The evaluation of antioxidant enzymes role in seed yield of some wheat (Triticum aestivum L.) genotypes under drought stress at post anthesis
Subject Areas : Journal of Plant EcophysiologyP. Sharifi 1 , N. Mohammadkhani 2
1 - مرکز آموزش عالی شهید باکری میاندوآب، دانشگاه ارومیه، ارومیه، ایران
2 - مرکز آموزش عالی شهید باکری میاندوآب، دانشگاه ارومیه، ارومیه، ایران
Keywords: Yield, Chlorophyll, Malondialdehyde, Antioxidant, Relative water content,
Abstract :
In order to study the effects of drought stress on antioxidant enzymes activity, lipid peroxidation, chlorophyll content and grain yield of wheat cultivars, an experiment was conducted with a factorial arrangement in randomized complete block design with three replicates in field of Agricultural Dryland Research Station, Maragheh, Iran. Six wheat genotypes and four irrigation treatments (control, 7, 17 and 23 days after anthesis) were used in this study. Genotypes were included Azar-2 and Sardari (Drought tolerant), HN7 and DH-2049 (moderately tolerant), and Sara and TEVEE (drought sensitive). Results showed that drought stress at different times after anthesis led to decrease in relative water content (on average from 82.5% to 53.5%) and chlorophyll content (on average from 12.33% to 3.17%) in flag leaves of different wheat genotypes. Activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) were significantly increased under drought conditions. It was also observed that tolerant genotypes which had lower MDA and RWC content and higher chlorophyll contents in drought conditions also showed the higher antioxidant enzymes activity than sensitive genotypes. It seems that lower antioxidant enzymes activity in sensitive genotypes caused a decrease in drought tolerance and therefore higher yield reduction in these genotypes (on average from 3150.23 kg per hectare to 1400.21 kg per hectare, 55.55% decrease) compare to tolerant genotypes (on average from 2800.72 kg per hectare to 1850.69 kg per hectare, 33.92% decrease).
