslane weed compared to rye. Essential oils do not have similar effects on weeds and their inhibitory effects will be different depending on the concentration and species of weeds, and the selectivity of these compounds should be investigated. The production of nano essential oil of yarrow as a natural herbicide is a solution. It offers to control weeds in organic farming systems.
Highlights:
1- Nanoemulsion particles were produced from Yarrow essential oil
2- Nanoemulsion particles had more inhibitory effects on the investigated weeds than the normal essential oil.
Introduction: Weeds are one of the most important problems in agriculture and cause a lot of damage to crops. Overconsumption of herbicides in recent decades has led to harmful impacts on the environment and living organisms, including humans. In order to deal with these problems today, efforts are being made to reduce reliance on artificial herbicides and change direction towards sustainable agriculture as a part of integrated weed management. Among natural compounds, essential oils, which are components of aromatic and medicinal plants, were investigated to discover new herbicides.
Material and Methods: In order to investigate the effects of yarrow essential oil (Achillea wilhelmsii C. Koch) on the germination and growth of purslane (Portulaca oleracea L.) and rye (Secale cereale L.) seedlings, two factorial experiments were conducted in the form of a completely randomized design in three replicates at Islamic Azad University, Science and Research Branch. The first factor was the type of essential oil in two levels (normal and nanoemulsion) and the second factor was the concentration of essential oil in six levels (0, 100, 200, 400, 800, and 1000 µl L-1).
Results and Discussion: Scanning electron microscopy images showed the particles were relatively sperhical and their size varied from 1 to 100 nm. The zeta potential of the nanoparticles was -13.8 mV, indicating particle stability. Both type of essential oils reduced germination percentage, germination rate, plumule length, radicel length and seedling dry weight of both weeds and germination percentage decreased significantly with increasing concentration. At a concentration of 200 µl L-1, purslane treated with essential oil germinated 55.25%, but at the same concentration, the germination percentage of seeds treated with nanoemulsion of essential oil was 30.50%. Nanoemulsion of essential oil at concentration of 800 µl L-1 was able to completely prevent the germination and growth of purslane seedlings. Nanoemulsion of essential oil at a concentration of 1000 µl L-1 completely prevented rye seed germination. Germination rate decreased under treatment of yarrow essential oil and there was no difference between two types of essential oils at concentration of 200 µl L-1, but at a concentration of 800 µl, the germination rate of rye seeds treated with nanoemulsion of essential oil and ordinary essential oil reached to 1.40 and 0.32, respectively which was a significant difference.
Conclusions: The inhibition percentage of the studied traits in both weed species showed that the essential oil nanoemulsion was more effective than the normal essential oil. Yarrow essential oil was more effective on purslane weed compared to rye. Essential oils do not have similar effects on weeds and their inhibitory effects will be different depending on the concentration and species of weeds, and the selectivity of these compounds should be investigated. The production of nano essential oil of yarrow as a natural herbicide is a solution. It offers to control weeds in organic farming systems.
Highlights:
1- Nanoemulsion particles were produced from Yarrow essential oil
2- Nanoemulsion particles had more inhibitory effects on the investigated weeds than the normal essential oil.
Hemmatollah Pirdashti, Yasser Yaghoubian, Zahra Nouri Akandi, Mehranoosh Emamian Tabarestani, Seyed Yaser Ashrafi, Faezeh Vadipour,
Volume 10, Issue 1 (9-2023)
Volume 10, Issue 1 (9-2023)
Abstract
Extended abstract
Introduction: Seed germination and emergence are the most sensitive stages of growth and development of rice plants. In this regard, the use of growth-promoting fungi in the form of seed biological pretreatment (bio-priming) for germination and optimal growth of seedlings can be feasible. Therefore, this study aimed to investigate the effect of isolated root symbiotic fungi on the improvement of germination and growth components of two traditional and bred rice (Oryza sativa L.) cultivars.
Materials and Methods: This experiment was done as a factorial-based completely randomized design with three replicates at Sari Agricultural Sciences and Natural Resources University in the summer of 2021. Experimental treatments included 22 isolates of root symbiotic fungi (isolated and identified from previous experiments) and control (without inoculation) and two native (Hashemi) and bred (Roshan) rice cultivars. After the end of the germination period, the number of normal seedlings was counted and five normal seedlings were randomly selected to measure the length of the root, stem, and seedling as well as the fresh and dry weight of the root, stem, and seedling.
Results: Based on the results of cluster analysis the fungi were divided into four and three groups in Roshan and Hashemi cultivars, respectively. In both cultivars, group I was selected as the best group. In this group, the highest positive effect on vegetative traits varied from 5 to 59% compared to the control in fungal treatments was related to Bjerkandera adusta (ST1), Trichoderma atroviride (SF1), Monosporascus cannonballus (B3) and Trichoderma atroviride (SN1) in Roshan cultivar and Bjerkand adusta (ST1) in Hashemi cultivar. The best fungal treatments in germination traits of Roshan and Hashemi cultivars were Chaetomium globosum (SE2) and Bjerkandera adusta (ST1), respectively.
Conclusions: Overall, the results indicated the positive effect of most symbiotic fungi on the growth and germination characteristics of rice in both Roshan and Hashemi cultivars. These results show that symbiotic fungi use different mechanisms to increase growth and improve germination indicators in plants.
Highlights:
1- Growth-promoting fungi in the form of seed biological pretreatment were used (bio-priming) for optimal growth and germination and of rice seedlings.
2- The effect of native fungi isolated was investigated for the first time in two native (Hashemi) and bred (Roshan) rice cultivars.
Introduction: Seed germination and emergence are the most sensitive stages of growth and development of rice plants. In this regard, the use of growth-promoting fungi in the form of seed biological pretreatment (bio-priming) for germination and optimal growth of seedlings can be feasible. Therefore, this study aimed to investigate the effect of isolated root symbiotic fungi on the improvement of germination and growth components of two traditional and bred rice (Oryza sativa L.) cultivars.
Materials and Methods: This experiment was done as a factorial-based completely randomized design with three replicates at Sari Agricultural Sciences and Natural Resources University in the summer of 2021. Experimental treatments included 22 isolates of root symbiotic fungi (isolated and identified from previous experiments) and control (without inoculation) and two native (Hashemi) and bred (Roshan) rice cultivars. After the end of the germination period, the number of normal seedlings was counted and five normal seedlings were randomly selected to measure the length of the root, stem, and seedling as well as the fresh and dry weight of the root, stem, and seedling.
Results: Based on the results of cluster analysis the fungi were divided into four and three groups in Roshan and Hashemi cultivars, respectively. In both cultivars, group I was selected as the best group. In this group, the highest positive effect on vegetative traits varied from 5 to 59% compared to the control in fungal treatments was related to Bjerkandera adusta (ST1), Trichoderma atroviride (SF1), Monosporascus cannonballus (B3) and Trichoderma atroviride (SN1) in Roshan cultivar and Bjerkand adusta (ST1) in Hashemi cultivar. The best fungal treatments in germination traits of Roshan and Hashemi cultivars were Chaetomium globosum (SE2) and Bjerkandera adusta (ST1), respectively.
Conclusions: Overall, the results indicated the positive effect of most symbiotic fungi on the growth and germination characteristics of rice in both Roshan and Hashemi cultivars. These results show that symbiotic fungi use different mechanisms to increase growth and improve germination indicators in plants.
Highlights:
1- Growth-promoting fungi in the form of seed biological pretreatment were used (bio-priming) for optimal growth and germination and of rice seedlings.
2- The effect of native fungi isolated was investigated for the first time in two native (Hashemi) and bred (Roshan) rice cultivars.
Bijan Shadkam, Mohammed Hussain Gharineh, Amin Lotfi Jalalabadi, Seyed Amir Mousavi,
Volume 10, Issue 1 (9-2023)
Volume 10, Issue 1 (9-2023)
Abstract
Extended Abstract
Introduction: Salinity stress is one of the important damaging factors for seed germination which interrupts the uptake of some nutrients by lowering soil water potential and causing ion toxicity due to salt accumulation inside the seeds. Since hyssop seeds are sensitive to salinity stress in the early stages of seed germination, it is necessary to investigate seed enhancement methods to improve seed germination in this species under saline conditions. In this research, the effects of seed priming using iron were studied on hyssop seed germination characteristics under salinity stress conditions.
Material and Methods: This research was conducted as two separate factorial experiments in complete random design with three replications. The treatments included five levels of iron nano-chelate and micro-chelate (zero, 50, 100, 200, and 400 mg /l) and six levels of salinity (zero, 50, 100, 150, 200, and 250 mM) and two priming durations. It included 12 and 24-hours.
Results: The results showed that with the increase in salinity, the germination characteristics declined so at 200 mM of salinity, seedling growth declined significantly and ceased completely at 250 mM level. Application of iron micro-chelate under non-stress conditions did not have any positive effect on hyssop germination, and the use of distilled water for 12 hours worked better than iron nano-chelate. No significant difference was observed among the different concentrations in micro-iron treatment. Application of nano and micro chelate at 100 and 150 mM salinity stress had a stronger effect so that nano iron chelate concentrations of 200 mg/L for 12 hours and 100 and 200 mg per liter concentrations of iron micro chelate had the highest germination, seedling growth, and seed germination in 24 hours. The amount of soluble protein and peroxidase and catalase activity increased at 50 mg/L salinity but decreased at higher salinities. Also, pretreatment of seeds with an iron micro-chelate and nano iron chelate concentration of 200 mg/liter intensified this process.
