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Sepideh Nikoumaram, Naeimeh Bayatian, Omid Ansari,
Volume 6, Issue 2 (3-2020)
Volume 6, Issue 2 (3-2020)
Abstract
Extended abstract
Introduction: Temperature is one of the primary environmental regulators of seed germination. Seed priming technique has been known as a challenge to improving germination and seedling emergence under different environmental stresses. Quantification of germination response to temperature and priming is possible, using non-liner regression models. Therefore, the objective of this study was to evaluate the effect of temperature and priming on germination and determination of cardinal temperatures (base, optimum and maximum) of Brassica napus L.
Material and Methods: Treatments included priming levels (non-priming, priming with water, gibberellin 50 and 100 mg/l) and temperature (5, 10, 15, 20, 30, 35 and 40 °C). Germination percentage and time to 50% maximum seed germination of Brassica napus L. were calculated for different temperatures and priming by fitting 3-parameter logistic functions to cumulative germination data. For the purpose of quantifying the response of germination rate to temperature, use was made of 3 nonlinear regression models (segmented, dent-like and beta). The root mean square of errors (RMSE), coefficient of determination (R2), CV and SE for the relationship between the observed and the predicted germination percentage were used to compare the models and select the superior model from among the methods employed.
Results: The results indicated that temperature and priming were effective in both germination percentage and germination rate. In addition, the results showed that germination percentage and rate increase with increasing temperature to the optimum level and using priming. As for the comparison of the 3 models, according to the root mean square of errors (RMSE) of germination time, the coefficient of determination (R2), CV and SE, the best model for the determination of cardinal temperatures of Brassica napus L. for non-primed seeds was the segmented model. For hydro-priming and hormone-priming with 50 mg/l GA, the best models were segmented and dent-like models and for hormone-priming with 100 mg/l GA, the dent-like model was the best. The results showed that for non-priming, hydropriming with water, gibberellin 50 and 100 mg/l treatments, the segmented model estimated base temperature as 3.54, 2.57, 2.34 and 2.34 °C and dent-model estimated base temperature as 3.34, 2.45, 2.21 and 2.83 °C, respectively. The segmented model estimated optimum temperature as 24.62, 23.23, 23.69 and 24.38 °C. The dent-model estimated lower limit of optimum temperature and upper limit of optimum temperature as 20.01, 19.62, 16.25, 19.87 and 28.81, 27.38, 29.58 and 27.31 °C.
Conclusion: Utilizing non-liner models (segmented, dent-like and beta) for quantification of germination of Brassica napus L. response to different temperatures and priming produced desirable results. Therefore, utilizing the output of these models at different temperatures can be useful in the prediction of germination rate in different treatments.
Highlights:
1-The effect of priming on germination of Brassica napuswas investigated.
2-The temperature range of rapeseed germination of Brassica napus changes with the use of seed priming.
Fatemeh Lkhoshnoodashkarian, Marjan Diyanat, Gorban Noormohammadi,
Volume 7, Issue 1 (9-2020)
Volume 7, Issue 1 (9-2020)
Abstract
Extended abstract
Introduction: London rocket is an important winter annual weed of the mustard family (Brassicaceae), which is propagated by seed. Germination of a seed population in response to water potential reduction is modeled using the concept of hydro time. This model has outputs that are physiologically and ecologically meaningful. One of the presumptions of the Hydro time model is the normal distribution of the base water potential among the seed population.
Materials and methods: In order to quantify the germination characteristics and determine the cardinal temperature of germination of London rocket (Sisymbrium irio L.), an experiment was done in 2018 at Science Research Branch, Islamic Azad University, Tehran, Iran. The seeds were placed at constant temperatures (5, 10, 15, 20, 25, 30, 35, 40 and 45 °C). Germination percentage, germination rate, root length, shoot length, seedling length and seedling fresh weight were evaluated. Intersected-lines, dent-like and quadratic polynomial models were used to determine cardinal temperatures. London rocket seed germination was tested across a range of water potential (0, -0.2, -0.4, -0.6 and -0.8 MPa) at the optimal temperature of 22.80 °C. The hydro time model, based on the normal distributions was fitted to data.
Results: Results showed that seed of London rocket did not germinate at temperatures of 5, 35, 40 and 45° C, and 25° C was the best temperature for seed germination (48%). The longest root length (4.49 mm) was observed at 20°C, which did not have significant differences with temperatures of 15 and 25 °C. The longest shoot length (10.19 mm) was obtained at 25 °C and there were not any significant differences among this temperature and temperatures of 15 and 20 °C. Similar trend with the trait of root length was observed for the trait of seedling length. The best model for estimating the cardinal temperatures in London rocket was intersected-line model with respect to coefficient of determination and mean square error. According to the intersected-lines model in London rocket, the minimum, optimum and maximum temperatures were calculated 5.83, 22.80 and 37.91°C. According to the hydro-time model based on normal distribution, the hydro-time constant and the base-water potential (which is a threshold for germination beginning) of London rocket degree were 284.28 (MPa/h) and -1.18 (MPa) at 22.80 °C, respectively.
Conclusions: Knowledge of germination and emergence of weeds also helps to predict the potential distribution to new habitats. The obtained coefficient of determination (0.94) between observed germination and predicted germination showed that the hydro time model based on normal distribution fitted well to germination percentage of London rocket seed. Due to the low hydrotime coefficient of this weed and the drought problem that most provinces face, it is expected that this weed will become more problematic in most provinces of Iran in the future.
Highlights:
1- The best temperature for germination of London rocket seed is 25 °C.
2- The best model for estimating the cardinal temperatures in London rocket is intersected-line model
3- The hydro-time constant and the base-water potential of London rocket degree based on normal distribution are 284.28 (MPa/h) and -1.18 (MPa) at 22.80 °C, respectively.
Esmaeil Gholnezhad, Naser Samsami, Abbas Abhari,
Volume 7, Issue 1 (9-2020)
Volume 7, Issue 1 (9-2020)
Abstract
Extended abstract
Introduction: Soybean is a plant that has a moderate tolerance to drought stress. Drought stress is one of the most important abiotic stresses affecting soybean production by about 40%. In addition, drought stress reduces seed vigor as a result of stress conditions. Positive effects of mycorrhizal fungi on the increment of dry matter and plant biomass, especially in low-irrigated conditions and in dry areas have been proven. The reason for the increase in crop yield in mycorrhizal inoculated plants is their water balance in water deficit stress conditions and as a result, absorption of water and mineral elements. Rhizobium bacteria, carbohydrates, and other foods are catched from the phloem vessels and the received energy is used to convert nitrogen to ammonium ion and eventually amino acids. Japonicum rhizobium bacterium is not naturally found in soils of Iran and the bacteria should be added to the soil along with seeds.
Materials and Methods: This experiment was carried out to determine the germination characteristics, seed vigor and its related traits in soybean Kosar cultivar grown under drought stress conditions and inoculation with mycorrhiza and bacteria with three replications during 2018. In the field experiment, drought stress included optimal irrigation (irrigation after 70 mm evaporation), moderate stress (irrigation after 110 mm evaporation) and severe drought stress (irrigation after 150 mm evaporation from class A evaporation pan), mycorrhizal fungus in three levels, mycorrhiza-free, and inoculation with glomus mosseae, Glomus intraradices and Rhizobium bacterium in two levels, including no inoculation and inoculation with Rhizobium japonicum.
Results: The mean comparison showed that the seeds obtained under normal irrigation, inoculation with mycorrhiza and bacteria had the highest dry weight of radicle, plumule and seedling, percentage and germination rate. The lowest electrical conductivity of the seeds and the mean time of germination were obtained under these condition. Severe and moderate drought stress reduced stress tolerance index, root tolerance index and stem tolerance index, seedling vigor index and seed vigor index compared to optimum irrigation about 42-23, 38-18, 30-18, 50-26 and 41-21) percent, respectively. Inoculation with Glomus mosseae and Glomus intraradices increased the seed vigor index, radicle lentgh, plumule lentgh and seedling length compared to non-inoculation with mycorhizal fungi by 48-42, 27-26, 41-37 and 35-33 percent, respectively. Inoculation with Rhizobium japonicum increased radicle lentgh, plumule lentgh and seedling lentgh compared to non-inoculation with bacterium by 21%, 16% and 18%, respectively. The highest water percentage in seedling tissue was obtained under optimum irrigation conditions, inoculation with mycorrhizal fungi and inoculation with rhizobium bacteria.
Conclusion: According to the results of this study, in all three different irrigation conditions to improve germination and increase seed vigor, the use of mycorrhiza fungi is effective especially glomus mosseae and inoculation with Rhizobium bacteria.
Highlights:
- Germination characteristics, germination rate and duration of soybean Kosar cultivar on seeds obtained under different irrigation conditions were investigated.
- The effect of mycorrhiza and bacteria on seed vigor and related traits were evaluated under different levels of drought stress.
- The damage done to the seed membranes due to the interaction of irrigation and inoculation with mycorrhiza and bacterium was investigated.
Ebrahim Gholamalipour Alamdari, Amir Ghorbani, Hossein Sabouri, Meisam Habibi,
Volume 7, Issue 1 (9-2020)
Volume 7, Issue 1 (9-2020)
Abstract
Extended abstract
Introduction: Without a doubt, plant hetrotoxicity is one of the important factors in determining the distribution and abundance of some species in plant communities. Thus, the purpose of this experiment was to evaluate the effect of phenolic composition obtained from the methanol extract of Echinochola crus-galli on germination traits and cytogenetic behavior of rice.
Materials and methods: This experiment was done to assess hetrotoxic potential of various concentrations (0, 0.024, 0.048, 0.076 and 0.1 mM) of the phenolic composition obtained from the methanol extract of whole-organ of E. crus-galli on germination traits of rice as well as mitosis division of meristematic cells of radicle in a completely randomized design. To extract thephenolic composition, warm extraction method using a methanol solvent was used. For studying mitosis division, first rice seeds were germinated. Then, each of the steps such as fixation, hydrolysis, staining, squashing and microscopic studies were done on the end of the radicle. Mitosis indices and percentage of mitosis inhibition were calculated and also percentage of each of chromosomal abnormalities at four stages of prophase, metaphase, anaphase and telophase as compared to total cells was calculated.
Results: The lowest percentage and rate of germination and relative germination were found in two concentrations of the 0.076 and 0.1 mM of phenolic composition of E. crus-galli, so that no germination was observed in these treatments. In this study, mitosis division was normal in control samples, so that the rice plant included 12 chromosomes in the metaphase stage. Also the chromosomes were normal in the telophase stage and chromosomal abnormalities were not observed in meristem cells of radicle tip of the control. The lowest value of mitosis indices and the number of dividing cells were related to the concentration of 0.048 mM wuth 30.19 and 385 cells, respectively. In the present study, chromosomal abnormalities in the stages of metaphase, anaphase and telophase were increased with increasing concentration of phenolic composition, and were 28.85 and 16.95% in 0.048 mM concentration of phenolic composition, respectively. The most chromosomal abnormalities were of sticky and laggard type, which were related to the concentration of 0.048 mM of phenolic composition with 39.83 and 32.25%, respectively. The highest number of chromosomal bridges and clumping were obtained in 0.024 mM of phenolic composition with about 19.27 and 29.83%, respectively.
