Abstract: [Objective] In order to understand the influence of water stress on plant layer of epicuticular wax and its component contents and the relationship between the leaf layer of epicuticular wax and plant drought resistance.[Method] The paper studied the variation of flag leaf and layer of flag leaf epicuticular wax content in two barley with strong drought resistance and 2 varieties with weak drought resistance.[Result] The results showed that the epicuticular wax content of barley leaves under drought stress increased and that of drought tolerant cultivars increased more than that of drought sensitive cultivars,and after drought stress,the main physiological parameters of photosynthesis were decreased.The main components of epicuticular wax of barley leaves were alcohols,alkanes,acids,aldehydes,esters and ketones;the increase of epicuticular wax of barley leaves under drought stress was mainly due to the increase of alcohols,esters and ketones while the increase of alkanes was not obvious;net photosynthetic rate of barley leaves was positively correlated with the alcohols content and negatively correlated with the alkanes content,indicating that alcohols and alkanes as the main components of epicuticular wax of barley leaves had significant auxo-action to photosynthesis;stomatal conductance was negatively correlated with total wax content and alcohols content.[Conclusion] The content of alcohols,esters and ketones of epicuticular wax in barley leaf will be increased under drought stress condition,then the photosynthetic characteristics is regulated by wax components to maintain a high photosynthetic rate,which can improve the drought tolerance of plants.

摘要： [目的]研究大麦叶片表皮蜡质组分及含量与植株抗旱性的关系.[方法]以2个抗旱性品种和2个弱抗旱性品种为材料,测定分析干旱胁迫下大麦灌浆期旗叶及旗叶鞘表皮蜡质组分及含量、光合作用生理参数变化及两类指标之间的相关性.[结果]大麦叶片表皮蜡质主要由烷烃类、醇类、酸类、醛类、酮类、酯类及其他一些未知组分组成;干旱胁迫促进大麦叶片醇类、酮类、酯类等物质含量的增加,导致叶片表皮蜡质总含量显著增加,且抗旱性品种比弱抗旱性品种表皮蜡质总含量增加的更多;干旱胁迫后,各主要光合作用生理参数降低;大麦植株的叶片净光合速率与烷烃类物质含量呈显著负相关,与醇类物质呈显著正相关;蜡质总含量、醇类含量与气孔导度显著负相关;蜡质的主要成分(烷烃和醇类物质)明显促进植株光合作用.[结论]在干旱条件下,大麦植株通过大量合成酮类、醇类、酯类等物质而使表皮蜡质总量显著增加,提高大麦植株的光合特性,从而增强植株抗旱性.