Evaluation of Drought and Salinity Tolerance in Pima Cotton (Gossypium barbadense L.) Genotypes Using Yield-Based Stress Indices

Abstract

Cotton, particularly Pima cotton (Gossypium barbadense L.), is a vital industrial crop whose productivity is increasingly limited by drought and salinity stresses, making the development of stress-tolerant, high-yielding genotypes essential for sustainable agriculture.This study aimed to evaluate drought and salinity tolerance of fine-fiber cotton (Gossypium barbadense L.) genotypes using stress tolerance indices under different environmental conditions. Ten cotton varieties and breeding lines were assessed under optimal, drought, and salinity stress conditions. The evaluation was carried out using stress indices such as Stress Susceptibility Index (SSI), Tolerance Index (TOL), Stress Tolerance Index (STI), Yield Index (YI), and Yield Stability Index (YSI). The results revealed significant variation among genotypes in response to stress factors. Among the studied genotypes, T-2090 demonstrated the highest tolerance under both drought and salinity conditions, characterized by low SSI and TOL values and high YSI. Genotypes T-481 and Duru-gavhar-2 also showed stable performance and adaptability across stress environments. In contrast, T-2025 and T-5570 exhibited high sensitivity to stress. The findings indicate that the combined use of stress indices is an effective approach for identifying stress-tolerant and high-yielding genotypes. The identified tolerant genotypes can be recommended as valuable donor material for cotton breeding programs aimed at improving drought and salinity tolerance.