Conclusion: In this study, phenolic composition obtained from the methanol extract of E. crus-galli had asignificant inhibitory effect on germination traits and mitosis division in root tip cells of rice. Thus, the amount of E. crus-galli residues in the field should be considered in direct and indirect cultivation of rice.
Highlights:
1-Difference in impact of the phenolic composition obtained from the methanol extract of Echinochola crus-galli on germination and reduced cytogenetic behavior of rice is related to their threshold concentration.
2- It is advised to cultivate varieties of rice resistant to the remnants of harmful compounds of E. crus-galli as direct cultivation or under nursery condition.
Faegheh Jangjoo, Mehdi Tajbakhsh-Shishvan,
Volume 7, Issue 1 (9-2020)
Volume 7, Issue 1 (9-2020)
Abstract
Extended abstract
Introduction: Seed deterioration is a physiological phenomenon that affects all germination, biochemical, cytological, and growth characteristics of plants. So it is necessary to use seed vigor enhancement methods to resolve these problems. One of these methods is the application of seed priming techniques to reduce deterioration effects. Therefore, the present study aimed to investigate the effect of different pre-treatments by using Nano-zinc, ascorbic acid, humic acid, gibberellin and KNO3 on germination indices and chromosomal aberration of aged onion seeds.
Material and Methods: This experiment was performed as factorial based on a completely randomized design with 3 replications (100 seeds per replicate) in the faculty of agriculture at Urmia University. The first factor was the level of aging at 4 levels (control, 12h, 24h, and 48h) and the second factor was seed pre-treatments at 6 levels (control, Nano-zinc (30 mg), ascorbic acid (100 mg), humic acid (150 mg), gibberellin (200 mg/l) and KNO3 (0.1%). Given that the germination was not similar at different levels of aging, the seeds were germinated at control and 12h of aging after 6 days, at 24 and 48h of aging after 8 and 9 days, respectively. Hence, germination percentage, germination rate, normal seedling, mean germination time, and seed vigor were evaluated after the mentioned times. Chromosomal aberrations were also examined.
Results and Discussion: The results showed that the interaction effect of aging and seed pre-treatments on germination indices were significant at %1 probability level. By increasing the period of aging, all germination characters decreased significantly. The highest germination percentage (80%, 70%, 50%) and germination rate (5.350, 3. 316, 1.525 seed/day) were obtained by using Nano-zinc At 12h, 24h and 48h ageing levels. Nano-zinc and gibberellin had the highest effect on seedling vigor and normal seedlings. Seedling vigor increased significantly by using Nano-zinc and gibberellin at 12h (1133, 933.9), 24h (742.9, 692), and 48h (369.9, 323.3). The chromosomal aberration was reduced by using pre-treatment.
Conclusion: In this study, the most effective pre-treatments to improve germination characteristics and reduce chromosomal aberrations were gibberellin (200 mg/l) and Nano-zinc (30 mg). Therefore, it can be stated that the use of Nano-zinc and gibberellin as seed pre-treatments can significantly reduce the effects of deterioration on onion seeds.
Highlights:
1- Nano-Zinc and gibberellin were the most effective priming treatments on seed germination and growth characteristics of the aged onion seeds.
2- Priming treatment reduced the percentage of chromosomal aberration in the onion and the highest effect was obtained using Nano-zinc and gibberellin.
Seyyed Hamidreza Ramazani, Fariba Armoon, Mohammad Ali Behdani,
Volume 7, Issue 2 (3-2021)
Volume 7, Issue 2 (3-2021)
Abstract
Extended Abstract
Introduction: Guar (Cyamopsis tetragonoloba L.) is a plant from the legumes family. Guar gum is obtained from endosperm in guar seeds. Guar gum is used in many industries such as pharmaceutical and food industries, paper, mining, oil and drilling, textiles, and explosives industries. Modeling is a method that is widely used in predicting plant growth stages and determining the required thermal units in each growing stage, especially germination.
Considering the important therapeutic and industrial uses of guar and the lack of sufficient information and reports to determine the cardinal temperatures of this plant, this study aimed to investigate the effect of temperature on germination traits and early seedling growth and predict the cardinal temperatures (minimum, optimal and maximum) of germination for this plant.
Materials and Methods: This research was carried out at the Seed Sciences and Technology Laboratory of Agricultural College of Sarayan, the University of Birjand in 2017. Experiments were carried out in a completely randomized design with 8 levels of temperature treatments (5, 10, 15, 20, 25, 30, 35, and 40°C), with 5 replications. Germination percentage, daily germination speed, mean daily germination, plumule length, root length, and seedling length were calculated. Cardinal temperatures of germination were calculated using regression analysis with the aid of the proposed models (logistic, two-way, quadratic, and third-order polynomials) using germination speed. The data were analyzed using SAS software and the comparison means were done by Duncan's test at a probability level of 5%. Sigma Plot software was used to plot the germination rate against temperature graphs (for fitting different models).
Results: The results showed that the effect of different temperature levels on the percentage, speed and mean seed germination was significant (P <0.05). According to the results, the lowest values for percentage, speed, and average germination were obtained at 5, 10, and 40°C, and the highest germination speed was observed at 15 °C and also the highest percentage of germination and average germination was observed at 35°C. The results of the effect of different temperature levels on seedling growth showed that the effect of temperature on the seedling length, stem, and root length was significant (P <0.01), so that the lowest values related to seedling length, plumule, and radicle was found at 5, 10 and 40°C, and the maximum seedling and plumule length were 30°C.
Conclusion: Quantification of the gauge seed germination reaction to different temperature levels was carried out using four dual-functions, logistic, quadratic and triple polynomials. The second-order multitasking regression model, based on the coefficient of explanation (R2) and the amount of deviation, had a suitable and significant fit with the data related to germination rate against the independent temperature variable. Based on the parameters of the model, the optimum temperature was obtained at 26.05°C and the minimum and maximum temperature of guar germination were calculated to be 6.09 and 40°C.
Highlights:
Introduction: Guar (Cyamopsis tetragonoloba L.) is a plant from the legumes family. Guar gum is obtained from endosperm in guar seeds. Guar gum is used in many industries such as pharmaceutical and food industries, paper, mining, oil and drilling, textiles, and explosives industries. Modeling is a method that is widely used in predicting plant growth stages and determining the required thermal units in each growing stage, especially germination.
Considering the important therapeutic and industrial uses of guar and the lack of sufficient information and reports to determine the cardinal temperatures of this plant, this study aimed to investigate the effect of temperature on germination traits and early seedling growth and predict the cardinal temperatures (minimum, optimal and maximum) of germination for this plant.
Materials and Methods: This research was carried out at the Seed Sciences and Technology Laboratory of Agricultural College of Sarayan, the University of Birjand in 2017. Experiments were carried out in a completely randomized design with 8 levels of temperature treatments (5, 10, 15, 20, 25, 30, 35, and 40°C), with 5 replications. Germination percentage, daily germination speed, mean daily germination, plumule length, root length, and seedling length were calculated. Cardinal temperatures of germination were calculated using regression analysis with the aid of the proposed models (logistic, two-way, quadratic, and third-order polynomials) using germination speed. The data were analyzed using SAS software and the comparison means were done by Duncan's test at a probability level of 5%. Sigma Plot software was used to plot the germination rate against temperature graphs (for fitting different models).
Results: The results showed that the effect of different temperature levels on the percentage, speed and mean seed germination was significant (P <0.05). According to the results, the lowest values for percentage, speed, and average germination were obtained at 5, 10, and 40°C, and the highest germination speed was observed at 15 °C and also the highest percentage of germination and average germination was observed at 35°C. The results of the effect of different temperature levels on seedling growth showed that the effect of temperature on the seedling length, stem, and root length was significant (P <0.01), so that the lowest values related to seedling length, plumule, and radicle was found at 5, 10 and 40°C, and the maximum seedling and plumule length were 30°C.
Conclusion: Quantification of the gauge seed germination reaction to different temperature levels was carried out using four dual-functions, logistic, quadratic and triple polynomials. The second-order multitasking regression model, based on the coefficient of explanation (R2) and the amount of deviation, had a suitable and significant fit with the data related to germination rate against the independent temperature variable. Based on the parameters of the model, the optimum temperature was obtained at 26.05°C and the minimum and maximum temperature of guar germination were calculated to be 6.09 and 40°C.
Highlights:
Peyman Aligholizadeh Moghaddam, Gholam Ali Ranjbar, Hammid Najafi-Zarrini, Hosein Shahbazi,
Volume 7, Issue 2 (3-2021)
Volume 7, Issue 2 (3-2021)
Abstract
Extended Abstract
Introduction: Germination is one of the most important stages of plant growth that determines the durability, establishment and final yield of crops and in regions that due to drought conditions the growth of plant encounters with problem, improving germination traits count as one of the important breeding strategies. The present study was designed to determine the effect of different levels of osmotic stress on germination and seedling traits of some bread wheat cultivars cultivated in cold regions of Iran.
Materials and Methods: In order to investigate the effect of different levels of osmotic stress on germination characteristics of bread wheat cultivars cultivated in cold regions of Iran, a factorial experiment was conducted based on a completely randomized design with 3 replications in which, the first factor consisted of 20 bread wheat cultivars (including rain fed cultivars as well as end-of-season water stress tolerant varieties) and the second factor consisted of 3 levels of osmotic stress (non-stress, -3 and -6 bar stress). Seedling traits such as coleoptile length, shoot length, shoot weight, root length, root weight, root / shoot ratio, root growth angle, germination speed and the germination stress index (GSI) were evaluated. For the experiment concerning the yield comparison, 20 cultivars mentioned above were compared under non-stress and terminal drought stress conditions.
Results: The results showed that the ratio of root/shoot length and weight and shoot weight had the highest sensitivity and the lowest number of roots to osmotic stress. Increasing root length as root weight decreased with increasing stress showed that roots became longer and thinner due to stress. Among the genotypes, Saein, Zare, Pishgam, Sadra, Baran and Mihan had desirable traits and CrossMV17, Homa, Orum and Cross Azar2 had no desirable germination traits. In non-stress conditions, 11 genotypes had high coleoptile length including Hashtrood, Azar 2, Saein, CD62-6, CD91-12, Mihan, Baran, Heydari, Homa, Cross Azar 2 and Zare genotypes. At 3 bar stress, 11 genotypes had the highest coleoptile length, with the highest values being assigned to Hashtrood, Heidari and Saein. At 6 bar stress, CD91-12 and CD62-6 lines, Hashtrood, Homa, Pishgam, and Zare had the highest coleoptile length. At 3 bar stress cross Azar 2, Saein, CD62-6, Gascogen and HD2985 demonstrated the highest germination rate. Furthermore, Cross Azar2, HD2985, Gascogen, CD62-6 and Saein led to the best results, respectively. However, in both 3 and 6 bar stress conditions Saein, Cross Azar2, CD62-6 and HD2985 were superior for germination stress index (GSI). For grain yield under normal conditions, Gascogen, Heidari, Pishgam, Orum and Zarrineh had the highest yield and Baran, HD2985, C-88-4, C-9011 and Cross Azar2 were placed next. Under stress conditions Baran, Gascogen, HD2985, Cross Azar2, Heidari and Zarrineh consisted the highest performance. According to STI index Gascogen, Heidari, HD2985 and Zarrineh were the most tolerant genotypes to drought stress. Cluster analysis grouped the studied genotypes into 2 clusters, the first cluster comprising 13 genotypes Heidari, Mihan, HD2985, Baran, Pishgam, Hashtrood, Cross Azar 2, CD62-6, Gascogen, Azar 2, Saein, Sadra and Zare. The second cluster consisted of 7 genotypes C-88-4, Zarineh, C-90-11, Orum, CD91-12, CrossMV17 and Homa. Genotypes of cluster 1 were superior in terms of germination traits such as shoot length, coleoptile length, root length and root weight and reduced root/shoot ratio.
