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Sajad Mijani, Mehdi Rastgoo, Ali Ghanbari, Mehdi Nassiri Mahallati,
Volume 7, Issue 2 (3-2021)
Volume 7, Issue 2 (3-2021)
Abstract
Extended Abstract
Introduction: Tubers are considered as the most important vegetative organs in reproduction of purple nutsedge, as one of the most troublesome weeds worldwide. Therefore, it is great of importance to investigate the properties of the tuber response to the surrounding environment such as absorption and loss of water. Water uptake is the first step in the sprouting process, though the pattern of water uptake by purple nutsedge tubers has not been documented. Loss of water in tubers is one of the potent factors in reducing their ability to sprouting. Three separate experiments were carried out to investigate the absorption and loss of water content of purple nutsedge tubers.
Material and Methods: In the first experiment, the tubers were placed in a water bath at temperatures of 10, 20, 30, and 40 ° C. Then, the weight of the tubers was measured at different times (24 till 3600 minutes). The water uptake percentage of tubers at different temperatures was studied by fitting the Peleg model. In the second experiment, the initiation day of sprouting was investigated at constant temperatures of 10, 20, 30, and 40 ° C. In the third experiment, water loss and sprouting percentage of tubers were evaluated in two conditions refrigerator (4° C) and room (22 to 25 ° C).
Results: The results showed that the initial water content of tubers was 42% and absorbed 10% extra water after being immersed in water. The water uptake behavior was based on the Peleg model at two stages: (1) rapid uptake (less than 420 minutes (7 hours), and (2) a low uptake with a gentle slope afterward. In the Peleg model, the parameters K1 (minutes *.%weight -1) and K2 (%-1) are water absorption rate and water absorption capacity, respectively. The K1 parameter was negatively against temperature. The highest and lowest values were 49.56 and 28.55 at 10 and 40 ° C, respectively. On the other hand, the trend of the K2 was constant (0.1) at 10-30 °C but was 0.08 at 40 °C. The two-parameter Hyperbola model was superior to the Peleg and predicts the highest water absorption and time to 50 percent water absorption parameters. The results showed that sprouting of purple nutsedge tubers at 10, 20, 30, and 40 °C occurred after 14.44, 6.57, 3.24, and 3.12 days, respectively. Keeping the tubers in the room (22-25 °C) and refrigerator (4 °C), sprouting stopped after 3 and 9 months, respectively. The time required for 50% reduction of sprouting in the room and refrigerator was estimated to be 1.3 months (39 days) and 5.12 months (154 days), respectively. The time required for 50% loss weight of tubers in the room and refrigerator was 1.981 months (59 days) and about 6 months (180 days), respectively. Overall, weight loss (water loss) up 11.85%, resulted in 50% reduction in tuber sprouting.
Conclusion: Maximum water uptake in tubers occurred in less than 420 minutes (seven hours) at all temperatures. Slow sprouting in tubers at low temperatures is not associated with an obstacle in water absorption. Tubers lost half of their sprouting ability by losing water about 12%. On the other hand, the results show that the tubers at cool temperatures (4 °C) lose their water and sprouting capacity less than the ambient temperature (22 to 25 °C).
Highlights:
1- Determination of water absorption pattern on purple nutsedge tubers.
2- Effect of storage location in reducing water and sprouting ability of purple nutsedge tubers.
Introduction: Tubers are considered as the most important vegetative organs in reproduction of purple nutsedge, as one of the most troublesome weeds worldwide. Therefore, it is great of importance to investigate the properties of the tuber response to the surrounding environment such as absorption and loss of water. Water uptake is the first step in the sprouting process, though the pattern of water uptake by purple nutsedge tubers has not been documented. Loss of water in tubers is one of the potent factors in reducing their ability to sprouting. Three separate experiments were carried out to investigate the absorption and loss of water content of purple nutsedge tubers.
Material and Methods: In the first experiment, the tubers were placed in a water bath at temperatures of 10, 20, 30, and 40 ° C. Then, the weight of the tubers was measured at different times (24 till 3600 minutes). The water uptake percentage of tubers at different temperatures was studied by fitting the Peleg model. In the second experiment, the initiation day of sprouting was investigated at constant temperatures of 10, 20, 30, and 40 ° C. In the third experiment, water loss and sprouting percentage of tubers were evaluated in two conditions refrigerator (4° C) and room (22 to 25 ° C).
Results: The results showed that the initial water content of tubers was 42% and absorbed 10% extra water after being immersed in water. The water uptake behavior was based on the Peleg model at two stages: (1) rapid uptake (less than 420 minutes (7 hours), and (2) a low uptake with a gentle slope afterward. In the Peleg model, the parameters K1 (minutes *.%weight -1) and K2 (%-1) are water absorption rate and water absorption capacity, respectively. The K1 parameter was negatively against temperature. The highest and lowest values were 49.56 and 28.55 at 10 and 40 ° C, respectively. On the other hand, the trend of the K2 was constant (0.1) at 10-30 °C but was 0.08 at 40 °C. The two-parameter Hyperbola model was superior to the Peleg and predicts the highest water absorption and time to 50 percent water absorption parameters. The results showed that sprouting of purple nutsedge tubers at 10, 20, 30, and 40 °C occurred after 14.44, 6.57, 3.24, and 3.12 days, respectively. Keeping the tubers in the room (22-25 °C) and refrigerator (4 °C), sprouting stopped after 3 and 9 months, respectively. The time required for 50% reduction of sprouting in the room and refrigerator was estimated to be 1.3 months (39 days) and 5.12 months (154 days), respectively. The time required for 50% loss weight of tubers in the room and refrigerator was 1.981 months (59 days) and about 6 months (180 days), respectively. Overall, weight loss (water loss) up 11.85%, resulted in 50% reduction in tuber sprouting.
Conclusion: Maximum water uptake in tubers occurred in less than 420 minutes (seven hours) at all temperatures. Slow sprouting in tubers at low temperatures is not associated with an obstacle in water absorption. Tubers lost half of their sprouting ability by losing water about 12%. On the other hand, the results show that the tubers at cool temperatures (4 °C) lose their water and sprouting capacity less than the ambient temperature (22 to 25 °C).
Highlights:
1- Determination of water absorption pattern on purple nutsedge tubers.
2- Effect of storage location in reducing water and sprouting ability of purple nutsedge tubers.
Sajad Mijani, Mehdi Rastgoo, Ali Ghanbari, Mehdi Nassiri Mahallati,
Volume 8, Issue 1 (9-2021)
Volume 8, Issue 1 (9-2021)
Abstract
Extended abstract
Introduction: Purple nutsedge (Cyperus rotundus L.) is one of the problematic weeds worldwide prevalent in tropical and subtropical regions. Tubers are major tools through which purple nutsedge is propagated, whereas its seeds have a low ability to germinate. Therefore, evaluation of the response of tubers against environmental agents is great of importance to know the germination and emergence time. Germination, in turn, is mostly affected by temperature, among other environmental factors. Various models that are recognized as the Thermal Time model have been introduced to describe the seed germination pattern against temperature. Since predicting the emergence of reproductive organs through the modeling is great of importance for improving the control strategies; the present study was carried out to investigate the response of tuber sprouting of purple nutsedge (Cyperus rotundus) against temperature using thermal time models.
Material and methods: The experiment was carried out as a randomized complete block design with three replications in a germinator. Each replicate was placed on a separate shelf. For each replicate, 15 tubers were placed inside a 20 cm Petri dish on a filter paper and then 100 ml of water was added. The experiment was performed separately for constant temperatures of 10, 15, 20, 25, 30, 35, and 40 °C in absolute darkness. To analyze the data as modeling, five thermal time models were evaluated based on the statistical distributions of normal, Weibull, Gumble, logistic and log logistic. Indices such as R2, RMSE, RMSE%, and AICc were used to evaluate the models.
Results: The results showed that all models predicted the germination response of purple nutsedge tuber with high accuracy (R2 = 0.95). A comparison of models based on AICc values showed significant superiority of the Gumble model over other models. According to this index, there was no difference between logistic and log logistic models with normal. Among the models, Weibull was identified as the most inappropriate model. Different models estimated the final germination (Gmax) between 0.93 to 0.94 (93 to 94%). The base temperature was estimated through different models from 7.10 to 7.47 °C. Among the models, the model based on the Gumble distribution proved the skew to the right of the thermal time and Tm. According to the Gumble model, the thermal time parameters required to reach 50% germination (θT (50)) equals 123.8 ° C day and the maximum temperature for germination at 50% probability (Tc (50)) was estimated to be 46.10 ° C.
Conclusion: the thermal time model based on the Gumble probability distribution was most plausible among the models. Also, a distributed right skewness related to the thermal time and Tm was proved through the Gumble model. The parameters obtained from the Gumble model can be used to predict the sprouting of purple nutsedge tubers.
Highlights:
Introduction: Purple nutsedge (Cyperus rotundus L.) is one of the problematic weeds worldwide prevalent in tropical and subtropical regions. Tubers are major tools through which purple nutsedge is propagated, whereas its seeds have a low ability to germinate. Therefore, evaluation of the response of tubers against environmental agents is great of importance to know the germination and emergence time. Germination, in turn, is mostly affected by temperature, among other environmental factors. Various models that are recognized as the Thermal Time model have been introduced to describe the seed germination pattern against temperature. Since predicting the emergence of reproductive organs through the modeling is great of importance for improving the control strategies; the present study was carried out to investigate the response of tuber sprouting of purple nutsedge (Cyperus rotundus) against temperature using thermal time models.
Material and methods: The experiment was carried out as a randomized complete block design with three replications in a germinator. Each replicate was placed on a separate shelf. For each replicate, 15 tubers were placed inside a 20 cm Petri dish on a filter paper and then 100 ml of water was added. The experiment was performed separately for constant temperatures of 10, 15, 20, 25, 30, 35, and 40 °C in absolute darkness. To analyze the data as modeling, five thermal time models were evaluated based on the statistical distributions of normal, Weibull, Gumble, logistic and log logistic. Indices such as R2, RMSE, RMSE%, and AICc were used to evaluate the models.