Conclusion: Conclusion: The results of this study showed that seed germination of hyssop is highly declined due to salinity stress, so the seedlings were unable to grow at a salinity concentration of 200 mg/L. Moreover, germination does not occur at 250 mg/liter salinity. Also, seed pretreatment of this plant is not justifiable under non-stress and mild stress conditions, and pretreatment with iron chelate had negative effects and was ineffective at best. However, iron chelate application at high salinity levels- especially in the nanoscale with a concentration of 200 mg/liter for 12 hours- is effective in reducing the effect of salinity.
Highlights:
1- The role of the iron element was investigated by seed pretreatment method to alleviate the negative effects of salinity stress on hyssop seed germination characteristics.
2- The nanotechnology used in the production of iron fertilizer and its effect on improving the germination characteristics of hyssop under salinity stress were investigated.
Introduction: Salinity stress is one of the important damaging factors for seed germination which interrupts the uptake of some nutrients by lowering soil water potential and causing ion toxicity due to salt accumulation inside the seeds. Since hyssop seeds are sensitive to salinity stress in the early stages of seed germination, it is necessary to investigate seed enhancement methods to improve seed germination in this species under saline conditions. In this research, the effects of seed priming using iron were studied on hyssop seed germination characteristics under salinity stress conditions.
Material and Methods: This research was conducted as two separate factorial experiments in complete random design with three replications. The treatments included five levels of iron nano-chelate and micro-chelate (zero, 50, 100, 200, and 400 mg /l) and six levels of salinity (zero, 50, 100, 150, 200, and 250 mM) and two priming durations. It included 12 and 24-hours.
Results: The results showed that with the increase in salinity, the germination characteristics declined so at 200 mM of salinity, seedling growth declined significantly and ceased completely at 250 mM level. Application of iron micro-chelate under non-stress conditions did not have any positive effect on hyssop germination, and the use of distilled water for 12 hours worked better than iron nano-chelate. No significant difference was observed among the different concentrations in micro-iron treatment. Application of nano and micro chelate at 100 and 150 mM salinity stress had a stronger effect so that nano iron chelate concentrations of 200 mg/L for 12 hours and 100 and 200 mg per liter concentrations of iron micro chelate had the highest germination, seedling growth, and seed germination in 24 hours. The amount of soluble protein and peroxidase and catalase activity increased at 50 mg/L salinity but decreased at higher salinities. Also, pretreatment of seeds with an iron micro-chelate and nano iron chelate concentration of 200 mg/liter intensified this process.
Conclusion: Conclusion: The results of this study showed that seed germination of hyssop is highly declined due to salinity stress, so the seedlings were unable to grow at a salinity concentration of 200 mg/L. Moreover, germination does not occur at 250 mg/liter salinity. Also, seed pretreatment of this plant is not justifiable under non-stress and mild stress conditions, and pretreatment with iron chelate had negative effects and was ineffective at best. However, iron chelate application at high salinity levels- especially in the nanoscale with a concentration of 200 mg/liter for 12 hours- is effective in reducing the effect of salinity.
Highlights:
1- The role of the iron element was investigated by seed pretreatment method to alleviate the negative effects of salinity stress on hyssop seed germination characteristics.
2- The nanotechnology used in the production of iron fertilizer and its effect on improving the germination characteristics of hyssop under salinity stress were investigated.
Marziyeh Ababaf, Heshmat Omidi, Abdolmehdi Bakhshandeh,
Volume 10, Issue 1 (9-2023)
Volume 10, Issue 1 (9-2023)
Abstract
Extended Abstract
Introduction: Various strategies have been used to improve growth and productivity of crops through genetic approach, genetic engineering, and breeding. However, economic feasibility and ease of use can pave the way for the application of priming techniques as "stress relievers" in agricultural production. The aim of this study was to evaluate the ability of priming Catharanthus roseus seed with phytohormones of salicylic acid and Jasmonic acid under drought stress to reduce the effect of water limitation during the germination.
Materials and Methods: Two separate studies were conducted as a factorial experiment based on a completely randomized design with three replications at the Laboratory of Seed Science and Technology of Shahed University, Tehran. In the first experiment, treatments included priming in two levels of SA (0.5 and 1mM) and priming duration in two levels (24 and 48 hours), and drought stress with polyethylene glycol 6000 in 6 levels (0, 0.1, 0.5, 1, 1.5 and 2 Mpa). In the second experiment, treatments included JA (10 µM), priming duration in two levels (12, and 24 hours) and drought stress in levels six (0, 0.1, 0.5, 1, 1.5, and 2 Mpa). Dry seeds (without pretreatment) were considered as control.
Results: In this study, drought stress treatments -1.5 and -2 Mpa in the first experiment and -1, -1.5 and -2 Mpa in the second one had no germination. Seed priming with SA and JA improved the percentage of seed germination so that in the first experiment, the highest percentage of germination (97.33) was observed under stress-free conditions with the application of 0.5 mM salicylic acid for 48 hours, which was 12.2% higher than the control treatment. 0.5 Mm of SA treatment with 24 hours of priming showed the highest percentage of germination under drought stresses of -0.1 and -0.5 Mpa. However, under drought stress conditions of -1 Mpa, 0.5 mM SA+48 hours treatment was superior compared to other treatments of salicylic acid and time. In the second experiment, the highest percentage of germination (98.3) was in the concentration of 10 μM jasmonic acid during 24 hours of priming under stress-free conditions, which showed an increase of 40.4% compared to the control treatment.
Conclusion: The results of the present study showed the importance of salicylic acid and jasmonic acid during seed germination stage under drought stress. Seed priming with salicylic acid alleviated the damages caused by drought stress on germination and growth. The process of adaptation to stress started by jasmonic acid can be attributed to pretreatment with jasmonic acid before applying drought stress.
Highlights:
Introduction: Various strategies have been used to improve growth and productivity of crops through genetic approach, genetic engineering, and breeding. However, economic feasibility and ease of use can pave the way for the application of priming techniques as "stress relievers" in agricultural production. The aim of this study was to evaluate the ability of priming Catharanthus roseus seed with phytohormones of salicylic acid and Jasmonic acid under drought stress to reduce the effect of water limitation during the germination.
Materials and Methods: Two separate studies were conducted as a factorial experiment based on a completely randomized design with three replications at the Laboratory of Seed Science and Technology of Shahed University, Tehran. In the first experiment, treatments included priming in two levels of SA (0.5 and 1mM) and priming duration in two levels (24 and 48 hours), and drought stress with polyethylene glycol 6000 in 6 levels (0, 0.1, 0.5, 1, 1.5 and 2 Mpa). In the second experiment, treatments included JA (10 µM), priming duration in two levels (12, and 24 hours) and drought stress in levels six (0, 0.1, 0.5, 1, 1.5, and 2 Mpa). Dry seeds (without pretreatment) were considered as control.
Results: In this study, drought stress treatments -1.5 and -2 Mpa in the first experiment and -1, -1.5 and -2 Mpa in the second one had no germination. Seed priming with SA and JA improved the percentage of seed germination so that in the first experiment, the highest percentage of germination (97.33) was observed under stress-free conditions with the application of 0.5 mM salicylic acid for 48 hours, which was 12.2% higher than the control treatment. 0.5 Mm of SA treatment with 24 hours of priming showed the highest percentage of germination under drought stresses of -0.1 and -0.5 Mpa. However, under drought stress conditions of -1 Mpa, 0.5 mM SA+48 hours treatment was superior compared to other treatments of salicylic acid and time. In the second experiment, the highest percentage of germination (98.3) was in the concentration of 10 μM jasmonic acid during 24 hours of priming under stress-free conditions, which showed an increase of 40.4% compared to the control treatment.
Conclusion: The results of the present study showed the importance of salicylic acid and jasmonic acid during seed germination stage under drought stress. Seed priming with salicylic acid alleviated the damages caused by drought stress on germination and growth. The process of adaptation to stress started by jasmonic acid can be attributed to pretreatment with jasmonic acid before applying drought stress.
Highlights:
- The effect of priming Catharanthus roseus seeds with salicylic acid and jasmonic acid phytohormones on the germination characteristics of seeds under drought stress was investigated.
- Priming Catharanthus roseus seeds with salicylic acid improved the germination percentage and characteristics of seeds under drought stress.
Farzad Delfan, Feizollah Shahbazi, Hamidreza Esvand,
Volume 10, Issue 2 (3-2024)
Volume 10, Issue 2 (3-2024)
Abstract
Extended abstract
Introduction: The seeds of agricultural products are constantly subjected to impact forces from machines from the moment they are harvested to the time they are transferred into storage. Improper design and performance of machines in each of these stages can cause mechanical damage to seeds. Mechanical damage caused by free fall on the seed of agricultural products, which occurs during different stages of harvesting, transportation and other processes, causes a decrease in their quality and an increase in waste. This study aimed to evaluate the amount of mechanical damage caused to chickpea seeds due to the impact of free fall.