Conclusion: Significant differences in all studied traits among genotypes indicated sufficient genetic variation for selection in germination traits. Results showed that Saein, Zare, Pishgam, Sadra, Baran and Mihan cultivars had desirable germination traits and were superior to other genotypes.
Highlights:
1- The tested genotypes are either newly named or advanced lines and have not been studied for germination traits.
2-The growth angle trait of seed roots through filter paper has received little attention in studies.
Introduction: Germination is one of the most important stages of plant growth that determines the durability, establishment and final yield of crops and in regions that due to drought conditions the growth of plant encounters with problem, improving germination traits count as one of the important breeding strategies. The present study was designed to determine the effect of different levels of osmotic stress on germination and seedling traits of some bread wheat cultivars cultivated in cold regions of Iran.
Materials and Methods: In order to investigate the effect of different levels of osmotic stress on germination characteristics of bread wheat cultivars cultivated in cold regions of Iran, a factorial experiment was conducted based on a completely randomized design with 3 replications in which, the first factor consisted of 20 bread wheat cultivars (including rain fed cultivars as well as end-of-season water stress tolerant varieties) and the second factor consisted of 3 levels of osmotic stress (non-stress, -3 and -6 bar stress). Seedling traits such as coleoptile length, shoot length, shoot weight, root length, root weight, root / shoot ratio, root growth angle, germination speed and the germination stress index (GSI) were evaluated. For the experiment concerning the yield comparison, 20 cultivars mentioned above were compared under non-stress and terminal drought stress conditions.
Results: The results showed that the ratio of root/shoot length and weight and shoot weight had the highest sensitivity and the lowest number of roots to osmotic stress. Increasing root length as root weight decreased with increasing stress showed that roots became longer and thinner due to stress. Among the genotypes, Saein, Zare, Pishgam, Sadra, Baran and Mihan had desirable traits and CrossMV17, Homa, Orum and Cross Azar2 had no desirable germination traits. In non-stress conditions, 11 genotypes had high coleoptile length including Hashtrood, Azar 2, Saein, CD62-6, CD91-12, Mihan, Baran, Heydari, Homa, Cross Azar 2 and Zare genotypes. At 3 bar stress, 11 genotypes had the highest coleoptile length, with the highest values being assigned to Hashtrood, Heidari and Saein. At 6 bar stress, CD91-12 and CD62-6 lines, Hashtrood, Homa, Pishgam, and Zare had the highest coleoptile length. At 3 bar stress cross Azar 2, Saein, CD62-6, Gascogen and HD2985 demonstrated the highest germination rate. Furthermore, Cross Azar2, HD2985, Gascogen, CD62-6 and Saein led to the best results, respectively. However, in both 3 and 6 bar stress conditions Saein, Cross Azar2, CD62-6 and HD2985 were superior for germination stress index (GSI). For grain yield under normal conditions, Gascogen, Heidari, Pishgam, Orum and Zarrineh had the highest yield and Baran, HD2985, C-88-4, C-9011 and Cross Azar2 were placed next. Under stress conditions Baran, Gascogen, HD2985, Cross Azar2, Heidari and Zarrineh consisted the highest performance. According to STI index Gascogen, Heidari, HD2985 and Zarrineh were the most tolerant genotypes to drought stress. Cluster analysis grouped the studied genotypes into 2 clusters, the first cluster comprising 13 genotypes Heidari, Mihan, HD2985, Baran, Pishgam, Hashtrood, Cross Azar 2, CD62-6, Gascogen, Azar 2, Saein, Sadra and Zare. The second cluster consisted of 7 genotypes C-88-4, Zarineh, C-90-11, Orum, CD91-12, CrossMV17 and Homa. Genotypes of cluster 1 were superior in terms of germination traits such as shoot length, coleoptile length, root length and root weight and reduced root/shoot ratio.
Conclusion: Significant differences in all studied traits among genotypes indicated sufficient genetic variation for selection in germination traits. Results showed that Saein, Zare, Pishgam, Sadra, Baran and Mihan cultivars had desirable germination traits and were superior to other genotypes.
Highlights:
1- The tested genotypes are either newly named or advanced lines and have not been studied for germination traits.
2-The growth angle trait of seed roots through filter paper has received little attention in studies.
Ahmad Zare, Elham Elahifard, Zahra Asadinejad,
Volume 7, Issue 2 (3-2021)
Volume 7, Issue 2 (3-2021)
Abstract
Extended Abstract
Introduction: Syrian mesquite is introduced as a weed in wheat and barley fields, saffron, cotton and vegetables, and in orchards. The spread of this weed in different climates raises the question of how much native plant conditions can affect germination characteristics. Therefore, the purpose of this study was to evaluate the effect of native plant conditions on germination characteristics in response to environmental stresses (temperature, salinity, and drought).
Materials and Methods: To investigate dormancy elimination and germination response thresholds of two Syrian mesquite ecotypes (Khuzestan and Fars) to environmental factors (temperature, salinity, and drought), four separate experiments were carried out as factorial based on completely block design with three replications at Agricultural Sciences and Natural Resources University of Khuzestan. Treatments included immersion the seeds with concentrated sulfuric acid (96%) (0, 10, 15, 20, 25, and 30 min), different temperature (0, 5, 10, 15, 20, 25, 30, 35, 40, and 45 °C), salinity levels (0, 100, 200, 300, 400, 500, and 600 mM), and different levels of drought stress (0, 0.2, 0.4, 0.6, 0.8, 1 and 1.2 MPa).
Results: The time required for immersion of seeds in sulfuric acid to dormancy breaking for two ecotypes was different. The estimated parameters indicated time of immersion in sulfuric acid to reach 50% germination in the Khuzestan ecotype (11.38 min) was longer than the Fars ecotype (8.10 min). The Khuzestan ecotype was also able to germinate (45%) at 40 ° C, whereas germination in the Fars ecotype was stopped at this temperature. Germination rate and cumulative germination percentage at temperatures below 25 ° C were higher in Fars ecotype than in the Khuzestan ecotype. The results of the salinity experiment showed that 50% reduction in seed vigor index, final germination percentage, and germination rate in the Fars ecotype were 167.48, 404.46, and 307.02 mM respectively and in the Khuzestan ecotype were 0.89. 229, 380.16, and 299.57 mM, respectively. For drought treatments, 50% reduction in final germination percentage, seed vigor index, and germination rate in Fars ecotype were -0.50, -0.38, and -0.39 MPa, respectively, and in Khuzestan ecotype were -0.46, -0.46, and -0.50 MPa, respectively.
Conclusion: Overall, the results showed that native plant climatic conditions (latitude and longitude, elevation, rainfall, and temperature) can affect the degree of seed dormancy, resistance to environmental stresses such as temperature, salinity, and drought.
Highlights:
1- Seed germination response thresholds of two ecotypes of Fars and Khuzestan for exposure to temperature and drought and salinity stresses were compared.
Mahdi Asadi, Majid Rahimizadeh,
Volume 8, Issue 1 (9-2021)
Volume 8, Issue 1 (9-2021)
Abstract
Extended abstract
Introduction: Velvetleaf is one of the most important weeds of cotton, corn, tomato, and soybean fields. Certainly, knowledge of weed seed response to environmental factors (light and temperature) is essential for better understanding the germination mechanism and establishment patterns of weeds community. The present study aimed to evaluate the interaction between light regimes and alternate temperature on the seed germination of velvetleaf.
Materials and Methods: The experiment was conducted in 2015 at the plant physiology laboratory of Bojnourd Branch, IAU. This study was performed as a factorial experiment based on a completely randomized design (CRD) with four replications. The treatments were temperature regimes at four levels (constant temperatures 25°C, alternating temperatures 25-15, 30-20 and 35-25°C) and photoperiod treatments at three levels (continuous darkness, 12-12 light and dark and 16-8 light and dark). Germination percentage, germination rate, germination uniformity, time to 10% germination, and time to 90% germination were evaluated by the Germin program.
Results: The results showed that all traits were affected by temperature and light. Velvetleaf seeds germinated better in the presence of light and alternating temperature. The percentage and rate of germination increased as temperature rised to 30°c and then decreased. However, seed reaction to the night temperature was higher than that of the day temperature. The highest germination percent (98 percent) was achieved under alternating temperature 25-15°C with 12-12h light-dark. In this study, the lowest time required for 10% and 90% germination and highest germination uniformity were observed under alternating temperatures 30-20°C in darkness.
Conclusion: According to the results of this experiment, velvetleaf seeds are able to germinate in a wide range of light and temperature conditions, although they germinate better in the presence of light and alternate temperatures. Therefore, plowing with a moldboard plow can stimulate germination and drain the soil seed bank.
Highlights:
1- Since light stimulates the germination of velvetleaf seeds, so no-tillage system is able to control this weed.
2- Increasing the environment temperature reduces the chance of germination of velvetleaf seeds.
Farshid Yousefi, Abdolreza Sihampoosh, Abdolmahdi Bakhshandeh, Seyyed Amir Mousavi,
Volume 8, Issue 1 (9-2021)
Volume 8, Issue 1 (9-2021)
Abstract
Extended Abstract
Introduction: Coneflower herbal medicinal plant is from the Asteraceae family, native to North America. Because of its immune-boosting properties, it is used to treat a variety of pathogens. The seed germination stage is one of the crucial and crucial stages in the growth cycle of plant species that can play an important role in the production process by optimal establishment of seedlings. Seed of Coneflower germinates and grows very slowly and weakly. Therefore, the use of some plant growth regulators, such as the gibberellin hormone, can play an important role in improving seed germination. The aim of this study was investigate the effect of hormone seed priming using gibberellin on seed germination quality of Coneflower.
Material and Methods: A factorial experiment was conducted based on the complete randomized design arranged with three replications. The experiment was conducted at the seed technology laboratory of Agricultural Sciences and Natural Resources University of Khuzestan, 2018. Experimental treatments were different concentrations of gibberellin (0, 50, 100, 200, 400, and 800 mg/l) as the first factor and the durations of seed priming (12, 24, and 48 hour) as the second factor.
