Evaluating Water Stress Adaptation in Cotton: Multivariate Analysis in F6–F7 Generations for Yield, Fibre Quality and Variety Selection

Abstract

The impact of drought stress on productivity of cotton (Gossypium hirsutum L.) is a well-known challenge in agricultural production, and concurrently, the question of whether using the same or different selection criteria in well-watered and water-deficit conditions to select drought-tolerant cotton varieties remains unclear. This study aimed to comprehensively assess the single plant progeny lines within the F6 and F7 generations for determine response to DS and select the tolerant lines within the F7 generation. Single plant progeny rows were established, with the deficit water condition comprising 108 and 136 single plants for the F6 and F7 generations, respectively, and the WW condition consisting of 120 and 156 single plants for the F6 and F7 generations, respectively, with four blocks in Augmented experimental design. These progeny rows have length of 12 m, incorporate five control varieties (Karizma, Gloria, Carla, Candia and Claudia) to facilitate a comprehensive comparison. The study findings showed that fibre length, boll number and lint percentage were identified as the most crucial selection criteria under both WW and deficit irrigation conditions through principal component analysis. These indicators are highly beneficial for evaluating cotton's drought tolerance and screening potential drought-tolerant lines under both irrigation scenarios. According to the decision tree analysis, FL and BN have emerged as the most critical decision-making parameter in both irrigation conditions. Furthermore, the analysis revealed that each selection criterion has different impact in the comprehensive selection process. Also, as a result of all statistical analysis results and breeder observations, a total of 10 cotton lines were selected in the F7 generation. These selected genotypes hold promise for future cotton breeding programmes, providing an avenue to enhance drought tolerance and elevate cotton yield and productivity.

Clinical Trial Registration: This study does not involve a clinical trial, and therefore, clinical trial registration is not applicable.