Materials and methods: The experiment was conducted as a factorial in the form of a completely randomized design with three replications. The factors included drop height (3, 6, 9 and 12 m), the contact surface (concrete, plywood, metal (iron) and seed-on-seed) and seed moisture content (10, 15, 20 and 25 %). The studied traits or the amount of damage to the seeds included the measurement of seed deterioration by the accelerated aging method (loss in germination percentage in the accelerated aging test) and the measurement of electrical conductivity.
Results: The results of the analysis of variance showed that all three factors (drop height, the contact surface and moisture content) had significant effects at p<0.01 on the loss in germination percentage in the accelerated aging test and changes in electrical conductivity of chickpea seeds. In terms of loss in germination percentage, the highest damage to seeds occurred in the metal contact (41.96%) and the least in the seed-on-seed treatments(29.71%). Also, the highest amount of electrical conductivity was related to the seeds dropped on the metal (36.09 μS cm-1g-1) and the lowest was related to seed-on-seed contact (21.68 μS cm-1g-1). As the drop height rose from 3 to 12 m, the loss in germination and electrical conductivity of seeds increased from 27.74 to 48.08% and from 18.72 to 40.47 μS cm-1g-1, respectively. Increasing the moisture content of chickpea seeds from 10 to 25% causes a decrease in the amount of damage to the seeds in terms of electrical conductivity (from 38.40 to 21.18 μS cm-1g-1). However, the damage was in the form of loss in germination percentage during the accelerated aging test (from 29.22 to 42.88 %).
Conclusion: The findings of this study revealed that the movement of chickpea seeds and the subsequent free fall had a notable impact on their latent damage, leading to a decrease in germination rate and alterations in electrical conductivity. Therefore, it is recommended to minimize fall height and prevent seeds from hitting hard surfaces during seed processing and transportation to mitigate the damage.
Highlights:
Introduction: The seeds of agricultural products are constantly subjected to impact forces from machines from the moment they are harvested to the time they are transferred into storage. Improper design and performance of machines in each of these stages can cause mechanical damage to seeds. Mechanical damage caused by free fall on the seed of agricultural products, which occurs during different stages of harvesting, transportation and other processes, causes a decrease in their quality and an increase in waste. This study aimed to evaluate the amount of mechanical damage caused to chickpea seeds due to the impact of free fall.
Materials and methods: The experiment was conducted as a factorial in the form of a completely randomized design with three replications. The factors included drop height (3, 6, 9 and 12 m), the contact surface (concrete, plywood, metal (iron) and seed-on-seed) and seed moisture content (10, 15, 20 and 25 %). The studied traits or the amount of damage to the seeds included the measurement of seed deterioration by the accelerated aging method (loss in germination percentage in the accelerated aging test) and the measurement of electrical conductivity.
Results: The results of the analysis of variance showed that all three factors (drop height, the contact surface and moisture content) had significant effects at p<0.01 on the loss in germination percentage in the accelerated aging test and changes in electrical conductivity of chickpea seeds. In terms of loss in germination percentage, the highest damage to seeds occurred in the metal contact (41.96%) and the least in the seed-on-seed treatments(29.71%). Also, the highest amount of electrical conductivity was related to the seeds dropped on the metal (36.09 μS cm-1g-1) and the lowest was related to seed-on-seed contact (21.68 μS cm-1g-1). As the drop height rose from 3 to 12 m, the loss in germination and electrical conductivity of seeds increased from 27.74 to 48.08% and from 18.72 to 40.47 μS cm-1g-1, respectively. Increasing the moisture content of chickpea seeds from 10 to 25% causes a decrease in the amount of damage to the seeds in terms of electrical conductivity (from 38.40 to 21.18 μS cm-1g-1). However, the damage was in the form of loss in germination percentage during the accelerated aging test (from 29.22 to 42.88 %).
Conclusion: The findings of this study revealed that the movement of chickpea seeds and the subsequent free fall had a notable impact on their latent damage, leading to a decrease in germination rate and alterations in electrical conductivity. Therefore, it is recommended to minimize fall height and prevent seeds from hitting hard surfaces during seed processing and transportation to mitigate the damage.
Highlights:
- Seed deterioration tests using accelerated aging and electrical conductivity can be used as appropriate criteria to measure the mechanical damage to chickpea seeds.
- When designing machines that come into contact with the seeds, it is important to choose surfaces made of soft materials to minimize the destructive effects of the seeds falling from greater heights.
- The moisture content during the processing and transportation of the seeds should be at an optimal level of around 15%.
Farshid Ghaderi-Far, Majid Azimmohseni, Seyed Hamidreza Bagheri,
Volume 10, Issue 2 (3-2024)
Volume 10, Issue 2 (3-2024)
Abstract
Extended abstract
Introduction: In seed research, germination percentage data is the result of counting and has a binomial distribution. Therefore, seed researchers use data transformation, especially square root transformation, to stabilize the variance and normalize the data before performing analysis of variance and comparison of treatments. Despite the use of data transformation, this method has fundamental issues in the structure that misleads the test results. Therefore, it is important to introduce and replace a method that preserves the research assumptions and provides acceptable results for researchers without using data transformation. The use of generalized linear model is an alternative method for analyzing germination data with binomial distribution. In this research, the generalized linear model will be introduced first. Then, the efficiency of this method will be illustrated using simulated and actual germination data.
Materials and Methods: In this research, first the simulated data was generated by the Monte Carlo method. Based on the simulated data, the significance level and the power of test of generalized linear model were computed. Then the actual data related to three experiments including the effect of acidity on germination of wheat varieties, the effect of water stress and salinity on germination of yellow sweet clover seeds, and the effect of alternating temperatures on germination of three lavender populations were used and the results of the generalized linear model were compared with the square root transformation method based on the data of three experiments.
Results: The simulation results showed that the generalized linear model has a high efficiency to preserve the predetermined significance level and a high power in detecting significant differences in germination of the treatments. Moreover, the results of the comparison of the generalized linear model with the square root transformation method illustrated that the generalized linear model had a higher capability to detect significant differences between various treatments, especially in the treatments with unequal seeds in the Petri dish, and in the treatments in which the square root transformation method resulted in no significant difference among treatments, the generalized linear method showed a significant difference.
Conclusions: Generally, the results of this research demonstrated that the generalized linear model can be used as an alternative method to square root transformation in studies on the germination percentage of seeds with binomial distribution, without having the problems of the square root transformation method. Moreover, this model outperforms the square root transformation in detecting significant differences in germination of treatments with fixed and different seeds.
Highlights:
Introduction: In seed research, germination percentage data is the result of counting and has a binomial distribution. Therefore, seed researchers use data transformation, especially square root transformation, to stabilize the variance and normalize the data before performing analysis of variance and comparison of treatments. Despite the use of data transformation, this method has fundamental issues in the structure that misleads the test results. Therefore, it is important to introduce and replace a method that preserves the research assumptions and provides acceptable results for researchers without using data transformation. The use of generalized linear model is an alternative method for analyzing germination data with binomial distribution. In this research, the generalized linear model will be introduced first. Then, the efficiency of this method will be illustrated using simulated and actual germination data.
Materials and Methods: In this research, first the simulated data was generated by the Monte Carlo method. Based on the simulated data, the significance level and the power of test of generalized linear model were computed. Then the actual data related to three experiments including the effect of acidity on germination of wheat varieties, the effect of water stress and salinity on germination of yellow sweet clover seeds, and the effect of alternating temperatures on germination of three lavender populations were used and the results of the generalized linear model were compared with the square root transformation method based on the data of three experiments.
Results: The simulation results showed that the generalized linear model has a high efficiency to preserve the predetermined significance level and a high power in detecting significant differences in germination of the treatments. Moreover, the results of the comparison of the generalized linear model with the square root transformation method illustrated that the generalized linear model had a higher capability to detect significant differences between various treatments, especially in the treatments with unequal seeds in the Petri dish, and in the treatments in which the square root transformation method resulted in no significant difference among treatments, the generalized linear method showed a significant difference.
Conclusions: Generally, the results of this research demonstrated that the generalized linear model can be used as an alternative method to square root transformation in studies on the germination percentage of seeds with binomial distribution, without having the problems of the square root transformation method. Moreover, this model outperforms the square root transformation in detecting significant differences in germination of treatments with fixed and different seeds.
Highlights:
- The generalized linear model was used for the analysis of germination percentage data.
- The data simulated using the Monte-Carlo method was utilized to examine the significance level and power of the generalized linear model test.
- The generalized linear model was compared with the square root transformation method during different germination experiments with fixed and different seeds in each Petri dish.
Haniyeh Saadat, Mohammad Sedghi, Raouf Seyed Sharifi, Salim Farzaneh,
Volume 10, Issue 2 (3-2024)
Volume 10, Issue 2 (3-2024)
Abstract
Extended Abstract
Introduction: At present, the drastic increase in population has created an additional burden on the world's agricultural resources. As a result, meeting global food demand and increasing farmers' incomes has become a challenging task. Salinity is one of the abiotic stresses that strongly affect the germination, growth, and yield of crops. Seed priming is a simple technology that hydrates seeds to the point where the metabolic activity for germination is initiated without radicle emergence. In fact, the seeds are physiologically and biochemically prepared to germinate before being placed in their bed and exposed to environmental conditions. This research was conducted to investigate the effect of seed priming with chitosan on germination indices and biochemical traits of beans under salt stress.