Results: Results of in vitro studies showed that the interaction of gibberellin in priming time on percentage, rate and mean germination time, root and shoot length, seed vigor index, peroxidase activity at 1% and Seed soluble protein content was significant at 5% level. Seed germination quality and protein content increased by the application of 200 mg/l gibberellin for the 24 hours, whereas at the concentrations of 400 and 800 mg/l, gibberellin reduced germination quality and antioxidant enzymes activities. Results of stepwise regression models of antioxidant enzymes activity and protein content with germination indices showed that these traits were significantly entered into the prediction model. It was observed that in all traits except for the rate and the mean germination time, the amount of protein entered the prediction equation. In general, stepwise regression models predicted stem length and power index better than other traits and showed the highest coefficients in these traits with values of 0.85 and 0.83. Also, catalase and peroxidase activities were significantly correlated with rate and mean germination time only. The amount of soluble protein had a positive and significant correlation with all studied traits except germination rate and mean germination time. The highest correlation coefficients for protein content were obtained from longitudinal power index with correlation coefficient (r = 0.856).
Conclusion: Based on the obtained results, the best hormone priming treatment was 200 mg/l gibberellin for the durations of 24 hour.
Highlights:
1- The role of gibberellin hormone on seed germination traits Coneflower was evaluated
2- The effect of gibberellin hormone on the activity of antioxidant enzymes and soluble proteins during seed germination was investigated.
Introduction: Coneflower herbal medicinal plant is from the Asteraceae family, native to North America. Because of its immune-boosting properties, it is used to treat a variety of pathogens. The seed germination stage is one of the crucial and crucial stages in the growth cycle of plant species that can play an important role in the production process by optimal establishment of seedlings. Seed of Coneflower germinates and grows very slowly and weakly. Therefore, the use of some plant growth regulators, such as the gibberellin hormone, can play an important role in improving seed germination. The aim of this study was investigate the effect of hormone seed priming using gibberellin on seed germination quality of Coneflower.
Material and Methods: A factorial experiment was conducted based on the complete randomized design arranged with three replications. The experiment was conducted at the seed technology laboratory of Agricultural Sciences and Natural Resources University of Khuzestan, 2018. Experimental treatments were different concentrations of gibberellin (0, 50, 100, 200, 400, and 800 mg/l) as the first factor and the durations of seed priming (12, 24, and 48 hour) as the second factor.
Results: Results of in vitro studies showed that the interaction of gibberellin in priming time on percentage, rate and mean germination time, root and shoot length, seed vigor index, peroxidase activity at 1% and Seed soluble protein content was significant at 5% level. Seed germination quality and protein content increased by the application of 200 mg/l gibberellin for the 24 hours, whereas at the concentrations of 400 and 800 mg/l, gibberellin reduced germination quality and antioxidant enzymes activities. Results of stepwise regression models of antioxidant enzymes activity and protein content with germination indices showed that these traits were significantly entered into the prediction model. It was observed that in all traits except for the rate and the mean germination time, the amount of protein entered the prediction equation. In general, stepwise regression models predicted stem length and power index better than other traits and showed the highest coefficients in these traits with values of 0.85 and 0.83. Also, catalase and peroxidase activities were significantly correlated with rate and mean germination time only. The amount of soluble protein had a positive and significant correlation with all studied traits except germination rate and mean germination time. The highest correlation coefficients for protein content were obtained from longitudinal power index with correlation coefficient (r = 0.856).
Conclusion: Based on the obtained results, the best hormone priming treatment was 200 mg/l gibberellin for the durations of 24 hour.
Highlights:
1- The role of gibberellin hormone on seed germination traits Coneflower was evaluated
2- The effect of gibberellin hormone on the activity of antioxidant enzymes and soluble proteins during seed germination was investigated.
Mahnaz Mansouri, Ali Moradi, Hamidreza Balouchi, Elias Soltani,
Volume 8, Issue 1 (9-2021)
Volume 8, Issue 1 (9-2021)
Abstract
Extended abstract
Introduction: Seed is the most important sexual reproductive factor in plants that plays an important role in transmitting hereditary characteristics, plant distribution, and establishment in different regions. Seed germination as one of the most important and complex stages in the life cycle of plants is affected by genetic and environmental factors. Drought stress is one of the main barriers of crop plants and trees, production in many parts of the world, especially in arid and semi-arid regions such as Iran. The purpose of this study was to investigate the effect of drought stress on biochemical and seed germination indices of different seed lot of Ziziphus spina–christi as suitable medicinal species for controlling soil erosion in arid regions.
Materials and Methods: This experiment was conducted as a factorial based on a completely randomized design with four replications at the Seed Science and Technology Laboratory of Yasouj University in 2018. Experimental factors included Ziziphus spina–Christi seeds collected from the regions of Minab, Kazeroon, Masjed Soleiman, and Dehdasht and five water potentials including zero, -2, -4, -6, and -8 bar.
Results: In the present study, the effect of osmotic potential, seed lot, and their interaction were significant in each seed lot on germination (germination percentage, germination rate, seedling length, allometric index, longitudinal vigor) and biochemical (hydrogen peroxide, soluble protein content, Proline, catalase, and ascorbate peroxidase) indices of Ziziphus spina–christi. The results showed that except for allometric index response of all studied germination traits to osmotic potential was decreasing, Also with increasing osmotic potential, seed soluble protein was decreased and the amount of proline and activity of catalase and ascorbate peroxidase increased. With increasing osmotic stress, the root length was significantly increased, which increased the allometric coefficient of the seedling.
Conclusion: Germination and biochemical indices of seeds of all seedlots had significant changes with the reduction of osmotic potential and the reduction of osmotic potential was associated with reduced germination and plant establishment capability. These results can help us to recognize the prerequisites of germination and the development of the forests.
Highlights:
1- Germination indices of seeds related to several Ziziphus spina–christi seed lots were investigated under different water potentials.
2- Biochemical aspects related to seed dormancy in several Ziziphus spina–christi seed lots were evaluated.
Introduction: Seed is the most important sexual reproductive factor in plants that plays an important role in transmitting hereditary characteristics, plant distribution, and establishment in different regions. Seed germination as one of the most important and complex stages in the life cycle of plants is affected by genetic and environmental factors. Drought stress is one of the main barriers of crop plants and trees, production in many parts of the world, especially in arid and semi-arid regions such as Iran. The purpose of this study was to investigate the effect of drought stress on biochemical and seed germination indices of different seed lot of Ziziphus spina–christi as suitable medicinal species for controlling soil erosion in arid regions.
Materials and Methods: This experiment was conducted as a factorial based on a completely randomized design with four replications at the Seed Science and Technology Laboratory of Yasouj University in 2018. Experimental factors included Ziziphus spina–Christi seeds collected from the regions of Minab, Kazeroon, Masjed Soleiman, and Dehdasht and five water potentials including zero, -2, -4, -6, and -8 bar.
Results: In the present study, the effect of osmotic potential, seed lot, and their interaction were significant in each seed lot on germination (germination percentage, germination rate, seedling length, allometric index, longitudinal vigor) and biochemical (hydrogen peroxide, soluble protein content, Proline, catalase, and ascorbate peroxidase) indices of Ziziphus spina–christi. The results showed that except for allometric index response of all studied germination traits to osmotic potential was decreasing, Also with increasing osmotic potential, seed soluble protein was decreased and the amount of proline and activity of catalase and ascorbate peroxidase increased. With increasing osmotic stress, the root length was significantly increased, which increased the allometric coefficient of the seedling.
Conclusion: Germination and biochemical indices of seeds of all seedlots had significant changes with the reduction of osmotic potential and the reduction of osmotic potential was associated with reduced germination and plant establishment capability. These results can help us to recognize the prerequisites of germination and the development of the forests.
Highlights:
1- Germination indices of seeds related to several Ziziphus spina–christi seed lots were investigated under different water potentials.
2- Biochemical aspects related to seed dormancy in several Ziziphus spina–christi seed lots were evaluated.
Morteza Gorzin, Farshid Ghaderi-Far, Hamid Reza Sadeghipour, Ebrahim Zeinali,
Volume 8, Issue 1 (9-2021)
Volume 8, Issue 1 (9-2021)
Abstract
Extended abstract
Introduction: Since the maximum percentage and rate of germination of rapeseed occur at a certain temperature, finding these temperatures can play an important role in determining the appropriate time and place for the cultivation of different cultivars. Also, light can affect the germination percentage of rapeseed at different temperatures, but the response of rapeseed to light, especially at lower and higher temperatures, has not been studied. Therefore, this study aimed to investigate the changes in the germination of rapeseed cultivars at different temperatures and determine cardinal germination temperatures based on germination percentage and rate under both the presence and absence of light conditions.
Materials and methods: In this study, germination tests were carried out at 5, 10, 15, 20, 25, 30, 35, 37, and 40°C temperatures in two light conditions (12 h light / 12 h dark) and darkness on nine spring cultivars (Traper, Agamax, Hayola-50, Hayola-420, RGS, Mahtab, Hayola-61, Zafar, and Zarfam) and one winter cultivar (Garo). The four-parameter Hill model was used to describe germination changes over time and the dent model was used to calculate cardinal temperatures. Seed viability at lower and higher temperatures was evaluated by the tetrazolium test.
Results: The evaluation of the trend of cumulative germination percentage over time in different cultivars showed that maximum germination percentage of all cultivars happened in the temperature range between 15-30 °C, some in the temperature range of 10-30 °C (Hyola-61) and others even in the temperature range of 5-30 °C (RGS, Mahtab, Garo, Zafar, and Zarfam) had the highest germination percentage. The highest germination rate in all cultivars was observed at the temperature range of 22-35 °C. Light only had an effect on the germination percentage of the seeds at sub and super optimal temperatures. At these temperatures, light increased the germination percentage. The remaining seed of 5, 10, 35, 37, and 40 °C temperature after transfer to 20 °C did not germinate, whereas most of them were viable based on the tetrazolium test.
Conclusion: The difference in the optimum temperature range for germination percentage and rate showed that to optimize seed performance, the optimal temperature range between the germination percentage and germination rate should be considered as the optimum temperature for germination. At sub and supra optimal temperatures, light leads to improved germination in some cultivars. The effect of light on germination at supra optimal temperatures was far higher than that of sub-optimal ones. Survival of the remaining seeds at the sub and supra optimal temperatures in some cultivars provided evidence of thermo-dormancy in these cultivars, this issue needs further investigation in the future.
Highlights:
1- The cardinal temperatures were studied based on both the percentage and rate of germination and the effect of light on them.
2- Some new varieties such as Traper and Agamax that little information about their characteristics is available were examined.
3- In this study, the reason for the lack of germination of rapeseed at the sub and supra optimal temperatures especially in the darkness has been mentioned.
Introduction: Since the maximum percentage and rate of germination of rapeseed occur at a certain temperature, finding these temperatures can play an important role in determining the appropriate time and place for the cultivation of different cultivars. Also, light can affect the germination percentage of rapeseed at different temperatures, but the response of rapeseed to light, especially at lower and higher temperatures, has not been studied. Therefore, this study aimed to investigate the changes in the germination of rapeseed cultivars at different temperatures and determine cardinal germination temperatures based on germination percentage and rate under both the presence and absence of light conditions.
