春小麦水分利用效率日变化及其生理生态基础的研究  

Diurnal change of water use efficiency of spring wheat and its physioecological basis.

作　　者：黄占斌[1] 山仑[1] 

机构地区：[1]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业重点实验室,杨陵712100

出　　处：《应用生态学报》1997年第3期263-269,共7页Chinese Journal of Applied Ecology

基　　金：国家攀登计划!( 92 1 9-5);国家自然科学基金资助项目!( 3 94 70 4 3 0 )

摘　　要：采用光合速率和蒸腾速率之比 (Pn/Tr)表示植物水分利用效率 (WUE) ,发现在两种不同水分处理下春小麦拔节期 .WUE日变化中都有上午高于下午值 ,且 8∶0 0～ 1 0∶0 0为明显峰值的特征 ,这种特征与Pn、Tr日变化存在的上、下午值不对称性和反向性 (Pn为上午高于下午 ,Tr相反 )紧密相关 ,水分胁迫处理中 ,Pn、Tr值均有降低 ,但不同品种的WUE反应不一 .研究表明 ,叶水势 ( ψw)、气孔阻力 (Rs)等生理因素和空气相对湿度 (RH)、光照 (Q)及冠层温度 (Tc)等生态因子 ,通过对Tr和Pn的不同影响而同WUE显著相关 ,40 %RH是WUE变化的一个重要阈值 .Using a ratio of photosynthetic rate (Pn) and transpiration rate (Tr) to express water use efficiency (WUE), the WUE of two varieties of spring wheat and its physioecological affecting factors under different water treatments are analyzed . It is found that the WUE of both varieties is higher in the morning, with a peak at 8～10 am than in the afternoon.The change of WUE is determined by non symmetry and contrary characteristics of Pn and Tr, i.e.,Pn is higher in the morning than in the afternoon, but Tr is on the contrary.The Pn and Tr values are all lower under water stress condition, but the WUE of different varieties is not the same. The results indicate that some physiological factors, such as leaf water potential(ψ w) and stomatal resistance (Rs), and some ecological factors, such as relative air humidity (RH), solar radiation (Q) and canopy temperature(Tc), are significantly correlated with WUE, although both physiological and ecological factors have different effects on it. 40% of RH is an important threshold value to WUE change.

关 键 词：春小麦 水分利用效率 日变化 生理生态因素 

分 类 号：S512.101[农业科学—作物学]