Morpho-anatomical and Antioxidant Responses of Sesame (Sesamum indicum L.) Genotypes under Waterlogging Stress

Abstract

Waterlogging stress is major abiotic stress negatively impact crop yield. This problem will persist in 21st century due to unpredicted heavy rainfall in era of climate change. Sesame (Sesamum indicum L.) is important oilseed crop cultivated in tropical and sub tropical region of world. The present experiment was performed to understand the variation in traits expression of sesame genotypes under waterlogging condition. It was laid out in two factor completely randomised design in which genotypes (GT 2, Purva 1, GT 4 and GT 10) is first factor and duration of waterlogging (12, 24, 36, 48 h) is second factor in 4 replication. Four seed of each genotype were sown in plastic bags with soil vermicompost mixture in the ratio of 1:1, waterlogging stress was imposed at 30 days after sowing. Results, showed morphological characters shoot and root length as well dry weight was significantly (p<0.05) reduced under waterlogging condition in all the genotypes. After, 48 h of waterlogging as compared to initial stage (12h), adaptive root traits like number of lacunae and aerenchyma area increased while root cross sectional area, total stele area, total cortex area and xylem vessel area declined across the genotypes. Average arenchyma area of two year for GT 2 and Purva 1 was 0.35 mm2 and 0.32 mm2 respectively, was comparatively higher than GT 4 (0.22 mm2) and GT 10 (0.13 mm2) under water logging stress. SOD and catalase activity was also higher in GT 2 and Purva 1 under water logging as compared to initial stage 12 h of waterlogging stress. Thus genotypes GT 2 and Purva 1 have better capacity to adapt under waterlogging condition since they maintain higher biomass, more aerenchyma tissue,  with higher expression of SOD and catalase activity under water logging conditions.