مطالعه فعالیت آنزیم آنتی‌اکسیدانت و صفات فیزیولوژی توده‌های وحشی یونجه (Medicago spp.) در شرایط تنش خشکی

Drought is an important abiotic stress that causes major damage to crops. To investigate the effect of drought on traits leaf dry weight, RWC, osmotic potential, osmo regulation and Catalase activity in 9 wild accessions of alfalfa and a genotypes of perennial crops an experiment was conducted under mild and severe drought stress. Pot experiment was carried out as a factorial with three replications in a randomized complete blocks design. Drought stress was applied in two separate experiments as mild stress (50% of filed capacity of water content) and severe stress (30% of field capacity of water content). The experiment were conducted in 2013. The results showed there was significant differences among all accessions for all traits (p=0.01) implying high genetic variation among them. In this research altogether genotypes Nikshahri, 130 and 175 are introduced as the most tolerant genotypes. Reduction in leaves dry weight, RWC and increase osmotic potential and Catalase activity in stress. The genotypes 129, 163 and 207 in server drought died and could not increase their osmotic potential, catalase activity under mild stress significantly increased. So these genotypes are considered as the most sensitive genotypes in this research.