草业学报2016，Vol.25Issue(10)：86-94,9.DOI:10.11686/cyxb2015578
干旱胁迫对新疆三个优势牧草种的光合特性与水分利用效率的影响
Effect of drought stress on the photosynthetic characteristics and water use efficiency of three dominant forage grasses in Sinkiang
摘要
Abstract
This paper explores the adaptive mechanisms of three forage grasses (Bromus inermis ,Dactylis glomerata and Poa pratensis )that are predominant in Sinkiang natural grasslands.Using pot experiment methods,drought stress was simulated to determine the effects of three different soil water contents levels (80%,60% and 30% of field water capacity)on leaf photo-physiological characteristics and water use efficien-cy (WUE).With decreasing soil water contents,the daily average value of intercellular CO2 (C i )in the three grasses increased.The daily average values of stomatal conductance (G s ),net photosynthetic rate (P n ),tran-spiration rate (T r ),the ratio of P n to C i and evapotranspiration decreased,but the variation ranges of these characteristics differed across the three grasses.As drought stress increased,the daily average accumulated bi-omass of P .pratensis significantly decreased (P <0.05),but there was no obvious change in the other two grasses (P >0.05).The net water use efficiency (WUEET )and the daily average value of instantaneous water use efficiency (WUEi )of D .glomerata changed very little (P >0.05 ),but in the other two grasses both WUEET and WUEi significantly decreased (P <0.05).The WUEET of P .pratensis was significantly positively correlated with its daily average values for T r and evapotranspiration (P <0.05).The WUEET of the three for-age grasses was significantly positively correlated with their daily average accumulated biomass (P <0.05 ). The WUEi and WUEET of the three grasses followed different change trends with the decrease in soil water con-tents.This study suggests that the adaptability of the three forage grasses to arid environments depends not only on their WUE but is also related to their biological characteristics and life history strategies.关键词
新疆天然草地/土壤含水量/优势牧草种/光合特性/水分利用效率Key words
natural grassland of Sinkiang/soil moisture content/dominant forage grass/photosynthetic charac-teristics/water use efficiency引用本文复制引用
覃凤飞,沈益新,李兰海,胡增运,程亮,马旭龙,陈青青,王凌越..干旱胁迫对新疆三个优势牧草种的光合特性与水分利用效率的影响[J].草业学报,2016,25(10):86-94,9.基金项目
新疆维吾尔自治区重点实验室干旱区水循环与水利用实验室开放课题（XJYS0907-2011-01），“十二五”江苏省重点学科建设项目－草学和南京农业大学大学生实践创新计划训练项目（1215A06）资助。 （）
