Impact of heat and drought stress on phenological development and yield in bread wheat

The combination of high temperature and water deficit is common in dry and semi-dry regions worldwide and claims extensive yield losses. A total of 36 genotypes were evaluated for yield traits, phenological traits, plant architectural traits, physiological traits, and stress index under drought heat and combined stress environments. The yield loss assessment over the control experiment had shown more significant loss under combined stress (55.96%), followed by drought (41.11%) and least affected by heat alone (4.77%). PCA analysis indicated yield is positively associated with thousand-grain weight and grain filling duration. The negative association of yield with days to heading and days to maturity in all the stress environments trials indicates that drought escape mechanism by earliness and short duration has been recognized as a key criterion for breeding for drought and high-temperature tolerance. AMMI for yield indicated that E, G and G × E contributed to the tune of 71.66, 14.79, and 13.56%, respectively. In our study, three genotypes MACS 6729, HD 2932, and MACS 6733, found ideal based on yield and stability performance across the environments.