Results: The results showed that all models predicted the germination response of purple nutsedge tuber with high accuracy (R2 = 0.95). A comparison of models based on AICc values showed significant superiority of the Gumble model over other models. According to this index, there was no difference between logistic and log logistic models with normal. Among the models, Weibull was identified as the most inappropriate model. Different models estimated the final germination (Gmax) between 0.93 to 0.94 (93 to 94%). The base temperature was estimated through different models from 7.10 to 7.47 °C. Among the models, the model based on the Gumble distribution proved the skew to the right of the thermal time and Tm. According to the Gumble model, the thermal time parameters required to reach 50% germination (θT (50)) equals 123.8 ° C day and the maximum temperature for germination at 50% probability (Tc (50)) was estimated to be 46.10 ° C.
Conclusion: the thermal time model based on the Gumble probability distribution was most plausible among the models. Also, a distributed right skewness related to the thermal time and Tm was proved through the Gumble model. The parameters obtained from the Gumble model can be used to predict the sprouting of purple nutsedge tubers.
Highlights:
- Thermal time models were evaluated for prediction of tuber sprouting of purple nutsedge.
- The thermal time model based on the Gumble distribution was superior over the normal distribution.
- Thermal time and Tm for tuber sprouting of purple nutsedge were distributed as right skewness.
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.
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
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.
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.
Mohammad Mohammadi, Reza Tavakol Afshari, Jafar Nabati, Ehsan Oskoueian,
Volume 9, Issue 2 (3-2023)
Volume 9, Issue 2 (3-2023)
Abstract
Extended Abstract
Introduction: One of the major reasons behind the unstable yield of chickpea, is the simultaneity of the reproductive stage with drought and late-season heat. Autumn sowing of chickpea is among the suitable approaches to improve chickpea yield. On the other hand, freezing stress is a limiting factor in the autumn sowing of chickpea. Recently, seed priming has been developed as an essential method to induce plant tolerance to environmental stress. The priming will result in a rapid response of the plant to stress. Freezing, as an environmental stress, limits the growth and development of many plants in different parts of the world. Studies show that in addition to acclimation, short-term biotic and abiotic stresses as pretreatment could also increase the plant's tolerance to cold stress. This process alters the freezing response positively.
Material and Methods: This experiment was conducted as a factorial in a completely randomized design with three replicates at the greenhouse of the Research Center for Plant Sciences of Ferdowsi University, Mashhad Iran, in 2018. The experimental factors consisted of various temperatures (0, -12, -15, and -17 °C), seed priming at 10 levels (control (without priming), hydropriming, priming with sodium chloride, salicylic acid, sodium nitroprusside, phosphate solubilizing bacteria and potassium solubilizing bacteria, amino acids, potassium nitrate, and zinc sulfate) and different chickpea genotypes (MCC505, ILC8617, MCC495, and Saral cultivar). In this experiment, the measured parameters included survival percentage, electrolyte leakage percentage, and lethal temperature resulting in 50% mortality according to the electrolyte leakage and survival percentage.
Results: The results showed that the application of hydropriming, priming with sodium nitroprusside and zinc sulfate had favorable effects on the survival rate and electrolyte leakage. Among these, priming with sodium nitroprusside increased the survival percentage compared to the control (23%) at the -15 and -17 °C in the Saral cultivar, at -15 °C in the ILC8617 genotype, and at -12 and -15 °C in the MCC495 genotype treatment to 68, 58, 85 and 55 percent, respectively. In addition, this treatment reduced the electrolyte leakage by 13% at -15 °C in the ILC8617 genotype compared to the control treatment. Further, the mentioned treatment resulted in a 40% reduction in lethal temperature resulting in 50% mortality according to the survival percentage. In the MCC495 genotype compared to the control treatment.
Conclusion: Overall, the cold stress in the chickpea plants resulted in an increase in electrolyte leakage and a decrease in the survival percentage. Application of sodium nitroprusside priming by improving cold stress tolerance resulted in a reduction of lethal temperature resulting in 50% mortality based on electrolyte leakage and survival percentage results. Additionally, the applied priming in improving the cold stress tolerance mainly improved the survival percentage compared to the improvement in the electrolyte leakage.
Highlights:
Introduction: One of the major reasons behind the unstable yield of chickpea, is the simultaneity of the reproductive stage with drought and late-season heat. Autumn sowing of chickpea is among the suitable approaches to improve chickpea yield. On the other hand, freezing stress is a limiting factor in the autumn sowing of chickpea. Recently, seed priming has been developed as an essential method to induce plant tolerance to environmental stress. The priming will result in a rapid response of the plant to stress. Freezing, as an environmental stress, limits the growth and development of many plants in different parts of the world. Studies show that in addition to acclimation, short-term biotic and abiotic stresses as pretreatment could also increase the plant's tolerance to cold stress. This process alters the freezing response positively.
Material and Methods: This experiment was conducted as a factorial in a completely randomized design with three replicates at the greenhouse of the Research Center for Plant Sciences of Ferdowsi University, Mashhad Iran, in 2018. The experimental factors consisted of various temperatures (0, -12, -15, and -17 °C), seed priming at 10 levels (control (without priming), hydropriming, priming with sodium chloride, salicylic acid, sodium nitroprusside, phosphate solubilizing bacteria and potassium solubilizing bacteria, amino acids, potassium nitrate, and zinc sulfate) and different chickpea genotypes (MCC505, ILC8617, MCC495, and Saral cultivar). In this experiment, the measured parameters included survival percentage, electrolyte leakage percentage, and lethal temperature resulting in 50% mortality according to the electrolyte leakage and survival percentage.
Results: The results showed that the application of hydropriming, priming with sodium nitroprusside and zinc sulfate had favorable effects on the survival rate and electrolyte leakage. Among these, priming with sodium nitroprusside increased the survival percentage compared to the control (23%) at the -15 and -17 °C in the Saral cultivar, at -15 °C in the ILC8617 genotype, and at -12 and -15 °C in the MCC495 genotype treatment to 68, 58, 85 and 55 percent, respectively. In addition, this treatment reduced the electrolyte leakage by 13% at -15 °C in the ILC8617 genotype compared to the control treatment. Further, the mentioned treatment resulted in a 40% reduction in lethal temperature resulting in 50% mortality according to the survival percentage. In the MCC495 genotype compared to the control treatment.
Conclusion: Overall, the cold stress in the chickpea plants resulted in an increase in electrolyte leakage and a decrease in the survival percentage. Application of sodium nitroprusside priming by improving cold stress tolerance resulted in a reduction of lethal temperature resulting in 50% mortality based on electrolyte leakage and survival percentage results. Additionally, the applied priming in improving the cold stress tolerance mainly improved the survival percentage compared to the improvement in the electrolyte leakage.
Highlights:
- The effect of different primings on the freezing tolerance of chickpeas was investigated and determined.
- The freezing tolerance threshold of chickpea seedlings was determined at the laboratory under different primings.
- The respondents of genotypes to priming and the behavior of genotypes towards each other were investigated.
Mansoor Barahouei, Seyyed Gholamreza Moosavi, Mohamad Javad Seghatoleslami, Reza Baradaran, Seyyed Mahdi Javadzadeh,
Volume 9, Issue 2 (3-2023)
Volume 9, Issue 2 (3-2023)
Abstract
Extended Abstract
Introduction: Safflower is a plant that has been considered due to its high medicinal and nutritional value, especially in the extraction of edible oils in developed countries. Drought is one of the most important harmful factors in arid and semi-arid regions of the world that affects plant production. Modifiers play an important role in plant adaptation to stress conditions. Among these compounds are the hormone gibberellic acid and the antioxidant ascorbic acid, which increase plant tolerance to adverse environmental conditions. The present study investigated the effect of gibberellic acid and ascorbic acid on seed germination parameters and some enzymatic indices of safflower under drought stress.
Materials and Methods: The experiment was conducted as a factorial based on a completely randomized design with three replications in the Agricultural Science Laboratory of Iranshahr University in 2020. Experimental treatments included three levels of control (pretreatment with distilled water), pretreatment with gibberellic acid and ascorbic acid, and four levels of drought stress (0, -3, -6, and -9 bar). Drought stress was applied using polyethylene glycol 6000. Seed germination was carried out inside a germinator at 25 ° C for 14 days in darkness. Germination traits and enzymatic indices were measured using standard methods.
Results: The results of variance showed that most germination and growth indices of safflower seedlings decreased with increasing drought stress. Also, drought stress led to changes in the activity of antioxidant enzymes. Seed priming with gibberellic acid and ascorbic acid increased germination indices and seedling growth and improved enzymatic activity, including catalase, peroxidase, and superoxide dismutase in comparison with untreated seeds. Priming with gibberellic acid had a significant advantage. Seed priming in drought stress conditions has increased germination rate, protein content, and catalase, peroxidase, and ascorbic dismutase activity, respectively, compared to the control.
Conclusion: In general, seed priming of safflower using gibberellic acid changed the activity of antioxidant enzymes. These activities ultimately moderated the negative effects of drought stress and increased germination parameters.
Highlights:
Introduction: Safflower is a plant that has been considered due to its high medicinal and nutritional value, especially in the extraction of edible oils in developed countries. Drought is one of the most important harmful factors in arid and semi-arid regions of the world that affects plant production. Modifiers play an important role in plant adaptation to stress conditions. Among these compounds are the hormone gibberellic acid and the antioxidant ascorbic acid, which increase plant tolerance to adverse environmental conditions. The present study investigated the effect of gibberellic acid and ascorbic acid on seed germination parameters and some enzymatic indices of safflower under drought stress.
