combined stress severely reduced the photosynthetic pigment contents, carotenoids contents, chlorophyll stability, relative water contents, membrane stability compared to individual stress, which were significantly improved by foliar application of 10 ppm of 6-BAP. Reduction was more in sensitive genotypes (KO-307) as compared to tolerant genotypes (C-306). However, the response of KO-307 was more pronounced to exogenous application of BAP compared to C-306. The levels of antioxidant enzyme activity (peroxidase and SOD) and proline were higher under combined stress conditions which were enhanced further by 6-BAP in both the genotypes. Membrane injury and lipid peroxidation were also significantly reduced by the 6-BAP.Overall, combined effect of drought + high temperature stress was more detrimental than the individual stress however, the effect was hypo-additive in nature, which may be due to cross adaptation effect and further exogenous application of cytokinin (6-BAP) ameliorates the adverse affect of combined stress as well individual stress. .
