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Ahmad Zare, Elham Elahifard, Zahra Asadinejad,
Volume 7, Issue 2 (3-2021)
Volume 7, Issue 2 (3-2021)
Abstract
Extended Abstract
Introduction: Syrian mesquite is introduced as a weed in wheat and barley fields, saffron, cotton and vegetables, and in orchards. The spread of this weed in different climates raises the question of how much native plant conditions can affect germination characteristics. Therefore, the purpose of this study was to evaluate the effect of native plant conditions on germination characteristics in response to environmental stresses (temperature, salinity, and drought).
Materials and Methods: To investigate dormancy elimination and germination response thresholds of two Syrian mesquite ecotypes (Khuzestan and Fars) to environmental factors (temperature, salinity, and drought), four separate experiments were carried out as factorial based on completely block design with three replications at Agricultural Sciences and Natural Resources University of Khuzestan. Treatments included immersion the seeds with concentrated sulfuric acid (96%) (0, 10, 15, 20, 25, and 30 min), different temperature (0, 5, 10, 15, 20, 25, 30, 35, 40, and 45 °C), salinity levels (0, 100, 200, 300, 400, 500, and 600 mM), and different levels of drought stress (0, 0.2, 0.4, 0.6, 0.8, 1 and 1.2 MPa).
Results: The time required for immersion of seeds in sulfuric acid to dormancy breaking for two ecotypes was different. The estimated parameters indicated time of immersion in sulfuric acid to reach 50% germination in the Khuzestan ecotype (11.38 min) was longer than the Fars ecotype (8.10 min). The Khuzestan ecotype was also able to germinate (45%) at 40 ° C, whereas germination in the Fars ecotype was stopped at this temperature. Germination rate and cumulative germination percentage at temperatures below 25 ° C were higher in Fars ecotype than in the Khuzestan ecotype. The results of the salinity experiment showed that 50% reduction in seed vigor index, final germination percentage, and germination rate in the Fars ecotype were 167.48, 404.46, and 307.02 mM respectively and in the Khuzestan ecotype were 0.89. 229, 380.16, and 299.57 mM, respectively. For drought treatments, 50% reduction in final germination percentage, seed vigor index, and germination rate in Fars ecotype were -0.50, -0.38, and -0.39 MPa, respectively, and in Khuzestan ecotype were -0.46, -0.46, and -0.50 MPa, respectively.
Conclusion: Overall, the results showed that native plant climatic conditions (latitude and longitude, elevation, rainfall, and temperature) can affect the degree of seed dormancy, resistance to environmental stresses such as temperature, salinity, and drought.
Highlights:
1- Seed germination response thresholds of two ecotypes of Fars and Khuzestan for exposure to temperature and drought and salinity stresses were compared.
Mahdi Asadi, Majid Rahimizadeh,
Volume 8, Issue 1 (9-2021)
Volume 8, Issue 1 (9-2021)
Abstract
Extended abstract
Introduction: Velvetleaf is one of the most important weeds of cotton, corn, tomato, and soybean fields. Certainly, knowledge of weed seed response to environmental factors (light and temperature) is essential for better understanding the germination mechanism and establishment patterns of weeds community. The present study aimed to evaluate the interaction between light regimes and alternate temperature on the seed germination of velvetleaf.
Materials and Methods: The experiment was conducted in 2015 at the plant physiology laboratory of Bojnourd Branch, IAU. This study was performed as a factorial experiment based on a completely randomized design (CRD) with four replications. The treatments were temperature regimes at four levels (constant temperatures 25°C, alternating temperatures 25-15, 30-20 and 35-25°C) and photoperiod treatments at three levels (continuous darkness, 12-12 light and dark and 16-8 light and dark). Germination percentage, germination rate, germination uniformity, time to 10% germination, and time to 90% germination were evaluated by the Germin program.
Results: The results showed that all traits were affected by temperature and light. Velvetleaf seeds germinated better in the presence of light and alternating temperature. The percentage and rate of germination increased as temperature rised to 30°c and then decreased. However, seed reaction to the night temperature was higher than that of the day temperature. The highest germination percent (98 percent) was achieved under alternating temperature 25-15°C with 12-12h light-dark. In this study, the lowest time required for 10% and 90% germination and highest germination uniformity were observed under alternating temperatures 30-20°C in darkness.
Conclusion: According to the results of this experiment, velvetleaf seeds are able to germinate in a wide range of light and temperature conditions, although they germinate better in the presence of light and alternate temperatures. Therefore, plowing with a moldboard plow can stimulate germination and drain the soil seed bank.
Highlights:
1- Since light stimulates the germination of velvetleaf seeds, so no-tillage system is able to control this weed.
2- Increasing the environment temperature reduces the chance of germination of velvetleaf seeds.
Morteza Gorzin, Farshid Ghaderi-Far, Hamid Reza Sadeghipour, Ebrahim Zeinali,
Volume 8, Issue 1 (9-2021)
Volume 8, Issue 1 (9-2021)
Abstract
Extended abstract
Introduction: Since the maximum percentage and rate of germination of rapeseed occur at a certain temperature, finding these temperatures can play an important role in determining the appropriate time and place for the cultivation of different cultivars. Also, light can affect the germination percentage of rapeseed at different temperatures, but the response of rapeseed to light, especially at lower and higher temperatures, has not been studied. Therefore, this study aimed to investigate the changes in the germination of rapeseed cultivars at different temperatures and determine cardinal germination temperatures based on germination percentage and rate under both the presence and absence of light conditions.
Materials and methods: In this study, germination tests were carried out at 5, 10, 15, 20, 25, 30, 35, 37, and 40°C temperatures in two light conditions (12 h light / 12 h dark) and darkness on nine spring cultivars (Traper, Agamax, Hayola-50, Hayola-420, RGS, Mahtab, Hayola-61, Zafar, and Zarfam) and one winter cultivar (Garo). The four-parameter Hill model was used to describe germination changes over time and the dent model was used to calculate cardinal temperatures. Seed viability at lower and higher temperatures was evaluated by the tetrazolium test.
Results: The evaluation of the trend of cumulative germination percentage over time in different cultivars showed that maximum germination percentage of all cultivars happened in the temperature range between 15-30 °C, some in the temperature range of 10-30 °C (Hyola-61) and others even in the temperature range of 5-30 °C (RGS, Mahtab, Garo, Zafar, and Zarfam) had the highest germination percentage. The highest germination rate in all cultivars was observed at the temperature range of 22-35 °C. Light only had an effect on the germination percentage of the seeds at sub and super optimal temperatures. At these temperatures, light increased the germination percentage. The remaining seed of 5, 10, 35, 37, and 40 °C temperature after transfer to 20 °C did not germinate, whereas most of them were viable based on the tetrazolium test.
Conclusion: The difference in the optimum temperature range for germination percentage and rate showed that to optimize seed performance, the optimal temperature range between the germination percentage and germination rate should be considered as the optimum temperature for germination. At sub and supra optimal temperatures, light leads to improved germination in some cultivars. The effect of light on germination at supra optimal temperatures was far higher than that of sub-optimal ones. Survival of the remaining seeds at the sub and supra optimal temperatures in some cultivars provided evidence of thermo-dormancy in these cultivars, this issue needs further investigation in the future.
Highlights:
1- The cardinal temperatures were studied based on both the percentage and rate of germination and the effect of light on them.
2- Some new varieties such as Traper and Agamax that little information about their characteristics is available were examined.
3- In this study, the reason for the lack of germination of rapeseed at the sub and supra optimal temperatures especially in the darkness has been mentioned.
Introduction: Since the maximum percentage and rate of germination of rapeseed occur at a certain temperature, finding these temperatures can play an important role in determining the appropriate time and place for the cultivation of different cultivars. Also, light can affect the germination percentage of rapeseed at different temperatures, but the response of rapeseed to light, especially at lower and higher temperatures, has not been studied. Therefore, this study aimed to investigate the changes in the germination of rapeseed cultivars at different temperatures and determine cardinal germination temperatures based on germination percentage and rate under both the presence and absence of light conditions.