Materials and Methods: The experiment was conducted as a factorial based on a completely randomized design with three replications in the Agricultural Science Laboratory of Iranshahr University in 2020. Experimental treatments included three levels of control (pretreatment with distilled water), pretreatment with gibberellic acid and ascorbic acid, and four levels of drought stress (0, -3, -6, and -9 bar). Drought stress was applied using polyethylene glycol 6000. Seed germination was carried out inside a germinator at 25 ° C for 14 days in darkness. Germination traits and enzymatic indices were measured using standard methods.
Results: The results of variance showed that most germination and growth indices of safflower seedlings decreased with increasing drought stress. Also, drought stress led to changes in the activity of antioxidant enzymes. Seed priming with gibberellic acid and ascorbic acid increased germination indices and seedling growth and improved enzymatic activity, including catalase, peroxidase, and superoxide dismutase in comparison with untreated seeds. Priming with gibberellic acid had a significant advantage. Seed priming in drought stress conditions has increased germination rate, protein content, and catalase, peroxidase, and ascorbic dismutase activity, respectively, compared to the control.
Conclusion: In general, seed priming of safflower using gibberellic acid changed the activity of antioxidant enzymes. These activities ultimately moderated the negative effects of drought stress and increased germination parameters.
Highlights:
- The role of gibberellic acid and ascorbic acid on safflower seed germination traits was investigated.
Fatemeh Ghorbannezhad, Mohsen Zavareh, Farzad Sharifzadeh,
Volume 10, Issue 1 (9-2023)
Volume 10, Issue 1 (9-2023)
Abstract
Extended abstract
Introduction: Linseed (Linum usitatissimum L.) is a multipurpose crop and is cultivated to obtain oil, fiber, and seeds. Under optimal moisture conditions, the temperature is considered an environmental factor affecting the germination of this crop. Hence, knowing the cardinal temperatures can help farmers to predict the successful germination, emergence, and even yield of linseed and help scientists to develop new cultivars that are more tolerant to high temperatures. Therefore, this study was performed to determine the temperature range and the cardinal temperatures of germination in two linseed genotypes.
Material and methods: The germination response of two linseed genotypes (Golchin genotype and Line 286) to nine temperatures (3, 5, 10, 15, 20, 25, 30, 35, and 40 Celsius degrees) was quantified in a CRD based split-plot experiment with four replications. For this purpose, three nonlinear regression models (beta, segmented, and dent-like) were used to fit to the data and select the superior model. The superior model was selected using the Akaike information index (AIC), the modified Akaike index (AICc), and ∆i.
Results: Findings showed that the beta model had the best performance in estimating the line 286 cardinal temperatures according to its lower AIC (-3.96), AICc (-89.61), and ∆i (0). Accordingly, the base, optimum, and maximum temperature as well as the number of biological hours estimated by this model for Line 286 were 7.18, 24.22, 40.16 Celsius degrees, and 19.25 hours, respectively. In the Golchin genotype, the beta model with the lowest AIC=-3.89 and AICc= -89.083 fitted better compared with the other models. Nonetheless, considering ∆i for beta which was respectively 0, 1.61, and 4.49 for beta, segmented, and dent-like models, Beta and segmented models had a similar accuracy in estimation of cardinal temperatures for Golchin genotype. These findings represent that the suitable temperature range for germination of the Golchin genotype is 3.8- 23.85 Celsius degrees and the range of biological hours to 50% of germination varied from 16.42 to 19.77 hours.
Conclusion: Overall, according to the results of this study, it is possible to predict the time to germination under optimal moisture conditions using the beta model for Line 286 and one of the two beta and segmented models for the Golchin genotype.
Highlights:
1. A suitable model was developed for a suitable prediction of the seed germination percentage of two linseed genotypes (Golchin genotype and Line 286).
2. The cardinal temperatures for two linseed genotypes (Golchin genotype and Line 286) were determined.
Introduction: Linseed (Linum usitatissimum L.) is a multipurpose crop and is cultivated to obtain oil, fiber, and seeds. Under optimal moisture conditions, the temperature is considered an environmental factor affecting the germination of this crop. Hence, knowing the cardinal temperatures can help farmers to predict the successful germination, emergence, and even yield of linseed and help scientists to develop new cultivars that are more tolerant to high temperatures. Therefore, this study was performed to determine the temperature range and the cardinal temperatures of germination in two linseed genotypes.
Material and methods: The germination response of two linseed genotypes (Golchin genotype and Line 286) to nine temperatures (3, 5, 10, 15, 20, 25, 30, 35, and 40 Celsius degrees) was quantified in a CRD based split-plot experiment with four replications. For this purpose, three nonlinear regression models (beta, segmented, and dent-like) were used to fit to the data and select the superior model. The superior model was selected using the Akaike information index (AIC), the modified Akaike index (AICc), and ∆i.
Results: Findings showed that the beta model had the best performance in estimating the line 286 cardinal temperatures according to its lower AIC (-3.96), AICc (-89.61), and ∆i (0). Accordingly, the base, optimum, and maximum temperature as well as the number of biological hours estimated by this model for Line 286 were 7.18, 24.22, 40.16 Celsius degrees, and 19.25 hours, respectively. In the Golchin genotype, the beta model with the lowest AIC=-3.89 and AICc= -89.083 fitted better compared with the other models. Nonetheless, considering ∆i for beta which was respectively 0, 1.61, and 4.49 for beta, segmented, and dent-like models, Beta and segmented models had a similar accuracy in estimation of cardinal temperatures for Golchin genotype. These findings represent that the suitable temperature range for germination of the Golchin genotype is 3.8- 23.85 Celsius degrees and the range of biological hours to 50% of germination varied from 16.42 to 19.77 hours.
Conclusion: Overall, according to the results of this study, it is possible to predict the time to germination under optimal moisture conditions using the beta model for Line 286 and one of the two beta and segmented models for the Golchin genotype.
Highlights:
1. A suitable model was developed for a suitable prediction of the seed germination percentage of two linseed genotypes (Golchin genotype and Line 286).
2. The cardinal temperatures for two linseed genotypes (Golchin genotype and Line 286) were determined.
Hemmatollah Pirdashti, Yasser Yaghoubian, Zahra Nouri Akandi, Mehranoosh Emamian Tabarestani, Seyed Yaser Ashrafi, Faezeh Vadipour,
Volume 10, Issue 1 (9-2023)
Volume 10, Issue 1 (9-2023)
Abstract
Extended abstract
Introduction: Seed germination and emergence are the most sensitive stages of growth and development of rice plants. In this regard, the use of growth-promoting fungi in the form of seed biological pretreatment (bio-priming) for germination and optimal growth of seedlings can be feasible. Therefore, this study aimed to investigate the effect of isolated root symbiotic fungi on the improvement of germination and growth components of two traditional and bred rice (Oryza sativa L.) cultivars.
Materials and Methods: This experiment was done as a factorial-based completely randomized design with three replicates at Sari Agricultural Sciences and Natural Resources University in the summer of 2021. Experimental treatments included 22 isolates of root symbiotic fungi (isolated and identified from previous experiments) and control (without inoculation) and two native (Hashemi) and bred (Roshan) rice cultivars. After the end of the germination period, the number of normal seedlings was counted and five normal seedlings were randomly selected to measure the length of the root, stem, and seedling as well as the fresh and dry weight of the root, stem, and seedling.
Results: Based on the results of cluster analysis the fungi were divided into four and three groups in Roshan and Hashemi cultivars, respectively. In both cultivars, group I was selected as the best group. In this group, the highest positive effect on vegetative traits varied from 5 to 59% compared to the control in fungal treatments was related to Bjerkandera adusta (ST1), Trichoderma atroviride (SF1), Monosporascus cannonballus (B3) and Trichoderma atroviride (SN1) in Roshan cultivar and Bjerkand adusta (ST1) in Hashemi cultivar. The best fungal treatments in germination traits of Roshan and Hashemi cultivars were Chaetomium globosum (SE2) and Bjerkandera adusta (ST1), respectively.
Conclusions: Overall, the results indicated the positive effect of most symbiotic fungi on the growth and germination characteristics of rice in both Roshan and Hashemi cultivars. These results show that symbiotic fungi use different mechanisms to increase growth and improve germination indicators in plants.
Highlights:
1- Growth-promoting fungi in the form of seed biological pretreatment were used (bio-priming) for optimal growth and germination and of rice seedlings.
2- The effect of native fungi isolated was investigated for the first time in two native (Hashemi) and bred (Roshan) rice cultivars.
Introduction: Seed germination and emergence are the most sensitive stages of growth and development of rice plants. In this regard, the use of growth-promoting fungi in the form of seed biological pretreatment (bio-priming) for germination and optimal growth of seedlings can be feasible. Therefore, this study aimed to investigate the effect of isolated root symbiotic fungi on the improvement of germination and growth components of two traditional and bred rice (Oryza sativa L.) cultivars.
Materials and Methods: This experiment was done as a factorial-based completely randomized design with three replicates at Sari Agricultural Sciences and Natural Resources University in the summer of 2021. Experimental treatments included 22 isolates of root symbiotic fungi (isolated and identified from previous experiments) and control (without inoculation) and two native (Hashemi) and bred (Roshan) rice cultivars. After the end of the germination period, the number of normal seedlings was counted and five normal seedlings were randomly selected to measure the length of the root, stem, and seedling as well as the fresh and dry weight of the root, stem, and seedling.
Results: Based on the results of cluster analysis the fungi were divided into four and three groups in Roshan and Hashemi cultivars, respectively. In both cultivars, group I was selected as the best group. In this group, the highest positive effect on vegetative traits varied from 5 to 59% compared to the control in fungal treatments was related to Bjerkandera adusta (ST1), Trichoderma atroviride (SF1), Monosporascus cannonballus (B3) and Trichoderma atroviride (SN1) in Roshan cultivar and Bjerkand adusta (ST1) in Hashemi cultivar. The best fungal treatments in germination traits of Roshan and Hashemi cultivars were Chaetomium globosum (SE2) and Bjerkandera adusta (ST1), respectively.
