ASSESSING HEAT TOLERANCE IN WHEAT GENOTYPES: UTILIZING AGROPHYSIOLOGICAL AND QUALITY INDICES WITH MULTIVARIATE ANALYSES

Rising air temperatures pose a significant threat to global wheat harvests, making the development of heat-tolerant genotypes crucial.Using multivariate techniques, plant breeders can enhance the genetic stability of key agro-physiological indicators to boost wheat yield.This study analyzed 48 bread wheat genotypes using 20 characteristics to identify those best suited for heat tolerance, providing valuable insights for breeding programs.Variations in phenotypic and genetic features were identified using multivariate analyses of agro-physiological and quality indices.These were combined to create accurate and consistent selection criteria.The analysis of 20 indicators revealed considerable genotypic and environmental diversity.Our selection process identified eight indices with high heritability and genetic gain, making them useful markers for heat tolerance.The lines GS/2019-20/6046, HTWYT/2019-20/40, and GS/2019-20/7004 were top performers across six principal components with the highest positive scores.The genotypes were classified as follows based on five essential indices [effective tillers/plant (ET), biological yield/plant (BY), chlorophyll content index (CCI), grain filling rate (GFR) and grain yield (GY)] that were obtained via correlation, path, and PCA analysis: ten heat-sensitive, fifteen moderately sensitive, seven highly heat-sensitive, seven moderately heat-tolerant, seven heat-tolerant and two highly heat-tolerant.The wheat genotypes GS/2019-20/6046, HTWYT/2019-20/40, SAWYT-2018-19/309, and GS/2019-20/7004 are promising sources for heat-tolerant breeding programs.