Materials and methods: In this study, germination tests were carried out at 5, 10, 15, 20, 25, 30, 35, 37, and 40°C temperatures in two light conditions (12 h light / 12 h dark) and darkness on nine spring cultivars (Traper, Agamax, Hayola-50, Hayola-420, RGS, Mahtab, Hayola-61, Zafar, and Zarfam) and one winter cultivar (Garo). The four-parameter Hill model was used to describe germination changes over time and the dent model was used to calculate cardinal temperatures. Seed viability at lower and higher temperatures was evaluated by the tetrazolium test.
Results: The evaluation of the trend of cumulative germination percentage over time in different cultivars showed that maximum germination percentage of all cultivars happened in the temperature range between 15-30 °C, some in the temperature range of 10-30 °C (Hyola-61) and others even in the temperature range of 5-30 °C (RGS, Mahtab, Garo, Zafar, and Zarfam) had the highest germination percentage. The highest germination rate in all cultivars was observed at the temperature range of 22-35 °C. Light only had an effect on the germination percentage of the seeds at sub and super optimal temperatures. At these temperatures, light increased the germination percentage. The remaining seed of 5, 10, 35, 37, and 40 °C temperature after transfer to 20 °C did not germinate, whereas most of them were viable based on the tetrazolium test.
Conclusion: The difference in the optimum temperature range for germination percentage and rate showed that to optimize seed performance, the optimal temperature range between the germination percentage and germination rate should be considered as the optimum temperature for germination. At sub and supra optimal temperatures, light leads to improved germination in some cultivars. The effect of light on germination at supra optimal temperatures was far higher than that of sub-optimal ones. Survival of the remaining seeds at the sub and supra optimal temperatures in some cultivars provided evidence of thermo-dormancy in these cultivars, this issue needs further investigation in the future.
Highlights:
1- The cardinal temperatures were studied based on both the percentage and rate of germination and the effect of light on them.
2- Some new varieties such as Traper and Agamax that little information about their characteristics is available were examined.
3- In this study, the reason for the lack of germination of rapeseed at the sub and supra optimal temperatures especially in the darkness has been mentioned.
Marjan Diyanat, Pouya Sonboli-Hamedani, Fereidoon Ghasem-Khan Ghajar,
Volume 8, Issue 1 (9-2021)
Volume 8, Issue 1 (9-2021)
Abstract
Extended Abstract
Introduction: Seed dormancy is the most important factor that prevents weed seed germination. Lack of simultaneous germination of weed seeds causes a number of problems in their control due to seed dormancy in the fields; therefore, weed seed dormancy is considered to be an undesirable trait for farmers. The aim of this study was to investigate the effect of magnetic field on seed dormancy elimination in some weed species.
Material and Methods: In order to study the effect of Magnetic field on germination and seedling growth of redroot pigweed (Amaranthus retroflexus), spring wild oat (Avena fatua) and common purslane (Portulaca oleraceae), a factorial experiment based on completely randomized design was conducted at the Ecology laboratory of Science Research Branch, Islamic Azad University in 2019. Factors consisted of dormancy breaking treatment at 8 levels (gibberellic acid 1000 mg/l for 20 minutes, gibberellic acid 2000 mg/l for 20 minutes, sulfuric acid for 5 minutes, sulfuric acid for 10 minutes, sulfuric acid for 20 minutes, nitrate potassium at 0.01 g/L, nitrate potassium at 0.05 g/L and control) and magnetic field at 4 levels (0, 25, 50 and 100 mT).
Results: Results showed that responses of three weed species to magnetic field were different. Magnetic field increased percentage of germination, fresh weight of plumule and length of plumule of redroot pigweed, so magnetic field at 100 mT was the best treatment for dormancy breaking. The highest germination percentage of wild oat was obtained in 0.01 mM potassium nitrate at 50 mT. The length plumule of wild oat increased significantly at 2000 mg/l gibberellic acid with increasing magnetic field level from zero to 25 mM. Nitrate potassium at 0.05 g/L was the best treatment for breaking the dormancy of common purslane. Magnetic field at 100 mT could increase percentage of germination of this weed.
Conclusion: In general, the results of this study showed that sulfuric acid treatment was not a suitable option for the removal of dormancy in the three weed species because of the elimination of seed embryos. Magnetic field treatment significantly increased the studied traits in all three species of redroot pigweed, spring wild oat and purslane. The interaction between dormancy breaking treatment and magnetic field was significant in many of the studied traits and the effect of dormancy breaking treatment was intensified by magnetic field. Therefore, the use of magnetic field treatment is recommended to increase the germination of these three species.
Highlights:
1- There is a positive and significant interaction between seed dormancy elimination treatments and magnetic field.
2- Sulfuric acid treatment is not a suitable option for breaking the dormancy of redroot pigweed, spring wild oat and purslane.
Introduction: Seed dormancy is the most important factor that prevents weed seed germination. Lack of simultaneous germination of weed seeds causes a number of problems in their control due to seed dormancy in the fields; therefore, weed seed dormancy is considered to be an undesirable trait for farmers. The aim of this study was to investigate the effect of magnetic field on seed dormancy elimination in some weed species.
Material and Methods: In order to study the effect of Magnetic field on germination and seedling growth of redroot pigweed (Amaranthus retroflexus), spring wild oat (Avena fatua) and common purslane (Portulaca oleraceae), a factorial experiment based on completely randomized design was conducted at the Ecology laboratory of Science Research Branch, Islamic Azad University in 2019. Factors consisted of dormancy breaking treatment at 8 levels (gibberellic acid 1000 mg/l for 20 minutes, gibberellic acid 2000 mg/l for 20 minutes, sulfuric acid for 5 minutes, sulfuric acid for 10 minutes, sulfuric acid for 20 minutes, nitrate potassium at 0.01 g/L, nitrate potassium at 0.05 g/L and control) and magnetic field at 4 levels (0, 25, 50 and 100 mT).
Results: Results showed that responses of three weed species to magnetic field were different. Magnetic field increased percentage of germination, fresh weight of plumule and length of plumule of redroot pigweed, so magnetic field at 100 mT was the best treatment for dormancy breaking. The highest germination percentage of wild oat was obtained in 0.01 mM potassium nitrate at 50 mT. The length plumule of wild oat increased significantly at 2000 mg/l gibberellic acid with increasing magnetic field level from zero to 25 mM. Nitrate potassium at 0.05 g/L was the best treatment for breaking the dormancy of common purslane. Magnetic field at 100 mT could increase percentage of germination of this weed.
Conclusion: In general, the results of this study showed that sulfuric acid treatment was not a suitable option for the removal of dormancy in the three weed species because of the elimination of seed embryos. Magnetic field treatment significantly increased the studied traits in all three species of redroot pigweed, spring wild oat and purslane. The interaction between dormancy breaking treatment and magnetic field was significant in many of the studied traits and the effect of dormancy breaking treatment was intensified by magnetic field. Therefore, the use of magnetic field treatment is recommended to increase the germination of these three species.
Highlights:
1- There is a positive and significant interaction between seed dormancy elimination treatments and magnetic field.
2- Sulfuric acid treatment is not a suitable option for breaking the dormancy of redroot pigweed, spring wild oat and purslane.
Habib Nejadgharebaghi, Esfandiar Fateh, Amir Aynehband,
Volume 8, Issue 1 (9-2021)
Volume 8, Issue 1 (9-2021)
Abstract
Extended Abstract
Introduction: In Iran, the majority of research has been done on the depth of burial on crops and the effect of these factors on weeds resulted from seeds and rhziomes of seedlings has been less studied. Strangle Wort weed is one of the most problematic weeds in sugarcane fields, orchards, especially pistachio orchards, barren lands, and roads. Thus, this study aimed to find out the effect of different levels of burial depth and flood stress on the extent and quality of seedlings resulted from its rhizomes.
Material and Methods: Two separate greenhouse experiments based on completely randomized design with four replications were conducted in the experimental farm of Sugarcane Research Institute of Khuzestan province at 2014-2015 growing season. Flooding stress treatment included 7 levels of flooding stress (4, 8, 16, 24, 48, 72, and 96 flooding hours) and 6 levels of seed burial (1, 3, 5, 7, 10, and 15 cm) and rhizome burial depth treatment included 7 levels (1, 3, 5, 7, 10, and cm 15).