Conclusions: Overall, the results indicated the positive effect of most symbiotic fungi on the growth and germination characteristics of rice in both Roshan and Hashemi cultivars. These results show that symbiotic fungi use different mechanisms to increase growth and improve germination indicators in plants.
Highlights:
1- Growth-promoting fungi in the form of seed biological pretreatment were used (bio-priming) for optimal growth and germination and of rice seedlings.
2- The effect of native fungi isolated was investigated for the first time in two native (Hashemi) and bred (Roshan) rice cultivars.
Farzad Delfan, Feizollah Shahbazi, Hamidreza Esvand,
Volume 10, Issue 2 (2-2024)
Volume 10, Issue 2 (2-2024)
Abstract
Extended abstract
Introduction: The seeds of agricultural products are constantly subjected to impact forces from machines from the moment they are harvested to the time they are transferred into storage. Improper design and performance of machines in each of these stages can cause mechanical damage to seeds. Mechanical damage caused by free fall on the seed of agricultural products, which occurs during different stages of harvesting, transportation and other processes, causes a decrease in their quality and an increase in waste. This study aimed to evaluate the amount of mechanical damage caused to chickpea seeds due to the impact of free fall.
Materials and methods: The experiment was conducted as a factorial in the form of a completely randomized design with three replications. The factors included drop height (3, 6, 9 and 12 m), the contact surface (concrete, plywood, metal (iron) and seed-on-seed) and seed moisture content (10, 15, 20 and 25 %). The studied traits or the amount of damage to the seeds included the measurement of seed deterioration by the accelerated aging method (loss in germination percentage in the accelerated aging test) and the measurement of electrical conductivity.
Results: The results of the analysis of variance showed that all three factors (drop height, the contact surface and moisture content) had significant effects at p<0.01 on the loss in germination percentage in the accelerated aging test and changes in electrical conductivity of chickpea seeds. In terms of loss in germination percentage, the highest damage to seeds occurred in the metal contact (41.96%) and the least in the seed-on-seed treatments(29.71%). Also, the highest amount of electrical conductivity was related to the seeds dropped on the metal (36.09 μS cm-1g-1) and the lowest was related to seed-on-seed contact (21.68 μS cm-1g-1). As the drop height rose from 3 to 12 m, the loss in germination and electrical conductivity of seeds increased from 27.74 to 48.08% and from 18.72 to 40.47 μS cm-1g-1, respectively. Increasing the moisture content of chickpea seeds from 10 to 25% causes a decrease in the amount of damage to the seeds in terms of electrical conductivity (from 38.40 to 21.18 μS cm-1g-1). However, the damage was in the form of loss in germination percentage during the accelerated aging test (from 29.22 to 42.88 %).
Conclusion: The findings of this study revealed that the movement of chickpea seeds and the subsequent free fall had a notable impact on their latent damage, leading to a decrease in germination rate and alterations in electrical conductivity. Therefore, it is recommended to minimize fall height and prevent seeds from hitting hard surfaces during seed processing and transportation to mitigate the damage.
Highlights:
Introduction: The seeds of agricultural products are constantly subjected to impact forces from machines from the moment they are harvested to the time they are transferred into storage. Improper design and performance of machines in each of these stages can cause mechanical damage to seeds. Mechanical damage caused by free fall on the seed of agricultural products, which occurs during different stages of harvesting, transportation and other processes, causes a decrease in their quality and an increase in waste. This study aimed to evaluate the amount of mechanical damage caused to chickpea seeds due to the impact of free fall.
Materials and methods: The experiment was conducted as a factorial in the form of a completely randomized design with three replications. The factors included drop height (3, 6, 9 and 12 m), the contact surface (concrete, plywood, metal (iron) and seed-on-seed) and seed moisture content (10, 15, 20 and 25 %). The studied traits or the amount of damage to the seeds included the measurement of seed deterioration by the accelerated aging method (loss in germination percentage in the accelerated aging test) and the measurement of electrical conductivity.
Results: The results of the analysis of variance showed that all three factors (drop height, the contact surface and moisture content) had significant effects at p<0.01 on the loss in germination percentage in the accelerated aging test and changes in electrical conductivity of chickpea seeds. In terms of loss in germination percentage, the highest damage to seeds occurred in the metal contact (41.96%) and the least in the seed-on-seed treatments(29.71%). Also, the highest amount of electrical conductivity was related to the seeds dropped on the metal (36.09 μS cm-1g-1) and the lowest was related to seed-on-seed contact (21.68 μS cm-1g-1). As the drop height rose from 3 to 12 m, the loss in germination and electrical conductivity of seeds increased from 27.74 to 48.08% and from 18.72 to 40.47 μS cm-1g-1, respectively. Increasing the moisture content of chickpea seeds from 10 to 25% causes a decrease in the amount of damage to the seeds in terms of electrical conductivity (from 38.40 to 21.18 μS cm-1g-1). However, the damage was in the form of loss in germination percentage during the accelerated aging test (from 29.22 to 42.88 %).
Conclusion: The findings of this study revealed that the movement of chickpea seeds and the subsequent free fall had a notable impact on their latent damage, leading to a decrease in germination rate and alterations in electrical conductivity. Therefore, it is recommended to minimize fall height and prevent seeds from hitting hard surfaces during seed processing and transportation to mitigate the damage.
Highlights:
- Seed deterioration tests using accelerated aging and electrical conductivity can be used as appropriate criteria to measure the mechanical damage to chickpea seeds.
- When designing machines that come into contact with the seeds, it is important to choose surfaces made of soft materials to minimize the destructive effects of the seeds falling from greater heights.
- The moisture content during the processing and transportation of the seeds should be at an optimal level of around 15%.
Farshid Ghaderi-Far, Majid Azimmohseni, Seyed Hamidreza Bagheri,
Volume 10, Issue 2 (2-2024)
Volume 10, Issue 2 (2-2024)
Abstract
Extended abstract
Introduction: In seed research, germination percentage data is the result of counting and has a binomial distribution. Therefore, seed researchers use data transformation, especially square root transformation, to stabilize the variance and normalize the data before performing analysis of variance and comparison of treatments. Despite the use of data transformation, this method has fundamental issues in the structure that misleads the test results. Therefore, it is important to introduce and replace a method that preserves the research assumptions and provides acceptable results for researchers without using data transformation. The use of generalized linear model is an alternative method for analyzing germination data with binomial distribution. In this research, the generalized linear model will be introduced first. Then, the efficiency of this method will be illustrated using simulated and actual germination data.
Materials and Methods: In this research, first the simulated data was generated by the Monte Carlo method. Based on the simulated data, the significance level and the power of test of generalized linear model were computed. Then the actual data related to three experiments including the effect of acidity on germination of wheat varieties, the effect of water stress and salinity on germination of yellow sweet clover seeds, and the effect of alternating temperatures on germination of three lavender populations were used and the results of the generalized linear model were compared with the square root transformation method based on the data of three experiments.
Results: The simulation results showed that the generalized linear model has a high efficiency to preserve the predetermined significance level and a high power in detecting significant differences in germination of the treatments. Moreover, the results of the comparison of the generalized linear model with the square root transformation method illustrated that the generalized linear model had a higher capability to detect significant differences between various treatments, especially in the treatments with unequal seeds in the Petri dish, and in the treatments in which the square root transformation method resulted in no significant difference among treatments, the generalized linear method showed a significant difference.
Conclusions: Generally, the results of this research demonstrated that the generalized linear model can be used as an alternative method to square root transformation in studies on the germination percentage of seeds with binomial distribution, without having the problems of the square root transformation method. Moreover, this model outperforms the square root transformation in detecting significant differences in germination of treatments with fixed and different seeds.
Highlights:
Introduction: In seed research, germination percentage data is the result of counting and has a binomial distribution. Therefore, seed researchers use data transformation, especially square root transformation, to stabilize the variance and normalize the data before performing analysis of variance and comparison of treatments. Despite the use of data transformation, this method has fundamental issues in the structure that misleads the test results. Therefore, it is important to introduce and replace a method that preserves the research assumptions and provides acceptable results for researchers without using data transformation. The use of generalized linear model is an alternative method for analyzing germination data with binomial distribution. In this research, the generalized linear model will be introduced first. Then, the efficiency of this method will be illustrated using simulated and actual germination data.
Materials and Methods: In this research, first the simulated data was generated by the Monte Carlo method. Based on the simulated data, the significance level and the power of test of generalized linear model were computed. Then the actual data related to three experiments including the effect of acidity on germination of wheat varieties, the effect of water stress and salinity on germination of yellow sweet clover seeds, and the effect of alternating temperatures on germination of three lavender populations were used and the results of the generalized linear model were compared with the square root transformation method based on the data of three experiments.
Results: The simulation results showed that the generalized linear model has a high efficiency to preserve the predetermined significance level and a high power in detecting significant differences in germination of the treatments. Moreover, the results of the comparison of the generalized linear model with the square root transformation method illustrated that the generalized linear model had a higher capability to detect significant differences between various treatments, especially in the treatments with unequal seeds in the Petri dish, and in the treatments in which the square root transformation method resulted in no significant difference among treatments, the generalized linear method showed a significant difference.
Conclusions: Generally, the results of this research demonstrated that the generalized linear model can be used as an alternative method to square root transformation in studies on the germination percentage of seeds with binomial distribution, without having the problems of the square root transformation method. Moreover, this model outperforms the square root transformation in detecting significant differences in germination of treatments with fixed and different seeds.
Highlights:
- The generalized linear model was used for the analysis of germination percentage data.
