Drought Resilience of <i>Gossypium </i>spp.: PEG-6000 Induced Responses at Germination and Seedling Stages

This laboratory experiment was conducted in the Forestry Department of Bing&ouml;l University, Vocational School of Youth, in 2023. It aimed to investigate the responses of cotton genotypes to drought stress by creating osmotic pressure stresses of 0 MPa (control), -4 MPa, -6 MPa, -8 MPa, and -10 MPa using PEG 6000 chemical on the advanced lines SC32 and SC38, as well as the varieties Aşkabat 71 and May 505. Various parameters such as Root length (RL), Root Fresh Weight (RFW), Root Dry Weight (RDW), Shoot Length (SL), Shoot Fresh Weight (SFW), Shoot Dry Weight (SDW), Relative Water Content (RWC), Germination percent (GP), Vigor Seed Index (VSI), and Number of Lateral roots (NLRs) were measured. It was observed that as the severity of drought increased, the root system expanded in parallel. However, the plant&rsquo;s tolerance decreased with increasing drought severity. The genotypes SC32 and SC38, which were obtained from the breeding program for developing drought-tolerant varieties, exhibited high averages in almost all drought measurement parameters, demonstrating a high level of heterosis. As a conclusion, continuing the breeding program with these genotypes was found tolerant to contribute to the success of breeding. May 505 variety showed high tolerance to drought in terms of Relative Water Content (RWC), and it also exhibited promising results in other parameters compared to G. barbadense variety Aşkabat 71 and segregating population genotypes. May 505 variety showed a high germination rate and rapid germination, suggesting its potential use as a parent in both drought and early variety breeding programs.