Climate change adaptation in heat tolerant elite wheat varieties from different zones of India

Five durum wheat varieties and 20 bread wheat varieties developed by various breeding programs across India for irrigated late sown conditions of the major wheat growing zones of India viz., North Western Plains Zone, North Eastern Plains Zone, Central Zone and Peninsular Zone were evaluated under heat stress and non-stress environments to elucidate physiological mechanisms of climate change adaptation among this diverse set of elite Indian wheat lines. Within each zone there were cultivars released during past decades, recently released varieties as well as pipeline varieties under final stage of testing. For physiological traits associated with crop adaptation under stress environments, the wheat varieties HD 2932, UAS 320 and HD 2864 had better mean performance for canopy temperature and chlorophyll content. The heat susceptibility index (HIS) indicating stability of performance under changing climate also revealed that varieties UAS 320 was good for canopy temperature, whereas LOK 62 and HD 2932 were better for chlorophyll content. The durum varieties HI 8703 and HI 8704 had lowest HSI for biomass, whereas, DBW 14 and MP 4010 performed better for grain yield. Thus the varieties from other zones exhibited greater resilience to changing environment, although the mechanism of adaptation/tolerance was different as indicated by their excellence in specific component characters.