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Showing 218 results for Type of Study: Research
Aidin Hamidi, Samad Allah Karami, Victoria Askari,
Volume 8, Issue 1 (9-2021)
Volume 8, Issue 1 (9-2021)
Abstract
Extended Abstract
Introduction: Cotton is the most important fiber-oil seed crop. Seed germination, vigour and health are the most important aspects of cotton seed quality. In Iran, annual cotton seed requirement is near 4000 tones, half of which is delinted and half is provided as fuzzy seed and therefore infection of fuzzy seeds to seed borne disease pathogens is possible. Every year a part of produced cotton seed does not possess standard quality and is not certify for various reasons including infection with seed borne disease pathogens. Thereafter, this research was conducted in order to study the relationship among cotton commercial cultivars seed germination, vigour and health.
Materials and Methods: Fuzzy seeds lots samples of Sahel, Varamin, Bakhtegan and Mehr cotton commercial cultivars with of 80, 90, and 95 percent intial germination ability (normal seedlings percent) produced at Golestan, Khorasan Razavi, Fars, and Ardabil provinces respectively underwent Standard germination and accelerated ageing tests. Final germination percent before and after accelerated ageing, normal seedlings percent after accelerated ageing, decayed seeds percent before and after accelerated ageing, mean germination time, seedling length, dry weight, seedling length and weight vigour indices after accelerated ageing were measured and the fungus on decayed seeds were determined by blotter test. Then, their average frequency was determined.
Results: Sahel and Bakhtegan cultivars and seeds having the highest primary germination ability had the most final germination percent before accelerated ageing and Sahel cultivar seed with the highest and moderate initial germination had the highest final germination percent after accelerated ageing. Sahel cultivar seeds had the highest normal seedlings percent after accelerated ageing. The highest decayed seeds percent before accelerated ageing belonged to Varamin and Mehr cultivars with moderate and low intial germination ability, and the highest decayed seeds percent after accelerated ageing belonged to Varamin and Mehr cultivars with low intial germination ability. Seeds having the lowest primary germination ability had the highest mean germination time and Sahel cultivar seeds had the highest seedling length and weight vigour indices. All studied cultivars seeds had been contaminated with Fusarium spp., Alternaria spp., Aspergillus spp. and Trichothecium roseum. Also, Varamin and Mehr cultivars seeds had the highest and Sahel cultivar seeds had the lowest average frequency of fungus on decayed seeds. Final germination percent before and after accelerated ageing and seedling length and weight vigour indices had significant negative correlation with decayed seeds percent before and after accelerated ageing.
Conclusion: Seeds decay was the most important factor of studied cotton cultivars seed deterioration and germination and seedling vigour decrease. Sahel and Mehr cultivars seeds and seeds with the highest (95 percent) and lowest (80 percent) intial germination ability seeds respectively had the highest (91 percent) and lowest (58 percent) seed final germination percent and seedling vigour. Alternaria spp., Aspergillus spp. on Mehr cultivar seeds, Fusarium spp. on Varamin cultivar seeds and Trichothecium roseum on Bakhtegan cultivars seeds with average frequency on decayed seeds after accelerated ageing of respectively 100, 99, 80.70 and 63 percent were the fungus that led to the most seeds germination and seedlings vigour decrease.
Highlights:
Introduction: Cotton is the most important fiber-oil seed crop. Seed germination, vigour and health are the most important aspects of cotton seed quality. In Iran, annual cotton seed requirement is near 4000 tones, half of which is delinted and half is provided as fuzzy seed and therefore infection of fuzzy seeds to seed borne disease pathogens is possible. Every year a part of produced cotton seed does not possess standard quality and is not certify for various reasons including infection with seed borne disease pathogens. Thereafter, this research was conducted in order to study the relationship among cotton commercial cultivars seed germination, vigour and health.
Materials and Methods: Fuzzy seeds lots samples of Sahel, Varamin, Bakhtegan and Mehr cotton commercial cultivars with of 80, 90, and 95 percent intial germination ability (normal seedlings percent) produced at Golestan, Khorasan Razavi, Fars, and Ardabil provinces respectively underwent Standard germination and accelerated ageing tests. Final germination percent before and after accelerated ageing, normal seedlings percent after accelerated ageing, decayed seeds percent before and after accelerated ageing, mean germination time, seedling length, dry weight, seedling length and weight vigour indices after accelerated ageing were measured and the fungus on decayed seeds were determined by blotter test. Then, their average frequency was determined.
Results: Sahel and Bakhtegan cultivars and seeds having the highest primary germination ability had the most final germination percent before accelerated ageing and Sahel cultivar seed with the highest and moderate initial germination had the highest final germination percent after accelerated ageing. Sahel cultivar seeds had the highest normal seedlings percent after accelerated ageing. The highest decayed seeds percent before accelerated ageing belonged to Varamin and Mehr cultivars with moderate and low intial germination ability, and the highest decayed seeds percent after accelerated ageing belonged to Varamin and Mehr cultivars with low intial germination ability. Seeds having the lowest primary germination ability had the highest mean germination time and Sahel cultivar seeds had the highest seedling length and weight vigour indices. All studied cultivars seeds had been contaminated with Fusarium spp., Alternaria spp., Aspergillus spp. and Trichothecium roseum. Also, Varamin and Mehr cultivars seeds had the highest and Sahel cultivar seeds had the lowest average frequency of fungus on decayed seeds. Final germination percent before and after accelerated ageing and seedling length and weight vigour indices had significant negative correlation with decayed seeds percent before and after accelerated ageing.
Conclusion: Seeds decay was the most important factor of studied cotton cultivars seed deterioration and germination and seedling vigour decrease. Sahel and Mehr cultivars seeds and seeds with the highest (95 percent) and lowest (80 percent) intial germination ability seeds respectively had the highest (91 percent) and lowest (58 percent) seed final germination percent and seedling vigour. Alternaria spp., Aspergillus spp. on Mehr cultivar seeds, Fusarium spp. on Varamin cultivar seeds and Trichothecium roseum on Bakhtegan cultivars seeds with average frequency on decayed seeds after accelerated ageing of respectively 100, 99, 80.70 and 63 percent were the fungus that led to the most seeds germination and seedlings vigour decrease.
Highlights:
- Cotton commercial cultivars seed lots seed borne fungi and contamination rate were identified.
The relationship of cotton commercial cultivars seeds germination percent and seedling vigour with contamination to seed borne fungi were determined
Ahmad Zare, Fatemeh Deris, Zahra Karimi,
Volume 8, Issue 1 (9-2021)
Volume 8, Issue 1 (9-2021)
Abstract
Extended Abstract
Introduction: Notobasis (Syrian Thistle (has been introduced as a weed - medicinal plant. In Khuzestan province, the presence of Notobasis is abundant in cereal fields, especially field margins. For successful weed control, knowledge of weed biology and ecology (temperature, salinity and drought stresses) plays a key role in population dynamics of weeds and weed management. Therefore, the study aimed to evaluate Syrian Thistle response to temperature, salinity and drought, as well as to determine the cardinal temperature based on segmented, beta-four-parameter and dent-like models.
Materials and Methods: To investigate the effect of temperature (5, 10, 15, 20, 25, 30, 35 and 40 °C), salinity (zero, 50, 100, 150, 200, 250 and 300 mM) and drought stress (zero, 2) -0.0, -0.4, -0.6, -0.8, -1, -1.2 and -1.4 MPa). Three separate experiments were conducted in 2019 at agricultural science and natural resources university of Khuzestan at the laboratory of weed science with 6 replications. In each Petri dish, 25 seeds were placed and 7 ml of solution was added. In salinity and drought stresses experiments, sodium chloride solution and polyethylene glycol 6000 were used.
Results: Germination of Notobasis at temperatures of 5-30°C was more than 90%, and germination percent decreased to 24% as the temperature increased to 35°C, Based on three models segmented, beta 4 parameter and Dent-like, the Base temperature was estimated 2.95, 2.01 and 0.67°C respectively. Also, the optimum temperature in two models (segmented and beta parameter) was obtained 22.26 and 23.40°C respectively. Ceiling temperature was predicted 40.57, 39.75 and 40.03°C in three models (segmented, beta 4 parameter and Dent- like). Salinity required to reduce 50% of germination percentage, germination rate, seedling length and seedling fresh weight were 152, 85, 151 and 127 mM. 50% reduction of traits such as germination percent, germination rate, seedling length and seedling fresh weight were -0.81, -0.41, -0.43 and -0.45 MPa of drought stress respectively.
Conclusion: The results indicated that Notobasis had germination in a wide range of temperatures (5-35°C). In response to environmental stress, Notobasis have been identified as a weed resistant to salinity and drought stresses. Therefore, the presence of this weed in saline fields and arid areas is not unexpected.
Highlights:
1-To determine of cardinal temperature of Notobasis based on different models.
2-To evaluate germination ecology of Notobasis to environmental factors (temperature, salinity and drought stress) as the first report.
Shamsaldin Skandarnejad, Manoochehr Gholipoor, Hassan Makarian,
Volume 8, Issue 2 (3-2022)
Volume 8, Issue 2 (3-2022)
Abstract
Extended Abstract
Introduction: A large number of experimental evidence indicates the positive effect of irradiating the seed with ultrasonic waves; so that irradiation causes the production of a more vigorous seedling. Conversely, inappropriate intensity and duration of irradiation can impose deleterious effects on seedlings by damaging the enzymatic activity. There are complex inter-and intra-relations between irradiation components (pre-soaking duration, temperature, and duration of irradiation) and response variables [seedling dry weight (SDW) and percent of abnormal seedlings (PAS)]. Therefore the balance values of the irradiation components cannot be precisely obtained by mean comparison. This study aimed to optimize (finding the balance values of) irradiation components for increased SDW, but diminished PAS of mung bean, using an artificial neural network.
Materials and Methods: A factorial experiment was conducted based on a completely randomized design with three replications. The factors were six pre-soaking durations (2, 4, 6, 8, 10, and 12 hours), 5 irradiation durations (0, 3, 6, 9 and 12 minutes), and 4 irradiation temperatures (17, 22, 27, and 32 oC). The 25 seeds were chosen for each petri dish. The multi-layer perceptron neural network was used to quantify the relations between variables; the experimental factors were used as the input (regressors), and PAS and SDW as the output of the model (response variables).
