Chlorophyll and carotenoid content of wheat (Triticum aestivum L.) seedlings under heat stress as affected by trehalose application

Presently, chlorophyll and carotenoid contents were evaluated under control (25±2°C), heat stress (35±2°C and 40±2°C) and interactive effect of heat stress and trehalose in six wheat (Triticum aestivum L.) genotypes (HD2967, PBW175, C306, PBW343, PBW621 and PBW590). Trehalose an osmoprotectant, at concen-tration of 1mM and 1.5mM was applied at 7 days after sowing (DAS) followed by heat stress of 35±2°C (moderate) and 40±2°C (severe) on 8DAS for 4 and8 hours. As chloroplast thylakoid membranes, are highly vulnerable to heat stress, the chlorophyll content decreased with increased temperature stress in all selected genotypes. Heat stress significantly reduced (P< 0.05) the carotenoid content in all genotypes. Severe heat stress (8 hours) more adversely affected these mentioned parameters. The application of Trehalose @ 1.5mM as compared with 1mM concentration was found more effective to ameliorate the adverse effect of heat stress on chlorophyll and carotenoid contents to sustain photosynthetic process.