Results: With increasing levels of flood stress, all studied traits including root length, stem height, total dry matter biomass, shoot dry weight and root dry weight of strangle wort rhizomes decreased at 96 hours of waterlogged stress compared to the control by 63, 70, 59, 98 and 74 percent, respectively. Also, in second experiment, buried rhizomes of this weed with a length of 5 cm at a depth of 15 cm were not able to produce new seedlings.
Conclusion: According to these results, for proper management of this weed, highly contaminated areas in the field should be identified (especially in sugarcane fallow fields because at this time there is no weed control limitation). Then, the weed should be turned it into pieces smaller than 5 cm with plowing tools. Also, if possible, with suitable tools, transfer rhizomes should be transferred to a depth of more than 15 cm and integrated weed control management with drought and flooding stress and burial depth with at least two times of plowing could be implemented to control weed and prevent its expansion.
Highlights:
1-Germination characteristics of strangle wort seedlings under burial depths and flooding stress were evaluated.
2-The effect of burial depth and flooding stress on control and management of strangle wort was examined.
3-Precise determination of weed biology and weed germination behavior will lead to proper execution of weed control program.
Introduction: In Iran, the majority of research has been done on the depth of burial on crops and the effect of these factors on weeds resulted from seeds and rhziomes of seedlings has been less studied. Strangle Wort weed is one of the most problematic weeds in sugarcane fields, orchards, especially pistachio orchards, barren lands, and roads. Thus, this study aimed to find out the effect of different levels of burial depth and flood stress on the extent and quality of seedlings resulted from its rhizomes.
Material and Methods: Two separate greenhouse experiments based on completely randomized design with four replications were conducted in the experimental farm of Sugarcane Research Institute of Khuzestan province at 2014-2015 growing season. Flooding stress treatment included 7 levels of flooding stress (4, 8, 16, 24, 48, 72, and 96 flooding hours) and 6 levels of seed burial (1, 3, 5, 7, 10, and 15 cm) and rhizome burial depth treatment included 7 levels (1, 3, 5, 7, 10, and cm 15).
Results: With increasing levels of flood stress, all studied traits including root length, stem height, total dry matter biomass, shoot dry weight and root dry weight of strangle wort rhizomes decreased at 96 hours of waterlogged stress compared to the control by 63, 70, 59, 98 and 74 percent, respectively. Also, in second experiment, buried rhizomes of this weed with a length of 5 cm at a depth of 15 cm were not able to produce new seedlings.
Conclusion: According to these results, for proper management of this weed, highly contaminated areas in the field should be identified (especially in sugarcane fallow fields because at this time there is no weed control limitation). Then, the weed should be turned it into pieces smaller than 5 cm with plowing tools. Also, if possible, with suitable tools, transfer rhizomes should be transferred to a depth of more than 15 cm and integrated weed control management with drought and flooding stress and burial depth with at least two times of plowing could be implemented to control weed and prevent its expansion.
Highlights:
1-Germination characteristics of strangle wort seedlings under burial depths and flooding stress were evaluated.
2-The effect of burial depth and flooding stress on control and management of strangle wort was examined.
3-Precise determination of weed biology and weed germination behavior will lead to proper execution of weed control program.
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.
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
Seyedeh Tina Mousavi Kani, Davoud Kartoolinejad, Zohreh Bahrami, Ali Asghar Zolfaghari, Elahe Nikouee,
Volume 9, Issue 1 (9-2022)
Volume 9, Issue 1 (9-2022)
Abstract
Extended Abstract
Introduction: Nowadays, due to land use change and destruction of natural resources induced by human activities, attention to desertification has immensely become widespread. One of the most important species for biological rehabilitation of desert areas on a large scale is the hawthorn plant. Hawthorn is a plant belonging to the family Amaranthaceae, the two species of which are called white saxaul (Haloxylon persicum Bunge ex Boissier & Buhse) and black saxaul (Haloxylon aphyllum (Minkw.) Iljin) are more notorious and widespread in Iran. These plants own extensive root systems and stabilize running sands. The aim of this study was to investigate the effect of mesoporous titanium dioxide nanoparticles on germination traits of black saxaul seeds under drought stress, as an important species in desert areas.
Materials and Methods: The experiment was performed as a factorial experiment in a completely randomized design with 3 replications. Experimental treatments included five titanium nano dioxides with concentrations of 0, 25, 50, 100 and 200 mg / l and six drought stress levels including 0, -4, -8, -12, -16 and -20 bar. After nanopriming, black saxaul seeds were subjected to drought stress for 15 days in a germinator at a temperature of 20 °C with four replications. After germination, in each of the treatments, germination percentage (GP), germination rate (GS), mean germination time (MGT) and seed vigor index (VI) were calculated.
Results: The results of two-way ANOVA and mean comparison of germination indices showed that the highest germination percentage (74%) belonged to the zero level of stress treatment with a concentration of 200 mg/l and the lowest one (3%) belonged to -20 bar treatment with 25 and 200 mg/l nano-titanium dioxide. With increasing drought stress intensity from zero to -20 bar level, germination rate decreased from 7.01 to 0.43 seeds per day. The highest amount of seed vigor index at zero drought level belonged to the treatment of 200 mg/l concentration of nano-titanium, with a rate of 325.77.
Conclusion: The results showed that germination indices and initial growth of black saxaul seeds decreased in all primed and unprimed treatments with increasing drought stress, and nanopriming with titanium dioxide had a positive effect on seed germination traits.
Highlights:
1- Seed priming using mesoporous nano-titanium dioxide improved the germination percentage of black saxaul seeds under drought stress.
2- The concentration of 200 mg/l of mesoporous nano titanium dioxide revealed a better effect on seed germination index, mean germination time, germination rate and percentage
3- Seed nano priming using titanium dioxide did not have much effect on the growth characteristics of black saxaul seedlings at higher levels of drought stress.
Asieh Siahmarguee, Farshid Ghaderifa, Javid Gherekhloo, Atefeh Akbari Gelvardi, Maryam Gorgani,
Volume 9, Issue 1 (9-2022)
Volume 9, Issue 1 (9-2022)
Abstract
Extended abstract:
Introduction: Reports indicate the invasion of two species of Ivy-leaved morning-glory (Ipomoea hederaceae Jacq) and Asian spider flower (Cleome viscosa L.) to summer crops fields such as soybeans in Golestan province. Considering the importance of knowing the cardinal temperatures of germination in the models for predicting the presence of weeds and consequently designing correct management strategies on these plants, this experiment was conducted to study the germination behavior and to compare the cardinal temperatures of germination for two species of Ivy-leaved morning-glory and Asian spider flower under two conditions of constant and alternating temperatures.
Materials and Methods: In order to study the effects of constant and alternating temperature on the percent, rate and estimating cardinal temperature of germination for Ivy-leaved morning glory and Asian spider flower, two separate experiments as a Completely Randomized Design with four replications were carried out at the seed laboratory of Gorgan University of Agricultural Sciences and Natural Resources. Studied temperature treatments on Ivy-leaved morning glory included the constant temperatures of 10,15,17,20,25,30,35 and 40 oC and alternating temperatures of 12.5:7.5,10:15, 12.5:20, 15:25, 20:30, 25:37.5, 30:42.5 and 35:45 oC. Temperature treatments on Asian spider flower included the constant temperatures of 15, 20, 23, 25, 28, 30, 35, 40, 45 and 50 o C and alternating temperatures of 15:20, 20:25, 20:30, 25:30, 25:35, 30:40, 30:45, 30:50 and 40:50 oC.
Results: Results indicated that alternating temperatures had a positive effect on the germination of Ivy-leaved morning glory, which increased from 78% at constant temperatures to 94% at alternative temperatures. However, the maximum germination percentage of Asian spiderflower at the alternative temperature of 20:30 was 79%, which had no significant difference with a constant temperature of 30 with 84% germination. The base temperature for seed germination of Ivy-leaved morning glory at alternating temperatures (10.09 oC) was a little lower than that of constant temperatures (11.25 oC). But in Asian spider flower, the base temperature at alternating temperatures (17.57 oC) was more than that of constant temperatures (15.43 o C).