Results: The analysis of variance results indicated that the simple and interactive effects of factors were significant on PAS and SDW. The structure 3:3:2 of the neural network, which is based on Secant Hyperbolic function, was suitable. The SDW and PAS were negligibly different for the contribution of the factors in determining their changes. In terms of relative contribution, the factors ranked from higher to lower as irradiation duration, irradiation temperature, and pre-soaking duration. The optimized values of components of irradiation by the neural network were irradiation temperature of 17.96 oC, irradiation duration of 5.3 minutes, and pre-soaking duration of 11.25 hours. For these components, SDW was 27% higher, and PAS tended to be 0.6% lower, compared to the best component combination gotten by mean comparison.
Conclusion: Due to the highly strong interaction of irradiation components on seedling growth, the effect of component (s) tends to be changed intensively with changing the quantity of each component. In terms of finding the best combination of irradiation components, the neural network was more efficient than the mean comparison. Therefore, the neural network could be used as a complementary procedure in such investigations.
Highlights:
1- Irradiation components including irradiation duration and temperature, and pre-soaking duration affected seedling growth.
2- Inappropriate irradiation components diminished seedling growth to the below of no-irradiation conditions.
3- The optimum (balanced) levels of irradiation components increased seedling growth remarkably.
Maryam Boroujerdnia, Hamed Hasanzade Khankahdani,
Volume 8, Issue 2 (3-2022)
Volume 8, Issue 2 (3-2022)
Abstract
Extend abstract
Introduction: Guava (Psidium guajava L.) is one of the most important fruit crops of tropical and subtropical regions. Guava (Psidium guajava L.) can be propagated by seed, layering, grafting, cutting or tissue culture. Propagation by seed is used for the production of seedlings usable in breeding programs or rootstock production for grafting. Guava seeds germinate poorly and unevenly and require more time for seedling emergence. The dormancy in seeds might be due to hard seed coat and different methods are used for breaking dormancy in seeds to improve germination. The aim of this study was to evaluate efficiency of the different pretreatment on seed dormancy breaking and germination characteristics of guava.
Materials and Methods: The experiment was laid out in a completely randomized design with three replications on guava seeds in genetic and breeding laboratory of Date Palm and Tropical Fruit Research Center at the summer of 2018. Treatments consisted of distilled water (24 and 48 h), 0.5 and 1% potassium nitrate (KNO3) for 24 h, warm water (70 ° C) for 5 and 10 min, 25% and 50% sulphuric acid for 5 min, and control (non-treated). In this study, the traits of germination percentage, germination rate and mean of daily germination, seed vigour index and fresh weight and length of seedling were measured. Data analysis was done using the SAS 9.2 software and the Duncan's test at 5% probability level was used for mean comparison.
Results: Results showed that the effect of treatments on seed germination indices (germination percentage, germination rate and mean of daily germination, seed vigour index) of guava was significant at p<0.01. The greatest germination percentage (53.1%), germination rate (6.6 seed/day) and seed vigour (2636.7) were observed in treatment of 1% potassium nitrate (KNO3) for 24 h. The lowest Mean time to germination (14 days) was obtained in distilled water for 48h. Warm water treatments at 70 °C and 25% and 50% sulfuric acid were not effective in improving seed germination compared to control. The highest seed length and weight were observed in 1% potassium nitrate and 0.5% potassium nitrate pretreatments, respectively.
Conclusions: the results of this study show that among the different treatments, pre-treatment of seeds with 1%potassium nitrate may be considered as an effective way to improve seed germination of guava. Also, pretreatment with distilled water for 48 hours is an easy, low cost and effective way to increase guava seed germination indices.
Highlights:
1- The effect of different chemical treatments on germination characteristics of guava was investigated.
2- The suitable method for seed dormancy elimination and seed germination improvement of guava was introduced.
Introduction: Guava (Psidium guajava L.) is one of the most important fruit crops of tropical and subtropical regions. Guava (Psidium guajava L.) can be propagated by seed, layering, grafting, cutting or tissue culture. Propagation by seed is used for the production of seedlings usable in breeding programs or rootstock production for grafting. Guava seeds germinate poorly and unevenly and require more time for seedling emergence. The dormancy in seeds might be due to hard seed coat and different methods are used for breaking dormancy in seeds to improve germination. The aim of this study was to evaluate efficiency of the different pretreatment on seed dormancy breaking and germination characteristics of guava.
Materials and Methods: The experiment was laid out in a completely randomized design with three replications on guava seeds in genetic and breeding laboratory of Date Palm and Tropical Fruit Research Center at the summer of 2018. Treatments consisted of distilled water (24 and 48 h), 0.5 and 1% potassium nitrate (KNO3) for 24 h, warm water (70 ° C) for 5 and 10 min, 25% and 50% sulphuric acid for 5 min, and control (non-treated). In this study, the traits of germination percentage, germination rate and mean of daily germination, seed vigour index and fresh weight and length of seedling were measured. Data analysis was done using the SAS 9.2 software and the Duncan's test at 5% probability level was used for mean comparison.
Results: Results showed that the effect of treatments on seed germination indices (germination percentage, germination rate and mean of daily germination, seed vigour index) of guava was significant at p<0.01. The greatest germination percentage (53.1%), germination rate (6.6 seed/day) and seed vigour (2636.7) were observed in treatment of 1% potassium nitrate (KNO3) for 24 h. The lowest Mean time to germination (14 days) was obtained in distilled water for 48h. Warm water treatments at 70 °C and 25% and 50% sulfuric acid were not effective in improving seed germination compared to control. The highest seed length and weight were observed in 1% potassium nitrate and 0.5% potassium nitrate pretreatments, respectively.
Conclusions: the results of this study show that among the different treatments, pre-treatment of seeds with 1%potassium nitrate may be considered as an effective way to improve seed germination of guava. Also, pretreatment with distilled water for 48 hours is an easy, low cost and effective way to increase guava seed germination indices.
Highlights:
1- The effect of different chemical treatments on germination characteristics of guava was investigated.
2- The suitable method for seed dormancy elimination and seed germination improvement of guava was introduced.
Kamran Alimardani, Amin Salehi, Mohsen Movahhedi Dehnavi, Ali Moradi,
Volume 8, Issue 2 (3-2022)
Volume 8, Issue 2 (3-2022)
Abstract
Extended Abstract
Introduction: Schrophularia striata is one of the medicinal plants of the Scrophulariaceae family and contains phenolic compounds. Locals have traditionally used this herbal medicine to treat infections caused by wounds, gastrointestinal diseases, and eye diseases. Due to excessive consumption by indigenous people and climate change, especially increasing temperature, the cold required to eliminate seed dormancy is not presently available and its germination and growth has decreased. Therefore, this plant is at the risk of extinction. Since this plant is propagated in natural habitats through seed and due to deep seed dormancy, evaluation of different seed dormancy methods is necessary for conservation and domestication of this species. In this study, suitable methods to eliminate seed dormancy of this plant using chilling and gibberellic acid treatments were studied on the seeds collected from different habitats of Ilam province.
Materials and Methods: To investigate the effect of using chilling and gibberellic acid on Schrophularia striata dormancy, a split plot factorial experiment based on completely randomized design with four replications was conducted at the seed laboratory of Yasouj University in 2018. The first factor included the duration of moist chilling period (0, 4, 8, 12 and 16 weeks), the second factor included gibberellic acid (0, 300 and 600 mg/L) and the third factor included five habitats (Ilam, Ivan, Mehran, Abadan and Dehloran).
Results: The results showed that the 16-week Chilling and zero gibberellic acid treatments had the highest germination percentage in all habitats, as the percentage of germination in Mehran, Ivan, Ilam, Abadan and Dehloran habitats was 66, 50, 36, 30 and 25%, respectively. Also, the highest germination rate was observed in all habitats at 16 weeks chilling and zero mg/L gibberellic acid concentration. The highest germination uniformity was obtained at 16 and 12 weeks of chilling.
Conclusions: Chilling period duration was effective on germination percentage and rate and with increasing chilling period, germination percentage and rate increased. This indicates that the seeds studied had some degree of physiological dormancy, and the seed of higher altitude habitats required longer chilling periods than those of the lower ones for germination. Also, according to the results of this experiment, chilling periods above 16 weeks should be used to increase germination percentage.
Highlights:
1- Chilling period duration in the presence of gibberellic acid was the most important factor for the elimination of Schrophularia striata seed Dormancy and increased germination.
2- With increasing altitude and in the same chilling period duration, habitats with lower altitude had higher germination percentage and rate
Introduction: Schrophularia striata is one of the medicinal plants of the Scrophulariaceae family and contains phenolic compounds. Locals have traditionally used this herbal medicine to treat infections caused by wounds, gastrointestinal diseases, and eye diseases. Due to excessive consumption by indigenous people and climate change, especially increasing temperature, the cold required to eliminate seed dormancy is not presently available and its germination and growth has decreased. Therefore, this plant is at the risk of extinction. Since this plant is propagated in natural habitats through seed and due to deep seed dormancy, evaluation of different seed dormancy methods is necessary for conservation and domestication of this species. In this study, suitable methods to eliminate seed dormancy of this plant using chilling and gibberellic acid treatments were studied on the seeds collected from different habitats of Ilam province.
Materials and Methods: To investigate the effect of using chilling and gibberellic acid on Schrophularia striata dormancy, a split plot factorial experiment based on completely randomized design with four replications was conducted at the seed laboratory of Yasouj University in 2018. The first factor included the duration of moist chilling period (0, 4, 8, 12 and 16 weeks), the second factor included gibberellic acid (0, 300 and 600 mg/L) and the third factor included five habitats (Ilam, Ivan, Mehran, Abadan and Dehloran).
Results: The results showed that the 16-week Chilling and zero gibberellic acid treatments had the highest germination percentage in all habitats, as the percentage of germination in Mehran, Ivan, Ilam, Abadan and Dehloran habitats was 66, 50, 36, 30 and 25%, respectively. Also, the highest germination rate was observed in all habitats at 16 weeks chilling and zero mg/L gibberellic acid concentration. The highest germination uniformity was obtained at 16 and 12 weeks of chilling.
Conclusions: Chilling period duration was effective on germination percentage and rate and with increasing chilling period, germination percentage and rate increased. This indicates that the seeds studied had some degree of physiological dormancy, and the seed of higher altitude habitats required longer chilling periods than those of the lower ones for germination. Also, according to the results of this experiment, chilling periods above 16 weeks should be used to increase germination percentage.
