جستجوی مقالات مرتبط با کلیدواژه "sorghum" در نشریات گروه "علوم پایه"

Sorghum (Sorghum bicolor L. Moench), known for its high photosynthetic efficiency and biomass production, is utilized for various purposes, including food, animal feed, fiber, and fossil fuels. Salinity stress stands as a significant abiotic stressor that exerts numerous adverse effects on growth and crop yield. In order to investigate the physiological and morphological response of sorghum to salinity stress, a pot experiment was conducted in the greenhouse and laboratory of the University of Guilan, Iran, following a factorial split-plot design based on a randomized complete blocks design with three replications in 2021. The sorghum cultivars, Fuman and Sepideh, were subjected to salinity stress at four different levels, including control, 75 mM, 125 mM, and 175 mM NaCl, in the 4-5 leaf stage, with subsequent measurements taken at 24, 48, 72, and 96 hours after stress exposure. The results of the variance analysis demonstrated that the interaction between cultivars Fuman and Sepideh, various levels of salinity stress, and sampling times had a significant effect on the measured indices at the 1% level. Mean comparisons of treatment combinations indicated that proline, soluble sugars, ascorbate peroxidase, peroxidase, electrolyte leakage, and root length traits increased under salinity stress, showing a positive correlation with stress intensity. In contrast, chlorophyll a, chlorophyll b, carotenoid, protein, plant height, relative water content (RWC), leaf area, plant fresh weight, and plant dry weight decreased under salinity stress, with these traits declining as the stress level increased. In terms of the percentage of changes, soluble sugars had the greatest effect on stress, while RWC had the least impact. Based on the results, it can be concluded that sorghum employs mechanisms such as increasing the activity of antioxidant enzymes, proteins, and osmotic regulation through important osmolytes such as proline and soluble sugars to achieve tolerance to salinity stress. Additionally, the findings revealed that the Foman cultivar, known for its higher tolerance, exhibited a more favorable response to reducing oxidative damage caused by salinity stress compared to the Sepideh cultivar, making it a potential candidate for areas exposed to salinity stress through the implementation of appropriate management strategies.

In order to investigate the effect of drought stress and nitrogen application on growth and some physiological characteristics of sorghum genotypes, an experiment was conducted in a split-split plot with randomized complete block design in three replications at Research farm of collage of agriculture, Isfahan University of Technology. Experimental treatments consisted of two irrigation regimes (50% and 85% depletion of available soil water), two levels of nitrogen fertilizer (available rate, 121.5 kg ha-1, nitrogen from Urea fertilizer, N= 45%) and 15 sorghum genotypes (Pegah, Sepideh, GS4, GS5 , GS24, GS25, GS26, GS28, KGS29, KGS33, MGS1, MGS5, SF001, SF002, SF003). The results showed that drought stress significantly decreased biological yield by decreasing plant leaf area, plant height, quantum efficiency of photosystem II and chlorophyll content. In contrast, the activity of antioxidant enzymes including catalase, ascorbate peroxidase and peroxidase was significantly increased under drought stress conditions. Application of nitrogen under normal irrigation and drought stress increased all the above traits except chlorophyll a/b ratio and ascorbate peroxidase activity, however, this increase was less in drought condition. Therefore, application of nitrogen fertilizer under drought stress can modulate the effect of stress and increase yield. Among the studied genotypes, SF001, SF002 and MGS5 genotypes had the highest response to nitrogen and the least sensitivity to drought stress. Therefore, they can be used in areas of water scarcity.