Conclusion: The most important factor in the occurrence of such different responses to constant and alternating temperatures in Ivy-leaved morning glory and Asian spider flower is their adaptation to environmental conditions and their survival in highly degraded agricultural environments. These two weeds are warm-season plants and their seeds enter the soil seed bank in autumn. The presence of dormancy (regardless of its type) in the seeds of these two plants prevents the germination of their seeds in winter; and the experience of alternating temperatures at this time prepares the seeds for germination in the spring. The base temperature of Ivy-leaved morning glory was not much different under the constant and alternating temperature conditions. But the base temperature of Asian spider flower was higher under alternating temperatures compared with constant temperatures.
Highlights:
1- The Response of germination percentage of Ivy-leaved morning-glory and Asian spider flower were investigated under constant and alternating temperatures.
2- Cardinal temperatures of germination for these two weeds were compared at constant and alternating temperature conditions.
Introduction: Reports indicate the invasion of two species of Ivy-leaved morning-glory (Ipomoea hederaceae Jacq) and Asian spider flower (Cleome viscosa L.) to summer crops fields such as soybeans in Golestan province. Considering the importance of knowing the cardinal temperatures of germination in the models for predicting the presence of weeds and consequently designing correct management strategies on these plants, this experiment was conducted to study the germination behavior and to compare the cardinal temperatures of germination for two species of Ivy-leaved morning-glory and Asian spider flower under two conditions of constant and alternating temperatures.
Materials and Methods: In order to study the effects of constant and alternating temperature on the percent, rate and estimating cardinal temperature of germination for Ivy-leaved morning glory and Asian spider flower, two separate experiments as a Completely Randomized Design with four replications were carried out at the seed laboratory of Gorgan University of Agricultural Sciences and Natural Resources. Studied temperature treatments on Ivy-leaved morning glory included the constant temperatures of 10,15,17,20,25,30,35 and 40 oC and alternating temperatures of 12.5:7.5,10:15, 12.5:20, 15:25, 20:30, 25:37.5, 30:42.5 and 35:45 oC. Temperature treatments on Asian spider flower included the constant temperatures of 15, 20, 23, 25, 28, 30, 35, 40, 45 and 50 o C and alternating temperatures of 15:20, 20:25, 20:30, 25:30, 25:35, 30:40, 30:45, 30:50 and 40:50 oC.
Results: Results indicated that alternating temperatures had a positive effect on the germination of Ivy-leaved morning glory, which increased from 78% at constant temperatures to 94% at alternative temperatures. However, the maximum germination percentage of Asian spiderflower at the alternative temperature of 20:30 was 79%, which had no significant difference with a constant temperature of 30 with 84% germination. The base temperature for seed germination of Ivy-leaved morning glory at alternating temperatures (10.09 oC) was a little lower than that of constant temperatures (11.25 oC). But in Asian spider flower, the base temperature at alternating temperatures (17.57 oC) was more than that of constant temperatures (15.43 o C).
Conclusion: The most important factor in the occurrence of such different responses to constant and alternating temperatures in Ivy-leaved morning glory and Asian spider flower is their adaptation to environmental conditions and their survival in highly degraded agricultural environments. These two weeds are warm-season plants and their seeds enter the soil seed bank in autumn. The presence of dormancy (regardless of its type) in the seeds of these two plants prevents the germination of their seeds in winter; and the experience of alternating temperatures at this time prepares the seeds for germination in the spring. The base temperature of Ivy-leaved morning glory was not much different under the constant and alternating temperature conditions. But the base temperature of Asian spider flower was higher under alternating temperatures compared with constant temperatures.
Highlights:
1- The Response of germination percentage of Ivy-leaved morning-glory and Asian spider flower were investigated under constant and alternating temperatures.
2- Cardinal temperatures of germination for these two weeds were compared at constant and alternating temperature conditions.
Nafiseh Sheibany, Sina Fallah, Hossein Barani-Beiranvand, Aliyeh Salehi,
Volume 9, Issue 2 (3-2023)
Volume 9, Issue 2 (3-2023)
Abstract
Extended abstract Introduction: The use of nanotechnology is increasing in many fields including agricultural sciences. Concurrently, the release of these particles into the environment is inevitable, which may have adverse effects on plants. Therefore, it is important to understand the interactions between nanoparticles and crops as an essential component of all agricultural ecosystems. In this regard, a study was conducted on the effects of nanoparticles on germination potential and initial growth of F2 seeds by cultivating soybean in soil containing copper oxide nanoparticles. Materials and Methods: To evaluate the nourishment effects of maternal soybean with copper compounds on its seedlings, two factorial experiments (in a growth chamber and pot) were conducted in a completely randomized design at the Faculty of Agriculture, Shahrekord University in 2021. Treatments in the maternal plant included different copper compounds (copper oxide nanoparticles with sizes of 25, 50 nm and copper chloride) and five concentrations of copper compounds (0, 50, 100, 200 and 500 mg/kg soil), and the seeds produced from these treatments were evaluated under controlled and pot conditions. Results: An increase in the concentration of copper chloride and copper oxide nanoparticle (25 nm) in maternal plants reduced the germination percentage (25 and 78%), radicle length (56 and 82%), radicle weight (35 and 81%), plumule length (19 and 71%), plumule weight (32 and 73%) and seedling vigor index (49 and 94%) of produced seeds, respectively. The evaluation of soybean seedlings nourished with different copper compounds also showed the nourishment with copper chloride and copper oxide nanoparticle (25 nm) significantly decreased the content of chlorophyll a (10 and 74%), chlorophyll b (38, 49%), carotenoids (136 and 145%), root length (27 and 61%), seedling height (31 and 58%), leaf area (44 and 64%), and shoot weight (34 and 64%) compared to the control, respectively. Conclusion: In general, it is concluded that the toxicity of copper compounds in the rhizosphere of the maternal plant for the produced seeds is directly related to the concentration. Therefore, the toxic effects are intensified when the maternal plant is nourished with copper oxide nanoparticles, and the seeds produced under these conditions have poor vigor. Highlights: 1. Nourishment of the maternal soybean plant with copper oxide nanoparticles reduces the seedling growth of the produced seeds. 2. Reducing the size of copper oxide nanoparticles has a more toxic effect on the germination of produced seeds. 3. The toxic effects of copper oxide nanoparticles continue until the seedling stage.
Hassan Gholami, Roohollah Abdolshahi, Mehdi Mohayeji, Mohsen Esmaeilizadeh-Moghadam,
Volume 9, Issue 2 (3-2023)
Volume 9, Issue 2 (3-2023)
Abstract
Extended Abstract
Introduction: Wheat coleoptile protects the plumule and the first leaf so they can move from the embryo to the soil surface. Coleoptile is essential for plant establishment. Cultivars with longer coleoptiles and mesocotyls are sown deeper and are more successful under drought stress conditions. However, there is not much information about their genetics. The objective of the present study was to evaluate the coleoptile and mesocotyl of Iranian, overseas and the lines developed as a part of Shahid Bahonar University breeding program, and estimate of genetic parameters of these traits.
Materials and Methods: In this research, 30 bread wheat genotypes originated from Iran, CIMMYT, ICARDA, USA, and Australia and five lines from Shahid Bahonar University of Kerman breeding programs were sown at a 10 cm depth of soil in the research field of Shahid Bahonar University in a randomized complete block design with seven replications. Each plot consisted of three rows with two meters long and a 5 cm intra-row spacing. At harvest, the plants were gently removed from the soil, and after removing the soil from the root area, the roots were washed. In this study, coleoptile and mesocotyl length, number of seminal roots, root length, root and shoot dry weight were measured.
Results: Coleoptile and mesocotyl are important traits for increasing drought tolerance in bread wheat. In the present research, mesocotyl length varied from 5.20 for Excalibur to 2.08 for Zagros, and showed a high heritability (0.48) and response to selection (11.61%). Furthermore, this trait had a positive significant correlation with coleoptile length (r=0.53**), root weight (r=0.38*) and shoot weight (r=0.36*). Seminal and nodal root number had the highest (0.59), while root length had the lowest (0.13) narrow-sense heritability. Overall, suitable cultivars for rain-fed conditions had higher coleoptile and mesocotyl than the others. Breeding lines in Shahid Bahonar University of Kerman suitable for rain-fed conditions had longer coleoptile and mesocotyl lengths. Root and shoot dry weight had a significant positive correlation (r=0.82**).