Highlights:
1- Chilling period duration in the presence of gibberellic acid was the most important factor for the elimination of Schrophularia striata seed Dormancy and increased germination.
2- With increasing altitude and in the same chilling period duration, habitats with lower altitude had higher germination percentage and rate
Behzad Nouri Feli, Hamid Reza Eisvand, Naser Akbari, Dariush Goodarzi,
Volume 8, Issue 2 (3-2022)
Volume 8, Issue 2 (3-2022)
Abstract
Extended Abstract
Introduction: Providing important and effective elements such as zinc and boron- especially in areas where the soil for some reason cannot meet the needs of the plant- will be a good solution to improve seed and seedling quality and nutrition, and community health status. A considerable part of the wheat producing regions in the country are faced with late season haet during seed development stages. Thus, the present study will investigate the effect of heat stress and mother plant nutrition with zinc and boron micronutrients on seed deterioration and physiological quality of wheat seedlings.
Material and Methods: In a field experiment, wheat seeds were planted on two suitable planting dates (November 20) and late (January 5) to apply late-season heat stress during the seed development stage with three replications in Ramhormoz, Iran. The nutrition of mother plants with zinc and boron elements was done at three levels (nutrient-free and application of zinc and boron) as a foliar application. After harvest, the seeds were transferred to the laboratory and membrane integrity of seed cells was investigated using an electrical conductivity test as an indicator of deterioration. Another part of the seeds was planted in a factorial pot experiment based on RCBD with three replications to evaluate the quality of seeds and seedlings in the greenhouse.
Results: The results showed that exposure of seeds to heat stress during development reduced seed quality as well as seedlings so that the cell membrane in the seeds produced under heat stress conditions was damaged and their electrical conductivity increased by 19%. Also, these seeds showed more sensitivity to deterioration. The percentage of seedling emergence in the stressed seeds decreased by 21.66%. Heat stress also reduced seedling quality indices such as chlorophyll content, shoot dry weight, and root dry weight. Application of zinc and boron on the mother plant not only led to improved quality of seeds and seedlings under normal conditions but also the negative effects of heat stress on seed and seedling quality were reduced. There was a significant negative correlation between the seed electrical conductivity test and qualitative parameters. Therefore, the use of this test is recommended to determine the quality of seeds, especially seeds produced under late-season heat stress conditions.
Conclusion: Noting the negative effect of heat during seed development on seed quality, planting dates should be adjusted as much as possible so that the seed development stage does not coincide with the late-season heat stress. Due to the beneficial effects of using zinc and boron in the mother plant on many traits related to the quality of seeds and seedlings, their application- especially zinc- in soils with deficiency or the possibility of heat stress at the end of the season is recommended.
Highlights:
Introduction: Providing important and effective elements such as zinc and boron- especially in areas where the soil for some reason cannot meet the needs of the plant- will be a good solution to improve seed and seedling quality and nutrition, and community health status. A considerable part of the wheat producing regions in the country are faced with late season haet during seed development stages. Thus, the present study will investigate the effect of heat stress and mother plant nutrition with zinc and boron micronutrients on seed deterioration and physiological quality of wheat seedlings.
Material and Methods: In a field experiment, wheat seeds were planted on two suitable planting dates (November 20) and late (January 5) to apply late-season heat stress during the seed development stage with three replications in Ramhormoz, Iran. The nutrition of mother plants with zinc and boron elements was done at three levels (nutrient-free and application of zinc and boron) as a foliar application. After harvest, the seeds were transferred to the laboratory and membrane integrity of seed cells was investigated using an electrical conductivity test as an indicator of deterioration. Another part of the seeds was planted in a factorial pot experiment based on RCBD with three replications to evaluate the quality of seeds and seedlings in the greenhouse.
Results: The results showed that exposure of seeds to heat stress during development reduced seed quality as well as seedlings so that the cell membrane in the seeds produced under heat stress conditions was damaged and their electrical conductivity increased by 19%. Also, these seeds showed more sensitivity to deterioration. The percentage of seedling emergence in the stressed seeds decreased by 21.66%. Heat stress also reduced seedling quality indices such as chlorophyll content, shoot dry weight, and root dry weight. Application of zinc and boron on the mother plant not only led to improved quality of seeds and seedlings under normal conditions but also the negative effects of heat stress on seed and seedling quality were reduced. There was a significant negative correlation between the seed electrical conductivity test and qualitative parameters. Therefore, the use of this test is recommended to determine the quality of seeds, especially seeds produced under late-season heat stress conditions.
Conclusion: Noting the negative effect of heat during seed development on seed quality, planting dates should be adjusted as much as possible so that the seed development stage does not coincide with the late-season heat stress. Due to the beneficial effects of using zinc and boron in the mother plant on many traits related to the quality of seeds and seedlings, their application- especially zinc- in soils with deficiency or the possibility of heat stress at the end of the season is recommended.
Highlights:
- Zinc and boron micronutrients were used to mitigate the harmful effects of heat stress on seed quality.
- Physiological characteristics of seedlings obtained from seeds produced in the field under late-season heat stress conditions were investigated.
Nader Shahbazi, Seyyed Kamal Kazemitabar, Ghaffar Kiani, Ali Pakdin Parizi, Pooyan Mehraban Joubani,
Volume 8, Issue 2 (3-2022)
Volume 8, Issue 2 (3-2022)
Abstract
Extended abstract
Introduction: One of the ways to overcome the limitation of fresh water and lack of sufficient water reserves for agriculture is to use unconventional waters such as seawater. Salinity stress is the most important abiotic stress in seawater application. Identification and planting of salinity tolerant genotypes of a plant species is one of the effective and valuable strategies in reducing the effects of salinity stress. Germination, growth and seedling establishment are among the salinity-sensitive stages in most plants. Therefore, for improvement of abiotic stress tolerance in plants, it is necessary to study the traits and indicators related to tolerance in the germination stage.
Material and Methods: A factorial experiment was conducted based on a completely randomized design with three replications at the laboratory of Plant Breeding Department of Sari University of Agricultural Sciences and Natural Resources in 2020. The first factor included the cultivars and the second included 5 salinity levels (control (no seawater), 3, 6, 9 and 11 dS (deciSiemens per meter) obtained from the incorporation of Caspian Sea and urban water. The number of germinated seeds was counted during eight days of salinity stress. Then, germination percentage, time required for 50% germination, seedling vigor index and germination rate were calculated. On the eighth day, radicle and plumule dry and fresg weights, radicle and plumule length and seedling dry weight were measured.
Results: The results of analysis of variance showed the significance of the effect of different salinity levels, genotype and the interaction of salinity and genotype for all calculated indices at p<0.01. Mean comparison of the interaction of different levels of salinity and cultivars and landraces showed that all the studied traits except for the time to reach fifty percent germination decreased with increasing salinity. Among the studied cultivars, Oltan cultivar had the highest value of germination percentage (100%), germination rate (24.17 seeds per day), seedling vigor index (5.03), plumule length (55.67 mm), radicle length (70 mm), plumule fresh weight (62 mg), radicle fresh weight (45 mg), plumule dry weight (4.77 mg), seedling dry weight (6/23 Mg) and the lowest amount of the time required for 50% germination (24.17 hours) in control treatment. In contrast, Pakistani cultivar had the lowest germination rate (3.06 seeds per day), seedling vigor index (1), plumule length (8.33 mm), radicle length (3 mm), plumule fresh weight (10 mg), radicle fresh weight (2 mg), plumule dry weight (0.57 mg), seedling dry weight (0.84 mg) and the highest time required for 50% germination (24.17 hours) in 11 dS / m salinity level. Using the results of this experiment, among the studied cultivars, Oltan cultivar was selected as the most tolerant and Pakistani cultivar as the most sensitive cultivars to salinity stress at the germination stage.
Conclusion: The studied cultivars and landraces showed different reactions in terms of germination indices when treated with salinity from seawater. The high significant difference in this experiment indicated the high genetic diversity among the studied genotypes. It is possible to choose from these genotypes for salinity tolerance breeding programs in sesame plant.
Highlights:
Introduction: One of the ways to overcome the limitation of fresh water and lack of sufficient water reserves for agriculture is to use unconventional waters such as seawater. Salinity stress is the most important abiotic stress in seawater application. Identification and planting of salinity tolerant genotypes of a plant species is one of the effective and valuable strategies in reducing the effects of salinity stress. Germination, growth and seedling establishment are among the salinity-sensitive stages in most plants. Therefore, for improvement of abiotic stress tolerance in plants, it is necessary to study the traits and indicators related to tolerance in the germination stage.
Material and Methods: A factorial experiment was conducted based on a completely randomized design with three replications at the laboratory of Plant Breeding Department of Sari University of Agricultural Sciences and Natural Resources in 2020. The first factor included the cultivars and the second included 5 salinity levels (control (no seawater), 3, 6, 9 and 11 dS (deciSiemens per meter) obtained from the incorporation of Caspian Sea and urban water. The number of germinated seeds was counted during eight days of salinity stress. Then, germination percentage, time required for 50% germination, seedling vigor index and germination rate were calculated. On the eighth day, radicle and plumule dry and fresg weights, radicle and plumule length and seedling dry weight were measured.
Results: The results of analysis of variance showed the significance of the effect of different salinity levels, genotype and the interaction of salinity and genotype for all calculated indices at p<0.01. Mean comparison of the interaction of different levels of salinity and cultivars and landraces showed that all the studied traits except for the time to reach fifty percent germination decreased with increasing salinity. Among the studied cultivars, Oltan cultivar had the highest value of germination percentage (100%), germination rate (24.17 seeds per day), seedling vigor index (5.03), plumule length (55.67 mm), radicle length (70 mm), plumule fresh weight (62 mg), radicle fresh weight (45 mg), plumule dry weight (4.77 mg), seedling dry weight (6/23 Mg) and the lowest amount of the time required for 50% germination (24.17 hours) in control treatment. In contrast, Pakistani cultivar had the lowest germination rate (3.06 seeds per day), seedling vigor index (1), plumule length (8.33 mm), radicle length (3 mm), plumule fresh weight (10 mg), radicle fresh weight (2 mg), plumule dry weight (0.57 mg), seedling dry weight (0.84 mg) and the highest time required for 50% germination (24.17 hours) in 11 dS / m salinity level. Using the results of this experiment, among the studied cultivars, Oltan cultivar was selected as the most tolerant and Pakistani cultivar as the most sensitive cultivars to salinity stress at the germination stage.
