Evaluation of Water Stress Memory in Compensation Response of Cotton (Gossypium hirsutum L.) during Subsequent Water Deficiency

This research was carried out to provide suitable cotton seed for seed propagation in dryland. In this study, the potential of cotton seeds that have been stressed for the third-consecutive year was investigated to evaluate water stress memory responses. The experiment was arranged in split-plot factorial design with four irrigation levels of W-0 (No- irrigation), W-1 (33% FC), W-2 (66% FC), and W-3 (100% FC), as the main factor, and five seed treatments (four third-stressed seeds, i.e. S-21 to S-24, and registered seed), as a sub-plot. Seeds of cotton were grown under different levels of water-stress exposure for three crop-seasons. As results showed, S-32 received water stress signal in both W-0 and W-3 conditions through physiological mechanisms change. Seeds of S-32 accumulated the lowest ABA and the highest calcium in exposure to W-0 and W-3. Enhancement to superoxide dismutase and Aspartate peroxidase activity in leaves of S-32 in exposure to W-0 and W-1 is another memorial stress mechanism for scarce water acclimation. The highest-potential thirty-boll weight, thirty-fiber weight, and first-harvesting yield were obtained from S-32 against W-0, W-1, and W-2.. Also, the seeds of S-32 had the most seedling vigor and germination percentage in exposure to W-0, W-1, and W-2. It can be concluded that stress memory, via modification of physiology and morphology of plant behavior, helps plants to tolerate water deficiency when subjected to recurrent drought.