不同抗旱性棉花品种蜡质含量与水分利用效率的关系

【目的】在新疆自然生态条件下,研究不同抗旱性棉花品种蜡质含量变化及与水分利用效率(WUE)的关系。【方法】以抗旱性不同的棉花品种新陆早22号(抗旱性强)和新陆早17号(抗旱性弱)为试材,采用膜下滴灌技术设置正常灌溉和干旱处理,测定分析棉花产量形成期叶片蜡质含量、净光合速率(Pn)、蒸腾速率(Tr)、相对含水量(RWC)及籽棉产量。【结果】与正常灌溉相比,干旱处理显著降低了棉花籽棉产量,但盛花至吐絮期叶片蜡质含量提高10.84%、叶片WUE则增加23.96%。不同品种对水分处理响应不同,正常灌溉下新陆早22号与新陆早17号的棉花籽棉产量、RWC、WUE和叶片蜡质含量均无明显差异,干旱条件下新陆早22号的籽棉产量、叶片蜡质、RWC和WUE分别比新陆早17号高41.38%、14.27%、13.1%和3.84%;。相关分析表明,棉花叶片表皮蜡质含量与Tr、Pn呈显著负相关关系,且Tr的负相关系数高于Pn;与RWC呈显著正相关关系。【结论】抗旱性强棉花品种主要通过增加盛花至吐絮期内叶片蜡质含量,降低叶片蒸腾耗水,提高WUE及籽棉产量。

Changes in Epicuticular Wax Content of Cotton Cultivars with Different Drought-Resistances and Its Relationship with Water Use Efficiency

【Objective】 The project aims to study changes of epicuticular wax content in cotton cultivars with different drought-resistance and its relationship with water use efficiency (WUE) in natural ecological conditions of Xinjiang, China.【Method】 Different drought resistance cotton cultivars Xinluzao22 (drought-resistance) and Xinluzao17 (drought-sensitive) were used under mulch drip irrigation systems with a normal irrigation and drought stress and analysis was carried out of the correlation among cotton leaf epicuticular wax content and net photosynthetic rate, transpiration rate, relative water content and seed cotton yield during critical growth period.【Result】 The results showed that, compared with normal irrigation, drought treated plants significantly reduced seed cotton yield, but increased the wax content and water use efficiency by 10.84% and 23.96%, respectively, from full flowering to boll-opening stage. No significant difference was found in term of seed cotton yield, RWC, WUE and wax content between Xinluzao22 and Xinluzao17 under normal irrigation, while under drought stress, Xinluzao22 resulted in 41.38%, 13.1%, 3.84% and 14.27% more seed cotton yield, RWC, WUE and wax content respectively compared with Xinluzao17 cultivar. The correlation analysis showed that there was a significant negative correlation between the wax content of cotton leaf epidermis and Tri and PN, and the negative correlation coefficient of Tr was higher than that of PN, and there was a significant positive correlation between Tr and RWC.【Conclusion】 Cotton varieties with strong drought resistance decrease leaf transpiration rate and water consumption by increasing the wax content of leaves during florescence to boll-opening stage, thus increasing WUE and seed cotton yield.