不同土壤水分条件下幼龄中天杨叶生理参数的光响应  

Light Response of Populus×xiaozhuanica 'Zhongtian' Physiological Parameters under Different Soil Moisture Conditions

作　　者：王永红[1] 刘茂秀[1] 史军辉[1] 王新英[1] 

机构地区：[1]新疆林业科学院,乌鲁木齐830046

出　　处：《东北林业大学学报》2013年第4期17-21,共5页Journal of Northeast Forestry University

基　　金：中央财政林业科技推广示范跨区域重点推广示范项目([2011]TK126号)

摘　　要：利用Li-6400便携式光合仪测定了不同土壤水分条件下2年生中天杨叶光合速率、蒸腾速率及水分利用效率等生理参数的光响应过程,探讨了幼龄中天杨(Populus×xiaozhuanica‘Zhongtian’)正常生长所需的土壤水分和光照条件。结果表明:幼龄中天杨叶的光合速率、蒸腾速率及水分利用效率对土壤水分和光照强度的变化具有明显的阈值响应,维持幼龄中天杨正常生长(同时具有较高光合速率和水分利用效率)的土壤湿度范围为:土壤质量含水量为13.23%～17.96%(相对含水量为60.6%～82.3%),最佳土壤湿度约为15.25%、相对含水量69.7%;土壤水分条件适宜时,光强在800～1 600μmol.m-2.s-1范围内,叶片都能维持较高的光合速率和水分利用效率水平;土壤质量含水量在8.48%～19.76%(相对含水量为38.8%～89.3%)水分梯度范围内,光合作用主要受气孔限制,受光照强度的影响较小。Two-year-old Populusxxiaozhuanica ＇ Zhongtian ＇ was selected to measure the light response of its leaves net photosynthetic rate （ P, ）, transpiration rate （ Tr） and water use efficiency （WUE） under different soil moisture conditions by using Li-6400 portable photosynthesis system and ascertain the optimal soil moisture and light conditions for Populusxxiaozhuani- ca ＇ Zhongtian＇ growth. The results showed that the P,, Tr and WuE have clear threshold value responses to the variations of soil moisture and light intensity. Soil mass moisture content （ Wm ） and relative moisture content （ Wr ） for maintaining the normal growth and higher levels P, and WuE of Populusxxiaozhuanica ＇Zhongtian＇ should be within the range of 13.23% - 17.96% and 60.6% -82.3%, respectively. The optimal Wcn and We are 15.25% and 69.7%, respectively. Populusxxiaozhuanica ＇ Zhongtian＇ leaves has stronger adaptability to light conditions. P and WuE are at higher level, when the photosynthetic active radiation （PAs） is 800-1 600 I.Lmol · m-2 · s-j. When Wcn is in the range of 8.48%-19.76% and Wr in 38.8% -89.3%, the decline of P_ is mainly affected bv stomatal limit rather than P,o.

关 键 词：中天杨 土壤水分 光合特性 水分利用效率 

分 类 号：S718.43[农业科学—林学]