Estimation of heat stress tolerance for grain yield and its contributing traits in bread wheat (Triticum aestivum)

Abstract

Hence the research work was performed to analyze the effect of late season heat stress on grain yield and yield components of ten bread wheat cultivars and 45 F1’s. Based on heat susceptibility index the wheat genotypes Raj 3077, Raj 1482 and Raj 3777 were highly tolerant to increased temperature as compared to other wheat genotypes. The cross combinations Raj 4079 x Raj 3765, Raj 3077 x PBW 550, WH 1021 x DBW 90, Raj 1482 x HD 3086 and Raj 4238 x WH 1021 which demonstrated comparatively more tolerance for grain yield per plant. These were predictable for thermo tolerance in very late sown conditions. The HSI could be taken as important criteria for breeding wheat genotypes suitable for late sown conditions. These genotypes can be used in wheat breeding programmes related to high temperature stress. In very late sown condition the parents Raj 3765, Raj 3077 and WH 1021 and cross combinations WH 1021 x PBW 550, Raj 3765 x Raj 3077 and Raj 4238 x WH 1021 emerged as good general combiner and specific cross combinations. Therefore, these genotypes may be used in the future breeding programme for development of a heat tolerant wheat variety suitable for warmer areas to maximize production.