Drought-tolerance Evaluation of Cotton with
Abstract£ºEight upland cotton cultivars, two sea island cotton ones and three Asian cotton ones with varied levels of drought tolerance were used. Cotton samples at germination, bud-stage, cotyledon-stage and real-leaf stage were exposed to PEG6000 stress for 12 hours. After 12-hour osmotic treatment £¬ the survival rates were calculated, then by statistical method, curves of the mutative level of drought tolerance were obtained, proving that the 3¡«6-leaf stage is the key period related to cotton drought tolerance. With different PEG6000 concentrations, the rates which 3¡«6-leaf seedlings revived were calculated to compare with the revival rate in real drought situation. And the results revealed that: With 17% PEG6000 treatment, the rate which seedlings revived corresponded with the results in drought-shed. The results suggested that osmotic adjustment of cotton could be used to evaluate simply the drought tolerance of cotton,though the cotton after PEG-treated differed slightly in physiology with cotton after drought-treated. The method with osmotic adjustment of PEG is simple, fast and easily operated, could be used to evaluate the drought tolerance of cotton in principle, and will establish foundations for study on cotton drought-tolerance molecular biology.