Materials and methods: In this study, germination tests were carried out at 5, 10, 15, 20, 25, 30, 35, 37, and 40°C temperatures in two light conditions (12 h light / 12 h dark) and darkness on nine spring cultivars (Traper, Agamax, Hayola-50, Hayola-420, RGS, Mahtab, Hayola-61, Zafar, and Zarfam) and one winter cultivar (Garo). The four-parameter Hill model was used to describe germination changes over time and the dent model was used to calculate cardinal temperatures. Seed viability at lower and higher temperatures was evaluated by the tetrazolium test.
Results: The evaluation of the trend of cumulative germination percentage over time in different cultivars showed that maximum germination percentage of all cultivars happened in the temperature range between 15-30 °C, some in the temperature range of 10-30 °C (Hyola-61) and others even in the temperature range of 5-30 °C (RGS, Mahtab, Garo, Zafar, and Zarfam) had the highest germination percentage. The highest germination rate in all cultivars was observed at the temperature range of 22-35 °C. Light only had an effect on the germination percentage of the seeds at sub and super optimal temperatures. At these temperatures, light increased the germination percentage. The remaining seed of 5, 10, 35, 37, and 40 °C temperature after transfer to 20 °C did not germinate, whereas most of them were viable based on the tetrazolium test.
Conclusion: The difference in the optimum temperature range for germination percentage and rate showed that to optimize seed performance, the optimal temperature range between the germination percentage and germination rate should be considered as the optimum temperature for germination. At sub and supra optimal temperatures, light leads to improved germination in some cultivars. The effect of light on germination at supra optimal temperatures was far higher than that of sub-optimal ones. Survival of the remaining seeds at the sub and supra optimal temperatures in some cultivars provided evidence of thermo-dormancy in these cultivars, this issue needs further investigation in the future.
Highlights:
1- The cardinal temperatures were studied based on both the percentage and rate of germination and the effect of light on them.
2- Some new varieties such as Traper and Agamax that little information about their characteristics is available were examined.
3- In this study, the reason for the lack of germination of rapeseed at the sub and supra optimal temperatures especially in the darkness has been mentioned.
Marjan Diyanat, Pouya Sonboli-Hamedani, Fereidoon Ghasem-Khan Ghajar,
Volume 8, Issue 1 (9-2021)
Volume 8, Issue 1 (9-2021)
Abstract
Extended Abstract
Introduction: Seed dormancy is the most important factor that prevents weed seed germination. Lack of simultaneous germination of weed seeds causes a number of problems in their control due to seed dormancy in the fields; therefore, weed seed dormancy is considered to be an undesirable trait for farmers. The aim of this study was to investigate the effect of magnetic field on seed dormancy elimination in some weed species.
Material and Methods: In order to study the effect of Magnetic field on germination and seedling growth of redroot pigweed (Amaranthus retroflexus), spring wild oat (Avena fatua) and common purslane (Portulaca oleraceae), a factorial experiment based on completely randomized design was conducted at the Ecology laboratory of Science Research Branch, Islamic Azad University in 2019. Factors consisted of dormancy breaking treatment at 8 levels (gibberellic acid 1000 mg/l for 20 minutes, gibberellic acid 2000 mg/l for 20 minutes, sulfuric acid for 5 minutes, sulfuric acid for 10 minutes, sulfuric acid for 20 minutes, nitrate potassium at 0.01 g/L, nitrate potassium at 0.05 g/L and control) and magnetic field at 4 levels (0, 25, 50 and 100 mT).
Results: Results showed that responses of three weed species to magnetic field were different. Magnetic field increased percentage of germination, fresh weight of plumule and length of plumule of redroot pigweed, so magnetic field at 100 mT was the best treatment for dormancy breaking. The highest germination percentage of wild oat was obtained in 0.01 mM potassium nitrate at 50 mT. The length plumule of wild oat increased significantly at 2000 mg/l gibberellic acid with increasing magnetic field level from zero to 25 mM. Nitrate potassium at 0.05 g/L was the best treatment for breaking the dormancy of common purslane. Magnetic field at 100 mT could increase percentage of germination of this weed.
Conclusion: In general, the results of this study showed that sulfuric acid treatment was not a suitable option for the removal of dormancy in the three weed species because of the elimination of seed embryos. Magnetic field treatment significantly increased the studied traits in all three species of redroot pigweed, spring wild oat and purslane. The interaction between dormancy breaking treatment and magnetic field was significant in many of the studied traits and the effect of dormancy breaking treatment was intensified by magnetic field. Therefore, the use of magnetic field treatment is recommended to increase the germination of these three species.
Highlights:
1- There is a positive and significant interaction between seed dormancy elimination treatments and magnetic field.
2- Sulfuric acid treatment is not a suitable option for breaking the dormancy of redroot pigweed, spring wild oat and purslane.
Introduction: Seed dormancy is the most important factor that prevents weed seed germination. Lack of simultaneous germination of weed seeds causes a number of problems in their control due to seed dormancy in the fields; therefore, weed seed dormancy is considered to be an undesirable trait for farmers. The aim of this study was to investigate the effect of magnetic field on seed dormancy elimination in some weed species.
Material and Methods: In order to study the effect of Magnetic field on germination and seedling growth of redroot pigweed (Amaranthus retroflexus), spring wild oat (Avena fatua) and common purslane (Portulaca oleraceae), a factorial experiment based on completely randomized design was conducted at the Ecology laboratory of Science Research Branch, Islamic Azad University in 2019. Factors consisted of dormancy breaking treatment at 8 levels (gibberellic acid 1000 mg/l for 20 minutes, gibberellic acid 2000 mg/l for 20 minutes, sulfuric acid for 5 minutes, sulfuric acid for 10 minutes, sulfuric acid for 20 minutes, nitrate potassium at 0.01 g/L, nitrate potassium at 0.05 g/L and control) and magnetic field at 4 levels (0, 25, 50 and 100 mT).
Results: Results showed that responses of three weed species to magnetic field were different. Magnetic field increased percentage of germination, fresh weight of plumule and length of plumule of redroot pigweed, so magnetic field at 100 mT was the best treatment for dormancy breaking. The highest germination percentage of wild oat was obtained in 0.01 mM potassium nitrate at 50 mT. The length plumule of wild oat increased significantly at 2000 mg/l gibberellic acid with increasing magnetic field level from zero to 25 mM. Nitrate potassium at 0.05 g/L was the best treatment for breaking the dormancy of common purslane. Magnetic field at 100 mT could increase percentage of germination of this weed.
Conclusion: In general, the results of this study showed that sulfuric acid treatment was not a suitable option for the removal of dormancy in the three weed species because of the elimination of seed embryos. Magnetic field treatment significantly increased the studied traits in all three species of redroot pigweed, spring wild oat and purslane. The interaction between dormancy breaking treatment and magnetic field was significant in many of the studied traits and the effect of dormancy breaking treatment was intensified by magnetic field. Therefore, the use of magnetic field treatment is recommended to increase the germination of these three species.
Highlights:
1- There is a positive and significant interaction between seed dormancy elimination treatments and magnetic field.
2- Sulfuric acid treatment is not a suitable option for breaking the dormancy of redroot pigweed, spring wild oat and purslane.
Majid Ghanbari, Seyed Ali Mohammad Modarres-Sanavy, Ali Mokhtassi-Bidgoli,
Volume 8, Issue 1 (9-2021)
Volume 8, Issue 1 (9-2021)
Abstract
Extended Abstract
Introduction: Medicinal herbs are of particular importance in the treatment and prevention of diseases. Indian Cheese Maker has strengthening, liver repair, anti-inflammatory properties and is useful in the treatment of bronchitis, asthma, wounds, neurological disorders such as Parkinson's and Alzheimer's. Evaluation of seed quality as a propagating organ and the most important input for crop production and medicinal products has a special place in seed production, control and certification. Studying germination and biological properties of seeds of medicinal plants and methods of breaking dormancy in them are among basic and primary studies of domestication of medicinal plants. In the meantime, scrubbing with abrasives changes the integrity of the seed shell and allows the seeds to be permeable to water and gases. The researchers stated that the dormancy of seeds containing inhibitory metabolic materials can be reduced by removing the seed shell through mechanical scarification and osmopriming. For this purpose, the effect of scarification and potassium nitrate on germination and enzymatic properties of Indian Cheese Maker was evaluated.
Material and Method: This study was conducted as factorial based on a completely randomized design with three replications during 2015-16 at the laboratory of Department of Agronomy, Tarbiat Modares University. Potassium nitrate solution (0, 0.5, 1 and 1.5 mg.l-1 from KNO3), scarification (un-use and scarification with soft sanding) and osmopriming durations (8, 16, 24 and 32 hour) were experimental factors. The experiment was performed on Indian Cheese Maker seeds, landrace of Khash. Petri dishes were placed in a germinator at 25 ° C and in full lighting for 14 days. In this experiment, germination rate and percentage of germination, mean of germination time and daily germination, seed vigority, alpha and beta amylase were measured.
Results: The results of the experiment showed that in scarification, the highest germination percentage (69.47%) was obtained by seed priming at a concentration of 1.5 mg.l-1 potassium nitrate for 19 hours under abrasion. In scarification, germination rate increased at 16 and 32 hour, 0.62 and 1.17 No.day-1 for each mg.l-1 of potassium nitrate. The highest daily mean germination (0.15) was observed at 1.5 mg.l-1 potassium nitrate and 24 hour time and decreased to 8 hours mean germination time (7.39 days) by reducing pretreatment time. Also, the highest mean germination time (9.35 days) was observed in 32 hours pretreatment with potassium nitrate and the highest mean germination time in non-scarification condition (9.13 days) and in scarification condition decreased with mean of germination time (8.04 days). The activity of alpha and beta-amylase germination enzymes was affected by different concentrations of potassium nitrate and scarification and at high concentrations of potassium nitrate the activity of these enzymes decreased.
Conclusions: In general, application of potassium nitrate osmopriming, by improving the activity of germination enzymes and increasing seed germination properties of Indian Cheese Maker, increased the activity of hydrolyzing enzymes in the endosperm of germinated seeds, which reduced the mean germination time, increased germination rate and germination percentage. In general, seed scarification with low concentrations of potassium nitrate at 16 to 24 hours is recommended for breaking seed dormancy of Indian Cheese Maker.
Highlights:
Introduction: Medicinal herbs are of particular importance in the treatment and prevention of diseases. Indian Cheese Maker has strengthening, liver repair, anti-inflammatory properties and is useful in the treatment of bronchitis, asthma, wounds, neurological disorders such as Parkinson's and Alzheimer's. Evaluation of seed quality as a propagating organ and the most important input for crop production and medicinal products has a special place in seed production, control and certification. Studying germination and biological properties of seeds of medicinal plants and methods of breaking dormancy in them are among basic and primary studies of domestication of medicinal plants. In the meantime, scrubbing with abrasives changes the integrity of the seed shell and allows the seeds to be permeable to water and gases. The researchers stated that the dormancy of seeds containing inhibitory metabolic materials can be reduced by removing the seed shell through mechanical scarification and osmopriming. For this purpose, the effect of scarification and potassium nitrate on germination and enzymatic properties of Indian Cheese Maker was evaluated.
