Evaluation of Wheat Genotypes for Combined Heat and Drought Stress Tolerance

A field experiment was carried out from November 2021 to April 2022 to assess the tolerance of five wheat genotypes to combined heat and drought stress. The study followed a split plot design with three replications. The main plot treatment consisted of two growing conditions (normal condition and combined heat and drought condition) and the sub-plot treatments consisted of five wheat genotypes (BARI Gom 29, BARI Gom 30, BARI Gom 31, BWMRI Gom 3 and BAW 1290). Under stress, BARI Gom 30 and BAW 1290 showed comparatively smaller reduction in days to anthesis and plant height than under the normal condition. In the case of days to physiological maturity, number of spikes m−2 and grains spike−1, the lowest reduction was found in BWMRI Gom 3 under combined heat and drought conditions and spike length and spikelets spike−1 were the same both under normal and combined heat and drought conditions. In the case of BARI Gom 30 the number of spikes m−2 was increased in stress conditions more than normal conditions. The lowest reduction of 1000-grain weight was found in BARI Gom 30 and in case of grain yield and above ground biological yield reduction was less in BWMRI Gom 3 and BARI Gom 30 under stress conditions than normal. Better yield components such as number of spikes m−2 and grains spike−1 under stress conditions, contributed to enhanced combined heat and drought tolerance in BWMRI Gom 3 and BARI Gom 30 compared to BAW 1290, BARI Gom 31 and BARI Gom 29. Based on stress susceptibility index (SSI) for grain yield, the genotypes were ranked as BWMRI Gom 3 (0.75) > BARI Gom 30 (0.84) > BAW 1290 (0.93) > BARI Gom 31 (1.09) > BARI Gom 29 (1.34) where BWMRI Gom 3 and BARI Gom 30 was found most tolerant. Thus, BARI Gom 30 and BWMRI Gom 3 appear suitable for cultivation in heat- and drought-prone regions of Bangladesh. Bangladesh Agron. J. 2026, 29(1): 20-31