Conclusion: The studied cultivars and landraces showed different reactions in terms of germination indices when treated with salinity from seawater. The high significant difference in this experiment indicated the high genetic diversity among the studied genotypes. It is possible to choose from these genotypes for salinity tolerance breeding programs in sesame plant.
Highlights:
- Different sesame genotypes at different levels of sea salt salinity showed different response at germination stage.
- Among the cultivars studied, Oltan, Nazetakshakhe, Halil and Dashtashtan 2 showed a high degree of tolerance to salinity stress.
Mohammad Hossein Banakar, Hamzeh Amiri, Gholam Hassan Ranjbar, Mohammad Raza Sarafraz Ardakani,
Volume 8, Issue 2 (3-2022)
Volume 8, Issue 2 (3-2022)
Abstract
Extended Abstract
Introduction: Fenugreek, is a medicinal plant that has been considered as a salt tolerant crop. This research was conducted to investigate the effects of salt stress on seedling emergence characteristics and determination of the salt tolerance threshold, declivity of emergence and salt tolerance index of some fenugreek ecotypes.
Material and Methods: Seeds of five ecotypes (Ardestani, Isfahani, hendi, Mashhadi, Neyrizi) were subjected to seven levels of salinity (0.5, 3, 6, 9, 12, 15 and 18 dS/m) in a factorial experiment based on a completely randomized design with three replications. In this research, experimental models (linear, sigmoidal, exponential and multi-component) were used.
Results: Results showed that increasing levels of salinity decreased seedling emergence percentage and rate. In Ardestani and Isfahani ecotypes, increase of salinity up to 3 dS/m had no effect on seedling emergence percentage and thereafter, decreased it, significantly. The maximum seedling emergence percentage (94.62%) belonged to Hendi in control treatment. Hendi ecotype had also the highest emergence percentage (25.81%) at 18 dS/m. Although the highest seedling emergence rate (5.93 per day) belonged to Mashhadi ecotype in control treatment, it didn’t show any significant difference to Hendi, Neyrizi and Isfahani ecotypes. In Ardestani, Mashhadi and Neyrizi ecotypes, seedling length decreased significantly with increasing salinity, but this decrease was not significant in Isfahani ecotype between salinities of 3 and 6 dS/m and also 12 and 15 dS/m. In Hendi ecotype, seedling length at 3 dS/m was similar to control, but higher salinities caused a significant reduction. The maximum value of seedling vigor index (20.44) belonged to Mashhadi and Neyrizi ecotypes in control treatment and Ardestani ecotype had the lowest one (0.39) at 18 dS/m. Results showed that seedling dry weight was first unchanged up to salinity level of 3 dS/m and then gradually decreased with increasing salinity. In Hendi and Neyrizi ecotypes, applying salinities higher than 6 dS/m, gradually decreased seedling dry weight. The salt tolerance threshold of fenugreek for Ardestani, Isfahani, Hindi, Mashhadi and Neyrizi ecotypes was 4.69, 4.90, 7.83, 1.69 and 1.57 dS/m, respectively. Thus, the highest salt tolerance threshold (7.83 dS/m) and the declivity of emergence percentage (7.55%) was obtained from Hendi ecotype and the lowest one from Neyrizi ecotype (1.57 and 4.63 dS/m, respectively). Results of nonlinear models showed that the highest salinity in which 50 percent of seedlings emerged was obtained in Hendi ecotype (14.24 dS/m).
Conclusion: Based on the results, comparing the salt tolerance index of fenugreek ecotypes and also evaluating of some experimental models showed that Hendi ecotype may be introduced as the most tolerant ecotype to salinity stress at the emergence stage to exploit saline soil and water resources.
Highlights:
- Different fenugreek ecotypes in terms of salinity tolerance at seedling emergence stage were compared using some experimental models.
- The salt tolerance threshold, declivity of emergence and also salt tolerance index was reported for some fenugreek ecotypes.
Mohadeseh Latifzadeh Shahkhali, Seyed Mohmmad Reza Ehtehsami, Foad Moradi,
Volume 8, Issue 2 (3-2022)
Volume 8, Issue 2 (3-2022)
Abstract
Extended abstract
Introduction: Seed deterioration is associated with oxidative stress and uncontrolled accumulation of reactive oxygen species. Seeds have a group of enzymatic and non-enzymatic antioxidants that protect them against reactive oxygen species and help maintain seed vigor and support seed germination processes. The response of different cultivars to seed deterioration is different. Knowledge about the sources and mechanisms of deterioration and how different cultivars respond can help to select the appropriate cultivar for the region and also provide useful information in selecting and applying appropriate management methods for storage and increasing the storage time of seeds.
Materials and Methods: The Experiment was conducted as factorial based on a completely randomized block design with three replications. Treatments included one and six months of natural storage (4˚C, 11 percent moisture content of seeds and 60% RH) and accelerated aging (96 hours at 45˚C and 100% RH) applied on four cultivars including Hashemi, Gilaneh, Khazar and Domsiyah. Germination percentage, germination rate, shoot length, radicle length, shoot dry weight, radicle dry weight, shoot vigor index (SVI), α-amylase activity, catalase (CAT), peroxidase (POX), superoxide dismutase (SOD) activity, malondialdehyde (MDA) and hydrogen peroxide (H2O2) content were evaluated.
Results: The results showed that accelerated ageing and storage of seeds for six months led to reduced germination percentage, germination rate, shoot length, radicle length, shoot dry weight, radicle dry weight, shoot vigor index (SVI), α-amylase activity reduced in all four cultivars. This decrease was accompanied by an increase in the free radical content of MDA and H2O2 and a decrease in the activity of the antioxidant enzymes SOD and POX. Malondialdehyde content was lower in the seeds stored for six months. The activity of CAT increased after deterioration treatment, this increase was more intense in the seeds stored for six months. These seeds also showed lower H2O2 content compared to accelerated aging seeds. Khazar cultivar showed lower H2O2 content as a result of higher CAT enzyme activity. Moreover, this cultivar showed better germination percentage and germination rate after deterioration treatment compared to other cultivars. The decrease in germination percentage due to deterioration in Domsiyah was very severe. This cultivar showed the lowest germination percentage, germination rate, seed vigor and α-amylase activity in the accelerated aging treatment. Gilaneh and Hashemi cultivars showed higher germinability, α-amylase activity and SOD and POX at the beginning of the experiment, but after deterioration treatment, their germinability decreased along with the activity of antioxidant enzymes.
Conclusions: In all studied cultivars, the accelerated aging and storage of seeds for six months adversely affected germination rate. This decrease was accompanied by an increase in free radicals in the seeds and a decrease in the activity of antioxidant enzymes SOD and POX, which were less severe in Khazar cultivar and more severe in Domsiyah cultivar. These results indicate the greater importance of the storage conditions in Domsiyah cultivar.
Highlights:
1- The effect of storage and seed deterioration on the activity of antioxidant enzymes, reactive oxygen species and seed germination in rice was investigated.
2- The results of accelerated aging test and natural aging were compared for a better conclusion about the response of the cultivars.
3- The two improved cultivars were compared with two local cultivars (with high cultivation area).
Introduction: Seed deterioration is associated with oxidative stress and uncontrolled accumulation of reactive oxygen species. Seeds have a group of enzymatic and non-enzymatic antioxidants that protect them against reactive oxygen species and help maintain seed vigor and support seed germination processes. The response of different cultivars to seed deterioration is different. Knowledge about the sources and mechanisms of deterioration and how different cultivars respond can help to select the appropriate cultivar for the region and also provide useful information in selecting and applying appropriate management methods for storage and increasing the storage time of seeds.
Materials and Methods: The Experiment was conducted as factorial based on a completely randomized block design with three replications. Treatments included one and six months of natural storage (4˚C, 11 percent moisture content of seeds and 60% RH) and accelerated aging (96 hours at 45˚C and 100% RH) applied on four cultivars including Hashemi, Gilaneh, Khazar and Domsiyah. Germination percentage, germination rate, shoot length, radicle length, shoot dry weight, radicle dry weight, shoot vigor index (SVI), α-amylase activity, catalase (CAT), peroxidase (POX), superoxide dismutase (SOD) activity, malondialdehyde (MDA) and hydrogen peroxide (H2O2) content were evaluated.
Results: The results showed that accelerated ageing and storage of seeds for six months led to reduced germination percentage, germination rate, shoot length, radicle length, shoot dry weight, radicle dry weight, shoot vigor index (SVI), α-amylase activity reduced in all four cultivars. This decrease was accompanied by an increase in the free radical content of MDA and H2O2 and a decrease in the activity of the antioxidant enzymes SOD and POX. Malondialdehyde content was lower in the seeds stored for six months. The activity of CAT increased after deterioration treatment, this increase was more intense in the seeds stored for six months. These seeds also showed lower H2O2 content compared to accelerated aging seeds. Khazar cultivar showed lower H2O2 content as a result of higher CAT enzyme activity. Moreover, this cultivar showed better germination percentage and germination rate after deterioration treatment compared to other cultivars. The decrease in germination percentage due to deterioration in Domsiyah was very severe. This cultivar showed the lowest germination percentage, germination rate, seed vigor and α-amylase activity in the accelerated aging treatment. Gilaneh and Hashemi cultivars showed higher germinability, α-amylase activity and SOD and POX at the beginning of the experiment, but after deterioration treatment, their germinability decreased along with the activity of antioxidant enzymes.
Conclusions: In all studied cultivars, the accelerated aging and storage of seeds for six months adversely affected germination rate. This decrease was accompanied by an increase in free radicals in the seeds and a decrease in the activity of antioxidant enzymes SOD and POX, which were less severe in Khazar cultivar and more severe in Domsiyah cultivar. These results indicate the greater importance of the storage conditions in Domsiyah cultivar.
Highlights:
1- The effect of storage and seed deterioration on the activity of antioxidant enzymes, reactive oxygen species and seed germination in rice was investigated.
2- The results of accelerated aging test and natural aging were compared for a better conclusion about the response of the cultivars.
3- The two improved cultivars were compared with two local cultivars (with high cultivation area).