- The data simulated using the Monte-Carlo method was utilized to examine the significance level and power of the generalized linear model test.
- The generalized linear model was compared with the square root transformation method during different germination experiments with fixed and different seeds in each Petri dish.
Haniyeh Saadat, Mohammad Sedghi,
Volume 10, Issue 2 (2-2024)
Volume 10, Issue 2 (2-2024)
Abstract
Extended abstract
Introduction: Soybean is among the most important oil crops of the world. Currently, 55% of the world's oil is supplied by soybean. Seed aging, an undesirable feature of agriculture, is one of the main problems in agriculture that leads to economic losses. Although aging is an irreversible process, its speed is delayed by proper storage and optimal storage methods. While kept under inappropriate conditions after harvesting, its quality during storage declines. Priming has a direct and indirect effect on the growth and development of plants, and its indirect effects are more beneficial than its direct effects. Priming improves the longevity of low-vigor seeds. During the priming of these seeds, a long time can occur to repair metabolic damage before any progress in germination, which ultimately prevents further deterioration. Several studies have shown that seed treatment with sodium nitroprusside during reaction with reactive oxygen species and increased activity of antioxidant enzymes is essential to protecting plants against stress. The aim of this study was to the investigate the effect of sodium nitroprusside levels on germination indices and antioxidant enzyme activity in soybean seedlings under accelerated aging test.
Materials and Methods: This experiment was conducted in 2023 as a factorial in the form of a completely randomized design with 3 replications at the University of Mohaghegh Ardabili. Experimental treatments included accelerated aging treatment at three levels (0, 24, and 48 hours) and three levels of sodium nitroprusside (0, 100, and 200 ppm).
Results: The results showed that aging reduced germination indices including germination percentage (GP), germination value (GV), and mean daily germination (MDG). Also, priming with different levels of sodium nitroprusside, especially the 200 ppm level, improved these traits, but priming with sodium nitroprusside decreased the mean germination rate (MGR) and the mean germination time (MGT). The superoxide dismutase and ascorbate peroxidase enzyme activity due to priming with sodium nitroprusside 200 ppm compared to the control showed an increase of 22 and 26%, respectively. Also, the content of peroxidase enzyme activity showed an increase of about 34% compared to the control in priming with sodium nitroprusside 200 ppm and 48 hours aging compared to the control. The lowest catalase enzyme (7.7 units mg protein-1 min-1) was in pretreatment with sodium nitroprusside 100 ppm and without aging.
Conclusions: The results of this study show that among the different treatments, pre-treatment of seeds with sodium nitroprusside 200 ppm may be considered an effective way to improve germination indices and antioxidant enzymes activity of soybean and can be used as a treatment to deal with salinity conditions in soybean seedlings and improve their growth.
Highlights:
Introduction: Soybean is among the most important oil crops of the world. Currently, 55% of the world's oil is supplied by soybean. Seed aging, an undesirable feature of agriculture, is one of the main problems in agriculture that leads to economic losses. Although aging is an irreversible process, its speed is delayed by proper storage and optimal storage methods. While kept under inappropriate conditions after harvesting, its quality during storage declines. Priming has a direct and indirect effect on the growth and development of plants, and its indirect effects are more beneficial than its direct effects. Priming improves the longevity of low-vigor seeds. During the priming of these seeds, a long time can occur to repair metabolic damage before any progress in germination, which ultimately prevents further deterioration. Several studies have shown that seed treatment with sodium nitroprusside during reaction with reactive oxygen species and increased activity of antioxidant enzymes is essential to protecting plants against stress. The aim of this study was to the investigate the effect of sodium nitroprusside levels on germination indices and antioxidant enzyme activity in soybean seedlings under accelerated aging test.
Materials and Methods: This experiment was conducted in 2023 as a factorial in the form of a completely randomized design with 3 replications at the University of Mohaghegh Ardabili. Experimental treatments included accelerated aging treatment at three levels (0, 24, and 48 hours) and three levels of sodium nitroprusside (0, 100, and 200 ppm).
Results: The results showed that aging reduced germination indices including germination percentage (GP), germination value (GV), and mean daily germination (MDG). Also, priming with different levels of sodium nitroprusside, especially the 200 ppm level, improved these traits, but priming with sodium nitroprusside decreased the mean germination rate (MGR) and the mean germination time (MGT). The superoxide dismutase and ascorbate peroxidase enzyme activity due to priming with sodium nitroprusside 200 ppm compared to the control showed an increase of 22 and 26%, respectively. Also, the content of peroxidase enzyme activity showed an increase of about 34% compared to the control in priming with sodium nitroprusside 200 ppm and 48 hours aging compared to the control. The lowest catalase enzyme (7.7 units mg protein-1 min-1) was in pretreatment with sodium nitroprusside 100 ppm and without aging.
Conclusions: The results of this study show that among the different treatments, pre-treatment of seeds with sodium nitroprusside 200 ppm may be considered an effective way to improve germination indices and antioxidant enzymes activity of soybean and can be used as a treatment to deal with salinity conditions in soybean seedlings and improve their growth.
Highlights:
- Seed priming using sodium nitroprusside improved germination indices of seed common soybean under aging.
- Priming with sodium nitroprusside increased antioxidant enzyme activity.
- The concentration of 200 ppm sodium nitroprusside showed a better effect on germination indices and biochemical characteristics.
Ronak Talebi Qormik, Hadi Alipour, Reza Darvishzadeh,
Volume 11, Issue 1 (9-2024)
Volume 11, Issue 1 (9-2024)
Abstract
Extended abstract
Introduction: The germination stage in plants, including wheat, is an extremely susceptible stage to biotic and abiotic stresses. Plant establishment the in the early stages of growth, especially in the germination stage, is always notably important. Salinity stress is one of the abiotic stresses that cause much damage annually, especially in arid and semi-arid regions. Therefore, identification and use of cultivars tolerant to salinity stress is one of the effective ways to reduce the negative effects of salinity stress.
Materials and Methods: In the present study, response of 64 spring wheat cultivars during the germination stage at two levels of salinity stress (zero as a control and 12 dS/m of sodium chloride) was investigated in the form of a simple lattice design with two replications at the Genetics Laboratory of the Faculty of Agriculture, Urmia University. During seven days, germination percentage, germination index, germination rate, germination energy, seedling vigor, mean germination time, and mean germination rate, and after the seventh day, seedling length, shoot length, root length, ratio of shoot length to root length, seedling fresh weight, and seedling dry weight were measured.
Results: Among the studied cultivars, a statistically significant difference was observed at the probability level of 1% in terms of all traits including radicle length, shoot length, seedling length, fresh weight, dry weight, radicle to shoot length ratio, germination index, germination rate, germination energy, germination percentage, seedling vigor, mean germination time, and mean germination rate. Based on the results of factor analysis, under both normal conditions and salinity stress, the studied traits were grouped into four main factors, and these four factors explained 92.74% of the changes under normal and 93.85% under salinity stress conditions. Using cluster analysis, cultivars were grouped into three and two clusters under normal and salinity stress conditions, respectively.
Conclusions: Based on the results of bi-plot obtained from factor and cluster analyses, the cultivars Moghan 2, Bistun, Akbari, Moghan 3, Dastjardi, Marvdasht, Gahar, and Mahdavi are the preferred cultivars and the cultivars Darya, Bam, Tajan, Sistan, Frontana, Kavir, and Afogh were introduced as undesirable cultivars in terms of the traits measured in this experiment, which can be used in breeding projects.
Keywords: Bread wheat, Germination, Multivariate analysis, Salinity stress
Highlights:
Introduction: The germination stage in plants, including wheat, is an extremely susceptible stage to biotic and abiotic stresses. Plant establishment the in the early stages of growth, especially in the germination stage, is always notably important. Salinity stress is one of the abiotic stresses that cause much damage annually, especially in arid and semi-arid regions. Therefore, identification and use of cultivars tolerant to salinity stress is one of the effective ways to reduce the negative effects of salinity stress.
Materials and Methods: In the present study, response of 64 spring wheat cultivars during the germination stage at two levels of salinity stress (zero as a control and 12 dS/m of sodium chloride) was investigated in the form of a simple lattice design with two replications at the Genetics Laboratory of the Faculty of Agriculture, Urmia University. During seven days, germination percentage, germination index, germination rate, germination energy, seedling vigor, mean germination time, and mean germination rate, and after the seventh day, seedling length, shoot length, root length, ratio of shoot length to root length, seedling fresh weight, and seedling dry weight were measured.
Results: Among the studied cultivars, a statistically significant difference was observed at the probability level of 1% in terms of all traits including radicle length, shoot length, seedling length, fresh weight, dry weight, radicle to shoot length ratio, germination index, germination rate, germination energy, germination percentage, seedling vigor, mean germination time, and mean germination rate. Based on the results of factor analysis, under both normal conditions and salinity stress, the studied traits were grouped into four main factors, and these four factors explained 92.74% of the changes under normal and 93.85% under salinity stress conditions. Using cluster analysis, cultivars were grouped into three and two clusters under normal and salinity stress conditions, respectively.
Conclusions: Based on the results of bi-plot obtained from factor and cluster analyses, the cultivars Moghan 2, Bistun, Akbari, Moghan 3, Dastjardi, Marvdasht, Gahar, and Mahdavi are the preferred cultivars and the cultivars Darya, Bam, Tajan, Sistan, Frontana, Kavir, and Afogh were introduced as undesirable cultivars in terms of the traits measured in this experiment, which can be used in breeding projects.
Keywords: Bread wheat, Germination, Multivariate analysis, Salinity stress
Highlights:
- A great diversity was observed among Iranian spring wheat cultivars in terms of salt tolerance during germination.
- Mahdavi, Dastjardi, Bistun, Akbari, Moghan 2, Moghan 3, Gahar, and Marvdasht were identified as salt-tolerant cultivars during germination.