Material and Method: This study was conducted as factorial based on a completely randomized design with three replications during 2015-16 at the laboratory of Department of Agronomy, Tarbiat Modares University. Potassium nitrate solution (0, 0.5, 1 and 1.5 mg.l-1 from KNO3), scarification (un-use and scarification with soft sanding) and osmopriming durations (8, 16, 24 and 32 hour) were experimental factors. The experiment was performed on Indian Cheese Maker seeds, landrace of Khash. Petri dishes were placed in a germinator at 25 ° C and in full lighting for 14 days. In this experiment, germination rate and percentage of germination, mean of germination time and daily germination, seed vigority, alpha and beta amylase were measured.
Results: The results of the experiment showed that in scarification, the highest germination percentage (69.47%) was obtained by seed priming at a concentration of 1.5 mg.l-1 potassium nitrate for 19 hours under abrasion. In scarification, germination rate increased at 16 and 32 hour, 0.62 and 1.17 No.day-1 for each mg.l-1 of potassium nitrate. The highest daily mean germination (0.15) was observed at 1.5 mg.l-1 potassium nitrate and 24 hour time and decreased to 8 hours mean germination time (7.39 days) by reducing pretreatment time. Also, the highest mean germination time (9.35 days) was observed in 32 hours pretreatment with potassium nitrate and the highest mean germination time in non-scarification condition (9.13 days) and in scarification condition decreased with mean of germination time (8.04 days). The activity of alpha and beta-amylase germination enzymes was affected by different concentrations of potassium nitrate and scarification and at high concentrations of potassium nitrate the activity of these enzymes decreased.
Conclusions: In general, application of potassium nitrate osmopriming, by improving the activity of germination enzymes and increasing seed germination properties of Indian Cheese Maker, increased the activity of hydrolyzing enzymes in the endosperm of germinated seeds, which reduced the mean germination time, increased germination rate and germination percentage. In general, seed scarification with low concentrations of potassium nitrate at 16 to 24 hours is recommended for breaking seed dormancy of Indian Cheese Maker.
Highlights:
- Germination rate and percentage of Indian Cheese Maker seed were monitored by osmopriming and scarification.
- The role of α and β amylase germination enzymes in accelerating dormancy breaking of Indian Cheese Maker was studied.
- Mean time and mean daily germination during the dormancy breaking process of Indian Cheese Maker were estimated.
Aidin Hamidi, Samad Allah Karami, Victoria Askari,
Volume 8, Issue 1 (9-2021)
Volume 8, Issue 1 (9-2021)
Abstract
Extended Abstract
Introduction: Cotton is the most important fiber-oil seed crop. Seed germination, vigour and health are the most important aspects of cotton seed quality. In Iran, annual cotton seed requirement is near 4000 tones, half of which is delinted and half is provided as fuzzy seed and therefore infection of fuzzy seeds to seed borne disease pathogens is possible. Every year a part of produced cotton seed does not possess standard quality and is not certify for various reasons including infection with seed borne disease pathogens. Thereafter, this research was conducted in order to study the relationship among cotton commercial cultivars seed germination, vigour and health.
Materials and Methods: Fuzzy seeds lots samples of Sahel, Varamin, Bakhtegan and Mehr cotton commercial cultivars with of 80, 90, and 95 percent intial germination ability (normal seedlings percent) produced at Golestan, Khorasan Razavi, Fars, and Ardabil provinces respectively underwent Standard germination and accelerated ageing tests. Final germination percent before and after accelerated ageing, normal seedlings percent after accelerated ageing, decayed seeds percent before and after accelerated ageing, mean germination time, seedling length, dry weight, seedling length and weight vigour indices after accelerated ageing were measured and the fungus on decayed seeds were determined by blotter test. Then, their average frequency was determined.
Results: Sahel and Bakhtegan cultivars and seeds having the highest primary germination ability had the most final germination percent before accelerated ageing and Sahel cultivar seed with the highest and moderate initial germination had the highest final germination percent after accelerated ageing. Sahel cultivar seeds had the highest normal seedlings percent after accelerated ageing. The highest decayed seeds percent before accelerated ageing belonged to Varamin and Mehr cultivars with moderate and low intial germination ability, and the highest decayed seeds percent after accelerated ageing belonged to Varamin and Mehr cultivars with low intial germination ability. Seeds having the lowest primary germination ability had the highest mean germination time and Sahel cultivar seeds had the highest seedling length and weight vigour indices. All studied cultivars seeds had been contaminated with Fusarium spp., Alternaria spp., Aspergillus spp. and Trichothecium roseum. Also, Varamin and Mehr cultivars seeds had the highest and Sahel cultivar seeds had the lowest average frequency of fungus on decayed seeds. Final germination percent before and after accelerated ageing and seedling length and weight vigour indices had significant negative correlation with decayed seeds percent before and after accelerated ageing.
Conclusion: Seeds decay was the most important factor of studied cotton cultivars seed deterioration and germination and seedling vigour decrease. Sahel and Mehr cultivars seeds and seeds with the highest (95 percent) and lowest (80 percent) intial germination ability seeds respectively had the highest (91 percent) and lowest (58 percent) seed final germination percent and seedling vigour. Alternaria spp., Aspergillus spp. on Mehr cultivar seeds, Fusarium spp. on Varamin cultivar seeds and Trichothecium roseum on Bakhtegan cultivars seeds with average frequency on decayed seeds after accelerated ageing of respectively 100, 99, 80.70 and 63 percent were the fungus that led to the most seeds germination and seedlings vigour decrease.
Highlights:
Introduction: Cotton is the most important fiber-oil seed crop. Seed germination, vigour and health are the most important aspects of cotton seed quality. In Iran, annual cotton seed requirement is near 4000 tones, half of which is delinted and half is provided as fuzzy seed and therefore infection of fuzzy seeds to seed borne disease pathogens is possible. Every year a part of produced cotton seed does not possess standard quality and is not certify for various reasons including infection with seed borne disease pathogens. Thereafter, this research was conducted in order to study the relationship among cotton commercial cultivars seed germination, vigour and health.
Materials and Methods: Fuzzy seeds lots samples of Sahel, Varamin, Bakhtegan and Mehr cotton commercial cultivars with of 80, 90, and 95 percent intial germination ability (normal seedlings percent) produced at Golestan, Khorasan Razavi, Fars, and Ardabil provinces respectively underwent Standard germination and accelerated ageing tests. Final germination percent before and after accelerated ageing, normal seedlings percent after accelerated ageing, decayed seeds percent before and after accelerated ageing, mean germination time, seedling length, dry weight, seedling length and weight vigour indices after accelerated ageing were measured and the fungus on decayed seeds were determined by blotter test. Then, their average frequency was determined.
Results: Sahel and Bakhtegan cultivars and seeds having the highest primary germination ability had the most final germination percent before accelerated ageing and Sahel cultivar seed with the highest and moderate initial germination had the highest final germination percent after accelerated ageing. Sahel cultivar seeds had the highest normal seedlings percent after accelerated ageing. The highest decayed seeds percent before accelerated ageing belonged to Varamin and Mehr cultivars with moderate and low intial germination ability, and the highest decayed seeds percent after accelerated ageing belonged to Varamin and Mehr cultivars with low intial germination ability. Seeds having the lowest primary germination ability had the highest mean germination time and Sahel cultivar seeds had the highest seedling length and weight vigour indices. All studied cultivars seeds had been contaminated with Fusarium spp., Alternaria spp., Aspergillus spp. and Trichothecium roseum. Also, Varamin and Mehr cultivars seeds had the highest and Sahel cultivar seeds had the lowest average frequency of fungus on decayed seeds. Final germination percent before and after accelerated ageing and seedling length and weight vigour indices had significant negative correlation with decayed seeds percent before and after accelerated ageing.
Conclusion: Seeds decay was the most important factor of studied cotton cultivars seed deterioration and germination and seedling vigour decrease. Sahel and Mehr cultivars seeds and seeds with the highest (95 percent) and lowest (80 percent) intial germination ability seeds respectively had the highest (91 percent) and lowest (58 percent) seed final germination percent and seedling vigour. Alternaria spp., Aspergillus spp. on Mehr cultivar seeds, Fusarium spp. on Varamin cultivar seeds and Trichothecium roseum on Bakhtegan cultivars seeds with average frequency on decayed seeds after accelerated ageing of respectively 100, 99, 80.70 and 63 percent were the fungus that led to the most seeds germination and seedlings vigour decrease.
Highlights:
- Cotton commercial cultivars seed lots seed borne fungi and contamination rate were identified.
The relationship of cotton commercial cultivars seeds germination percent and seedling vigour with contamination to seed borne fungi were determined
Ahmad Zare, Fatemeh Deris, Zahra Karimi,
Volume 8, Issue 1 (9-2021)
Volume 8, Issue 1 (9-2021)
Abstract
Extended Abstract
Introduction: Notobasis (Syrian Thistle (has been introduced as a weed - medicinal plant. In Khuzestan province, the presence of Notobasis is abundant in cereal fields, especially field margins. For successful weed control, knowledge of weed biology and ecology (temperature, salinity and drought stresses) plays a key role in population dynamics of weeds and weed management. Therefore, the study aimed to evaluate Syrian Thistle response to temperature, salinity and drought, as well as to determine the cardinal temperature based on segmented, beta-four-parameter and dent-like models.
Materials and Methods: To investigate the effect of temperature (5, 10, 15, 20, 25, 30, 35 and 40 °C), salinity (zero, 50, 100, 150, 200, 250 and 300 mM) and drought stress (zero, 2) -0.0, -0.4, -0.6, -0.8, -1, -1.2 and -1.4 MPa). Three separate experiments were conducted in 2019 at agricultural science and natural resources university of Khuzestan at the laboratory of weed science with 6 replications. In each Petri dish, 25 seeds were placed and 7 ml of solution was added. In salinity and drought stresses experiments, sodium chloride solution and polyethylene glycol 6000 were used.
Results: Germination of Notobasis at temperatures of 5-30°C was more than 90%, and germination percent decreased to 24% as the temperature increased to 35°C, Based on three models segmented, beta 4 parameter and Dent-like, the Base temperature was estimated 2.95, 2.01 and 0.67°C respectively. Also, the optimum temperature in two models (segmented and beta parameter) was obtained 22.26 and 23.40°C respectively. Ceiling temperature was predicted 40.57, 39.75 and 40.03°C in three models (segmented, beta 4 parameter and Dent- like). Salinity required to reduce 50% of germination percentage, germination rate, seedling length and seedling fresh weight were 152, 85, 151 and 127 mM. 50% reduction of traits such as germination percent, germination rate, seedling length and seedling fresh weight were -0.81, -0.41, -0.43 and -0.45 MPa of drought stress respectively.