Habibolah Moazen, Mehdi Hosseinifarahi, Azam Amiri,
Volume 8, Issue 2 (3-2022)
Volume 8, Issue 2 (3-2022)
Abstract
Extended Abstract
Introduction: Today, seed priming is widely used to improve seed germination in a wide range of plant species. As a result of seed pre-treatment, several molecular and biochemical changes occur, including increased macromolecule synthesis, enzyme activity and formation of different metabolites. Enzymatic and metabolic activities, synthesis of proteins in quantitative and qualitative terms, and respiratory activities and, the formation of ATP for the synthesis of macromolecules, membranes, and materials required for the cell wall are increased during and after seed preparation. The aim of this study was to investigate the effect of seed priming using some hormonal and nutritional treatments as well as the type of culture medium on germination characteristics and quality of Karun tomato seedlings.
Materials and Methods: Two separate experiments were performed in two laboratory and pot stages in a completely randomized design with three replications. In the first experiment, the treatment used included seed priming at six levels (distilled water, 0.2 mM salicylic acid, 0.2 mM putrescine, 1.5% humic acid, 0.03% zinc sulfate, and 0.2 mM potassium nitrate). In the second experiment, the treatments used included the culture media type at six levels (coco peat, perlite, peat moss, 50% cocopeat + 50% perlite, 50% coco peat + 50% peat moss and 50% perlite + 50% peat-moss).
Results: Analysis of variance showed that the effect of different levels of seed priming on seed germination percentage and root length was significant. The highest germination percentage was obtained six days after cultivation in salicylic acid treatment and was equal to 97.1%. The highest shoot dry weight in peat moss treatment was 1.7 g and the lowest shoot dry weight in perlite treatment was 0.3 g. The use of peat moss treatment in comparison with coco peat increased seedling length by 31.3%.
Conclusion: Application of 0.2 mM salicylic acid, putrescine and humic acid improved seed germination compared with zinc sulfate and potassium nitrate. Also, application of peat moss and combined peat moss treatments in comparison with coco peat and perlite, increased the dry weight of roots and shoots of the plant as well as increasing the absorption of various elements.
Introduction: Today, seed priming is widely used to improve seed germination in a wide range of plant species. As a result of seed pre-treatment, several molecular and biochemical changes occur, including increased macromolecule synthesis, enzyme activity and formation of different metabolites. Enzymatic and metabolic activities, synthesis of proteins in quantitative and qualitative terms, and respiratory activities and, the formation of ATP for the synthesis of macromolecules, membranes, and materials required for the cell wall are increased during and after seed preparation. The aim of this study was to investigate the effect of seed priming using some hormonal and nutritional treatments as well as the type of culture medium on germination characteristics and quality of Karun tomato seedlings.
Materials and Methods: Two separate experiments were performed in two laboratory and pot stages in a completely randomized design with three replications. In the first experiment, the treatment used included seed priming at six levels (distilled water, 0.2 mM salicylic acid, 0.2 mM putrescine, 1.5% humic acid, 0.03% zinc sulfate, and 0.2 mM potassium nitrate). In the second experiment, the treatments used included the culture media type at six levels (coco peat, perlite, peat moss, 50% cocopeat + 50% perlite, 50% coco peat + 50% peat moss and 50% perlite + 50% peat-moss).
Results: Analysis of variance showed that the effect of different levels of seed priming on seed germination percentage and root length was significant. The highest germination percentage was obtained six days after cultivation in salicylic acid treatment and was equal to 97.1%. The highest shoot dry weight in peat moss treatment was 1.7 g and the lowest shoot dry weight in perlite treatment was 0.3 g. The use of peat moss treatment in comparison with coco peat increased seedling length by 31.3%.
Conclusion: Application of 0.2 mM salicylic acid, putrescine and humic acid improved seed germination compared with zinc sulfate and potassium nitrate. Also, application of peat moss and combined peat moss treatments in comparison with coco peat and perlite, increased the dry weight of roots and shoots of the plant as well as increasing the absorption of various elements.
Highlights:
1- Germination percentage and rate of tomato var. Karun significantly increased by salicylic acid and putrescine application (Karun cultivar)
2- Peat mass is the best culture medium for the commercial production of tomato seedlings var. Karun
1- Germination percentage and rate of tomato var. Karun significantly increased by salicylic acid and putrescine application (Karun cultivar)
2- Peat mass is the best culture medium for the commercial production of tomato seedlings var. Karun
Meysam Miri, Mohammdreza Amerian, Mohsen Edalat, Mehdi Baradaran Firouzabadi, Hasan Makarian,
Volume 8, Issue 2 (3-2022)
Volume 8, Issue 2 (3-2022)
Abstract
Extended Abstract
Introduction: Germination is considered the first and most important stage of establishment and consequently, successful competition which is influenced by genetic and environmental factors. Among the environmental factors influencing the germination, temperature and light are the most important ones. Using different models, the germination response of seeds to temperature can be quantified; therefore, this study was performed to investigate the effect of temperature on germination and to quantify the germination response of Buckwheat seed (Fagopyrum esculentum Moenc) to temperature using nonlinear regression models and thermal-time model.
Materials and methods: The seeds were germinated in 4 replications of 25 seeds under 8 constant temperature treatments (5, 10, 15, 20, 25, 30, 35 and 40 ° C). Using a three-parameter logistic model, Buckwheat seed germination was quantified at different temperature levels and the percentage and time to reach 50% germination were obtained. Four nonlinear regression models and a thermal-time model were used to quantify the response of Buckwheat seed germination rate to temperature. To compare the models and determine the most appropriate model, the root mean square error index (RMSE), coefficient of determination (R2), coefficient of variation (CV) and standard error (SE) were used for the observed germination rate versus the predicted germination rate.
Results: The results indicated that temperature affected the seedling length, normal seedling percentage, seed vigor and the germination rate as well as germination percentage. Also, the results showed that germination characteristics increased with increasing temperature up to 20 and 25 °C. Comparison of the three models based on the root mean square error (RMSE) of germination time, the coefficient of determination (R2), CV and SE, the best model to determine the cardinal temperatures of Fagopyrum esculentum was the dent-like model. The results of thermal-time model showed that the base temperature of Fagopyrum esculentum seeds was 4.01 ° C and the thermal-time coefficient was 1242.6 h° C.
Conclusion: Utilization of non-linear regression models (segmented, dent-like and beta) and thermal-time model to quantify the germination response of Fagopyrum esculentum response to different temperatures led to acceptable results. Therefore, germination rate and percentage may be predicted using the outputs of these models at different temperatures.
Highlights:
Introduction: Germination is considered the first and most important stage of establishment and consequently, successful competition which is influenced by genetic and environmental factors. Among the environmental factors influencing the germination, temperature and light are the most important ones. Using different models, the germination response of seeds to temperature can be quantified; therefore, this study was performed to investigate the effect of temperature on germination and to quantify the germination response of Buckwheat seed (Fagopyrum esculentum Moenc) to temperature using nonlinear regression models and thermal-time model.
Materials and methods: The seeds were germinated in 4 replications of 25 seeds under 8 constant temperature treatments (5, 10, 15, 20, 25, 30, 35 and 40 ° C). Using a three-parameter logistic model, Buckwheat seed germination was quantified at different temperature levels and the percentage and time to reach 50% germination were obtained. Four nonlinear regression models and a thermal-time model were used to quantify the response of Buckwheat seed germination rate to temperature. To compare the models and determine the most appropriate model, the root mean square error index (RMSE), coefficient of determination (R2), coefficient of variation (CV) and standard error (SE) were used for the observed germination rate versus the predicted germination rate.
Results: The results indicated that temperature affected the seedling length, normal seedling percentage, seed vigor and the germination rate as well as germination percentage. Also, the results showed that germination characteristics increased with increasing temperature up to 20 and 25 °C. Comparison of the three models based on the root mean square error (RMSE) of germination time, the coefficient of determination (R2), CV and SE, the best model to determine the cardinal temperatures of Fagopyrum esculentum was the dent-like model. The results of thermal-time model showed that the base temperature of Fagopyrum esculentum seeds was 4.01 ° C and the thermal-time coefficient was 1242.6 h° C.
Conclusion: Utilization of non-linear regression models (segmented, dent-like and beta) and thermal-time model to quantify the germination response of Fagopyrum esculentum response to different temperatures led to acceptable results. Therefore, germination rate and percentage may be predicted using the outputs of these models at different temperatures.
Highlights:
- The best temperature for Fagopyrum esculentum Moenc. seed germination is 20-25 Celsius.
- The dent-like model was determined the most appropriate model for estimating the cardinal temperatures of Buckwheat.
Fatemeh Lajorak Shirpour, Yazdan Izadi, Dr. Seyed Amir Moosavi,
Volume 8, Issue 2 (3-2022)
Volume 8, Issue 2 (3-2022)
Abstract
Extended Abstract
Introduction: Seed germination is one of the most important factors which determine the success of failure of crop establishment. In the absence of other environmental limiting factors such as moisture, temperature would determine the rate and overall seed germination. This research was conducted to investigate the effect of temperature regimes on seed germination, quantify the response of germination rate to temperature and determine the cardinal temperatures for different germination percentiles in Solanum lycopersicom.
Materials and Methods: Two-way factorial experiment including seven constant temperatures (5, 10, 15, 20, 25, 30 and 35 oC) and two tomato varieties (Red cherry: var. Cerasiformi and Yellow pearl: var. Yellow Pear) was conducted based on a completely randomized design arranged with thee replications at the seed technology laboratory of Agricultural Sciences and Natural Resources University of Khuzestan in 2019. Beta, segmented and dent-like functions were used to determine the relationship between germination rate and temperature. Logistic model was used to describe the suitable pattern for the germination of these two cultivars in response to each temperature level.
Results: Results of analysis of variance showed that the interaction effect of temperature and cultivar was significant on all studied traits. Results showed that respectively at temperatures of 15, 20, 25 and 30 oC, total seed germination for yellow pearl tomato was 93%, 96%, 95% and 86% and for red cherry tomato was 95, 98, 93 and 98 percent. There was no seed germination for both tomato varieties at 5, 10 and 35 oC. Based on the results of the fitted models, it was revealed that among the tested non-linear regression models, segmented model described the germination rate of the studied tomato cultivars against the temperature the best (AICc≤70, R2=0.93). Three parameters logistic functions exhibited a reasonable fit (R2=0.96) for germination time course under temperature range of 15 to 30 oC in both cultivars. Based on the segmented model, base, optimum and ceiling temperatures of Yellow pearl and Cherry tomato were estimated 11.25, 28.72, 35.00 oC and 10.97, 28.361 and 35 oC, respectively.
