节水灌溉对小麦旗叶主要光合参数和水分利用效率的影响

Effects of water-saving irrigation on some photosynthetic functions and water use efficiency in wheat

2007-2009年于山东省农业科学院作物研究所旱池,以济麦22为试验材料,研究了不灌水（W0）、拔节水60 mm（W1）、拔节水60 mm＋开花水60 mm（W2）和越冬水60 mm＋拔节水60 mm＋开花水60 mm（W3）4个灌水处理对小麦旗叶荧光动力学参数、光合速率（Pn）、气孔导度（Gs）、胞间CO2浓度（Ci）、蒸腾速率（Tr）和水分利用效率（WUE）的影响。结果表明：随着灌水次数的增加,光系统Ⅱ（PSⅡ）最大光化学量子效率（Fv/Fm）、光化学猝灭系数（qP）和光系统Ⅱ（PSⅡ）的实际光化学效率（ΦPSⅡ）明显改善,旗叶净光合速率显著提高;气孔导度（Gs）和胞间CO2浓度（Ci）随着灌水次数的增加而增加,与蒸腾速率（Tr）呈线性关系;4个灌水处理的水分利用效率以W0最高,W1和W3较低（P〈0.05）;W3处理的地上部干物质积累量和籽粒产量要显著高于其余3个处理（P〈0.05）;光合速率、蒸腾速率和水分利用效率存在显著的相关关系。

A field experiment for effects of water stress on photosynthetic functions was conducted in Jinan,Shandong,China（36°42′N,117°04′E） for wheat growing seasons during 2007~2009.There were four irrigation treatments,no irrigation（W0）,one irrigation at jointing stage（W1）,two irrigations at jointing and anthesis stage（W2）,three irrigations at over-wintering,jointing and anthesis（W3）.Each irrigation supplied water of 60 mm.The results showed that,during the period of grain filling（7 d after anthesis）,the photosynthetic indexes of flag leaf including the maximum photochemical efficiency（Fv/Fm）,the actual photochemical efficiency of photosystem Ⅱ（ΦPSⅡ） and the photochemical quenching coefficient（qP） were obviously higher with adding irrigation and net photosynthetic rates were significantly increased.There were linear relationship between leaf stomatal conductance,intercellular CO2 concentration and transpiration rate.There were significant changes in the maximal efficiency of PSⅡ photochemistry and apparent damages in PSⅡ reaction centre,its oxidising and acceptor sides,or its antennae system for W0.This was shown by the decrease in the efficiency of excitation energy capture by open PSⅡ reaction centers and the quantum yield of PSⅡ electron transport and a significant decrease in non-photochemical quenching.However,got the highest WUE in four treatments,while the dry matter accumulation and grain yield in W3 were higher than those in other treatments.Photosynthetic rate,transpiration rate and water use efficiency were significantly correlated.