Conclusion: The results indicated that Notobasis had germination in a wide range of temperatures (5-35°C). In response to environmental stress, Notobasis have been identified as a weed resistant to salinity and drought stresses. Therefore, the presence of this weed in saline fields and arid areas is not unexpected.
Highlights:
1-To determine of cardinal temperature of Notobasis based on different models.
2-To evaluate germination ecology of Notobasis to environmental factors (temperature, salinity and drought stress) as the first report.
Maryam Boroujerdnia, Hamed Hasanzade Khankahdani,
Volume 8, Issue 2 (3-2022)
Volume 8, Issue 2 (3-2022)
Abstract
Extend abstract
Introduction: Guava (Psidium guajava L.) is one of the most important fruit crops of tropical and subtropical regions. Guava (Psidium guajava L.) can be propagated by seed, layering, grafting, cutting or tissue culture. Propagation by seed is used for the production of seedlings usable in breeding programs or rootstock production for grafting. Guava seeds germinate poorly and unevenly and require more time for seedling emergence. The dormancy in seeds might be due to hard seed coat and different methods are used for breaking dormancy in seeds to improve germination. The aim of this study was to evaluate efficiency of the different pretreatment on seed dormancy breaking and germination characteristics of guava.
Materials and Methods: The experiment was laid out in a completely randomized design with three replications on guava seeds in genetic and breeding laboratory of Date Palm and Tropical Fruit Research Center at the summer of 2018. Treatments consisted of distilled water (24 and 48 h), 0.5 and 1% potassium nitrate (KNO3) for 24 h, warm water (70 ° C) for 5 and 10 min, 25% and 50% sulphuric acid for 5 min, and control (non-treated). In this study, the traits of germination percentage, germination rate and mean of daily germination, seed vigour index and fresh weight and length of seedling were measured. Data analysis was done using the SAS 9.2 software and the Duncan's test at 5% probability level was used for mean comparison.
Results: Results showed that the effect of treatments on seed germination indices (germination percentage, germination rate and mean of daily germination, seed vigour index) of guava was significant at p<0.01. The greatest germination percentage (53.1%), germination rate (6.6 seed/day) and seed vigour (2636.7) were observed in treatment of 1% potassium nitrate (KNO3) for 24 h. The lowest Mean time to germination (14 days) was obtained in distilled water for 48h. Warm water treatments at 70 °C and 25% and 50% sulfuric acid were not effective in improving seed germination compared to control. The highest seed length and weight were observed in 1% potassium nitrate and 0.5% potassium nitrate pretreatments, respectively.
Conclusions: the results of this study show that among the different treatments, pre-treatment of seeds with 1%potassium nitrate may be considered as an effective way to improve seed germination of guava. Also, pretreatment with distilled water for 48 hours is an easy, low cost and effective way to increase guava seed germination indices.
Highlights:
1- The effect of different chemical treatments on germination characteristics of guava was investigated.
2- The suitable method for seed dormancy elimination and seed germination improvement of guava was introduced.
Introduction: Guava (Psidium guajava L.) is one of the most important fruit crops of tropical and subtropical regions. Guava (Psidium guajava L.) can be propagated by seed, layering, grafting, cutting or tissue culture. Propagation by seed is used for the production of seedlings usable in breeding programs or rootstock production for grafting. Guava seeds germinate poorly and unevenly and require more time for seedling emergence. The dormancy in seeds might be due to hard seed coat and different methods are used for breaking dormancy in seeds to improve germination. The aim of this study was to evaluate efficiency of the different pretreatment on seed dormancy breaking and germination characteristics of guava.
Materials and Methods: The experiment was laid out in a completely randomized design with three replications on guava seeds in genetic and breeding laboratory of Date Palm and Tropical Fruit Research Center at the summer of 2018. Treatments consisted of distilled water (24 and 48 h), 0.5 and 1% potassium nitrate (KNO3) for 24 h, warm water (70 ° C) for 5 and 10 min, 25% and 50% sulphuric acid for 5 min, and control (non-treated). In this study, the traits of germination percentage, germination rate and mean of daily germination, seed vigour index and fresh weight and length of seedling were measured. Data analysis was done using the SAS 9.2 software and the Duncan's test at 5% probability level was used for mean comparison.
Results: Results showed that the effect of treatments on seed germination indices (germination percentage, germination rate and mean of daily germination, seed vigour index) of guava was significant at p<0.01. The greatest germination percentage (53.1%), germination rate (6.6 seed/day) and seed vigour (2636.7) were observed in treatment of 1% potassium nitrate (KNO3) for 24 h. The lowest Mean time to germination (14 days) was obtained in distilled water for 48h. Warm water treatments at 70 °C and 25% and 50% sulfuric acid were not effective in improving seed germination compared to control. The highest seed length and weight were observed in 1% potassium nitrate and 0.5% potassium nitrate pretreatments, respectively.
Conclusions: the results of this study show that among the different treatments, pre-treatment of seeds with 1%potassium nitrate may be considered as an effective way to improve seed germination of guava. Also, pretreatment with distilled water for 48 hours is an easy, low cost and effective way to increase guava seed germination indices.
Highlights:
1- The effect of different chemical treatments on germination characteristics of guava was investigated.
2- The suitable method for seed dormancy elimination and seed germination improvement of guava was introduced.
Kamran Alimardani, Amin Salehi, Mohsen Movahhedi Dehnavi, Ali Moradi,
Volume 8, Issue 2 (3-2022)
Volume 8, Issue 2 (3-2022)
Abstract
Extended Abstract
Introduction: Schrophularia striata is one of the medicinal plants of the Scrophulariaceae family and contains phenolic compounds. Locals have traditionally used this herbal medicine to treat infections caused by wounds, gastrointestinal diseases, and eye diseases. Due to excessive consumption by indigenous people and climate change, especially increasing temperature, the cold required to eliminate seed dormancy is not presently available and its germination and growth has decreased. Therefore, this plant is at the risk of extinction. Since this plant is propagated in natural habitats through seed and due to deep seed dormancy, evaluation of different seed dormancy methods is necessary for conservation and domestication of this species. In this study, suitable methods to eliminate seed dormancy of this plant using chilling and gibberellic acid treatments were studied on the seeds collected from different habitats of Ilam province.
Materials and Methods: To investigate the effect of using chilling and gibberellic acid on Schrophularia striata dormancy, a split plot factorial experiment based on completely randomized design with four replications was conducted at the seed laboratory of Yasouj University in 2018. The first factor included the duration of moist chilling period (0, 4, 8, 12 and 16 weeks), the second factor included gibberellic acid (0, 300 and 600 mg/L) and the third factor included five habitats (Ilam, Ivan, Mehran, Abadan and Dehloran).
Results: The results showed that the 16-week Chilling and zero gibberellic acid treatments had the highest germination percentage in all habitats, as the percentage of germination in Mehran, Ivan, Ilam, Abadan and Dehloran habitats was 66, 50, 36, 30 and 25%, respectively. Also, the highest germination rate was observed in all habitats at 16 weeks chilling and zero mg/L gibberellic acid concentration. The highest germination uniformity was obtained at 16 and 12 weeks of chilling.
Conclusions: Chilling period duration was effective on germination percentage and rate and with increasing chilling period, germination percentage and rate increased. This indicates that the seeds studied had some degree of physiological dormancy, and the seed of higher altitude habitats required longer chilling periods than those of the lower ones for germination. Also, according to the results of this experiment, chilling periods above 16 weeks should be used to increase germination percentage.
Highlights:
1- Chilling period duration in the presence of gibberellic acid was the most important factor for the elimination of Schrophularia striata seed Dormancy and increased germination.
2- With increasing altitude and in the same chilling period duration, habitats with lower altitude had higher germination percentage and rate
Introduction: Schrophularia striata is one of the medicinal plants of the Scrophulariaceae family and contains phenolic compounds. Locals have traditionally used this herbal medicine to treat infections caused by wounds, gastrointestinal diseases, and eye diseases. Due to excessive consumption by indigenous people and climate change, especially increasing temperature, the cold required to eliminate seed dormancy is not presently available and its germination and growth has decreased. Therefore, this plant is at the risk of extinction. Since this plant is propagated in natural habitats through seed and due to deep seed dormancy, evaluation of different seed dormancy methods is necessary for conservation and domestication of this species. In this study, suitable methods to eliminate seed dormancy of this plant using chilling and gibberellic acid treatments were studied on the seeds collected from different habitats of Ilam province.
Materials and Methods: To investigate the effect of using chilling and gibberellic acid on Schrophularia striata dormancy, a split plot factorial experiment based on completely randomized design with four replications was conducted at the seed laboratory of Yasouj University in 2018. The first factor included the duration of moist chilling period (0, 4, 8, 12 and 16 weeks), the second factor included gibberellic acid (0, 300 and 600 mg/L) and the third factor included five habitats (Ilam, Ivan, Mehran, Abadan and Dehloran).
Results: The results showed that the 16-week Chilling and zero gibberellic acid treatments had the highest germination percentage in all habitats, as the percentage of germination in Mehran, Ivan, Ilam, Abadan and Dehloran habitats was 66, 50, 36, 30 and 25%, respectively. Also, the highest germination rate was observed in all habitats at 16 weeks chilling and zero mg/L gibberellic acid concentration. The highest germination uniformity was obtained at 16 and 12 weeks of chilling.
Conclusions: Chilling period duration was effective on germination percentage and rate and with increasing chilling period, germination percentage and rate increased. This indicates that the seeds studied had some degree of physiological dormancy, and the seed of higher altitude habitats required longer chilling periods than those of the lower ones for germination. Also, according to the results of this experiment, chilling periods above 16 weeks should be used to increase germination percentage.
Highlights:
1- Chilling period duration in the presence of gibberellic acid was the most important factor for the elimination of Schrophularia striata seed Dormancy and increased germination.
2- With increasing altitude and in the same chilling period duration, habitats with lower altitude had higher germination percentage and rate
Nader Shahbazi, Seyyed Kamal Kazemitabar, Ghaffar Kiani, Ali Pakdin Parizi, Pooyan Mehraban Joubani,
Volume 8, Issue 2 (3-2022)
Volume 8, Issue 2 (3-2022)
Abstract
Extended abstract
Introduction: One of the ways to overcome the limitation of fresh water and lack of sufficient water reserves for agriculture is to use unconventional waters such as seawater. Salinity stress is the most important abiotic stress in seawater application. Identification and planting of salinity tolerant genotypes of a plant species is one of the effective and valuable strategies in reducing the effects of salinity stress. Germination, growth and seedling establishment are among the salinity-sensitive stages in most plants. Therefore, for improvement of abiotic stress tolerance in plants, it is necessary to study the traits and indicators related to tolerance in the germination stage.