Conclusion: Both tomato cultivars exhibited sensitivity to changes in temperature. Seed germination rate and number of the germinated seeds increased at temperatures higher than base. This increase continued until the optimum temperature and then started to decline as the temperature exceeded from optimum range. Also, results obtained from the logistic function showed that Yellow pearl cultivar is more sensitive to supra-optimal temperatures compared with Cherry tomato, and germination percentage of the 97.79 to 85.09 percent as temperature reached from 25 to 30 oC.
Highlights:
1- The pattern of seed germination in two new tomato cultivars was investigated under temperatures regimes
2- Cardinal temperatures of two new tomato varieties was estimated using nonlinear regression models
Introduction: Seed germination is one of the most important factors which determine the success of failure of crop establishment. In the absence of other environmental limiting factors such as moisture, temperature would determine the rate and overall seed germination. This research was conducted to investigate the effect of temperature regimes on seed germination, quantify the response of germination rate to temperature and determine the cardinal temperatures for different germination percentiles in Solanum lycopersicom.
Materials and Methods: Two-way factorial experiment including seven constant temperatures (5, 10, 15, 20, 25, 30 and 35 oC) and two tomato varieties (Red cherry: var. Cerasiformi and Yellow pearl: var. Yellow Pear) was conducted based on a completely randomized design arranged with thee replications at the seed technology laboratory of Agricultural Sciences and Natural Resources University of Khuzestan in 2019. Beta, segmented and dent-like functions were used to determine the relationship between germination rate and temperature. Logistic model was used to describe the suitable pattern for the germination of these two cultivars in response to each temperature level.
Results: Results of analysis of variance showed that the interaction effect of temperature and cultivar was significant on all studied traits. Results showed that respectively at temperatures of 15, 20, 25 and 30 oC, total seed germination for yellow pearl tomato was 93%, 96%, 95% and 86% and for red cherry tomato was 95, 98, 93 and 98 percent. There was no seed germination for both tomato varieties at 5, 10 and 35 oC. Based on the results of the fitted models, it was revealed that among the tested non-linear regression models, segmented model described the germination rate of the studied tomato cultivars against the temperature the best (AICc≤70, R2=0.93). Three parameters logistic functions exhibited a reasonable fit (R2=0.96) for germination time course under temperature range of 15 to 30 oC in both cultivars. Based on the segmented model, base, optimum and ceiling temperatures of Yellow pearl and Cherry tomato were estimated 11.25, 28.72, 35.00 oC and 10.97, 28.361 and 35 oC, respectively.
Conclusion: Both tomato cultivars exhibited sensitivity to changes in temperature. Seed germination rate and number of the germinated seeds increased at temperatures higher than base. This increase continued until the optimum temperature and then started to decline as the temperature exceeded from optimum range. Also, results obtained from the logistic function showed that Yellow pearl cultivar is more sensitive to supra-optimal temperatures compared with Cherry tomato, and germination percentage of the 97.79 to 85.09 percent as temperature reached from 25 to 30 oC.
Highlights:
1- The pattern of seed germination in two new tomato cultivars was investigated under temperatures regimes
2- Cardinal temperatures of two new tomato varieties was estimated using nonlinear regression models
Majed Chaab, Mohammad Ali Ebrahimi, Sara Ghezelbash, Nasim Zarinpanjeh,
Volume 8, Issue 2 (3-2022)
Volume 8, Issue 2 (3-2022)
Abstract
Extended Abstract
Introduction: Cow tail (Smirnovia iranica) is considered a valuable shrub species indigenous and adapted to the sandy lands of the Iranian central regions which besides playing an essential role in the desert cover for soil protection and of forage production, is considered important due to its great medicinal values. Considering the fact that seed germination of this plant does not easily occur due to its hard and solid seed coat, in this study, the in vitro tissue culture and seedling establishment is utilized for the first time in order to surmount the obstacles laid ahead of cow tail seed germination.
Materials and Methods: Scratched seed, unscratched seed and seed embryo of cow tail as different explants were placed in two culture media (MS, MS with free amino acids complex) following surface sterilization, and were exposed to two photoperiod treatments (16 hours of light and 8 hours of darkness as well as absolute darkness) and were investigated in a factorial experiment based on completely randomized design with six replications. Finally, germination percentage (10 days after seed culturing) and shoot length (30 days after seed germination) were evaluated.
Results: The results indicated that significance of the effect of investigated treatment conducted over some in vitro on germination characteristics. It was revealed that the cultivation of seed embryo in MS culture media along with free amino acids complex for 16 hours of light and 8 hours of darkness photo period can be considered as the best in vitro germination method, in terms of seed germination percentage (78.83%) and germinated shoot length (44.83 mm).
Conclusion: In vitro culture can be used to improve germination and seeding production of this species.
Highlights:
- The method for seed dormancy elimination of cow tail plant was introduced.
- The seed disinfection procedure for in vitro culture of cow tail plant was introduced.
- The components of in vitro culture medium for rapid and efficient seed germination of cow tail plant were introduced.
Mohaddese Heydarzade, Seyed Mohammadreza Ehteshami, Mohammad Rabiee,
Volume 9, Issue 1 (9-2022)
Volume 9, Issue 1 (9-2022)
Abstract
Extended Abstract
Introduction: Guar (Cyamopsis tetragonoloba L.) is an annual, dicotyledonous plant of the legume family, also known as cluster beans. This plant can tolerate salinity and drought stress well. Optimal planting date and plant density are factors affecting the quality and quantity of crops. The distribution of plants in the field influences the absorption and productivity of environmental factors affecting the growth and intra- and inter- competition and eventually is one of the factors determining the quantity and quality of yield. Different planting dates set off different conditions in terms of temperature day length, relative humidity, solar radiation, ripening and harvest time and thus, affect the quantitative and qualitative characteristics of seeds. The purpose of this experiment is to evaluate the quality and also to evaluate some of the germination characteristics of Guar seeds at different dates and planting densities under the climatic conditions of Guilan.
Materials and Methods: This experiment was conducted in the spring and summer of 2017 in the research farm of Rasht Rice Research Institute located in Gil Pardehsar village at Sangar as a factorial based on a randomized complete block design with three replications. Experimental treatments included four planting dates (12 May, 26 May, 9 June and 23 June) and three plant densities (20, 40 and 60 plants. m-2). Seed harvesting was done as the pods in 75% of the plants in each plot turned brown and traits such as germination percentage, germination rate, root and shoot length and fresh and dry weight of roots and shoots, longitudinal index of seedling vigor, 1000- grain weight, electrical conductivity and alpha-amylase activity were investigated.
Results: The results of the present study showed that guar seeds had the highest quality on 26 May and a density of 40 plants.m-2. Due to favorable climatic conditions during the period of seed filling, germination rate, germination percentage, seedling vigor index, root length and 1000- grain weight was high on 26 May. The amount of these traits decreased with delay in planting. The amount of electrical conductivity in 23 June date of planting treatment showed the highest value. The highest level of alpha-amylase activity was observed on 9 June.
Conclusions: In general, it can be concluded that the best planting date and plant density of guar seeds in Guilan province with the highest quality of seeds and germination is on 26 May and 40 plants.m-2.
Highlights:
1- Guar seed germination traits were evaluated at physiological maturity.
2- In terms of germination traits of guar seeds, the best planting date was 26 May and the best plant density was obtained at 40 per square meter
Mohammadreza Labbafi, Hamideh Khalaj, Maryam Delfani, Nasrin Qavami,
Volume 9, Issue 1 (9-2022)
Volume 9, Issue 1 (9-2022)
Abstract
Extended Abstract
Introduction: Lavandula angustifolia L. is one of the most important plants belonging to Lamiaceae which has abundant use in traditional and pharmacological medicine. Lavender seed dormancy is one of the problems in producing seedlings which increases seed consumption. In this regard, an experiment was carried out to investigate different treatments for seed dormancy elimination of Lavender and measuring germination and growth indices.
Materials and Methods: An experiment was conducted in a completely randomized design with three replications at the Ecophysiology Laboratory of Karaj Institute of Medicinal Plants in 2018. The experiment consisted of 14 treatments on seed dormancy elimination. The treatments included the control, hormonal treatments (Gibberellic acid with 250, 500, 750 and 1000 mg/l concentrations) and Prechilling treatments (7, 14 and 21 days of refrigeration). The integrated treatments were 7 days refrigeration + 500 mg/l gibberellic acid, 14 days refrigeration + 500 mg/l gibberellic acid, 7 days refrigeration + 1000 mg/l gibberellic acid, 14 days refrigeration + 1000 mg/l gibberellic acid, 30 minutes at 40 ° C water + 14 days refrigeration, and 30 minutes at water 40 degrees +14 days refrigeration + 500 mg/l gibberellic acid.
Results: The results showed that the highest germination percentage (70.67%), germination rate (24.26%) and germination index (246) were achieved in 750 mg/l Gibberellic acid, and the highest epicotyl length (5.09 cm), seedling length (6.23 cm) and seedling fresh weight (0.57 gr) were produced with 500 mg/l Gibberellic acid. Also, the lowest mean germination time (MGT) (4.12s day) was obtained in 1000 mg/l Gibberellic acid treatment. Also, 7 days of refrigeration + gibberellic acid at 500 mg/l treatment had no significant difference with the other concentrations of gibberellin treatments. Therefore, low gibberellin concentration with 7 days of prechilling had the same effect as higher gibberellic acid concentrations. In addition, 14 days of refrigeration + 1000 mg/l gibberellic acid treatment and treatment of 30 min in water at 40 ° C +14 days prechilling + 500 mg/l gibberellic acid produced the lowest shoot (0.78, 0.82 cm), seedling height (0.99, 1.04 cm) and fresh weight (0.013, 0.01 gr) that showed the negative effects of increased prechilling time and water at 40 ° C,
Conclusion: It was finally found that the lavender seed dormancy type is physiologically non-deep and moderate and Gibberellic acid is a suitable substitute for prechilling. The best treatment was gibberellic acid with a concentration of 750 mg/l to break the dormancy of lavender seeds.