Conclusions: In general, breeding programs to increase grain yield differ under rain-fed and irrigated conditions. In wheat breeding programs under rain-fed conditions, special attention should be paid to coleoptile and mesocotyl traits. These traits were not influenced by the plant growth habit.
Highlights:
Introduction: Wheat coleoptile protects the plumule and the first leaf so they can move from the embryo to the soil surface. Coleoptile is essential for plant establishment. Cultivars with longer coleoptiles and mesocotyls are sown deeper and are more successful under drought stress conditions. However, there is not much information about their genetics. The objective of the present study was to evaluate the coleoptile and mesocotyl of Iranian, overseas and the lines developed as a part of Shahid Bahonar University breeding program, and estimate of genetic parameters of these traits.
Materials and Methods: In this research, 30 bread wheat genotypes originated from Iran, CIMMYT, ICARDA, USA, and Australia and five lines from Shahid Bahonar University of Kerman breeding programs were sown at a 10 cm depth of soil in the research field of Shahid Bahonar University in a randomized complete block design with seven replications. Each plot consisted of three rows with two meters long and a 5 cm intra-row spacing. At harvest, the plants were gently removed from the soil, and after removing the soil from the root area, the roots were washed. In this study, coleoptile and mesocotyl length, number of seminal roots, root length, root and shoot dry weight were measured.
Results: Coleoptile and mesocotyl are important traits for increasing drought tolerance in bread wheat. In the present research, mesocotyl length varied from 5.20 for Excalibur to 2.08 for Zagros, and showed a high heritability (0.48) and response to selection (11.61%). Furthermore, this trait had a positive significant correlation with coleoptile length (r=0.53**), root weight (r=0.38*) and shoot weight (r=0.36*). Seminal and nodal root number had the highest (0.59), while root length had the lowest (0.13) narrow-sense heritability. Overall, suitable cultivars for rain-fed conditions had higher coleoptile and mesocotyl than the others. Breeding lines in Shahid Bahonar University of Kerman suitable for rain-fed conditions had longer coleoptile and mesocotyl lengths. Root and shoot dry weight had a significant positive correlation (r=0.82**).
Conclusions: In general, breeding programs to increase grain yield differ under rain-fed and irrigated conditions. In wheat breeding programs under rain-fed conditions, special attention should be paid to coleoptile and mesocotyl traits. These traits were not influenced by the plant growth habit.
Highlights:
- Mesocotyl of the Iranian cultivars was evaluated for the first time.
- Breeding lines developed by Shahid Bahonar University of Kerman suitable for rain-fed had appropriate coleoptiles and mesocotyls.
- Coleoptile and mesocotyl had a significant and positive correlation.
Iraj Rahimi, Ismail Asadi, Pejman Tahmasebi, Alireza Monfared, Ali Abbasi Suraki,
Volume 9, Issue 2 (3-2023)
Volume 9, Issue 2 (3-2023)
Abstract
Extended Abstract:
Introduction: Predation is the common fate of most seeds produced by plants. Loss of seeds due to predation can be harmful to plants and causes such species to become rare, as rare species are vulnerable to extinction through processes that disrupt the mechanisms of plant dispersal. Therefore, the purpose of this study was to investigate the effects of pre-dispersal seed predation on rare astragalus species and their common counterparts.
Materials and Methods: In order to investigate the effects of pre-dispersal seed predation, 12 species including 6 species with herbaceous life form (including three rare species (A. Caraganae, A. Heterophyllus and A. Holopsilus) and three common species (A. Angustiflorus, A. Curvirostris and A. Effusus) and 6 species with shrub life form (including three rare species (A. Cephalanthus, A. Camphylanthus and A. Cemerinus) and three common species (A. Verus, A. Susianus and A. Rhodosemius) were compared in 2018 and 2019. From each plant type, 20 and from each plant type 10 pods (for each plant type 200 pods), randomly selected and the parameters of area size, perimeter length, length, width, length-to-width ratio, circularity, and distance between IS and CG from the seed center were measured and compared for both pods and seeds of these species. Also, pod mass and seed mass, number of pods and seeds attacked by predators, number of healthy seeds, pod shape and seed shape of species were compared.
Results: The results of comparing the mean morphological characteristics of seeds between herbaceous and shrub astragalus species showed the highest and lowest area size, perimeter length, length, width, length-to-width ratio, circularity, and distance between IS and CG from the seed center, was related to common astragalus species. in the case of shrub species, most of the characteristics were related to common astragalus species, and the lowest characteristics were related to rare astragalus species. The results of morphological characteristics of pods between herbaceous and shrub species showed that the highest and lowest characteristics belonged to both groups of common and rare species. The results showed that the highest and lowest means of seed mass, number of damaged seeds, number of healthy seeds, and seed shape under the influence of pre-dispersal seed predation among herbaceous species showed that the highest and lowest means of seed mass, number of damaged seeds, belonged to common species. the highest and lowest numbers of healthy seeds and seed shapes belonged to rare species. Among the shrub astragalus species, the highest seed mass, the number of damaged seeds, the number of healthy seeds, and the seed shape were related to common astragalus species, and the lowest of these characteristics were related to rare astragalus species.
Conclusion: The overall results showed that the more species that can produce seeds of larger and smaller sizes, the better the distribution status. And the larger the seed and pod mass of the plant and the larger the shape, the more predators attack those species, but the amount of predator attacks does not lead to the rarity of the species.
Highlights:
- The role of pre-dispersal seed predation on rare and common astragalus species was investigated.
- Morphological characteristics of seeds and life forms of rare and common astragalus species were compared.
Omid Ansari, Esmaeil Shirghani, Khodadad Shabani,
Volume 10, Issue 1 (9-2023)
Volume 10, Issue 1 (9-2023)
Abstract
Extended abstract
Introduction: Due to the high sensitivity of seeds to damage caused by diseases or environmental stresses, germination is considered an important stage in the plant life cycle: Germination, its uniformity and emergence decline during storage due to seed vigor deterioration. Moisture stress is one of the important environmental factors affecting germination, especially during improper storage. Seed priming with gibberellic acid improves seedling characteristics in different plants under different environmental conditions. Therefore, this research aims to investigate the effect of gibberellic acid and seed deterioration on germination indices and antioxidant enzymes of safflower seeds (Carthamus tinctorius L.) under water stress conditions.
Introduction: Due to the high sensitivity of seeds to damage caused by diseases or environmental stresses, germination is considered an important stage in the plant life cycle: Germination, its uniformity and emergence decline during storage due to seed vigor deterioration. Moisture stress is one of the important environmental factors affecting germination, especially during improper storage. Seed priming with gibberellic acid improves seedling characteristics in different plants under different environmental conditions. Therefore, this research aims to investigate the effect of gibberellic acid and seed deterioration on germination indices and antioxidant enzymes of safflower seeds (Carthamus tinctorius L.) under water stress conditions.
Materials and Methods: In order to investigate the effect of gibberellic acid on germination indicators and changes in antioxidant enzymes of aged safflower seeds under osmotic stress conditions, a factorial experiment was conducted in the form of a completely randomized design with four replications. The first factor includes three osmotic stress levels: zero (control), -0.4, and -0.8 MPa, the second factor includes nine aging levels (zero, 1, 2, 3, 4, 5, 6, 7, and 8 days of aging). at a temperature of 41 degrees Celsius) and the third factor included seed priming treatment at three control levels (non-priming), zero (hydro-priming), and priming with 50 mg/l gibberellic acid. A 3-parametric sigmoid model was used to show the changes in germination indices at different levels of seed deterioration.
