Identification of salt-resilient cotton genotypes using integrated morpho-physiological and biochemical markers at the seedling stage.

Soil salinity drastically hinders cotton productivity (Gossypium hirsutum), and fiber quality. The current study evaluated morpho-physiological and biochemical responses of fifty cotton genotypes under different salinity levels (control, 12 dS/m, and 17 dS/m) at the seedling stage. The experiment was performed in a factorial complete randomized design with three replications. Significant genotype × treatment interactions were observed for most traits, including shoot length (SL), root length (RL), fresh and dry shoot weight (FSW, DSW), fresh and dry root weight (FRW, DRW), total soluble protein (TSP), proline content, and antioxidant enzymes. Severe salinity stress reduces shoot length (SL) and root length (RL) along with notable decreases in biomass and altered biochemical responses, including increased antioxidant activities and proline content, indicating stress adaptation. Moreover, PCA and Pearson's correlation analyses unveiled strong positive and negative correlations among studied attributes while MGIDI analyses assist in determining the salt-resilient cotton genotypes under applied treatments. The best-performing genotypes under control conditions were G, G, and G, while G, G, and G showed resilience under severe salinity stress. MGIDI effectively identified genotypes with outstanding salinity tolerance, such as G, G, G, and G, across all stress levels. This research assists in determining the salinity stress-tolerant cotton genotypes using morpho-physiological and biochemical parameters and MGIDI is used as a precise method for identifying salt-resilient cotton accessions.