Materials and Methods: This experiment was conducted at the University of Mohaghegh Ardabili in 2021 as a factorial in the form of a completely randomized design with four repetitions. The treatments included four levels of salinity (0, 50, 100, and 150 mM) and four levels of chitosan (0, 0.25, 0.50, and 0.75% w/v), all of which were dissolved in 1% acetic acid.
Results: The results showed that salinity stress decreased germination percentage (GP), peak value (PV), and germination value (GV). However, seed priming with different levels of chitosan, especially 0.75% chitosan, improved GP, PV, and GV by 7, 21, and 17%, respectively, compared to the control. Proline content and polyphenol oxidase enzyme activity went up with increasing salinity. However, the application of chitosan 0.75% increased these traits by 34% and 43%, respectively, compared to the control (priming with distilled water). Electrolyte leakage in priming with 0.75% chitosan decreased by 31% compared to the control, which indicates the maintenance of the cell membrane stability. The content of soluble sugars in the treatment with 0.75% chitosan and 150 mM salinity showed an increase of about 78% compared to the control. The highest correlation among traits was observed between peak value and germination coefficient (r2=0.99) and between proline and polyphenol oxidase enzyme (r2=0.92).
Conclusions: The results of this study show that among the different treatments, pre-treatment of seeds with 75 % Chitosan may be considered an effective way to improve germination indices and biochemical characteristics of beans and it can be used as a treatment to deal with salinity conditions in bean seedlings and improve their seedling growth.
Highlights:
Introduction: At present, the drastic increase in population has created an additional burden on the world's agricultural resources. As a result, meeting global food demand and increasing farmers' incomes has become a challenging task. Salinity is one of the abiotic stresses that strongly affect the germination, growth, and yield of crops. Seed priming is a simple technology that hydrates seeds to the point where the metabolic activity for germination is initiated without radicle emergence. In fact, the seeds are physiologically and biochemically prepared to germinate before being placed in their bed and exposed to environmental conditions. This research was conducted to investigate the effect of seed priming with chitosan on germination indices and biochemical traits of beans under salt stress.
Materials and Methods: This experiment was conducted at the University of Mohaghegh Ardabili in 2021 as a factorial in the form of a completely randomized design with four repetitions. The treatments included four levels of salinity (0, 50, 100, and 150 mM) and four levels of chitosan (0, 0.25, 0.50, and 0.75% w/v), all of which were dissolved in 1% acetic acid.
Results: The results showed that salinity stress decreased germination percentage (GP), peak value (PV), and germination value (GV). However, seed priming with different levels of chitosan, especially 0.75% chitosan, improved GP, PV, and GV by 7, 21, and 17%, respectively, compared to the control. Proline content and polyphenol oxidase enzyme activity went up with increasing salinity. However, the application of chitosan 0.75% increased these traits by 34% and 43%, respectively, compared to the control (priming with distilled water). Electrolyte leakage in priming with 0.75% chitosan decreased by 31% compared to the control, which indicates the maintenance of the cell membrane stability. The content of soluble sugars in the treatment with 0.75% chitosan and 150 mM salinity showed an increase of about 78% compared to the control. The highest correlation among traits was observed between peak value and germination coefficient (r2=0.99) and between proline and polyphenol oxidase enzyme (r2=0.92).
Conclusions: The results of this study show that among the different treatments, pre-treatment of seeds with 75 % Chitosan may be considered an effective way to improve germination indices and biochemical characteristics of beans and it can be used as a treatment to deal with salinity conditions in bean seedlings and improve their seedling growth.
Highlights:
- Seed priming using chitosan improved germination indices of common bean seeds under salt stress.
- Priming with chitosan increased proline and polyphenol oxidase enzyme.
- A chitosan concentration of 0.75 V/W showed a better effect on germination indices and biochemical characteristics.
- Priming with chitosan can be a suitable method to mitigate the negative effects of salinity, increase germination indices, and improve the biochemical characteristics of beans.
Ahmad Munir Amini, Farshid Ghaderi-Far, Dr Benjamin Torabi, Asieh Siahmargue, Hamid Reza Sadeghipour,
Volume 10, Issue 2 (3-2024)
Volume 10, Issue 2 (3-2024)
Abstract
Extended abstract
Introduction: With regard to the ever-growing water deficit in the world, the adoption of the direct-seeded rice cultivation system has been suggested as an alternative to the transplanting method. One of the disadvantages of the direct-seeded method is low and non-uniform germination and emergence due to low seed vigor in rice. Priming is a technique which improves the rate and uniformity of seed germination under these conditions. Thus, this study aimed to investigate the effects of priming treatments on seed germination of different rice cultivars under different temperature conditions using the thermal time model.
Materials and methods: This study was conducted in 2019 at the seed research laboratory of Gorgan University of Agricultural Sciences and Natural Resources. In this experiment, germination of primed and non-primed seeds in three rice cultivars (Nada, Anam, and Tolo) was investigated under different temperatures (15, 20, 25, 30, and 35°C). The priming treatments which consisted of control, hydropriming, and osmopriming with different chemicals (potassium chloride 2%, potassium nitrate 1%, calcium chloride 4%, glycine betaine 10 ppm, salicylic acid 10 ppm, and ascorbic acid 10 ppm) were investigated under different temperatures.
Results: The results showed that priming treatments had no significant effect on the seed germination percentage of rice cultivars at different temperatures. The thermal time model based on binomial distribution fitted well to cumulative germination percentages in all priming treatments. Among the parameters of the thermal time model, the greatest priming effect was on the reduction of the thermal coefficient, followed by the reduction of the sigma coefficient, which resulted in the increased rate and uniformity of germination. Priming treatments had no significant effect on base temperature. Also, the responses of rice cultivars to seed priming treatments varied so that in Anam and Neda, priming with calcium chloride but in Tolo, hydropriming was more effective on the model parameters, especially thermal time to 50% of germination.
Conclusion: In general, priming treatments did not affect the base temperature of germination in rice cultivars, but they significantly affected the rate and uniformity of seed germination. As the latter issue is one of the main problems in the direct-seeded rice system, suitable priming treatments for each cultivar can be adopted to increase the rate and uniformity of seed germination and emergence in this system.
Highlights:
Introduction: With regard to the ever-growing water deficit in the world, the adoption of the direct-seeded rice cultivation system has been suggested as an alternative to the transplanting method. One of the disadvantages of the direct-seeded method is low and non-uniform germination and emergence due to low seed vigor in rice. Priming is a technique which improves the rate and uniformity of seed germination under these conditions. Thus, this study aimed to investigate the effects of priming treatments on seed germination of different rice cultivars under different temperature conditions using the thermal time model.
Materials and methods: This study was conducted in 2019 at the seed research laboratory of Gorgan University of Agricultural Sciences and Natural Resources. In this experiment, germination of primed and non-primed seeds in three rice cultivars (Nada, Anam, and Tolo) was investigated under different temperatures (15, 20, 25, 30, and 35°C). The priming treatments which consisted of control, hydropriming, and osmopriming with different chemicals (potassium chloride 2%, potassium nitrate 1%, calcium chloride 4%, glycine betaine 10 ppm, salicylic acid 10 ppm, and ascorbic acid 10 ppm) were investigated under different temperatures.
Results: The results showed that priming treatments had no significant effect on the seed germination percentage of rice cultivars at different temperatures. The thermal time model based on binomial distribution fitted well to cumulative germination percentages in all priming treatments. Among the parameters of the thermal time model, the greatest priming effect was on the reduction of the thermal coefficient, followed by the reduction of the sigma coefficient, which resulted in the increased rate and uniformity of germination. Priming treatments had no significant effect on base temperature. Also, the responses of rice cultivars to seed priming treatments varied so that in Anam and Neda, priming with calcium chloride but in Tolo, hydropriming was more effective on the model parameters, especially thermal time to 50% of germination.
Conclusion: In general, priming treatments did not affect the base temperature of germination in rice cultivars, but they significantly affected the rate and uniformity of seed germination. As the latter issue is one of the main problems in the direct-seeded rice system, suitable priming treatments for each cultivar can be adopted to increase the rate and uniformity of seed germination and emergence in this system.
Highlights:
- The thermal time model can be used to select the appropriate priming treatment for improving seed germination components of rice cultivars.
- The responses of rice cultivars to different seed priming treatments were different.
- Priming treatments did not improve the base temperature of seed germination in rice cultivars, but they significantly affected seed germination rate and uniformity.
Abdolhosein Rezaei, Farshid Ghaderi-Far, Hamid Reza Sadeghipour,
Volume 10, Issue 2 (3-2024)
Volume 10, Issue 2 (3-2024)
Abstract
Extended Abstract
Introduction: Safflower seeds are rich in unsaturated fatty acids with a high capacity for peroxidation, which have a high potential to reduce germination and seed vigor during the storage period. Therefore, Introducing appropriate methods to preserve or improve their germplasm during storage would be advantageous. The aim of this study was to investigate the effects of seed priming on germination and vigor of safflower seeds (Sofeh and Sina cultivars).
