影响夏玉米单叶WUE的冠层因子分析

研究大田夏玉米单叶ＷＵＥ发现，不同叶层ＷＵＥ变化较大，以顶层第２叶ＷＵＥ最高；分析并得出了光照、叶温、水汽压、相对湿度、ＣＯ２等因子之间的定量关系，不同叶层间光合与蒸腾的变化主要受制于光照强度的变化；不同生育期每日不同时间ＷＵＥ各不相同，在玉米生长季节内单叶ＷＵＥ受多因子调控，而光照为主要因子。

The Analysis of Crown Factors Affecting Summer Maize Single Leaf WUE

The water use efficiency (WUE) of summer maize single leaf was studied in this paper. The WUE of various leaf layers is much different and there is a relation between WUE and leaf layer (x),i. e. WUE=2.807-0.156x. The correlation coefficient (r) is-0.9199^**.The WUE of the second leaf of top is the highest in all leaf layers. The research results showed that the factors affecting WUE are illumination intensity,temperature,vapor pressure,relative humidity,CO₂ concentration etc..The eqations between WUE and the factors were also sought. The results showed that the change of photosynthesis and transpiration in different leaf layers was mainly affected by illumination intensity. At the same time,the changes of the WUE in different growing periods and times of a day were studied,the results indicated that the WUE in 7:00~9:00 is rising,the WUE in 9:00~ 13:00 is steady and the WUE in 9:00 is the highest in a day. The WUE of the second leaf of top in 9:00 was markly different from other growing periods. The WUE of summer maize single leaf was affected by many factors,but the illumination intensity is the primary one.