棉 花 学 报    Cotton Science    2007，19(3)：205-209

Evaluation to the Drought Tolerance of Cotton by PEG Water-stress
ZHANG Xue-yan，LIU Chuan-liang，WANG Jun-juan，LI Fu-guang^*，YE Wu-wei
(Cotton Research Institute，Chinese Academy of Agriculture Sciences，Key Laboratory of Cotton Genetic Improvement，Ministry of Agriculture，Anyang，Henan 455004，China )

Abstract：This experiment was conducted with eight cultivars of upland cotton，two of island cotton and three of Asian cotton as types of different levels in drought tolerance. Cotton materials during germination，bud-stage，cotyledon-stage and real-leaf stage were exposed to osmotic adjustments of PEG6000 for 12 hours in order to imitate the drought circumstance. After the 12 hours osmotic menace，calculated the survival ratio of various materials，then through statistical method，curves of the mutative level of drought tolerance were obtained，proving that the3～6-leaf stage is the key stage on drought tolerance of cotton seedlings. With different PEG6000 concentration，the ratios which3～6-leaf seedlings recovered were calculated to compare with the results in real drought situation. And the results revealed that：With 17%(W/V) PEG6000 treatment，the ratio which seedlings recovered corresponded with the results in drought-shed. The above results suggested that osmotic adjustments 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 adjustments of PEG is simple，fast and easy 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.
Key words：cotton；PEG water-stress；drought tolerance；survival ratio  [Full Text，2113KB]