Materials and Methods: A three-factor experiment was conducted in a completely randomized design with three replications before and after artificial deterioration. The experimental factors included controlled deterioration of seeds at 45°C in six levels (no deterioration, 1, 2, 3, 4, and 6 days) and priming in four levels (no prime, hydropriming, salicylic acid 50 mg/l and sodium chloride 5 percent).
Results: Artificial aging strongly and linearly reduced the germination ability of safflower seeds, and germinability and seed vigor reach zero in a time interval which lasts between 2.5 to 4.5 days (depending on the treatment and the investigated trait). The use of priming prior to artificial aging was more advantageous than priming after artificial aging. In addition, priming with salicylic acid was more useful compared to other priming treatments.
Conclusion: Priming of safflower seeds before storage would result in the extended shelf-life of the stored seeds while also preserving the seed germination potential.
Highlights:
Introduction: Safflower seeds are rich in unsaturated fatty acids with a high capacity for peroxidation, which have a high potential to reduce germination and seed vigor during the storage period. Therefore, Introducing appropriate methods to preserve or improve their germplasm during storage would be advantageous. The aim of this study was to investigate the effects of seed priming on germination and vigor of safflower seeds (Sofeh and Sina cultivars).
Materials and Methods: A three-factor experiment was conducted in a completely randomized design with three replications before and after artificial deterioration. The experimental factors included controlled deterioration of seeds at 45°C in six levels (no deterioration, 1, 2, 3, 4, and 6 days) and priming in four levels (no prime, hydropriming, salicylic acid 50 mg/l and sodium chloride 5 percent).
Results: Artificial aging strongly and linearly reduced the germination ability of safflower seeds, and germinability and seed vigor reach zero in a time interval which lasts between 2.5 to 4.5 days (depending on the treatment and the investigated trait). The use of priming prior to artificial aging was more advantageous than priming after artificial aging. In addition, priming with salicylic acid was more useful compared to other priming treatments.
Conclusion: Priming of safflower seeds before storage would result in the extended shelf-life of the stored seeds while also preserving the seed germination potential.
Highlights:
- The effect of priming on germination and vigor of safflower seeds before and after artificial deterioration was compared and investigated.
- The effect of priming before and after artificial deterioration on the improvement of safflower seed quality varied in different cultivars.
Hamideh Javadi, Parvin Salehi Shanjani, Mohammad Dadmand, Masoumeh Ramazani Yeghaneh,
Volume 10, Issue 2 (3-2024)
Volume 10, Issue 2 (3-2024)
Abstract
Extended abstract
Introduction: Festuca species are forage grasses that are very important in terms of fodder supply and soil protection. The seeds of these plants have internal dormancy (physiological) and are unable to germinate easily. Therefore, they must be subjected to various treatments to germinate. In nature, this dormancy is broken during the cold period of winter (chilling). The purpose of this research is to investigate different methods of dormancy breaking in Festuca species for large-scale production and accelerate the germination process.
Materials and methods: In this research, three species of Festuca (Festuca arundinacea, F. ovina, and F. rubra) were subjected to different treatments of chilling (4°C, 14 days), osmo-priming with potassium nitrate (KNO3) 1.5% and gibberellic acid 150 and 200 ppm. After 14 days of germination test, various germination indices including percentage and rate of germination, mean germination time, seed vigor index, length of radicle, shoot and seedling, and the ratio of radicle to shoot length were calculated.
Results: The results of the analysis of variance showed a significant difference between species (except for germination percentage and root length traits) and treatments (for all traits). The interactions between the species and treatment were also significant for all traits (except for the length of radicle and seedling). Among the three species, the percentage of germination varied from 26.67 to 30.67% and the value of the germination rate varied from 1.92 to 3.31 n/d. The average time required for germination varied from 3.75 to 4.36 days and the seed vigor index varied from 26.74 to 43.02. The radicle length was between 37.22 and 45 mm and the shoot length was between 37.34 and 81.33 mm. Based on principal components analysis (PCA), percentage and rate of germination, seed vigor index, and length of radicle and seedling were introduced as the most important factors in creating diversity in Festuca species. In determining the correlation between traits, a high correlation of 70% was observed between germination percentage, germination rate, and seed vigor index.
Conclusion: Among the three species, Festuca rubra was superior to the other two species by having the highest percentage and rate of germination, seed vigor, radical length, and the shortest time required for germination. Among the applied treatments, 1.5% potassium nitrate (KNO3) with chilling (4°C, for 14 days), had a positive effect on the percentage and rate of germination, radical length, and gibberellic acid (150 ppm) treatment had a positive effect on the length of shoot and seedling. The presence of high germination percentage and rate indicated higher seed vigor.
Highlights:
Introduction: Festuca species are forage grasses that are very important in terms of fodder supply and soil protection. The seeds of these plants have internal dormancy (physiological) and are unable to germinate easily. Therefore, they must be subjected to various treatments to germinate. In nature, this dormancy is broken during the cold period of winter (chilling). The purpose of this research is to investigate different methods of dormancy breaking in Festuca species for large-scale production and accelerate the germination process.
Materials and methods: In this research, three species of Festuca (Festuca arundinacea, F. ovina, and F. rubra) were subjected to different treatments of chilling (4°C, 14 days), osmo-priming with potassium nitrate (KNO3) 1.5% and gibberellic acid 150 and 200 ppm. After 14 days of germination test, various germination indices including percentage and rate of germination, mean germination time, seed vigor index, length of radicle, shoot and seedling, and the ratio of radicle to shoot length were calculated.
Results: The results of the analysis of variance showed a significant difference between species (except for germination percentage and root length traits) and treatments (for all traits). The interactions between the species and treatment were also significant for all traits (except for the length of radicle and seedling). Among the three species, the percentage of germination varied from 26.67 to 30.67% and the value of the germination rate varied from 1.92 to 3.31 n/d. The average time required for germination varied from 3.75 to 4.36 days and the seed vigor index varied from 26.74 to 43.02. The radicle length was between 37.22 and 45 mm and the shoot length was between 37.34 and 81.33 mm. Based on principal components analysis (PCA), percentage and rate of germination, seed vigor index, and length of radicle and seedling were introduced as the most important factors in creating diversity in Festuca species. In determining the correlation between traits, a high correlation of 70% was observed between germination percentage, germination rate, and seed vigor index.
Conclusion: Among the three species, Festuca rubra was superior to the other two species by having the highest percentage and rate of germination, seed vigor, radical length, and the shortest time required for germination. Among the applied treatments, 1.5% potassium nitrate (KNO3) with chilling (4°C, for 14 days), had a positive effect on the percentage and rate of germination, radical length, and gibberellic acid (150 ppm) treatment had a positive effect on the length of shoot and seedling. The presence of high germination percentage and rate indicated higher seed vigor.
Highlights:
- Using potassium nitrate as a pre-treatment of seeds is better than watering seeds with potassium nitrate.
- The effect of osmo-priming (potassium nitrate 1.5%) on the germination characteristics of Festuca seeds is better than hormone priming (Gibberellic acid).
- Pre-treatment with 1.5% potassium nitrate increases the number of germinated seeds, while treatment with 150 ppm gibberellic acid increases seedling length in Festuca seeds.
Haniyeh Saadat, Mohammad Sedghi,
Volume 10, Issue 2 (3-2024)
Volume 10, Issue 2 (3-2024)
Abstract
Extended abstract
Introduction: Soybean is among the most important oil crops of the world. Currently, 55% of the world's oil is supplied by soybean. Seed aging, an undesirable feature of agriculture, is one of the main problems in agriculture that leads to economic losses. Although aging is an irreversible process, its speed is delayed by proper storage and optimal storage methods. While kept under inappropriate conditions after harvesting, its quality during storage declines. Priming has a direct and indirect effect on the growth and development of plants, and its indirect effects are more beneficial than its direct effects. Priming improves the longevity of low-vigor seeds. During the priming of these seeds, a long time can occur to repair metabolic damage before any progress in germination, which ultimately prevents further deterioration. Several studies have shown that seed treatment with sodium nitroprusside during reaction with reactive oxygen species and increased activity of antioxidant enzymes is essential to protecting plants against stress. The aim of this study was to the investigate the effect of sodium nitroprusside levels on germination indices and antioxidant enzyme activity in soybean seedlings under accelerated aging test.
Materials and Methods: This experiment was conducted in 2023 as a factorial in the form of a completely randomized design with 3 replications at the University of Mohaghegh Ardabili. Experimental treatments included accelerated aging treatment at three levels (0, 24, and 48 hours) and three levels of sodium nitroprusside (0, 100, and 200 ppm).
Results: The results showed that aging reduced germination indices including germination percentage (GP), germination value (GV), and mean daily germination (MDG). Also, priming with different levels of sodium nitroprusside, especially the 200 ppm level, improved these traits, but priming with sodium nitroprusside decreased the mean germination rate (MGR) and the mean germination time (MGT). The superoxide dismutase and ascorbate peroxidase enzyme activity due to priming with sodium nitroprusside 200 ppm compared to the control showed an increase of 22 and 26%, respectively. Also, the content of peroxidase enzyme activity showed an increase of about 34% compared to the control in priming with sodium nitroprusside 200 ppm and 48 hours aging compared to the control. The lowest catalase enzyme (7.7 units mg protein-1 min-1) was in pretreatment with sodium nitroprusside 100 ppm and without aging.