Results: The effect of osmotic stress, seed deterioration, and seed priming on the measured indices such as germination percentage, germination rate, seedling dry weight, normal seedling percentage, seedling length, seed germ, catalase, and ascorbate peroxidase, as well as seed protein were significant so that the measured indicators decreased with increasing seed deterioration and moisture stress. The results showed that the highest measured germination indices were obtained from seed treatment with 50 mg/l gibberellic acid under normal osmosis and non-deterioration conditions. Also, seed priming with gibberellic acid treatment caused an increase in catalase, ascorbate peroxidase, and protein activity compared to non-primed seeds under deterioration and non-deterioration conditions.
Conclusion: Results showed that the most suitable prime level used was gibberellic acid 50 mg/l, which had acceptable results under both stress conditions and normal conditions and deterioration and non-deterioration in comparison with other treatments. Therefore, the use of gibberellic acid hormone can help to improve germination indices as a result of changes in biochemical activities.
Highlights:
1. The effect of accelerated aging and priming on safflower seed germination under moisture stress conditions was investigated.
2.The effect of priming on catalase and peroxidase activity of aged safflower seeds was investigated.
Emad Shahmansouri, Zahra Abbasi,
Volume 10, Issue 1 (9-2023)
Volume 10, Issue 1 (9-2023)
Abstract
Extended Abstract
Introduction: The selection of optimum planting date for every climate and mother bulb size are important factors affecting the quantity and quality of seed production in different cultivars. This study was performed in Isfahan province, Frieden, during two growing years 2016-2017 to determine the effect of planting time and mother bulb size on the quantity and quality of short-day onion seed varieties Texas Early Grano 502
Materials and Methods: A split-plot experiment was performed in a randomized complete block design with four replications. The main factor was cultivation dates at four levels: the end of August, the first of September, the end of September and the first of October and mother bulb size at three levels with 3.55, 5.5-7, and 7.5-9cm diameters were assigned as sub-plots. The measured traits were number of umbel per unit area, the number of fertilized capsules in umbel, the number of seeds per capsule, 1000 seed weight, seed yield and germination rate.
Results: The results of combined analysis of variance showed that effect of year was only significant on the number of capsules per umbel at p<0.01. The interactions of year× mother bulb diameter and year× planting date× mother bulb diameter were not significant for any of the traits. The traits were not affected by the year. The results showed that the planting date had a significant effect on all traits except for 1000 seed weight, and the first planting date (the end of August) had the highest values in all traits. The highest germination percentage (89.83%) and the highest germination rate (12.8) were obtained on the first planting date, which showed a statistically significant difference with the subsequent planting dates. However, these two traits were not affected by mother bulb diameter treatment. The highest seed yield for onion diameter factor (505.65 kg h-1in the first year and 465.78 kg h-1 in the second year) was associated with mother bulb size of 7.5-9 cm.
Conclusions: The overall result showed that to obtain the highest and most desirable quality of onion seeds of Texas Early Grano 502 cultivar in Friedan of Isfahan, the planting date of the first of September and the size of the mother bulb “between” 7 to 9 cm is recommended.
Highlights:
1- Early planting time (the first of September) increased germination rate.
2- Increasing the mother bulb size increased the onion yield.
Introduction: The selection of optimum planting date for every climate and mother bulb size are important factors affecting the quantity and quality of seed production in different cultivars. This study was performed in Isfahan province, Frieden, during two growing years 2016-2017 to determine the effect of planting time and mother bulb size on the quantity and quality of short-day onion seed varieties Texas Early Grano 502
Materials and Methods: A split-plot experiment was performed in a randomized complete block design with four replications. The main factor was cultivation dates at four levels: the end of August, the first of September, the end of September and the first of October and mother bulb size at three levels with 3.55, 5.5-7, and 7.5-9cm diameters were assigned as sub-plots. The measured traits were number of umbel per unit area, the number of fertilized capsules in umbel, the number of seeds per capsule, 1000 seed weight, seed yield and germination rate.
Results: The results of combined analysis of variance showed that effect of year was only significant on the number of capsules per umbel at p<0.01. The interactions of year× mother bulb diameter and year× planting date× mother bulb diameter were not significant for any of the traits. The traits were not affected by the year. The results showed that the planting date had a significant effect on all traits except for 1000 seed weight, and the first planting date (the end of August) had the highest values in all traits. The highest germination percentage (89.83%) and the highest germination rate (12.8) were obtained on the first planting date, which showed a statistically significant difference with the subsequent planting dates. However, these two traits were not affected by mother bulb diameter treatment. The highest seed yield for onion diameter factor (505.65 kg h-1in the first year and 465.78 kg h-1 in the second year) was associated with mother bulb size of 7.5-9 cm.
Conclusions: The overall result showed that to obtain the highest and most desirable quality of onion seeds of Texas Early Grano 502 cultivar in Friedan of Isfahan, the planting date of the first of September and the size of the mother bulb “between” 7 to 9 cm is recommended.
Highlights:
1- Early planting time (the first of September) increased germination rate.
2- Increasing the mother bulb size increased the onion yield.
Ladan Zinati, Asieh Siahmarguee, Farshid Ghaderi-Far, Masomeh Yones-Abadi, Bhagirath Singh Chauhan,
Volume 10, Issue 1 (9-2023)
Volume 10, Issue 1 (9-2023)
Abstract
Extended Abstract
Introduction: The different species of Amaranthus species are among the most important damaging weeds in the world. Due to the importance of studying the effect of management factors on seed dynamics of different weed species, this experiment aimed to investigate the effect of burial depth and high temperatures on the seed dynamic of different species of Amaranthus in Golestan province including white pigweed (A. albus), prostrate pigweed (A. belitoides), hybrid Amaranthus (A. chlorostachys), redroot pigweed (A. retrofelexus) and green Amaranthus (A. viridis) were performed.
Materials and Methods: This research was conducted on five amaranthus species of white pigweed, prostrate pigweed, hybrid Amaranthus, redroot pigweed, and green Amaranthus at the seed laboratory and greenhouse of Gorgan University of Agricultural Sciences and Natural Resources. In the first experiment, seed emergence of different species of Amaranthus was studied in eight burial depths including 0, 1, 2, 3, 4, 5, 7, and 10 cm. In the second experiment, seeds were exposed to 50, 60, 70, 80, 90, 100, and 110 °C temperatures for 5, 10, and 15 minutes
Results: All seeds of A. blitoides and A. viridis germinated in the topsoil (zero depth); But, in A. albus, A. retroflexus, A. chlorostachys, 93%, 83%, and 3% of the seeds were emergence at the soil surface, respectively. By increasing the burial depth to one centimeter, the percentage of seeds emergence in different species of Amaranthus decreased significantly and was negligible at ≥ 2 cm depth. Germination test performed on retrieved seeds showed that zero to 16% of the seeds were able to germinate in petri dish, and most of the non-germinated seeds were viable. In all species except for A. chlorostachys high temperatures reduced the germination percentage.
Conclusion: Due to the reduction of seed germination percentage of different species of Amaranthus from a depth of more than one centimeter of soil, it seems that the use of conservation and conventional tillage methods has a good potential to reduce infestation of fields by these weeds. Also, although high temperatures reduce weed infestation in fields, they do not have a significant effect on depleting the seed bank of these species.
Highlights:
1- Seed dynamics of different species of Amaranthus were affected by burial depth and high temperature
2- Deep burial of seeds of different species of Amaranthus causes the stability of their seeds in the soil seed bank.
Introduction: The different species of Amaranthus species are among the most important damaging weeds in the world. Due to the importance of studying the effect of management factors on seed dynamics of different weed species, this experiment aimed to investigate the effect of burial depth and high temperatures on the seed dynamic of different species of Amaranthus in Golestan province including white pigweed (A. albus), prostrate pigweed (A. belitoides), hybrid Amaranthus (A. chlorostachys), redroot pigweed (A. retrofelexus) and green Amaranthus (A. viridis) were performed.
