Masomeh Ganji; Serolah Galeshi; Hamid Jabbari; Forough Sanjarian; Benjamin Torabi
Abstract
Objective: Water stress affects the crucial processes and yield of crops. This study aimed to investigate the effect of water stress on physiological and biochemical traits of safflower genotypes.Methods: A factorial experiment was carried out as randomized complete block design in Seed and Plant Improvement ...
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Objective: Water stress affects the crucial processes and yield of crops. This study aimed to investigate the effect of water stress on physiological and biochemical traits of safflower genotypes.Methods: A factorial experiment was carried out as randomized complete block design in Seed and Plant Improvement Research Institute during 2017-19. The treatments included two irrigation levels (40 and 80% depletion of available water) and Parnian, Goldasht and Kazak genotypes. Plants were sown in soil columns with a height of 150 and a diameter of 23 cm, and irrigated by a drip system. Antioxidant enzymes, malondialdehyde, proline, relative water content, chlorophyll, seed yield and fatty acid composition were measured at the end.Results: Water stress significantly increased the accumulation of hydrogen peroxide and malondialdehyde in safflower genotypes which led to increased catalase and peroxidase enzyme activity by 1 and 2.5 U, respectively. The proline content increased about 16 times under water stress conditions. In contrast, the relative water content showed a significant decrease, which resulted in increased canopy temperature and decreased seed yield by 70%. The Kazak genotype had the lowest increase in canopy temperature under stress conditions and showed higher yield stability. Moreover, the fatty acid composition of seed oil changed and the amount of linoleic acid decreased by 1.8% under water stress conditions.Conclusion: The results showed that in addition to drought-related physiological traits, no increase in saturated/unsaturated fatty acid ratio is also an important indicator in screening superior genotypes for cultivation in water shortage.
Sanaz Afshari-Behbahanizadeh; Gholam Ali Akbari; Maryam Shahbazi; Iraj Alahdadi
Abstract
In order to evaluate the effect of terminal water deficit stress on leaf traits and their relations to grain yield in different barley genotypes (‘Yousof’, ‘Fajr30’, ‘Nosrat’, ‘PBYT-46’, ‘PBYT-97’ and ‘Morocco’), two separated experiments ...
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In order to evaluate the effect of terminal water deficit stress on leaf traits and their relations to grain yield in different barley genotypes (‘Yousof’, ‘Fajr30’, ‘Nosrat’, ‘PBYT-46’, ‘PBYT-97’ and ‘Morocco’), two separated experiments were conducted in stress (water withholding from anthesis towards the end of growing season), and non stress (normal irrigation) conditions based on RCBD with three replications in 2010-2011 at Yazd Agricultural Research Station. The results indicated that drought stress significantly reduced leaf area index, greeness and increased canopy temperature and leaf rolling. Also, drought stress significantly increased epicuticular wax content at 21 days after anthesis. Studying by Scanning Electron Microscope (SEM) confirmed the increased dispersal of leaf wax crystals in leaf surface in ‘Yousof’ and ‘PBYT-46’ genotypes. ‘Fajr30’ genotype with the highest amount of cuticular transpiration and canopy temperature had the highest reduction in grain yield and ‘Yousof’ and ‘PBYT-46’ genotypes with higher amount of wax crystals dispersal, lower amount of cuticular transpiration, canopy temperature and greeness reduction in stress condition, had the least reduction percentage in grain yield. According to the non significant correlation between leaf wax and grain yield in both conditions (stress and normal) and in stress condition, it seems that increased epicuticular wax crystals had a more effective role than the quantity of wax in drought tolerance of barley genotypes.