Conclusions: The results of this study show that among the different treatments, pre-treatment of seeds with sodium nitroprusside 200 ppm may be considered an effective way to improve germination indices and antioxidant enzymes activity of soybean and can be used as a treatment to deal with salinity conditions in soybean seedlings and improve their growth.
Highlights:
Introduction: Soybean is among the most important oil crops of the world. Currently, 55% of the world's oil is supplied by soybean. Seed aging, an undesirable feature of agriculture, is one of the main problems in agriculture that leads to economic losses. Although aging is an irreversible process, its speed is delayed by proper storage and optimal storage methods. While kept under inappropriate conditions after harvesting, its quality during storage declines. Priming has a direct and indirect effect on the growth and development of plants, and its indirect effects are more beneficial than its direct effects. Priming improves the longevity of low-vigor seeds. During the priming of these seeds, a long time can occur to repair metabolic damage before any progress in germination, which ultimately prevents further deterioration. Several studies have shown that seed treatment with sodium nitroprusside during reaction with reactive oxygen species and increased activity of antioxidant enzymes is essential to protecting plants against stress. The aim of this study was to the investigate the effect of sodium nitroprusside levels on germination indices and antioxidant enzyme activity in soybean seedlings under accelerated aging test.
Materials and Methods: This experiment was conducted in 2023 as a factorial in the form of a completely randomized design with 3 replications at the University of Mohaghegh Ardabili. Experimental treatments included accelerated aging treatment at three levels (0, 24, and 48 hours) and three levels of sodium nitroprusside (0, 100, and 200 ppm).
Results: The results showed that aging reduced germination indices including germination percentage (GP), germination value (GV), and mean daily germination (MDG). Also, priming with different levels of sodium nitroprusside, especially the 200 ppm level, improved these traits, but priming with sodium nitroprusside decreased the mean germination rate (MGR) and the mean germination time (MGT). The superoxide dismutase and ascorbate peroxidase enzyme activity due to priming with sodium nitroprusside 200 ppm compared to the control showed an increase of 22 and 26%, respectively. Also, the content of peroxidase enzyme activity showed an increase of about 34% compared to the control in priming with sodium nitroprusside 200 ppm and 48 hours aging compared to the control. The lowest catalase enzyme (7.7 units mg protein-1 min-1) was in pretreatment with sodium nitroprusside 100 ppm and without aging.
Conclusions: The results of this study show that among the different treatments, pre-treatment of seeds with sodium nitroprusside 200 ppm may be considered an effective way to improve germination indices and antioxidant enzymes activity of soybean and can be used as a treatment to deal with salinity conditions in soybean seedlings and improve their growth.
Highlights:
- Seed priming using sodium nitroprusside improved germination indices of seed common soybean under aging.
- Priming with sodium nitroprusside increased antioxidant enzyme activity.
- The concentration of 200 ppm sodium nitroprusside showed a better effect on germination indices and biochemical characteristics.
Mahboubeh Shahbazi, Jafar Asghari, Behnam Kamkar, Edris Taghvaie Salimi,
Volume 10, Issue 2 (3-2024)
Volume 10, Issue 2 (3-2024)
Abstract
Extended abstract
Introduction: The germination process is one of the most critical stages of a plant's growth and determines the success of the emergence of a weed in an agroecosystem because it is the first stage in which the weed competes for a niche. Various environmental factors, including temperature and moisture, affect the germination of weed seeds. Modeling techniques are capable of predicting germination, seedling emergence, and establishment of weed species. The ability to predict weed germination in response to environmental conditions is very effective for the development of control programs. The experiment was conducted to determine the cardinal temperature and evaluate the best model for quantifying the response of the germination rate of Western ragweed weed seeds under different water stress conditions.
Materials and Methods: A factorial experiment was conducted in the form of a completely randomized design in three replications. The investigated factors include temperature with eight levels (5, 10, 15, 20, 25, 30, 35, and 40 C˚) and water potential with six levels (0, -0.3, -0.6, -0.9, -1.2, and -1.5 MPa) on the germination of Western ragweed. In order to quantify the response of Western ragweed germination rate to temperature, three non-linear Dent-like, Beta, and Segmented regression models were used.
Results: The results showed that the effect of temperature, water potential, and their interactions on maximum germination, germination rate, and time required to reach 10, 50, and 90 percent germination were significant. Also, the results showed that by increasing the temperature from 10 to 25 C˚, the percentage and rate of germination increased whereas by increasing water potential, the percentage and rate of germination decreased. In comparing the models, based on RMSE, R2, CV, and coefficients a and b parameters, the Beta model was the most suitable for estimating the temperatures of cardinal Western ragweed. The base, optimum, and ceiling temperatures using the Beta model were 3.88, 25, and 40 C˚, respectively.
Conclusions: The use of the Beta model to quantify the germination response of Western ragweed seeds to different levels of water potential at different temperatures had acceptable results. Therefore, by using the output of these models at different temperatures, it is possible to predict the germination rate at different potentials.
Highlights:
1- Germination cardinal temperatures and the effect of water potential on western ragweed weed were investigated.
2- Estimation of different models to quantify the response of germination rate to temperature and different water potentials.
Introduction: The germination process is one of the most critical stages of a plant's growth and determines the success of the emergence of a weed in an agroecosystem because it is the first stage in which the weed competes for a niche. Various environmental factors, including temperature and moisture, affect the germination of weed seeds. Modeling techniques are capable of predicting germination, seedling emergence, and establishment of weed species. The ability to predict weed germination in response to environmental conditions is very effective for the development of control programs. The experiment was conducted to determine the cardinal temperature and evaluate the best model for quantifying the response of the germination rate of Western ragweed weed seeds under different water stress conditions.
Materials and Methods: A factorial experiment was conducted in the form of a completely randomized design in three replications. The investigated factors include temperature with eight levels (5, 10, 15, 20, 25, 30, 35, and 40 C˚) and water potential with six levels (0, -0.3, -0.6, -0.9, -1.2, and -1.5 MPa) on the germination of Western ragweed. In order to quantify the response of Western ragweed germination rate to temperature, three non-linear Dent-like, Beta, and Segmented regression models were used.
Results: The results showed that the effect of temperature, water potential, and their interactions on maximum germination, germination rate, and time required to reach 10, 50, and 90 percent germination were significant. Also, the results showed that by increasing the temperature from 10 to 25 C˚, the percentage and rate of germination increased whereas by increasing water potential, the percentage and rate of germination decreased. In comparing the models, based on RMSE, R2, CV, and coefficients a and b parameters, the Beta model was the most suitable for estimating the temperatures of cardinal Western ragweed. The base, optimum, and ceiling temperatures using the Beta model were 3.88, 25, and 40 C˚, respectively.
Conclusions: The use of the Beta model to quantify the germination response of Western ragweed seeds to different levels of water potential at different temperatures had acceptable results. Therefore, by using the output of these models at different temperatures, it is possible to predict the germination rate at different potentials.
Highlights:
1- Germination cardinal temperatures and the effect of water potential on western ragweed weed were investigated.
2- Estimation of different models to quantify the response of germination rate to temperature and different water potentials.
Shahram Nowrouzieh, Elham Faghani, Ghorbanali Roshani,
Volume 10, Issue 2 (3-2024)
Volume 10, Issue 2 (3-2024)
Abstract
Extended abstract
Introduction: Currently, in most countries around the world, cotton seeds are used in delinted form. The fuzzy cotton seed often lead to slower germination, increased susceptibility of seeds and seedlings to pests and diseases, and disrupts mechanized cotton planting. Delinted cotton seeds have numerous advantages, including the possibility of mechanized planting, reduced seed consumption per unit area, faster germination in the soil, and more rapid field emergence of seedlings. Furthermore, delinted seeds are usually free from pathogenic agents, and the seed quality is improved with the availability of gravity separation and removal of broken, lightweight, and hollow seeds. One of the challenges faced by cotton seed delinting factories in Iran that employ acid-based methods is the reduction in the seed germination of the delinted seeds, which poses a challenge to the continued operation of these factories. This research was conducted to investigate the reasons behind the reduction in the viability cotton seeds in a delinting factory, to examine the physiological and mechanical characteristics of seeds at various stages of delinting in the factory.
Materials and methods: Seed sampling was carried out in a delinting factory in two replications. Traits such as seed vigor, germination percentage, ion leakage, seed density and volume, seed aging, level of abrasion and damage to the seed coat, and seed rupture force were studied. Finally, the data were analyzed using SAS, SPSS, and JMP software.
Results: The test results showed that seed sampling from both replications of the factory before centrifuge had the lowest germination percentage, leaf formation percentage, primary root length, primary stem length, dry weight of primary root, and dry weight of primary stem. These traits indicate that during the centrifugation stage, the seeds sustain significant mechanical damage, leading to a reduction in their vigor. The percentage of breakage, ion leakage, ageing, volume and density of seeds in the first repetition showed that these seeds had a lower quality compared to the seeds related to the second repetition. Therefore, different delinting stages in the factory have decreased the seed vigor. As the percentage of breakage and ion leakage increases, the seed rupture force declines non-linearly. Based on these findings, it can be concluded that acid contact with the cotton seed and the centrifugation process caused more mechanical damage to the seeds, leading to a significant reduction in seed rupture force.
