Fazileh Dahie-Zehi; Mahmood Ramroudi; Abdolshakor Raissi
Abstract
In order to investigate the effect of drought stress on some morphological traits, yield, yield components, and oil percentage of sesame genotypes, an experiment has been conducted in form of split plots in a randomized complete block design with three replications during 2018 at the Research Farm of ...
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In order to investigate the effect of drought stress on some morphological traits, yield, yield components, and oil percentage of sesame genotypes, an experiment has been conducted in form of split plots in a randomized complete block design with three replications during 2018 at the Research Farm of Velayat University, Iranshahr. Drought stress factor includes normal irrigation (based on 100 mm evaporation from Class A evaporation pan) and drought stress (based on 200 mm evaporation from Class A evaporation pan) as the main factor, while sesame cultivars, including Dashtestan 2 and 5, Yelovait, Jiroft13, Iandraces of Dom Siah, and Darab1 have been the subfactor. Results show that drought stress significantly reduces plant height, number of branch and capsule per plant, number of seed per capsule and seed, biological yield, and oil yield and percentage. The increase in seed yield under normal irrigation conditions has been 28.67%, compared to drought stress conditions. Among all cultivars, Darab-1 has had the highest seed and oil yield in comparison with other cultivars under both irrigation conditions; therefore, this cultivar will be suitable for cultivation in Iranshahr. The correlation results show that seed yield has had a positive and significant correlation with the number of capsules per plant, number of seed per capsule, biological yield, and 1000-seed weight, with the highest correlation being related to seed and oil yield.
Siavash Heshmati; Gholam Akbari; elias soltani; Majid Amini Dehaghi; Kayvan Fathi Amirkhiz; Keyvan Maleki
Abstract
In order to study the foliar application of melatonin on plants grown from safflower in different seed qualities under drought condition, two field experiments have been carried out at research farm of Aburaihan Campus, University of Tehran, between 2017 and 2018 growing seasons. The experimental design ...
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In order to study the foliar application of melatonin on plants grown from safflower in different seed qualities under drought condition, two field experiments have been carried out at research farm of Aburaihan Campus, University of Tehran, between 2017 and 2018 growing seasons. The experimental design is split-factorial in a randomized complete block design with four replicates, with the treatments being consisted of two levels of drought stress (1- normal irrigation (no-stress) and 2- irrigation after reaching 85% of soil moisture depletion of field capacity at flowering stage (drought stress)), in the main plots. The subplots include 4 treatments, including a factorial combination of seed quality (stored seed and recently harvested seeds) and foliar application (the control and melatonin foliar application). Results from these experiments illustrate that melatonin foliar application has significantly increased the seed yield of stored seed by 589Kg.ha-1, compared to the control. It is also shown that SOD and CAT activities have been increased in response to melatonin in plants grown from recently-harvested seeds under drought condition. Furthermore, it is indicated that foliar application of melatonin decrease the amount of leaf soluble proteins by 28% in plants grown from recently-harvested seeds under drought conditions. According to the results, the amount of malondialdehyde is decreased by 37% in plants grown from recently-harvested seeds by foliar application of melatonin under drought conditions. It seems that seed quality has an enormous influence on grown plants and that using melatonin may play a substantial role in ameliorating the injuries derived from stress on safflower plant.
jaber khordadi Varamin; Farzad Fanoodi; jafar masoud sinaki; Shahram rezvan; Ali Damavandi
Abstract
To investigate the physiological responses of sesame cultivars to the application of nano magnesium and chitosan biopolymer under different irrigation regimes, a split factorial based on randomized complete block design has been conducted with three replicates between 2017 and 2018. The irrigation cut-off, ...
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To investigate the physiological responses of sesame cultivars to the application of nano magnesium and chitosan biopolymer under different irrigation regimes, a split factorial based on randomized complete block design has been conducted with three replicates between 2017 and 2018. The irrigation cut-off, based on BBCH scale, has served as the main factor (normal irrigation, irrigation up to 50% flowering, and seed ripening), with the sub factors including Oltan and Dashtestan-2 sesame cultivars, and nano magnesium (application and non-application) and chitosan (control, 4.8, and 6.4 g.L-1). The highest mean grain yield belongs to the application of 6.4 g.L-1 chitosan under normal irrigation with an average of 1235.1 kg.ha-1. Also, the highest total chlorophyll content is observed in Dashtestan-2 genotype under normal irrigation with a mean of 24.7 mg.g-1 FW and the lowest mean have been obtained in both genotypes under irrigation up to 65 BBCH with a mean of 17.21 and 17.46 mg.g-1 FW, respectively. Application of nano fertilizer in Oltan genotype under irrigation up to 65 BBCH increases the catalase activity by 41.11%, compared to the control treatment. The highest activity of ascorbate peroxidase has been achieved when not applying chitosan under irrigation conditions up to 65 BBCH. It has risen by 55.06%, compared to the control treatment. In general, the results show that irrigation up to 65 BBCH reduces grain yield, in turn alleviated by the negative effects of stress on magnesium and chitosan nanoparticles (9.93% and 27.46%, respectively). Based on the regression analysis results, four traits, namely chlorophyll b, total chlorophyll, proline, and catalase, enter the model that explains 42.11% of the total grain yield variations. Results of simple correlation between traits and regression analysis indicate the indirect effects of physiological traits on grain yield and among the studied parameters, photosynthetic pigments has been of high account in stress conditions.