PEG胁迫方法评价棉花幼苗耐旱性研究

Evaluation to the Drought Tolerance of Cotton by PEG Water-stress

分别选用8个陆地棉、2个海岛棉、2个亚洲棉品种作为材料进行耐旱水平试验，以PEG6000作为水分胁迫剂，对棉花种子萌发期、芽期、子叶期和真叶期材料分别进行处理，得出了耐旱水平变化曲线，结果验证棉花耐旱性鉴定关键时期应在3～6片真叶幼苗。用不同浓度PEG6000对具有3～6片真叶的棉花幼苗进行12h连续处理后，统计其成活率。研究表明：PEG6000溶液浓度为17％（W／V）时，棉花幼苗的成活率与田间旱棚鉴定结果有较高的一致性。此方法简单、快速，易操作，基本可用于棉花品种的耐旱性评价与鉴定工作，并将为棉花耐旱分子生物学研究奠定基础。

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, budstage, 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 the 3～6-1eaf stage is the key stage on drought tolerance of cotton seedlings. With different PEG6000 concentration, the ratios which 3 ～6-1eaf 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.