Evaluation of Drought Tolerance of Some Wheat (Triticum aestivum L.) Genotypes through Phenology, Growth, and Physiological Indices

Increasing human population and changing climate, which have given rise to frequent drought spells, pose a serious threat to global food security, while identification of high yielding drought tolerant genotypes remains a proficient approach to cope with these challenges. To offer a methodology for the evaluation of the drought-tolerant wheat genotypes based on the pheno-physiological traits, a field experiment was executed, entailing four wheat genotypes viz. BARI Gom 26, BAW 1158, BAW 1167, and BAW 1169 and two water conditions viz. control treatment (three times irrigation at 20, 50, and 70 DAS, i.e., 100% field capacity) and stressed treatment (no irrigation during the entire growing season). The results revealed that drought stress drastically reduced the days to booting, heading, anthesis and physiological maturity, relative water content (RWC), chlorophyll content, canopy temperature depression (CTD), and photo-assimilates-spike dry matter (SDM), grains spike(-1) and grain yield of all wheat genotypes. In addition, the genotypes BAW 1167 and BARI Gom 26 remained more prone to adverse effects of drought as compared to BAW 1169 and BAW 1158. Furthermore, DS induced biosynthesis of compatible solutes such as proline, especially in BAW 1169, which enabled plants to defend against oxidative stress. It was inferred that BAW 1169 remained superior by exhibiting the best adaptation as indicated by the maximum relative values of RWC, total chlorophyll, CTD, proline content, SDM, grains spike(-1), and grain yield of wheat. Thus, based on our findings, BAW 1169 may be recommended for general adoption and utilization in future wheat breeding programs aimed at developing potent drought-tolerant wheat genotypes to ensure food security on a sustainable basis.