Highlights:
Introduction: Lavandula angustifolia L. is one of the most important plants belonging to Lamiaceae which has abundant use in traditional and pharmacological medicine. Lavender seed dormancy is one of the problems in producing seedlings which increases seed consumption. In this regard, an experiment was carried out to investigate different treatments for seed dormancy elimination of Lavender and measuring germination and growth indices.
Materials and Methods: An experiment was conducted in a completely randomized design with three replications at the Ecophysiology Laboratory of Karaj Institute of Medicinal Plants in 2018. The experiment consisted of 14 treatments on seed dormancy elimination. The treatments included the control, hormonal treatments (Gibberellic acid with 250, 500, 750 and 1000 mg/l concentrations) and Prechilling treatments (7, 14 and 21 days of refrigeration). The integrated treatments were 7 days refrigeration + 500 mg/l gibberellic acid, 14 days refrigeration + 500 mg/l gibberellic acid, 7 days refrigeration + 1000 mg/l gibberellic acid, 14 days refrigeration + 1000 mg/l gibberellic acid, 30 minutes at 40 ° C water + 14 days refrigeration, and 30 minutes at water 40 degrees +14 days refrigeration + 500 mg/l gibberellic acid.
Results: The results showed that the highest germination percentage (70.67%), germination rate (24.26%) and germination index (246) were achieved in 750 mg/l Gibberellic acid, and the highest epicotyl length (5.09 cm), seedling length (6.23 cm) and seedling fresh weight (0.57 gr) were produced with 500 mg/l Gibberellic acid. Also, the lowest mean germination time (MGT) (4.12s day) was obtained in 1000 mg/l Gibberellic acid treatment. Also, 7 days of refrigeration + gibberellic acid at 500 mg/l treatment had no significant difference with the other concentrations of gibberellin treatments. Therefore, low gibberellin concentration with 7 days of prechilling had the same effect as higher gibberellic acid concentrations. In addition, 14 days of refrigeration + 1000 mg/l gibberellic acid treatment and treatment of 30 min in water at 40 ° C +14 days prechilling + 500 mg/l gibberellic acid produced the lowest shoot (0.78, 0.82 cm), seedling height (0.99, 1.04 cm) and fresh weight (0.013, 0.01 gr) that showed the negative effects of increased prechilling time and water at 40 ° C,
Conclusion: It was finally found that the lavender seed dormancy type is physiologically non-deep and moderate and Gibberellic acid is a suitable substitute for prechilling. The best treatment was gibberellic acid with a concentration of 750 mg/l to break the dormancy of lavender seeds.
Highlights:
- Gibberellic acid is a good substitute for prechilling in seed dormancy elimination of lavender.
- Breaking the dormancy of the lavender seeds is necessary for producing seedlings from the seeds of this plant.
Roya Ghorbani, Ali Movafeghi, Ali Ganjeali, Jafar Nabati,
Volume 9, Issue 1 (9-2022)
Volume 9, Issue 1 (9-2022)
Abstract
Extended Abstract
Introduction: Drought stress, as abiotic and multidimensional stress, has severe effects on plant growth. One of the new approaches in the management of drought stress is the use of nanoparticles. Nanoparticles infilterate the seeds and increase nutrient and water uptake and ultimately, improve germination. The present research was conducted to evaluate the effects of titanium dioxide nanoparticles on chickpea plant germination factors to modify the negative effects of drought stress.
Materials and Methods: A factorial experiment was conducted in a completely randomized design with four replications on chickpea seeds of Arman cultivar in the Plant Sciences Research Institute of the Ferdowsi University of Mashhad in 2019. Seeds were primed with concentrations of 0, 5, 10, 15, and 20 mg L-1 titanium dioxide for 24 hours. The seeds were cultured in sterilized Petri dishes. Drought stress was applied using polyethylene glycol 6000 with 0, -2, -4 and -8 bar osmotic potentials.
Results: The analysis of variance results showed that the interaction effect of drought stress and titanium dioxide nanoparticles was significant on germination rate, the number of normal seedlings, seed vigor index, germination index, length of seedling, radicle length, and radicle dry weight. All germination traits were inhibited as a result of drought stress. On the other hand, the presence of titanium dioxide nanoparticles partially decreased this inhibition in some traits. Germination percentage, germination rate, normal seedling percentage, seed vigor index, germination index, epicotyl length, radicle length and radicle dry weight decreased as a result of stress.
Conclusion: At all drought stress levels, the concentration of titanium dioxide nanoparticles up to 20 mg L-1 significantly improved traits such as germination percentage, seed vigor index, epicotyl length, and epicotyl dry weight. It seems that nanoparticles can stimulate cell activity and increase the transformation of reserves to translocatable material and consequently, improve germination characteristics. Thus, the application of titanium dioxide nanoparticles up to a concentration of 20 mg L-1 can partially reduce the negative effects of drought stress on the germination characteristics of chickpeas.
Highlights:
1- Germination percentage and seed vigor index of chickpea increased with the application of titanium dioxide nanoparticles up to 20 mg l-1 at all drought stress levels.
2- The radicle length and dry weight of chickpea increased by titanium dioxide nanoparticles.
3- The negative effects of drought stress on chickpea seed germination decreased by titanium dioxide nanoparticles.
Introduction: Drought stress, as abiotic and multidimensional stress, has severe effects on plant growth. One of the new approaches in the management of drought stress is the use of nanoparticles. Nanoparticles infilterate the seeds and increase nutrient and water uptake and ultimately, improve germination. The present research was conducted to evaluate the effects of titanium dioxide nanoparticles on chickpea plant germination factors to modify the negative effects of drought stress.
Materials and Methods: A factorial experiment was conducted in a completely randomized design with four replications on chickpea seeds of Arman cultivar in the Plant Sciences Research Institute of the Ferdowsi University of Mashhad in 2019. Seeds were primed with concentrations of 0, 5, 10, 15, and 20 mg L-1 titanium dioxide for 24 hours. The seeds were cultured in sterilized Petri dishes. Drought stress was applied using polyethylene glycol 6000 with 0, -2, -4 and -8 bar osmotic potentials.
Results: The analysis of variance results showed that the interaction effect of drought stress and titanium dioxide nanoparticles was significant on germination rate, the number of normal seedlings, seed vigor index, germination index, length of seedling, radicle length, and radicle dry weight. All germination traits were inhibited as a result of drought stress. On the other hand, the presence of titanium dioxide nanoparticles partially decreased this inhibition in some traits. Germination percentage, germination rate, normal seedling percentage, seed vigor index, germination index, epicotyl length, radicle length and radicle dry weight decreased as a result of stress.
Conclusion: At all drought stress levels, the concentration of titanium dioxide nanoparticles up to 20 mg L-1 significantly improved traits such as germination percentage, seed vigor index, epicotyl length, and epicotyl dry weight. It seems that nanoparticles can stimulate cell activity and increase the transformation of reserves to translocatable material and consequently, improve germination characteristics. Thus, the application of titanium dioxide nanoparticles up to a concentration of 20 mg L-1 can partially reduce the negative effects of drought stress on the germination characteristics of chickpeas.
Highlights:
1- Germination percentage and seed vigor index of chickpea increased with the application of titanium dioxide nanoparticles up to 20 mg l-1 at all drought stress levels.
2- The radicle length and dry weight of chickpea increased by titanium dioxide nanoparticles.
3- The negative effects of drought stress on chickpea seed germination decreased by titanium dioxide nanoparticles.
Farhad Ghasemi Aghbash, Iman Pazhouhan, Zahra Rostami,
Volume 9, Issue 1 (9-2022)
Volume 9, Issue 1 (9-2022)
Abstract
Extended Abstract
Introduction: Iranian oak has the largest forest habitat in the country and has a high position in terms of economy and protection. Recent studies have confirmed the positive effects of carbon nanotubes on the germination and organ growth of herbaceous and woody species. Nanotechnology is an evolving field in all periods of human life and various research is done to use nanomaterials in different fields. Nanotechnology can provide a good medium for the production of plants with suitable characteristics or provide better growth conditions for plants. The aim of this study was to investigate the effect of carbon nanotube treatments, calcium chloride 1% and potassium nitrate 1% on the germination traits of Iranian oak seed (Quercus brantii Lindl).
Materials and Methods: Treatments included carbon nanotubes at five levels (concentrations of 10, 25, 50, 75, and 100 mg/l) for six hours, 1% calcium chloride for 48 hours, potassium nitrate for hours 24 hours and control treatment, which were primed without using any materials and germination traits were tested on them.
Results: According to the results, carbon nanotubes affected germination traits, so that Iranian oak seeds at a concentration of 75 mg/l had the highest germination percentage and rate, and primed seeds with a concentration of 100 mg/l had the highest mean germination time. The lowest germination percentage, speed and mean germination time were related to control seeds.
Conclusion: The results showed that carbon nanotubes with 75 mg/l had the most positive effect on germination traits. Therefore, from an economic point of view, the use of this concentration is recommended for priming oak seeds.
Highlights:
Introduction: Iranian oak has the largest forest habitat in the country and has a high position in terms of economy and protection. Recent studies have confirmed the positive effects of carbon nanotubes on the germination and organ growth of herbaceous and woody species. Nanotechnology is an evolving field in all periods of human life and various research is done to use nanomaterials in different fields. Nanotechnology can provide a good medium for the production of plants with suitable characteristics or provide better growth conditions for plants. The aim of this study was to investigate the effect of carbon nanotube treatments, calcium chloride 1% and potassium nitrate 1% on the germination traits of Iranian oak seed (Quercus brantii Lindl).
Materials and Methods: Treatments included carbon nanotubes at five levels (concentrations of 10, 25, 50, 75, and 100 mg/l) for six hours, 1% calcium chloride for 48 hours, potassium nitrate for hours 24 hours and control treatment, which were primed without using any materials and germination traits were tested on them.
Results: According to the results, carbon nanotubes affected germination traits, so that Iranian oak seeds at a concentration of 75 mg/l had the highest germination percentage and rate, and primed seeds with a concentration of 100 mg/l had the highest mean germination time. The lowest germination percentage, speed and mean germination time were related to control seeds.