Conclusion: The accuracy of operations at all stages of delinting significantly impacts seed quality. The centrifugation stage, the temperature of the dryer cylinders, and the acid neutralization process require greater attention and monitoring. Therefore, it is necessary to adjust the duration or concentration of the acid used for delinting in the delinting factory to match the seed condition in order to minimize damage to the seeds.
Highlights:
Introduction: Currently, in most countries around the world, cotton seeds are used in delinted form. The fuzzy cotton seed often lead to slower germination, increased susceptibility of seeds and seedlings to pests and diseases, and disrupts mechanized cotton planting. Delinted cotton seeds have numerous advantages, including the possibility of mechanized planting, reduced seed consumption per unit area, faster germination in the soil, and more rapid field emergence of seedlings. Furthermore, delinted seeds are usually free from pathogenic agents, and the seed quality is improved with the availability of gravity separation and removal of broken, lightweight, and hollow seeds. One of the challenges faced by cotton seed delinting factories in Iran that employ acid-based methods is the reduction in the seed germination of the delinted seeds, which poses a challenge to the continued operation of these factories. This research was conducted to investigate the reasons behind the reduction in the viability cotton seeds in a delinting factory, to examine the physiological and mechanical characteristics of seeds at various stages of delinting in the factory.
Materials and methods: Seed sampling was carried out in a delinting factory in two replications. Traits such as seed vigor, germination percentage, ion leakage, seed density and volume, seed aging, level of abrasion and damage to the seed coat, and seed rupture force were studied. Finally, the data were analyzed using SAS, SPSS, and JMP software.
Results: The test results showed that seed sampling from both replications of the factory before centrifuge had the lowest germination percentage, leaf formation percentage, primary root length, primary stem length, dry weight of primary root, and dry weight of primary stem. These traits indicate that during the centrifugation stage, the seeds sustain significant mechanical damage, leading to a reduction in their vigor. The percentage of breakage, ion leakage, ageing, volume and density of seeds in the first repetition showed that these seeds had a lower quality compared to the seeds related to the second repetition. Therefore, different delinting stages in the factory have decreased the seed vigor. As the percentage of breakage and ion leakage increases, the seed rupture force declines non-linearly. Based on these findings, it can be concluded that acid contact with the cotton seed and the centrifugation process caused more mechanical damage to the seeds, leading to a significant reduction in seed rupture force.
Conclusion: The accuracy of operations at all stages of delinting significantly impacts seed quality. The centrifugation stage, the temperature of the dryer cylinders, and the acid neutralization process require greater attention and monitoring. Therefore, it is necessary to adjust the duration or concentration of the acid used for delinting in the delinting factory to match the seed condition in order to minimize damage to the seeds.
Highlights:
- Delinting in the factory causes damage to the seeds, but proper management of temperature and acid concentration mitigates this damage.
- It is necessary to adjust the duration or concentration of the acid used for delinting in the factory to match the seed condition in order to minimize damage to the seeds.
- Managing the acid spray on the seeds and eliminating the centrifugation section in the delinting factory can prevent severe seed damage in this stage, and seed quality can be improved.
- Neutralizing the seeds at the end of the delinting process in the delinting factory results in an increase in the storage of delinted cottonseed.
Zeynab Savaedy, Abdol Mehdi Bakhshandeh, Seyed Ataollah Siadat, Amin Lotfi Jalal Abadi, Seyed Amir Moosavi,
Volume 10, Issue 2 (3-2024)
Volume 10, Issue 2 (3-2024)
Abstract
Extended abstract
Introduction: Deterioration reduces the quality of seeds. Oilseeds like Nigella are highly susceptible to seed aging. Seed priming enhances the quality of deteriorated seeds by improving germination indices and increasing the activity of antioxidant enzymes. This research aimed to investigate the extent of damage caused by accelerated aging treatment on the germination characteristics and antioxidant enzyme activity of Nigella seeds and the possibility of mitigating the adverse effects of aging through hormonal priming with cytokinin.
Materials and methods: This research was carried out in the form of a completely random basic design with four replications in the seed technology laboratory of Khuzestan University of Agricultural Sciences and Natural Resources in 2017. The treatments included hormonal priming with cytokinin at five levels (0 (control), 10, 20, 40, and 80 m/l) for two durations (12 and 24 hours), and aging under 100% relative humidity and a temperature of 45 °C at five levels (no aging, 24, 48, 72, and 96 h).
Results: The analysis of variance results indicated that germination indices were only influenced by main and two-way effects at the 5% and 1% probability levels, while the three-way interactions, including aging, hormone concentration, and priming duration, were significant for plant growth and longitudinal and weight indices at the 1% probability level. Furthermore, it was evident that the priming treatment mitigated the negative effects of aging, with the concentration of 10 milligrams per liter of cytokinin for a duration of 12 h having the most significant impact among the hormone concentrations used on the measured traits. The highest germination percentage (88%) and the lowest germination percentage (63.33%) were observed at concentrations of 10 and 80 mg/l, respectively. The use of cytokinin at optimal concentration improved catalase activity and protein levels. The results showed that in the control conditions, the activity of the catalase enzyme was 0.76 units per mg of protein and the amount of protein was 0.51 mg/g, which reached 0.97 units per mg of protein and 0.79 mg/g with seed priming.
Conclusion: Based on the results obtained from this research, aging led to a reduction in germination indices, the activity of antioxidant enzymes, and seed protein content. The best treatment applied was cytokinin hormone priming for aged Nigella seeds at a concentration of 10 mg/l for 12 h. According to the results, the application of cytokinin at its optimal concentration (10 mg/l) improved the catalase enzyme activity and protein content. Therefore, it can be suggested that hormonal priming with cytokinin helps mitigate the adverse effects of aging in Nigella plants.
Highlights:
Introduction: Deterioration reduces the quality of seeds. Oilseeds like Nigella are highly susceptible to seed aging. Seed priming enhances the quality of deteriorated seeds by improving germination indices and increasing the activity of antioxidant enzymes. This research aimed to investigate the extent of damage caused by accelerated aging treatment on the germination characteristics and antioxidant enzyme activity of Nigella seeds and the possibility of mitigating the adverse effects of aging through hormonal priming with cytokinin.
Materials and methods: This research was carried out in the form of a completely random basic design with four replications in the seed technology laboratory of Khuzestan University of Agricultural Sciences and Natural Resources in 2017. The treatments included hormonal priming with cytokinin at five levels (0 (control), 10, 20, 40, and 80 m/l) for two durations (12 and 24 hours), and aging under 100% relative humidity and a temperature of 45 °C at five levels (no aging, 24, 48, 72, and 96 h).
Results: The analysis of variance results indicated that germination indices were only influenced by main and two-way effects at the 5% and 1% probability levels, while the three-way interactions, including aging, hormone concentration, and priming duration, were significant for plant growth and longitudinal and weight indices at the 1% probability level. Furthermore, it was evident that the priming treatment mitigated the negative effects of aging, with the concentration of 10 milligrams per liter of cytokinin for a duration of 12 h having the most significant impact among the hormone concentrations used on the measured traits. The highest germination percentage (88%) and the lowest germination percentage (63.33%) were observed at concentrations of 10 and 80 mg/l, respectively. The use of cytokinin at optimal concentration improved catalase activity and protein levels. The results showed that in the control conditions, the activity of the catalase enzyme was 0.76 units per mg of protein and the amount of protein was 0.51 mg/g, which reached 0.97 units per mg of protein and 0.79 mg/g with seed priming.
Conclusion: Based on the results obtained from this research, aging led to a reduction in germination indices, the activity of antioxidant enzymes, and seed protein content. The best treatment applied was cytokinin hormone priming for aged Nigella seeds at a concentration of 10 mg/l for 12 h. According to the results, the application of cytokinin at its optimal concentration (10 mg/l) improved the catalase enzyme activity and protein content. Therefore, it can be suggested that hormonal priming with cytokinin helps mitigate the adverse effects of aging in Nigella plants.
Highlights:
- The impact of hormonal priming with cytokinin at concentrations of 10, 20, 40, and 80 mg/L on aged Nigella seeds was investigated.
- The use of a concentration of 10 mg/l of cytokinin hormone for 12 hours was introduced as the best treatment.
- Cytokinin was introduced as a significant hormone that enhances the activity of antioxidant enzymes and physiological traits in aged Nigella seeds.
Mahvash Majdi, Reza Tavakkol Afshari, Hamid Reza Khazaee, Amin Mirshamsi Kakhki,
Volume 10, Issue 2 (3-2024)
Volume 10, Issue 2 (3-2024)
Abstract
Extended abstract
Introduction: The effects of temperature increases on the growth of tomato fields are among the obvious results of global warming and are considered an important issue that should be investigated. To maintain and develop the cultivation systems of this crop, a proper understanding of the heat tolerance mechanisms and physiological responses in tomatoes should be achieved. The primary objective of this research is to discover the impact of heat stress on the germination and growth of pollen grains in research tomato germplasms. The researchers' knowledge about the response of different tomato cultivars to abiotic stresses is limited and only the effects of enzymes involved in the response process, heat shock proteins and some hormones have been investigated. The process of detecting heat stress-sensitive stages and their enhancement is facilitated by having a correct understanding of physiological processes.
