The latest study investigated the salt tolerance of 55 cotton genotypes at the seedling stage, focusing on morphological, physiological, and biochemical traits at four salinity levels (1.8, 10, 15, and 20 dSm^-1). Morphological parameters, including root and shoot lengths and weights, were adversely affected by increasing salinity levels. Chlorophyll contents decreased, indicating compromised photosynthetic efficiency. Sodium ion accumulation increased under salt stress, leading to altered ion balance. Biochemical assays highlighted increased activities of antioxidant enzymes, such as superoxide dismutase, peroxidase, elevated hydrogen peroxide levels, and proline content, indicating oxidative stress. The AA-933 showcased exceptional tolerance to salt stress across various levels for fresh and dry root and shoot lengths and weights. Also, NIAB-824 exhibited impressive performance for rootrelated traits. The resilience of SLH-33 was particularly noteworthy, excelling in morphological features, including fresh and dry root and shoot lengths, especially under the highest level of salinity stress (20 dSm^-1). Likewise, CRIS-625, Hataf 3, and FH-498 demonstrated robust adaptability by maintaining elevated K⁺/Na⁺ ratios. Hataf 3 stood out as a top performer across various physiological and biochemical traits, such as chlorophyll contents, K⁺, K⁺/Na⁺, superoxide dismutase, peroxidase, proline contents, and total antioxidant capacity, highlighting its remarkable salt tolerance. The biplot analysis further substantiated the distinct traits associated with different genotypes, aiding in identifying those with exceptional performance under varying salt-stress levels. This study highlights the importance of understanding salt-stress response in cotton, suggesting that breeding salt-tolerant varieties could improve crop resilience and productivity in challenging environments, promoting sustainable agriculture.

Keywords: Salinity, cotton germplasm, screening, oxidative stress, ionic imbalance, salt tolerance

Key findings: Based on morphological markers like root and shoot-related traits, SLH-33 was the top performer under all salinity-stress levels. Hataf 3 was the option as a salt-tolerant genotype based on the physiological (chlorophyll contents) and biochemical markers (K⁺/Na⁺, superoxide dismutase, peroxidase, proline content, and total antioxidant capacity).