Haniyeh Saadat, Mohammad Sedghi,
Volume 11, Issue 1 (9-2024)
Volume 11, Issue 1 (9-2024)
Abstract
Extended abstract
Introduction: Salinity is the most significant environmental stress that limits plant productivity by affecting morphology, physiology, and biochemistry of plants, especially in semi-arid and arid regions. Salinity disrupts and eventually delays seedling growth by delaying seed germination and reducing the germination rate. Seed priming stands out as a quick, easy, low-cost, and effective strategy for improving germination, seedling growth parameters, and overall plant defense against abiotic stresses in many crops. It is defined as the pre-sowing seed treatment during which seeds are immersed in water or chemical solutions and are dry until further use. The aim of this study was to assess the effect of priming with sodium nitroprusside on germination indices and biochemical traits in rice seedlings under salinity stress.
Materials and Methods: This experiment was conducted as a factorial based on a completely randomized design with three replications at the University of Mohaghegh Ardabili in 2023. Experimental treatments included four salinity levels (0, 50, 100, and 150 mM) and three levels of sodium nitroprusside (0, 40, and 80 µM).
Results: The results showed that salinity reduced germination and growth indicators including mean daily germination (MDG), germination coefficient (GC), allometric coefficient (AC), radicle length (RL), pedicel length (PL) and seedling length (SL), as well as radicle and pedicel fresh and dry weight (RFW, PFW, RDW and PDW), but seed pretreatment with different levels of sodium nitroprusside, especially the level of 80 µM, improved these traits. Salinity reduced the seedling moisture percentage (SMP), so that the highest SMP (70.13%) was observed in the control treatment. The highest daily germination rate (DGR) and malondialdehyde content (MDA) were observed at a salinity of 150 mM. Priming decreased DGS and MDA, so that the lowest DGS (0.08) and MDA (0.159 mM g-1 FW) were obtained in priming with 80 μM sodium nitroprusside. Also, salinity decreased the activity of the α-amylase enzyme, so the lowest α-amylase activity (7.93 mg g-1 FW seed) was obtained in the control (distilled water) and at a salinity of 150 mM.
Conclusions: The results showed that seed treatment with sodium nitroprusside at 80 µM is the most effective method to improve rice germination and biochemical traits under salinity stress. It can reduce the harmful effects of salinity on some traits in rice seedlings and improve seedling growth.
Highlights:
Introduction: Salinity is the most significant environmental stress that limits plant productivity by affecting morphology, physiology, and biochemistry of plants, especially in semi-arid and arid regions. Salinity disrupts and eventually delays seedling growth by delaying seed germination and reducing the germination rate. Seed priming stands out as a quick, easy, low-cost, and effective strategy for improving germination, seedling growth parameters, and overall plant defense against abiotic stresses in many crops. It is defined as the pre-sowing seed treatment during which seeds are immersed in water or chemical solutions and are dry until further use. The aim of this study was to assess the effect of priming with sodium nitroprusside on germination indices and biochemical traits in rice seedlings under salinity stress.
Materials and Methods: This experiment was conducted as a factorial based on a completely randomized design with three replications at the University of Mohaghegh Ardabili in 2023. Experimental treatments included four salinity levels (0, 50, 100, and 150 mM) and three levels of sodium nitroprusside (0, 40, and 80 µM).
Results: The results showed that salinity reduced germination and growth indicators including mean daily germination (MDG), germination coefficient (GC), allometric coefficient (AC), radicle length (RL), pedicel length (PL) and seedling length (SL), as well as radicle and pedicel fresh and dry weight (RFW, PFW, RDW and PDW), but seed pretreatment with different levels of sodium nitroprusside, especially the level of 80 µM, improved these traits. Salinity reduced the seedling moisture percentage (SMP), so that the highest SMP (70.13%) was observed in the control treatment. The highest daily germination rate (DGR) and malondialdehyde content (MDA) were observed at a salinity of 150 mM. Priming decreased DGS and MDA, so that the lowest DGS (0.08) and MDA (0.159 mM g-1 FW) were obtained in priming with 80 μM sodium nitroprusside. Also, salinity decreased the activity of the α-amylase enzyme, so the lowest α-amylase activity (7.93 mg g-1 FW seed) was obtained in the control (distilled water) and at a salinity of 150 mM.
Conclusions: The results showed that seed treatment with sodium nitroprusside at 80 µM is the most effective method to improve rice germination and biochemical traits under salinity stress. It can reduce the harmful effects of salinity on some traits in rice seedlings and improve seedling growth.
Highlights:
- Seed priming using sodium nitroprusside improved the germination indices of rice seeds under salinity.
- Priming with sodium nitroprusside decreased MDA content and increased α-amylase activity.
- The concentration of 80 µM sodium nitroprusside showed a better effect on germination indices and biochemical characteristics.
Haniyeh Saadat, Mohammad Sedghi,
Volume 11, Issue 1 (9-2024)
Volume 11, Issue 1 (9-2024)
Abstract
Extended abstract
Introduction: Environmental stresses, including salinity, result in the overproduction of reactive oxygen species, which, at high levels, can cause oxidative damage, impair membrane lipid functions, inactivate enzymes, and impede the metabolic activities of the plant. Salinity affects seedling growth through osmotic stress, ionic toxicity, lack of absorption of essential elements and water, production of free radicals, cell membrane destruction, and reduction of cell division. Seed priming is a quick, easy, low-cost, and effective strategy for improving germination. It is a seed treatment before planting in which seeds are fully immersed in special solutions and dried until further use. Seed priming assists the germinating seed in mitigating saline stress by neutralizing ionic toxicity or by promoting defense mechanisms. This study aimed to assess the effect of seed priming with vitamin U (S-Methylmethionine) on germination and the physiological and biochemical characteristics of sunflower seedlings under salinity stress.
Materials and Methods: This experiment was conducted in 2023 as a factorial based on a completely randomized design with three replications at the University of Mohaghegh Ardabili. Experimental treatments included four salinity levels (0, 50, 100, and 150 mM) and three levels of vitamin U (0, 2, and 4 mM).
Results: The results showed that salinity reduced the germination and growth indicators, including Germination Rate (GR), Germination Percentage (GP), Mean Daily Germination (MDG), Seedling Length (SL), Seedling Dry Weight (SDW), Seedling Length Vigor Index (SLVI), and Seedling Weight Vigor Index (SWVI); but seed pretreatment with different levels of vitamin U, especially the level of 4 mM, improved these traits. Daily Germination Speed (DGS) was higher by about 25% compared with the control treatment without salinity and, in priming with vitamin U compared with the control (distilled water), it showed a decrease of about 32%. Compared with the control (distilled water), the catalase, peroxidase, superoxide dismutase activities, and proline content of seedlings obtained from primed seeds increased respectively by 9%, 8%, 32%, and 47% after vitamin U treatment. With increasing salinity levels, there was a reduction trend in total seed protein content (0.384 mg g-1 FW), and the lowest total seed protein content was observed at salinity 150 mM. Mean Germination Time (MGT) and malondialdehyde content of seedlings in the priming with a concentration of 4 mM vitamin U and without salinity showed a decrease of about 73% and 21%, respectively, compared with the control (distilled water) and salinity 150 mM.
Conclusions: The results of this research showed that sunflower seed priming with vitamin U at a concentration of 4 mM is the most effective method to improve the germination and biochemical characteristics of seedlings, and stimulating antioxidant enzymes can reduce the harmful effects of salinity on some traits in sunflower seedlings and improve seedling growth.
Highlights:
Introduction: Environmental stresses, including salinity, result in the overproduction of reactive oxygen species, which, at high levels, can cause oxidative damage, impair membrane lipid functions, inactivate enzymes, and impede the metabolic activities of the plant. Salinity affects seedling growth through osmotic stress, ionic toxicity, lack of absorption of essential elements and water, production of free radicals, cell membrane destruction, and reduction of cell division. Seed priming is a quick, easy, low-cost, and effective strategy for improving germination. It is a seed treatment before planting in which seeds are fully immersed in special solutions and dried until further use. Seed priming assists the germinating seed in mitigating saline stress by neutralizing ionic toxicity or by promoting defense mechanisms. This study aimed to assess the effect of seed priming with vitamin U (S-Methylmethionine) on germination and the physiological and biochemical characteristics of sunflower seedlings under salinity stress.
Materials and Methods: This experiment was conducted in 2023 as a factorial based on a completely randomized design with three replications at the University of Mohaghegh Ardabili. Experimental treatments included four salinity levels (0, 50, 100, and 150 mM) and three levels of vitamin U (0, 2, and 4 mM).
Results: The results showed that salinity reduced the germination and growth indicators, including Germination Rate (GR), Germination Percentage (GP), Mean Daily Germination (MDG), Seedling Length (SL), Seedling Dry Weight (SDW), Seedling Length Vigor Index (SLVI), and Seedling Weight Vigor Index (SWVI); but seed pretreatment with different levels of vitamin U, especially the level of 4 mM, improved these traits. Daily Germination Speed (DGS) was higher by about 25% compared with the control treatment without salinity and, in priming with vitamin U compared with the control (distilled water), it showed a decrease of about 32%. Compared with the control (distilled water), the catalase, peroxidase, superoxide dismutase activities, and proline content of seedlings obtained from primed seeds increased respectively by 9%, 8%, 32%, and 47% after vitamin U treatment. With increasing salinity levels, there was a reduction trend in total seed protein content (0.384 mg g-1 FW), and the lowest total seed protein content was observed at salinity 150 mM. Mean Germination Time (MGT) and malondialdehyde content of seedlings in the priming with a concentration of 4 mM vitamin U and without salinity showed a decrease of about 73% and 21%, respectively, compared with the control (distilled water) and salinity 150 mM.