Materials and Methods: This research was conducted on five amaranthus species of white pigweed, prostrate pigweed, hybrid Amaranthus, redroot pigweed, and green Amaranthus at the seed laboratory and greenhouse of Gorgan University of Agricultural Sciences and Natural Resources. In the first experiment, seed emergence of different species of Amaranthus was studied in eight burial depths including 0, 1, 2, 3, 4, 5, 7, and 10 cm. In the second experiment, seeds were exposed to 50, 60, 70, 80, 90, 100, and 110 °C temperatures for 5, 10, and 15 minutes
Results: All seeds of A. blitoides and A. viridis germinated in the topsoil (zero depth); But, in A. albus, A. retroflexus, A. chlorostachys, 93%, 83%, and 3% of the seeds were emergence at the soil surface, respectively. By increasing the burial depth to one centimeter, the percentage of seeds emergence in different species of Amaranthus decreased significantly and was negligible at ≥ 2 cm depth. Germination test performed on retrieved seeds showed that zero to 16% of the seeds were able to germinate in petri dish, and most of the non-germinated seeds were viable. In all species except for A. chlorostachys high temperatures reduced the germination percentage.
Conclusion: Due to the reduction of seed germination percentage of different species of Amaranthus from a depth of more than one centimeter of soil, it seems that the use of conservation and conventional tillage methods has a good potential to reduce infestation of fields by these weeds. Also, although high temperatures reduce weed infestation in fields, they do not have a significant effect on depleting the seed bank of these species.
Highlights:
1- Seed dynamics of different species of Amaranthus were affected by burial depth and high temperature
2- Deep burial of seeds of different species of Amaranthus causes the stability of their seeds in the soil seed bank.
Farzaneh Amirikia, Majid Nabipour, Masoumeh Farzaneh,
Volume 10, Issue 1 (9-2023)
Volume 10, Issue 1 (9-2023)
Abstract
Extended Abstract
Introduction: The use of seed priming technology to accelerate the germination and seedling emergence of multi-purpose plants such as halophytes (Alhagi) with the ability to produce medicine and forage under environmental stress conditions or use of saline water (such as seawater of Persian Gulf) has received much attention today. Therefore, the present study was conducted to investigate seed priming methods and different salinity levels on germination, seedling emergence, and some growth responses of Alhagi plant.
Material and Methods: Two separate split-factorial experiments were conducted based on a randomized complete block design with four replications as a petri dish culture (first experiment) and a pot experiment in the field was performed in the Department of Plant Production and Genetics, Faculty of Agriculture, Shahid Chamran University (Ahwaz, Iran) during 2020-21. In both experiments, different levels of salinity (municipal water source with EC=0.96 dS.m-1, 8 and 16 dS.m-1 using seawater of Persian Gulf) were assigned as the main plot, and different methods of seed priming (non-priming, hydro priming, hormonal priming with 50 ppm gibberellin and hydro priming+hormonal priming with 50 ppm gibberellin) and species (A. maurorum and A. graecorum) were assigned as sub-factors.
Results: The results showed the significance of salinity × species × priming interaction on all studied traits. According to the mean comparison results, the highest values of germination percentage, seed vigor index, seedling emergence, plant height, number of branches, total dry matter and stomatal conductance were obtained from a municipal water source with EC=0.96 dS.m-1 and hydro priming+hormonal priming with 50 ppm gibberellin for A. graecorum (29.1, 90.2, 24.0, 32.3, 52.5, 52.1 and 32.4% increase compared to non-priming and control salinity stress on this species, respectively). The output of the fitted logistic model to seedling emergence percentage showed that this model well explained the relationship between seedling emergence of two Alhagi species in responses to salinity and seed priming (R2 adj≥0.98 and RMSE≤3.38). Therefore, in both studied species, the decline in seedling emergence started from the 8 dS/m salinity level. However, at the 16 dS/m salinity level, the slope of increase in seedling emergence percentage was slower per time unit.
Conclusion: To cultivate and exploit the saline coastal lands and also to restore the pastures in the country, A. graecorum species under the combined treatment of hydro priming + hormonal priming with 50 ppm gibberellin are recommended in comparison with other treatment levels.
Highlights:
1- Germination and growth responses of two Iranian Alhagi species and the possibility of production by irrigation of seawater of Persian Gulf were investigated.
2- Seed priming technique was used to accelerate seedling emergence and improve some traits in two Alhagi species.
Introduction: The use of seed priming technology to accelerate the germination and seedling emergence of multi-purpose plants such as halophytes (Alhagi) with the ability to produce medicine and forage under environmental stress conditions or use of saline water (such as seawater of Persian Gulf) has received much attention today. Therefore, the present study was conducted to investigate seed priming methods and different salinity levels on germination, seedling emergence, and some growth responses of Alhagi plant.
Material and Methods: Two separate split-factorial experiments were conducted based on a randomized complete block design with four replications as a petri dish culture (first experiment) and a pot experiment in the field was performed in the Department of Plant Production and Genetics, Faculty of Agriculture, Shahid Chamran University (Ahwaz, Iran) during 2020-21. In both experiments, different levels of salinity (municipal water source with EC=0.96 dS.m-1, 8 and 16 dS.m-1 using seawater of Persian Gulf) were assigned as the main plot, and different methods of seed priming (non-priming, hydro priming, hormonal priming with 50 ppm gibberellin and hydro priming+hormonal priming with 50 ppm gibberellin) and species (A. maurorum and A. graecorum) were assigned as sub-factors.
Results: The results showed the significance of salinity × species × priming interaction on all studied traits. According to the mean comparison results, the highest values of germination percentage, seed vigor index, seedling emergence, plant height, number of branches, total dry matter and stomatal conductance were obtained from a municipal water source with EC=0.96 dS.m-1 and hydro priming+hormonal priming with 50 ppm gibberellin for A. graecorum (29.1, 90.2, 24.0, 32.3, 52.5, 52.1 and 32.4% increase compared to non-priming and control salinity stress on this species, respectively). The output of the fitted logistic model to seedling emergence percentage showed that this model well explained the relationship between seedling emergence of two Alhagi species in responses to salinity and seed priming (R2 adj≥0.98 and RMSE≤3.38). Therefore, in both studied species, the decline in seedling emergence started from the 8 dS/m salinity level. However, at the 16 dS/m salinity level, the slope of increase in seedling emergence percentage was slower per time unit.
Conclusion: To cultivate and exploit the saline coastal lands and also to restore the pastures in the country, A. graecorum species under the combined treatment of hydro priming + hormonal priming with 50 ppm gibberellin are recommended in comparison with other treatment levels.
Highlights:
1- Germination and growth responses of two Iranian Alhagi species and the possibility of production by irrigation of seawater of Persian Gulf were investigated.
2- Seed priming technique was used to accelerate seedling emergence and improve some traits in two Alhagi species.
Mahnaz Kandi, Asa Ebrahimi, Marjan Diyanat, Hamid Saeidian,
Volume 10, Issue 1 (9-2023)
Volume 10, Issue 1 (9-2023)
Abstract
Extended Abstract
Introduction: Weeds are one of the most important problems in agriculture and cause a lot of damage to crops. Overconsumption of herbicides in recent decades has led to harmful impacts on the environment and living organisms, including humans. In order to deal with these problems today, efforts are being made to reduce reliance on artificial herbicides and change direction towards sustainable agriculture as a part of integrated weed management. Among natural compounds, essential oils, which are components of aromatic and medicinal plants, were investigated to discover new herbicides.
Material and Methods: In order to investigate the effects of yarrow essential oil (Achillea wilhelmsii C. Koch) on the germination and growth of purslane (Portulaca oleracea L.) and rye (Secale cereale L.) seedlings, two factorial experiments were conducted in the form of a completely randomized design in three replicates at Islamic Azad University, Science and Research Branch. The first factor was the type of essential oil in two levels (normal and nanoemulsion) and the second factor was the concentration of essential oil in six levels (0, 100, 200, 400, 800, and 1000 µl L-1).
Results and Discussion: Scanning electron microscopy images showed the particles were relatively sperhical and their size varied from 1 to 100 nm. The zeta potential of the nanoparticles was -13.8 mV, indicating particle stability. Both type of essential oils reduced germination percentage, germination rate, plumule length, radicel length and seedling dry weight of both weeds and germination percentage decreased significantly with increasing concentration. At a concentration of 200 µl L-1, purslane treated with essential oil germinated 55.25%, but at the same concentration, the germination percentage of seeds treated with nanoemulsion of essential oil was 30.50%. Nanoemulsion of essential oil at concentration of 800 µl L-1 was able to completely prevent the germination and growth of purslane seedlings. Nanoemulsion of essential oil at a concentration of 1000 µl L-1 completely prevented rye seed germination. Germination rate decreased under treatment of yarrow essential oil and there was no difference between two types of essential oils at concentration of 200 µl L-1, but at a concentration of 800 µl, the germination rate of rye seeds treated with nanoemulsion of essential oil and ordinary essential oil reached to 1.40 and 0.32, respectively which was a significant difference.
