水分胁迫对蹄叶橐吾光合特性的影响

Effects of Water Stress on Photosynthesis Character of L. fischeri

[目的]研究水分胁迫对蹄叶橐吾光合特性的影响。[方法]以1年生盆栽蹄叶橐吾幼苗为试验材料,研究了经正常处理和水分胁迫处理12 d后蹄叶橐吾光合特性的日变化。[结果]正常条件下的光合速率、蒸腾速率、水分利用率日变化呈"双峰型"曲线,在水分胁迫下,蹄叶橐吾的光合速率和蒸腾速率、水分利用率日变化均呈峰值很小的"单峰型"曲线,并且净光合速率的下降是由气孔因素与非气孔因素双重作用造成的,水分胁迫下非气孔限制是光合速率下降的主要原因。[结论]蹄叶橐吾的光合作用在城市中有一定的适应能力,但重度水分胁迫对其将造成严重影响。

[ Objective ] The research aimed to study the effects of water stress photosynthetic characteristics in L.fischeri [ Method ] The effect of water stress on diurnal variation of photosynthetic performance in one year old potted L. fischeri at the 12th day after the water stress and the natural condition treatment was investigated. [ Resultl The diurnal variation curves of Pn ,Tr and WUE were double-peak types under the natural condition, but the curves of Pn,Tr and WUE turned to single-peak types with low peak values under severe stress. The decrease of net photosynthesis rate was caused by stomatal and nonstomatal inhibition, while under severe stress by the nonstomatal factors. [ Conclusion] The photosynthesis of. L.fischeri exhibited a certain adaptability to water stresses except severe stress in city.