Conclusions: The results of this research showed that sunflower seed priming with vitamin U at a concentration of 4 mM is the most effective method to improve the germination and biochemical characteristics of seedlings, and stimulating antioxidant enzymes can reduce the harmful effects of salinity on some traits in sunflower seedlings and improve seedling growth.
Highlights:
- Seed priming using vitamin U improved germination indices of sunflower seed under salinity.
- Priming with vitamin U decreased the content of malondialdehyde and increased the amount of proline and protein.
- The concentration of 4 mM vitamin U revealed a better effect on germination indices and biochemical characteristics.
Fatemeh Vafaee, Hamidreza Nooryazdan, Rahmatolah Karimizadeh,
Volume 11, Issue 1 (9-2024)
Volume 11, Issue 1 (9-2024)
Abstract
Extended abstract
Introduction: Drought stress in dryland wheat cultivation, where the plant solely relies on rainwater, can have a detrimental effect on plant growth. Given the lengthy duration of breeding projects, identifying stress-tolerant breeding lines at the germination stage can significantly reduce the time and cost of dryland wheat breeding programs for developing drought-resistant varieties. Identifying the stress tolerance of unreleased lines through laboratory simulation of drought stress is among novel methods to aid in selecting drought-tolerant varieties in the final stages. Moreover, the germination stage is crucial for plant establishment. This stage is critical for plant growth and development and can significantly impact bread wheat yield in case tolerant lines are available.
Materials and Methods: This experiment was conducted to investigate the germination characteristics of 11 advanced dryland bread wheat lines at four osmotic potential levels (-2, -4, -6, and -8 bars) induced by polyethylene glycol 6000 along with a control (for a total of five levels), under laboratory (controlled) conditions at Persian Gulf University. The investigation was performed as a factorial experiment in a completely randomized design (CRD) with three replications. Traits in this experiment including germination percentage, germination rate, growth rates of radicles and plumules, dry weight and length of radicle and plumule, seed vigor indices I and II, seedling length, and allometric coefficient were measured.
Results: The mean of all traits decreased with increasing stress levels. Results of ANOVA showed a significant interaction at the 1% level between the lines and drought stress treatments. Therefore, physical slicing analysis was conducted at each stress level to compare the lines. The response of the lines to different traits was of an ordinal interaction type. As drought stress levels increased, germination percentage and rate, radicle and plumule growth rates, and seedling length decreased. Overall, lines 3 and 4 exhibited the highest germination percentage (58.86) and rate (3.60 seeds per day), as well as radicle (0.85 cm per day) and plumule rates (0.70 cm per day), and radicle (8.83 cm) and seedling (7.12 cm) length.
Conclusions: The response of the lines to different osmotic stress levels varied in terms of various traits. Based on the traits evaluated, lines 3 and 4 exhibited superior drought stress tolerance. These lines can be utilized in future breeding programs.
Highlights:
Introduction: Drought stress in dryland wheat cultivation, where the plant solely relies on rainwater, can have a detrimental effect on plant growth. Given the lengthy duration of breeding projects, identifying stress-tolerant breeding lines at the germination stage can significantly reduce the time and cost of dryland wheat breeding programs for developing drought-resistant varieties. Identifying the stress tolerance of unreleased lines through laboratory simulation of drought stress is among novel methods to aid in selecting drought-tolerant varieties in the final stages. Moreover, the germination stage is crucial for plant establishment. This stage is critical for plant growth and development and can significantly impact bread wheat yield in case tolerant lines are available.
Materials and Methods: This experiment was conducted to investigate the germination characteristics of 11 advanced dryland bread wheat lines at four osmotic potential levels (-2, -4, -6, and -8 bars) induced by polyethylene glycol 6000 along with a control (for a total of five levels), under laboratory (controlled) conditions at Persian Gulf University. The investigation was performed as a factorial experiment in a completely randomized design (CRD) with three replications. Traits in this experiment including germination percentage, germination rate, growth rates of radicles and plumules, dry weight and length of radicle and plumule, seed vigor indices I and II, seedling length, and allometric coefficient were measured.
Results: The mean of all traits decreased with increasing stress levels. Results of ANOVA showed a significant interaction at the 1% level between the lines and drought stress treatments. Therefore, physical slicing analysis was conducted at each stress level to compare the lines. The response of the lines to different traits was of an ordinal interaction type. As drought stress levels increased, germination percentage and rate, radicle and plumule growth rates, and seedling length decreased. Overall, lines 3 and 4 exhibited the highest germination percentage (58.86) and rate (3.60 seeds per day), as well as radicle (0.85 cm per day) and plumule rates (0.70 cm per day), and radicle (8.83 cm) and seedling (7.12 cm) length.
Conclusions: The response of the lines to different osmotic stress levels varied in terms of various traits. Based on the traits evaluated, lines 3 and 4 exhibited superior drought stress tolerance. These lines can be utilized in future breeding programs.
Highlights:
- Evaluating and screening wheat breeding lines for drought tolerance was performed by simulating stress conditions in the laboratory and comparing morphological traits in early plant growth stages.
- The response of the lines to similar levels of drought stress was heterogeneous, and physical slicing analysis based on each stress level revealed an ordinal interaction between stress and line levels.
Haniyeh Saadat, Mohammad Sedghi,
Volume 11, Issue 2 (3-2025)
Volume 11, Issue 2 (3-2025)
Abstract
Extended abstract
Introduction: Salinity stress leads to the excessive production of reactive oxygen species, which at high levels can cause oxidative damage, disrupt membrane lipid functions, inactivate enzymes, and hinder metabolic activities in plants. Salinity affects seedling growth through osmotic stress, ionic toxicity, deficient absorption of essential nutrients and water, production of free radicals, destruction of the cell membrane, and reduced cell division. Utilizing pretreatment methods serves as a simple approach to mitigate the adverse effects of environmental stress. Seed pretreatment induces biochemical changes, such as the activation of enzymes involved in cellular metabolism, inhibition of metabolism, and improved water absorption, thereby aiding the germination process. This study aims to assess the impact of pretreatment on germination characteristics, activity of certain hydrolytic enzymes, and the glyoxylate cycle in marigold seedlings under salinity stress.
Materials and Methods: A factorial experiment was conducted based on a completely randomized design with three replications at the University of Mohaghegh Ardabili in 2023. Experimental treatments included four salinity levels (0, 50, 100, and 150 mM sodium chloride) and four pretreatment methods (control with distilled water, pretreatment with salicylic acid at 100 mg/L, gibberellin at 20 mg/L, and chitosan at 0.8% w/v, dissolved in 1% acetic acid).
Results: The findings indicated that salinity reduced germination percentage, mean daily germination, petiole length, and seedling dry weight. However, pretreatment with salicylic acid, gibberellin, and particularly chitosan significantly improved these parameters. The germination coefficient, radicle length, and seedling fresh weight in chitosan-pretreated groups without salinity were approximately 75%, 68%, and 34% higher compared to the control (distilled water) and 150 mM salinity treatments, respectively. Additionally, the activities of amylase, protease, and malate synthase in chitosan-pretreated groups without salinity increased by approximately 82%, 46%, and 70%, respectively, compared with the control and 150 mM salinity.
Conclusions: The results of this research demonstrate that seed pretreatment using salicylic acid, gibberellin, and especially chitosan is an effective strategy for enhancing germination indices and the activity of certain hydrolytic enzymes and the glyoxylate cycle, thereby alleviating the detrimental effects of salinity on marigold seedlings and promoting their growth.
Highlights:
Introduction: Salinity stress leads to the excessive production of reactive oxygen species, which at high levels can cause oxidative damage, disrupt membrane lipid functions, inactivate enzymes, and hinder metabolic activities in plants. Salinity affects seedling growth through osmotic stress, ionic toxicity, deficient absorption of essential nutrients and water, production of free radicals, destruction of the cell membrane, and reduced cell division. Utilizing pretreatment methods serves as a simple approach to mitigate the adverse effects of environmental stress. Seed pretreatment induces biochemical changes, such as the activation of enzymes involved in cellular metabolism, inhibition of metabolism, and improved water absorption, thereby aiding the germination process. This study aims to assess the impact of pretreatment on germination characteristics, activity of certain hydrolytic enzymes, and the glyoxylate cycle in marigold seedlings under salinity stress.
Materials and Methods: A factorial experiment was conducted based on a completely randomized design with three replications at the University of Mohaghegh Ardabili in 2023. Experimental treatments included four salinity levels (0, 50, 100, and 150 mM sodium chloride) and four pretreatment methods (control with distilled water, pretreatment with salicylic acid at 100 mg/L, gibberellin at 20 mg/L, and chitosan at 0.8% w/v, dissolved in 1% acetic acid).
Results: The findings indicated that salinity reduced germination percentage, mean daily germination, petiole length, and seedling dry weight. However, pretreatment with salicylic acid, gibberellin, and particularly chitosan significantly improved these parameters. The germination coefficient, radicle length, and seedling fresh weight in chitosan-pretreated groups without salinity were approximately 75%, 68%, and 34% higher compared to the control (distilled water) and 150 mM salinity treatments, respectively. Additionally, the activities of amylase, protease, and malate synthase in chitosan-pretreated groups without salinity increased by approximately 82%, 46%, and 70%, respectively, compared with the control and 150 mM salinity.
Conclusions: The results of this research demonstrate that seed pretreatment using salicylic acid, gibberellin, and especially chitosan is an effective strategy for enhancing germination indices and the activity of certain hydrolytic enzymes and the glyoxylate cycle, thereby alleviating the detrimental effects of salinity on marigold seedlings and promoting their growth.
Highlights:
- Seed pretreatment with salicylic acid, gibberellin, and especially chitosan significantly improved germination indices of marigold seeds under salinity conditions.
- This pretreatment enhanced the enzymatic activity of amylase, protease, and malate synthase.
- Chitosan pretreatment exhibited superior effects on germination indices and biochemical characteristics.