Material and Methods: A factorial experiment was conducted based on a completely randomized design with three replications at the laboratory of Plant Breeding Department of Sari University of Agricultural Sciences and Natural Resources in 2020. The first factor included the cultivars and the second included 5 salinity levels (control (no seawater), 3, 6, 9 and 11 dS (deciSiemens per meter) obtained from the incorporation of Caspian Sea and urban water. The number of germinated seeds was counted during eight days of salinity stress. Then, germination percentage, time required for 50% germination, seedling vigor index and germination rate were calculated. On the eighth day, radicle and plumule dry and fresg weights, radicle and plumule length and seedling dry weight were measured.
Results: The results of analysis of variance showed the significance of the effect of different salinity levels, genotype and the interaction of salinity and genotype for all calculated indices at p<0.01. Mean comparison of the interaction of different levels of salinity and cultivars and landraces showed that all the studied traits except for the time to reach fifty percent germination decreased with increasing salinity. Among the studied cultivars, Oltan cultivar had the highest value of germination percentage (100%), germination rate (24.17 seeds per day), seedling vigor index (5.03), plumule length (55.67 mm), radicle length (70 mm), plumule fresh weight (62 mg), radicle fresh weight (45 mg), plumule dry weight (4.77 mg), seedling dry weight (6/23 Mg) and the lowest amount of the time required for 50% germination (24.17 hours) in control treatment. In contrast, Pakistani cultivar had the lowest germination rate (3.06 seeds per day), seedling vigor index (1), plumule length (8.33 mm), radicle length (3 mm), plumule fresh weight (10 mg), radicle fresh weight (2 mg), plumule dry weight (0.57 mg), seedling dry weight (0.84 mg) and the highest time required for 50% germination (24.17 hours) in 11 dS / m salinity level. Using the results of this experiment, among the studied cultivars, Oltan cultivar was selected as the most tolerant and Pakistani cultivar as the most sensitive cultivars to salinity stress at the germination stage.
Conclusion: The studied cultivars and landraces showed different reactions in terms of germination indices when treated with salinity from seawater. The high significant difference in this experiment indicated the high genetic diversity among the studied genotypes. It is possible to choose from these genotypes for salinity tolerance breeding programs in sesame plant.
Highlights:
Introduction: One of the ways to overcome the limitation of fresh water and lack of sufficient water reserves for agriculture is to use unconventional waters such as seawater. Salinity stress is the most important abiotic stress in seawater application. Identification and planting of salinity tolerant genotypes of a plant species is one of the effective and valuable strategies in reducing the effects of salinity stress. Germination, growth and seedling establishment are among the salinity-sensitive stages in most plants. Therefore, for improvement of abiotic stress tolerance in plants, it is necessary to study the traits and indicators related to tolerance in the germination stage.
Material and Methods: A factorial experiment was conducted based on a completely randomized design with three replications at the laboratory of Plant Breeding Department of Sari University of Agricultural Sciences and Natural Resources in 2020. The first factor included the cultivars and the second included 5 salinity levels (control (no seawater), 3, 6, 9 and 11 dS (deciSiemens per meter) obtained from the incorporation of Caspian Sea and urban water. The number of germinated seeds was counted during eight days of salinity stress. Then, germination percentage, time required for 50% germination, seedling vigor index and germination rate were calculated. On the eighth day, radicle and plumule dry and fresg weights, radicle and plumule length and seedling dry weight were measured.
Results: The results of analysis of variance showed the significance of the effect of different salinity levels, genotype and the interaction of salinity and genotype for all calculated indices at p<0.01. Mean comparison of the interaction of different levels of salinity and cultivars and landraces showed that all the studied traits except for the time to reach fifty percent germination decreased with increasing salinity. Among the studied cultivars, Oltan cultivar had the highest value of germination percentage (100%), germination rate (24.17 seeds per day), seedling vigor index (5.03), plumule length (55.67 mm), radicle length (70 mm), plumule fresh weight (62 mg), radicle fresh weight (45 mg), plumule dry weight (4.77 mg), seedling dry weight (6/23 Mg) and the lowest amount of the time required for 50% germination (24.17 hours) in control treatment. In contrast, Pakistani cultivar had the lowest germination rate (3.06 seeds per day), seedling vigor index (1), plumule length (8.33 mm), radicle length (3 mm), plumule fresh weight (10 mg), radicle fresh weight (2 mg), plumule dry weight (0.57 mg), seedling dry weight (0.84 mg) and the highest time required for 50% germination (24.17 hours) in 11 dS / m salinity level. Using the results of this experiment, among the studied cultivars, Oltan cultivar was selected as the most tolerant and Pakistani cultivar as the most sensitive cultivars to salinity stress at the germination stage.
Conclusion: The studied cultivars and landraces showed different reactions in terms of germination indices when treated with salinity from seawater. The high significant difference in this experiment indicated the high genetic diversity among the studied genotypes. It is possible to choose from these genotypes for salinity tolerance breeding programs in sesame plant.
Highlights:
- Different sesame genotypes at different levels of sea salt salinity showed different response at germination stage.
- Among the cultivars studied, Oltan, Nazetakshakhe, Halil and Dashtashtan 2 showed a high degree of tolerance to salinity stress.
Mohadeseh Latifzadeh Shahkhali, Seyed Mohmmad Reza Ehtehsami, Foad Moradi,
Volume 8, Issue 2 (3-2022)
Volume 8, Issue 2 (3-2022)
Abstract
Extended abstract
Introduction: Seed deterioration is associated with oxidative stress and uncontrolled accumulation of reactive oxygen species. Seeds have a group of enzymatic and non-enzymatic antioxidants that protect them against reactive oxygen species and help maintain seed vigor and support seed germination processes. The response of different cultivars to seed deterioration is different. Knowledge about the sources and mechanisms of deterioration and how different cultivars respond can help to select the appropriate cultivar for the region and also provide useful information in selecting and applying appropriate management methods for storage and increasing the storage time of seeds.
Materials and Methods: The Experiment was conducted as factorial based on a completely randomized block design with three replications. Treatments included one and six months of natural storage (4˚C, 11 percent moisture content of seeds and 60% RH) and accelerated aging (96 hours at 45˚C and 100% RH) applied on four cultivars including Hashemi, Gilaneh, Khazar and Domsiyah. Germination percentage, germination rate, shoot length, radicle length, shoot dry weight, radicle dry weight, shoot vigor index (SVI), α-amylase activity, catalase (CAT), peroxidase (POX), superoxide dismutase (SOD) activity, malondialdehyde (MDA) and hydrogen peroxide (H2O2) content were evaluated.
Results: The results showed that accelerated ageing and storage of seeds for six months led to reduced germination percentage, germination rate, shoot length, radicle length, shoot dry weight, radicle dry weight, shoot vigor index (SVI), α-amylase activity reduced in all four cultivars. This decrease was accompanied by an increase in the free radical content of MDA and H2O2 and a decrease in the activity of the antioxidant enzymes SOD and POX. Malondialdehyde content was lower in the seeds stored for six months. The activity of CAT increased after deterioration treatment, this increase was more intense in the seeds stored for six months. These seeds also showed lower H2O2 content compared to accelerated aging seeds. Khazar cultivar showed lower H2O2 content as a result of higher CAT enzyme activity. Moreover, this cultivar showed better germination percentage and germination rate after deterioration treatment compared to other cultivars. The decrease in germination percentage due to deterioration in Domsiyah was very severe. This cultivar showed the lowest germination percentage, germination rate, seed vigor and α-amylase activity in the accelerated aging treatment. Gilaneh and Hashemi cultivars showed higher germinability, α-amylase activity and SOD and POX at the beginning of the experiment, but after deterioration treatment, their germinability decreased along with the activity of antioxidant enzymes.
Conclusions: In all studied cultivars, the accelerated aging and storage of seeds for six months adversely affected germination rate. This decrease was accompanied by an increase in free radicals in the seeds and a decrease in the activity of antioxidant enzymes SOD and POX, which were less severe in Khazar cultivar and more severe in Domsiyah cultivar. These results indicate the greater importance of the storage conditions in Domsiyah cultivar.
Highlights:
1- The effect of storage and seed deterioration on the activity of antioxidant enzymes, reactive oxygen species and seed germination in rice was investigated.
2- The results of accelerated aging test and natural aging were compared for a better conclusion about the response of the cultivars.
3- The two improved cultivars were compared with two local cultivars (with high cultivation area).
Introduction: Seed deterioration is associated with oxidative stress and uncontrolled accumulation of reactive oxygen species. Seeds have a group of enzymatic and non-enzymatic antioxidants that protect them against reactive oxygen species and help maintain seed vigor and support seed germination processes. The response of different cultivars to seed deterioration is different. Knowledge about the sources and mechanisms of deterioration and how different cultivars respond can help to select the appropriate cultivar for the region and also provide useful information in selecting and applying appropriate management methods for storage and increasing the storage time of seeds.
Materials and Methods: The Experiment was conducted as factorial based on a completely randomized block design with three replications. Treatments included one and six months of natural storage (4˚C, 11 percent moisture content of seeds and 60% RH) and accelerated aging (96 hours at 45˚C and 100% RH) applied on four cultivars including Hashemi, Gilaneh, Khazar and Domsiyah. Germination percentage, germination rate, shoot length, radicle length, shoot dry weight, radicle dry weight, shoot vigor index (SVI), α-amylase activity, catalase (CAT), peroxidase (POX), superoxide dismutase (SOD) activity, malondialdehyde (MDA) and hydrogen peroxide (H2O2) content were evaluated.
Results: The results showed that accelerated ageing and storage of seeds for six months led to reduced germination percentage, germination rate, shoot length, radicle length, shoot dry weight, radicle dry weight, shoot vigor index (SVI), α-amylase activity reduced in all four cultivars. This decrease was accompanied by an increase in the free radical content of MDA and H2O2 and a decrease in the activity of the antioxidant enzymes SOD and POX. Malondialdehyde content was lower in the seeds stored for six months. The activity of CAT increased after deterioration treatment, this increase was more intense in the seeds stored for six months. These seeds also showed lower H2O2 content compared to accelerated aging seeds. Khazar cultivar showed lower H2O2 content as a result of higher CAT enzyme activity. Moreover, this cultivar showed better germination percentage and germination rate after deterioration treatment compared to other cultivars. The decrease in germination percentage due to deterioration in Domsiyah was very severe. This cultivar showed the lowest germination percentage, germination rate, seed vigor and α-amylase activity in the accelerated aging treatment. Gilaneh and Hashemi cultivars showed higher germinability, α-amylase activity and SOD and POX at the beginning of the experiment, but after deterioration treatment, their germinability decreased along with the activity of antioxidant enzymes.
Conclusions: In all studied cultivars, the accelerated aging and storage of seeds for six months adversely affected germination rate. This decrease was accompanied by an increase in free radicals in the seeds and a decrease in the activity of antioxidant enzymes SOD and POX, which were less severe in Khazar cultivar and more severe in Domsiyah cultivar. These results indicate the greater importance of the storage conditions in Domsiyah cultivar.
Highlights:
1- The effect of storage and seed deterioration on the activity of antioxidant enzymes, reactive oxygen species and seed germination in rice was investigated.
2- The results of accelerated aging test and natural aging were compared for a better conclusion about the response of the cultivars.
3- The two improved cultivars were compared with two local cultivars (with high cultivation area).
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