Conclusions: The inhibition percentage of the studied traits in both weed species showed that the essential oil nanoemulsion was more effective than the normal essential oil. Yarrow essential oil was more effective on purslane weed compared to rye. Essential oils do not have similar effects on weeds and their inhibitory effects will be different depending on the concentration and species of weeds, and the selectivity of these compounds should be investigated. The production of nano essential oil of yarrow as a natural herbicide is a solution. It offers to control weeds in organic farming systems.
Highlights:
1- Nanoemulsion particles were produced from Yarrow essential oil
2- Nanoemulsion particles had more inhibitory effects on the investigated weeds than the normal essential oil.
Introduction: Weeds are one of the most important problems in agriculture and cause a lot of damage to crops. Overconsumption of herbicides in recent decades has led to harmful impacts on the environment and living organisms, including humans. In order to deal with these problems today, efforts are being made to reduce reliance on artificial herbicides and change direction towards sustainable agriculture as a part of integrated weed management. Among natural compounds, essential oils, which are components of aromatic and medicinal plants, were investigated to discover new herbicides.
Material and Methods: In order to investigate the effects of yarrow essential oil (Achillea wilhelmsii C. Koch) on the germination and growth of purslane (Portulaca oleracea L.) and rye (Secale cereale L.) seedlings, two factorial experiments were conducted in the form of a completely randomized design in three replicates at Islamic Azad University, Science and Research Branch. The first factor was the type of essential oil in two levels (normal and nanoemulsion) and the second factor was the concentration of essential oil in six levels (0, 100, 200, 400, 800, and 1000 µl L-1).
Results and Discussion: Scanning electron microscopy images showed the particles were relatively sperhical and their size varied from 1 to 100 nm. The zeta potential of the nanoparticles was -13.8 mV, indicating particle stability. Both type of essential oils reduced germination percentage, germination rate, plumule length, radicel length and seedling dry weight of both weeds and germination percentage decreased significantly with increasing concentration. At a concentration of 200 µl L-1, purslane treated with essential oil germinated 55.25%, but at the same concentration, the germination percentage of seeds treated with nanoemulsion of essential oil was 30.50%. Nanoemulsion of essential oil at concentration of 800 µl L-1 was able to completely prevent the germination and growth of purslane seedlings. Nanoemulsion of essential oil at a concentration of 1000 µl L-1 completely prevented rye seed germination. Germination rate decreased under treatment of yarrow essential oil and there was no difference between two types of essential oils at concentration of 200 µl L-1, but at a concentration of 800 µl, the germination rate of rye seeds treated with nanoemulsion of essential oil and ordinary essential oil reached to 1.40 and 0.32, respectively which was a significant difference.
Conclusions: The inhibition percentage of the studied traits in both weed species showed that the essential oil nanoemulsion was more effective than the normal essential oil. Yarrow essential oil was more effective on purslane weed compared to rye. Essential oils do not have similar effects on weeds and their inhibitory effects will be different depending on the concentration and species of weeds, and the selectivity of these compounds should be investigated. The production of nano essential oil of yarrow as a natural herbicide is a solution. It offers to control weeds in organic farming systems.
Highlights:
1- Nanoemulsion particles were produced from Yarrow essential oil
2- Nanoemulsion particles had more inhibitory effects on the investigated weeds than the normal essential oil.
Mahboubeh Shahbazi, Jafar Asghari, Behnam Kamkar, Edris Taghvaie Salimi,
Volume 10, Issue 2 (3-2024)
Volume 10, Issue 2 (3-2024)
Abstract
Extended abstract
Introduction: The germination process is one of the most critical stages of a plant's growth and determines the success of the emergence of a weed in an agroecosystem because it is the first stage in which the weed competes for a niche. Various environmental factors, including temperature and moisture, affect the germination of weed seeds. Modeling techniques are capable of predicting germination, seedling emergence, and establishment of weed species. The ability to predict weed germination in response to environmental conditions is very effective for the development of control programs. The experiment was conducted to determine the cardinal temperature and evaluate the best model for quantifying the response of the germination rate of Western ragweed weed seeds under different water stress conditions.
Materials and Methods: A factorial experiment was conducted in the form of a completely randomized design in three replications. The investigated factors include temperature with eight levels (5, 10, 15, 20, 25, 30, 35, and 40 C˚) and water potential with six levels (0, -0.3, -0.6, -0.9, -1.2, and -1.5 MPa) on the germination of Western ragweed. In order to quantify the response of Western ragweed germination rate to temperature, three non-linear Dent-like, Beta, and Segmented regression models were used.
Results: The results showed that the effect of temperature, water potential, and their interactions on maximum germination, germination rate, and time required to reach 10, 50, and 90 percent germination were significant. Also, the results showed that by increasing the temperature from 10 to 25 C˚, the percentage and rate of germination increased whereas by increasing water potential, the percentage and rate of germination decreased. In comparing the models, based on RMSE, R2, CV, and coefficients a and b parameters, the Beta model was the most suitable for estimating the temperatures of cardinal Western ragweed. The base, optimum, and ceiling temperatures using the Beta model were 3.88, 25, and 40 C˚, respectively.
Conclusions: The use of the Beta model to quantify the germination response of Western ragweed seeds to different levels of water potential at different temperatures had acceptable results. Therefore, by using the output of these models at different temperatures, it is possible to predict the germination rate at different potentials.
Highlights:
1- Germination cardinal temperatures and the effect of water potential on western ragweed weed were investigated.
2- Estimation of different models to quantify the response of germination rate to temperature and different water potentials.
Introduction: The germination process is one of the most critical stages of a plant's growth and determines the success of the emergence of a weed in an agroecosystem because it is the first stage in which the weed competes for a niche. Various environmental factors, including temperature and moisture, affect the germination of weed seeds. Modeling techniques are capable of predicting germination, seedling emergence, and establishment of weed species. The ability to predict weed germination in response to environmental conditions is very effective for the development of control programs. The experiment was conducted to determine the cardinal temperature and evaluate the best model for quantifying the response of the germination rate of Western ragweed weed seeds under different water stress conditions.
Materials and Methods: A factorial experiment was conducted in the form of a completely randomized design in three replications. The investigated factors include temperature with eight levels (5, 10, 15, 20, 25, 30, 35, and 40 C˚) and water potential with six levels (0, -0.3, -0.6, -0.9, -1.2, and -1.5 MPa) on the germination of Western ragweed. In order to quantify the response of Western ragweed germination rate to temperature, three non-linear Dent-like, Beta, and Segmented regression models were used.
Results: The results showed that the effect of temperature, water potential, and their interactions on maximum germination, germination rate, and time required to reach 10, 50, and 90 percent germination were significant. Also, the results showed that by increasing the temperature from 10 to 25 C˚, the percentage and rate of germination increased whereas by increasing water potential, the percentage and rate of germination decreased. In comparing the models, based on RMSE, R2, CV, and coefficients a and b parameters, the Beta model was the most suitable for estimating the temperatures of cardinal Western ragweed. The base, optimum, and ceiling temperatures using the Beta model were 3.88, 25, and 40 C˚, respectively.
Conclusions: The use of the Beta model to quantify the germination response of Western ragweed seeds to different levels of water potential at different temperatures had acceptable results. Therefore, by using the output of these models at different temperatures, it is possible to predict the germination rate at different potentials.
Highlights:
1- Germination cardinal temperatures and the effect of water potential on western ragweed weed were investigated.
2- Estimation of different models to quantify the response of germination rate to temperature and different water potentials.
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Seed Science and Technology, Seed Physiology, Seed Ecology, Modeling, Seed Health, Germination Characteristics, Seed Dormancy, Seed Ageing, Seed Storage, Seed PrimingVote
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