Advancing Heat Tolerance in Cotton through Integration of Multiple Stress Tolerance Indices and Multivariate Analyses
Unknown authors
Abstract
In the context of current abrupt climate change scenarios, the yield under both stressful and normal conditions stands as a key indicator for identifying genotypes resilient to stress.Various studies have proposed different yield indices to discern genotypes tolerant to stress.To ascertain desirable genotypes across regions prone to heat stress, 23 cotton genotypes were assessed for their response to normal and heat stress conditions.Nine stress tolerance indices were employed to evaluate seed cotton yield under both conditions, aiming to identify the most effective overall index.Analysis, including correlation and principal component analysis, indicated that mean productivity (MP), geometric mean productivity (GMP), harmonic mean (HM), stress tolerance index (STI), and yield index (YI) exhibited positive associations with seed cotton yield under both conditions.These indices identified five genotypes as the most heattolerant and three as the most heat-sensitive.Hierarchical clustering and ranking based on stress indices highlighted genotypes G15 and G7 as the most heat-tolerant, given their superior mean rank and relatively low standard deviation of rank.Additionally, the strong correlation of GMP with physiological traits such as STI, YI, and AR further validated the ranking based on yield indices.