Conclusion: The results showed that carbon nanotubes with 75 mg/l had the most positive effect on germination traits. Therefore, from an economic point of view, the use of this concentration is recommended for priming oak seeds.
Highlights:
- The germination characteristics of Iranian oak seeds were investigated using carbon nanotubes.
- The effect of osmopriming and nanopriming on the germination of Iranian oak seeds was compared.
Mohammad Mehrabi Kooshki, Ali Moradi, Hamidreza Balouchi, Roya Behboud, Hojatollah Latifmanesh,
Volume 9, Issue 1 (9-2022)
Volume 9, Issue 1 (9-2022)
Abstract
Extended Abstract
Introduction: Pulses are among the best sources of plant protein and important components of crop rotation, which in recent years, have been considered one of the major options for plant research. Seed storage is one of the important traits in legume breeding. Storage temperature, seed moisture content, and storage duration are the most important factors affecting seed quality during storage. Inappropriate storage conditions lead to deterioration and reduction of seed quality during storage, which is severely affected by the environmental conditions of storage.
Materials and Methods: This research was conducted at the Seed Technology Laboratory, Faculty of Agriculture, Yasouj University in 2014 as a three-way factorial based on the completely randomized design with 5 replications of 20 seeds. Seeds with moisture content at 5 levels (6, 10, 14, 18, and 22%) and storage temperature at 4 levels (15, 25, 35 and 45 °C) were stored for 9 months (0, 30, 60, 90, 120, 150, 180, 210, 240 and 270 days). After sampling at the end of each month, a standard seed germination test was done using the pleated paper method in a germinator at 25 °C for 10 days. Also, an electrical conductivity test of the electrolytes leaked from the seeds incubated for 24h in water at 20 ˚C was done with 4 replicates. Some germination attributes and electrical conductivity of the electrolytes leaked from the seeds were measured according to standard methods.
Results: According to the results, interaction effects of storage temperature, seed moisture content, and storage duration on germination indices and electrical conductivity of bean seeds were significant (P<0.1). The germination trend during storage at 15 °C and seed moisture content of 6% decreased from 94% to 81% after 270 days of storage, so that germination decreased to 35% under similar moisture content after 270 days of storage as temperature increased from 15 to 45 °C. As the storage time passed, electrical conductivity increased and this increase was more pronounced at higher temperatures. Viability constants were calculated 9 months after storage using the seed viability equation, in which KE, CH, CW, and CQ were calculated -5.39697, 0.03201, 2.13041, and 0.000017, respectively.
Conclusions: The results showed that the electrical conductivity of the leaked material increased with increasing storage temperature and seed moisture content, which led to lower viability of seeds. At 15 °C and 6% seed moisture content provided better conditions for seed survival during the 9-month storage time compared with all other temperatures and moistures and had the lowest rate of deterioration. The results showed that with increasing seed temperature and moisture so that they had to lowest electrical conductivity of the leaked material from seeds and deterioration rate.
Highlights:
1- Over storage duration, the electrical conductivity of materials leaked from seeds increased.
2- With increasing moisture content up to 22% and storage temperature up to 45 °C, the electrical conductivity of the material leaked from seeds increased.
3- Bean seed viability coefficients were calculated to evaluate seed viability under controlled storage conditions.
Zahra Heidari Sureshjani, Ghasem Karimzadeh, Sajad Rashidi Monfared,
Volume 9, Issue 1 (9-2022)
Volume 9, Issue 1 (9-2022)
Abstract
Extended Abstract
Introduction: St. John’s wort is one of the most amazing and medicinal plants of interest worldwide, which is nowadays known as a certain cure for depression. However, the presence of dormancy and low seed germination is a barrier to the progress of its breeding programs. Despite the richness of the plant’s genetic resources, there are only a few studies reported on its propagation and maintenance in Iran, most of which do not mention the geographical origin of the used seeds or explants. The current study was carried out aiming to evaluate in vitro plant propagation of eight Iranian endemic populations of St. John’s wort seeds which belonged to different geographical origins, emphasizing seed dormancy phenomena.
Materials and Methods: Following the collection of eight populations of St. John’s wort (Hypericum perforatum L.) seeds from different geographical regions of Iran, the Murashige and Skoog culture media (common salt mixture as a control, MS improved with gibberellic acid and a modified combination of MS) was used in an effort to investigate the effect of culture medium as well as seed collection locations on the germination percentage of these populations.
Results: The results showed that the interaction between the seed collection locations and the culture medium on seed germination was significant at P<0.01. Besides, the effect of changing culture media on seed germination was significant in all populations at P<0.01, except for Meshkin-Shahr. In other words, the seeds collected from Meshkin-Shahr germinated easily as well as notably under in vitro conditions (97.3% on average), and there was no need either to modify the combination of MS medium or to use gibberellic acid for seed dormancy elimination. The seeds originated from Challus and Peresk had the lowest germination in the control medium (22.3%, on average). Seeds from Challus and Saqqez had better germination in the media enriched with gibberellic acid compared to the control and the modified MS media (88% and 65%, respectively). However, less than half of the Parvar seeds germinated in the MS medium improved with GA3, compared to the control. Cultivation of seeds obtained from Fereydunkenar in common MS medium also led to better germination than using GA3 and modifying the combination of medium with 95% and 99% confidence levels, respectively.
Conclusion: The results of the current study demonstrated that the observed difference in seed germination percentage is remarkable in the Iranian endemic St. John’s wort populations under in vitro conditions. Moreover, the variation among national populations was significant. Besides, the response of the seed populations originating from different locations varied with respect to the changes in the culture medium and in the different cases. This shows the considerable effect of the growth location of the maternal plant on the characteristics of the next generation seeds, especially the way they germinate. Hence, it is very important to pay attention to the seed’s origins in the studies and it is investigable.
Highlights:
Introduction: St. John’s wort is one of the most amazing and medicinal plants of interest worldwide, which is nowadays known as a certain cure for depression. However, the presence of dormancy and low seed germination is a barrier to the progress of its breeding programs. Despite the richness of the plant’s genetic resources, there are only a few studies reported on its propagation and maintenance in Iran, most of which do not mention the geographical origin of the used seeds or explants. The current study was carried out aiming to evaluate in vitro plant propagation of eight Iranian endemic populations of St. John’s wort seeds which belonged to different geographical origins, emphasizing seed dormancy phenomena.
Materials and Methods: Following the collection of eight populations of St. John’s wort (Hypericum perforatum L.) seeds from different geographical regions of Iran, the Murashige and Skoog culture media (common salt mixture as a control, MS improved with gibberellic acid and a modified combination of MS) was used in an effort to investigate the effect of culture medium as well as seed collection locations on the germination percentage of these populations.
Results: The results showed that the interaction between the seed collection locations and the culture medium on seed germination was significant at P<0.01. Besides, the effect of changing culture media on seed germination was significant in all populations at P<0.01, except for Meshkin-Shahr. In other words, the seeds collected from Meshkin-Shahr germinated easily as well as notably under in vitro conditions (97.3% on average), and there was no need either to modify the combination of MS medium or to use gibberellic acid for seed dormancy elimination. The seeds originated from Challus and Peresk had the lowest germination in the control medium (22.3%, on average). Seeds from Challus and Saqqez had better germination in the media enriched with gibberellic acid compared to the control and the modified MS media (88% and 65%, respectively). However, less than half of the Parvar seeds germinated in the MS medium improved with GA3, compared to the control. Cultivation of seeds obtained from Fereydunkenar in common MS medium also led to better germination than using GA3 and modifying the combination of medium with 95% and 99% confidence levels, respectively.
Conclusion: The results of the current study demonstrated that the observed difference in seed germination percentage is remarkable in the Iranian endemic St. John’s wort populations under in vitro conditions. Moreover, the variation among national populations was significant. Besides, the response of the seed populations originating from different locations varied with respect to the changes in the culture medium and in the different cases. This shows the considerable effect of the growth location of the maternal plant on the characteristics of the next generation seeds, especially the way they germinate. Hence, it is very important to pay attention to the seed’s origins in the studies and it is investigable.
Highlights:
- This is the first report on the in vitro seed dormancy elimination in the eight Iranian St. John’s wort populations.
- It was for the first time bringing up the geographical origins of seeds in the national germination studies on the St. John’s wort.
- It is a quite new method to use a modified combination of MS medium for seed dormancy elimination in the St. John’s wort.
Majid Azimmohseni, Farshid Ghaderi-Far, Mahnaz Khalafi, Hamid Reza Sadeghipour, Marzieh Ghezel,
Volume 9, Issue 1 (9-2022)
Volume 9, Issue 1 (9-2022)
Abstract
Extended abstract
Introduction: Numerous studies are being carried out to reveal the effects of different treatments on the germination of seeds from various plants. The most commonly used method of analysis is the nonlinear regression which estimates germination parameters. Although the nonlinear regression has been performed based on different models, some serious problems in its structure and results motivated researchers to investigate alternative approaches with higher accuracy and precision. The main purpose of the present research is to introduce the alternative parametric time to event model and comparing its reliability to the nonlinear regression in experiments carried out under different conditions.
Materials and Methods: The results of four different experiments were used here including the effect of Potassium cyanide on walnut seed germination, the effect of salinity on wheat seed germination, the effect of water potential on corn seed germination and the effect of temperature on cotton seed germination. The nonlinear regression and time to event methods were applied based on the Gompertz model. The obtained standard errors from the two models were further assessed using the Monte-Carlo method.
Results: Both methods provided well-fitting models according to the MSE and R2 criteria. Although the germination parameters were approximately identical in both models, the standard error of parameters in nonlinear regression was significantly less than those of time to event method except for the experiments in which all tested seeds germinated within the time frame of study so that in the latter case the estimated standard errors in both models were identical. The Monte-Carlo method confirmed the results of the time to event model and reveals the underestimation of the nonlinear regression method in estimating the standard error of parameters.
Conclusions: Generally, the results of this research showed that the time to event model can be trustfully utilized in seed germination studies under different conditions and treatments. This model, not only provides precise estimates of the germination parameters but also provides the precise standard error of parameters that have important roles in making inferences for parameters. The drc package in R software enables researchers to fit the different time to event models.
Highlights:
- Using the time to the event model in estimation of seed germination parameters.
- Comparing the time to event and nonlinear regression methods in different seed germination experiments.
- Using the Monte-Carlo method for investigating the accuracy of results of the used methods.
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Site Keywords
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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