Aidin Hamidi, Bita Oskuoei, Ali Shayanfar,
Volume 11, Issue 2 (3-2025)
Volume 11, Issue 2 (3-2025)
Abstract
Extended abstract
Introduction: Seed germination has always been of interest to plant ecologists due to its key role in plant population establishment. Also, due to the importance of this process in seed certification, this phenomenon is of interest to control and seed certification experts. Temperature, access to sufficient humidity, and the presence of light in light-sensitive species for seed germination are considered to be the most important natural factors for seed germination. Additionally, the time required for germination and sufficient early seedling growth are important to determine the potential seed germination. Therefore, determining the temperature, the need or lack of light, as well as the time required for germination and the suitable substrate for planting seeds, are of great importance in the process of seed certification laboratory tests.
Materials and Methods: In order to determine the optimal conditions for seed germination of three species of Salicornia persica, S. persepolitana, and S. bigelovi, the seeds were grown under three constant temperatures of 20, 25, and alternating temperatures of 20-25 °C (8-16 hours light-dark), two culture beds (top-of-paper (TP) and between-paper (BP)), and two germination periods of 7 and 12 days.
Results: The results showed that the seeds of S. bigelovi species had the highest percentage of normal seedlings at 25 °C constant temperature for 7 days in the top-of-paper (TP) substrate. Also, the seeds of S. persica had the highest percentage of normal seedlings at 20-25 °C alternating temperature for 7 days in the top-of-paper (TP) substrate. S. persepolitana seeds at 25 °C constant temperature for 7 days on the top-of-paper (TP) substrate had the highest percentage of normal seedlings. S. persica, S. bigelovi, and S. persepolitana seeds had a higher percentage of normal seedlings in both germination durations and temperatures, respectively.
Conclusions: The results of this research showed that the seeds of the studied Salicornia species did not require light for germination. Also, in terms of temperature requirements, the time required for germination, and the substrate, they differed from each other. The seeds of S. persica reached the maximum percentage of normal seedlings at 20-25 °C alternating temperatures. The seeds of S. bigelovi and S. persica species needed a shorter time to reach the maximum percentage of normal seedlings, while the seeds of S. persepolitana needed a longer time to germinate and reach the maximum percentage of normal seedlings. Therefore, it was determined that the best temperature, duration, and substrate to achieve the maximum percentage of normal seedlings in the standard seed germination test were 25 °C for 7 days and top-of-paper (TP) substrate for S. bigelovi, 20-25 °C alternating temperature for 7 days and top-of-paper (TP) substrate for S. persica, and 20 °C constant temperature for 7 days and top-of-paper (TP) substrate for S. persepolitana species.
Highlights:
Introduction: Seed germination has always been of interest to plant ecologists due to its key role in plant population establishment. Also, due to the importance of this process in seed certification, this phenomenon is of interest to control and seed certification experts. Temperature, access to sufficient humidity, and the presence of light in light-sensitive species for seed germination are considered to be the most important natural factors for seed germination. Additionally, the time required for germination and sufficient early seedling growth are important to determine the potential seed germination. Therefore, determining the temperature, the need or lack of light, as well as the time required for germination and the suitable substrate for planting seeds, are of great importance in the process of seed certification laboratory tests.
Materials and Methods: In order to determine the optimal conditions for seed germination of three species of Salicornia persica, S. persepolitana, and S. bigelovi, the seeds were grown under three constant temperatures of 20, 25, and alternating temperatures of 20-25 °C (8-16 hours light-dark), two culture beds (top-of-paper (TP) and between-paper (BP)), and two germination periods of 7 and 12 days.
Results: The results showed that the seeds of S. bigelovi species had the highest percentage of normal seedlings at 25 °C constant temperature for 7 days in the top-of-paper (TP) substrate. Also, the seeds of S. persica had the highest percentage of normal seedlings at 20-25 °C alternating temperature for 7 days in the top-of-paper (TP) substrate. S. persepolitana seeds at 25 °C constant temperature for 7 days on the top-of-paper (TP) substrate had the highest percentage of normal seedlings. S. persica, S. bigelovi, and S. persepolitana seeds had a higher percentage of normal seedlings in both germination durations and temperatures, respectively.
Conclusions: The results of this research showed that the seeds of the studied Salicornia species did not require light for germination. Also, in terms of temperature requirements, the time required for germination, and the substrate, they differed from each other. The seeds of S. persica reached the maximum percentage of normal seedlings at 20-25 °C alternating temperatures. The seeds of S. bigelovi and S. persica species needed a shorter time to reach the maximum percentage of normal seedlings, while the seeds of S. persepolitana needed a longer time to germinate and reach the maximum percentage of normal seedlings. Therefore, it was determined that the best temperature, duration, and substrate to achieve the maximum percentage of normal seedlings in the standard seed germination test were 25 °C for 7 days and top-of-paper (TP) substrate for S. bigelovi, 20-25 °C alternating temperature for 7 days and top-of-paper (TP) substrate for S. persica, and 20 °C constant temperature for 7 days and top-of-paper (TP) substrate for S. persepolitana species.
Highlights:
- Light was not necessary for the studied Salicornia species seeds' germination.
- The studied Salicornia species seeds' germination response to optimum temperature was different.
- The studied Salicornia species seeds' optimum germination duration was different.
Mohammad Reza Mirzaei,
Volume 11, Issue 2 (3-2025)
Volume 11, Issue 2 (3-2025)
Abstract
Extended abstract
Introduction: One of the most important factors in achieving optimal root yield of sugar beet at the time of harvest is proper plant density due to the high field emergence and subsequent seedling growth through the use quality seeds. Of the determining traits the vigor and quality of sugar beet seeds are different seedling traits.
Materials and Methods: For this purpose, the germination vigor and seedling growth rate in laboratory conditions by measuring the traits of maximum germination, hypocotyl length, radicle length, fresh and dry weight of seedling in 10 single cross hybrids along with the male parent produced in three locations was used. Also, the correlation of the mentioned traits with seedling emergence traits in the greenhouse and the chemical traits of sugar beet seed was studied.
Results: The results showed that seedling traits, which are represents trait of the seed vigor, are determined by two factors, seed production environment and genetics. The correlation coefficients between seedling traits in the laboratory with seedling emergence traits in the greenhouse and seed electrical conductivity showed that genotypes with low electrical conductivity and percentage of soluble solids on the pericarp of sugar beet seeds, germinated faster in greenhouse conditions and mean emergence time was decreased. Therefore, high level of electrical conductivity of sugar beet seed pericarp was associated with low seed vigor.Also, significant correlation was observed seedling emergence rate and mean seedling emergence time in greenhouse with hypocotyl length in the laboratory positive (+0.91**) and negative (-0.82**), respectively. It can be concluded that the genotypes with longer hypocotyl length in the laboratory resulted in faster seedling emergence rate in the greenhouse. Subsequently, single crosses such as MS KWS * OT 231 with greater root length (8.49 cm), seedling length (14.66 cm), and the ratio root length to hypocotyl (1.37) in laboratory conditions, increased the mean dry weight of shoot (1.89 mg) and SVI (8.26) in the greenhouse compared to the single crosses others were accompanied.
Conclusions: Therefore, it seems that seedling traits and the chemical characteristics of sugar beet seeds to predict the emergence of seedlings in greenhouse and perhaps in the field are recommended. However, in order to accurate validation and evaluation, it is recommended that the aforementioned experiment be conducted under field conditions.
Highlights:
Introduction: One of the most important factors in achieving optimal root yield of sugar beet at the time of harvest is proper plant density due to the high field emergence and subsequent seedling growth through the use quality seeds. Of the determining traits the vigor and quality of sugar beet seeds are different seedling traits.
Materials and Methods: For this purpose, the germination vigor and seedling growth rate in laboratory conditions by measuring the traits of maximum germination, hypocotyl length, radicle length, fresh and dry weight of seedling in 10 single cross hybrids along with the male parent produced in three locations was used. Also, the correlation of the mentioned traits with seedling emergence traits in the greenhouse and the chemical traits of sugar beet seed was studied.
Results: The results showed that seedling traits, which are represents trait of the seed vigor, are determined by two factors, seed production environment and genetics. The correlation coefficients between seedling traits in the laboratory with seedling emergence traits in the greenhouse and seed electrical conductivity showed that genotypes with low electrical conductivity and percentage of soluble solids on the pericarp of sugar beet seeds, germinated faster in greenhouse conditions and mean emergence time was decreased. Therefore, high level of electrical conductivity of sugar beet seed pericarp was associated with low seed vigor.Also, significant correlation was observed seedling emergence rate and mean seedling emergence time in greenhouse with hypocotyl length in the laboratory positive (+0.91**) and negative (-0.82**), respectively. It can be concluded that the genotypes with longer hypocotyl length in the laboratory resulted in faster seedling emergence rate in the greenhouse. Subsequently, single crosses such as MS KWS * OT 231 with greater root length (8.49 cm), seedling length (14.66 cm), and the ratio root length to hypocotyl (1.37) in laboratory conditions, increased the mean dry weight of shoot (1.89 mg) and SVI (8.26) in the greenhouse compared to the single crosses others were accompanied.
Conclusions: Therefore, it seems that seedling traits and the chemical characteristics of sugar beet seeds to predict the emergence of seedlings in greenhouse and perhaps in the field are recommended. However, in order to accurate validation and evaluation, it is recommended that the aforementioned experiment be conducted under field conditions.
Highlights:
- There were differences between the genotypes in terms of seed characteristics and the maternal environment in which the seeds were grown.
- Poor vigor and seed performance can reduce the percentage of seedling emergence potential as well as the rate and uniformity of seedling emergence compared to high vigor seeds.
- Seedling traits in sugar beet are traits of the seed vigor that are influenced by the sugar beet seed production environment and genetics.
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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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