Materials and methods: The seeds of heat-resistant (LA2661 and LA2662) and -sensitive (LA3911) research cultivars of tomato were used to evaluate the effects of increasing day and night temperatures. The obtained seedlings were grown under optimal temperature conditions (24°C day/18°C night), and after observing the first flower primordium, were incubated in growth chambers to apply daytime heat stress treatments, including temperatures of 28°C, 32°C and 36°C day/18°C night and night stress treatments including temperatures of 28°C, 32°C, and 36°C at night/ 24°C day for 7 days. Pollen grains were then evaluated for their survival, germination, and growth.
Results: The findings of the daytime heat stress tests show that the percentage of survival and germination of pollen grains and growth of pollen tubes of cultivars LA2661, LA2662 and LA3911 decreased as daytime temperature rose from 24°C to 36°C. This reduction is more noticeable for the sensitive cultivar LA3911. Degraded pollen grains increased in the LA3911 cultivar due to heat stress. The survival percentage of pollen grains in all three studied cultivars decreased due to the application of heat stress at night. The resistant cultivars LA2661 and LA2662 had a higher germination percentage compared to the sensitive cultivar LA3911. Pollen grains germination decreased by 50% as a result of increasing the night temperature from 18°C to 36°C. Pollen tube length was reduced in both cultivars and night treatments.
Conclusion: The effects of heat stress in the early stages of flowering when flowers are visible are high, and reproductive stages are very sensitive to high temperatures and affect fertility and processes after insemination, and finally, they lead to yield loss. The daytime temperature increase relative to the natural temperature range (22°C to 24°C) during growth severely impacts the number of pollen grains released from tomato flowers. The number of non-living pollen grains is higher at 36°C day and 32°C and 36°C night temperatures compared to optimal temperature conditions. It appears that the increase in nighttime temperature results in more severe consequences than the increase in daytime temperature.
Highlights:
Introduction: The effects of temperature increases on the growth of tomato fields are among the obvious results of global warming and are considered an important issue that should be investigated. To maintain and develop the cultivation systems of this crop, a proper understanding of the heat tolerance mechanisms and physiological responses in tomatoes should be achieved. The primary objective of this research is to discover the impact of heat stress on the germination and growth of pollen grains in research tomato germplasms. The researchers' knowledge about the response of different tomato cultivars to abiotic stresses is limited and only the effects of enzymes involved in the response process, heat shock proteins and some hormones have been investigated. The process of detecting heat stress-sensitive stages and their enhancement is facilitated by having a correct understanding of physiological processes.
Materials and methods: The seeds of heat-resistant (LA2661 and LA2662) and -sensitive (LA3911) research cultivars of tomato were used to evaluate the effects of increasing day and night temperatures. The obtained seedlings were grown under optimal temperature conditions (24°C day/18°C night), and after observing the first flower primordium, were incubated in growth chambers to apply daytime heat stress treatments, including temperatures of 28°C, 32°C and 36°C day/18°C night and night stress treatments including temperatures of 28°C, 32°C, and 36°C at night/ 24°C day for 7 days. Pollen grains were then evaluated for their survival, germination, and growth.
Results: The findings of the daytime heat stress tests show that the percentage of survival and germination of pollen grains and growth of pollen tubes of cultivars LA2661, LA2662 and LA3911 decreased as daytime temperature rose from 24°C to 36°C. This reduction is more noticeable for the sensitive cultivar LA3911. Degraded pollen grains increased in the LA3911 cultivar due to heat stress. The survival percentage of pollen grains in all three studied cultivars decreased due to the application of heat stress at night. The resistant cultivars LA2661 and LA2662 had a higher germination percentage compared to the sensitive cultivar LA3911. Pollen grains germination decreased by 50% as a result of increasing the night temperature from 18°C to 36°C. Pollen tube length was reduced in both cultivars and night treatments.
Conclusion: The effects of heat stress in the early stages of flowering when flowers are visible are high, and reproductive stages are very sensitive to high temperatures and affect fertility and processes after insemination, and finally, they lead to yield loss. The daytime temperature increase relative to the natural temperature range (22°C to 24°C) during growth severely impacts the number of pollen grains released from tomato flowers. The number of non-living pollen grains is higher at 36°C day and 32°C and 36°C night temperatures compared to optimal temperature conditions. It appears that the increase in nighttime temperature results in more severe consequences than the increase in daytime temperature.
Highlights:
- Night heat stress was assessed as a factor that influences the germination and survival of tomato pollen grains.
- Image analysis was used to measure the length of the pollen tube.
- The effect of thermal stress on pollination was investigated during a specific period of reproductive growth.
Ebrahim Gholamalipour Alamdari, Meisam Habibi, Mohammad Hadi Masoumi, Maral Babayani, Ali Asghar Saravani,
Volume 10, Issue 2 (3-2024)
Volume 10, Issue 2 (3-2024)
Abstract
Extended abstract
Introduction: In agricultural systems, several environmental stresses can remarkably alter the growth, physiological, and biochemical responses of plants under stress. One of these factors is the biochemical reactions between plants along with the production of secondary compounds. Allelochemicals mainly have defence and cell wall ligninization roles in plants and do not directly play a role in the growth processes of plants. Thus, an experiment was carried out to evaluate the effect of allelopathic stress of Hypericum perforatum on the germination, physiological, biochemical, and antioxidant activity characteristics of green pea, the benchmark plant sensitive to allelochemicals.
Materials and methods: The treatments included different concentrations of H. perforatum at 11 levels (i.e., 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100% of the aqueous extract). This research was carried out as a completely randomized design with three replications at the weed science laboratory of Gonbad Kavous University in 2023.
Results: The results of this study showed that one of the factors influencing the physiological, and biochemical characteristics of green pea is the concentration of the H. perforatum extract. In most cases, the percentage and rate of green pea germination, radicle and plumule length, and dry weight of radicle and plumule decreased with increased concentration of aqueous extract compared to the control, so that the greatest reduction in these characteristics was observed in 100% of H. perforatum extract. In contrast, the content of compatible osmolytes such as proline and soluble sugars, phenolic and flavonoid compounds, and antioxidant activity of green pea roots and plumules increased significantly in all studied treatments, with the highest increase in these characteristics observed at the concentration of 100% of H. perforatum aqueous extract. In general, the decrease in the dry weight of green pea seedlings due to the increase in the concentration of the aqueous extract of H. perforatum, despite the relative increase in the content of physiological and biochemical traits, indicates the high intensity of allelopathic stress of H. perforatum extract and their insufficiency, which leads to cytotoxicity against oxidative stress.
Conclusion: Considering the heterotoxicity effect of H. perforatum on green pea sensitive to allelochemicals and its distribution in gardens, barren lands, and wheat and corn fields, the possible effect of their residues in the next planting and even in case of presence in mixed cultivation should be considered.
Highlights:
Introduction: In agricultural systems, several environmental stresses can remarkably alter the growth, physiological, and biochemical responses of plants under stress. One of these factors is the biochemical reactions between plants along with the production of secondary compounds. Allelochemicals mainly have defence and cell wall ligninization roles in plants and do not directly play a role in the growth processes of plants. Thus, an experiment was carried out to evaluate the effect of allelopathic stress of Hypericum perforatum on the germination, physiological, biochemical, and antioxidant activity characteristics of green pea, the benchmark plant sensitive to allelochemicals.
Materials and methods: The treatments included different concentrations of H. perforatum at 11 levels (i.e., 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100% of the aqueous extract). This research was carried out as a completely randomized design with three replications at the weed science laboratory of Gonbad Kavous University in 2023.
Results: The results of this study showed that one of the factors influencing the physiological, and biochemical characteristics of green pea is the concentration of the H. perforatum extract. In most cases, the percentage and rate of green pea germination, radicle and plumule length, and dry weight of radicle and plumule decreased with increased concentration of aqueous extract compared to the control, so that the greatest reduction in these characteristics was observed in 100% of H. perforatum extract. In contrast, the content of compatible osmolytes such as proline and soluble sugars, phenolic and flavonoid compounds, and antioxidant activity of green pea roots and plumules increased significantly in all studied treatments, with the highest increase in these characteristics observed at the concentration of 100% of H. perforatum aqueous extract. In general, the decrease in the dry weight of green pea seedlings due to the increase in the concentration of the aqueous extract of H. perforatum, despite the relative increase in the content of physiological and biochemical traits, indicates the high intensity of allelopathic stress of H. perforatum extract and their insufficiency, which leads to cytotoxicity against oxidative stress.
Conclusion: Considering the heterotoxicity effect of H. perforatum on green pea sensitive to allelochemicals and its distribution in gardens, barren lands, and wheat and corn fields, the possible effect of their residues in the next planting and even in case of presence in mixed cultivation should be considered.
Highlights:
- Aqueous extract obtained from the H. perforatum drastically reduces the germination and seedling growth of green peas.
- The difference in the effect of the aqueous extract of H. perforatum on green pea, the benchmark plant sensitive to allelochemicals, depends on their concentration threshold.
- The high intensity of allelopathic stress of H. perforatum extract and insufficient non-enzymatic antioxidants lead to oxidative stress.
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Seed Science and Technology, Seed Physiology, Seed Ecology, Modeling, Seed Health, Germination Characteristics, Seed Dormancy, Seed Ageing, Seed Storage, Seed PrimingVote
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