南疆春季不同天气条件对设施桃树光合日变化的影响
Effect of Different Weather on Diurnal Variation of Photosynthesis of Peach Trees under Protected Cultivation in Spring in Southern Xinjiang

在设施桃树果实发育期，利用TPS-2型便携式光合仪测定南疆春季晴天、沙尘暴天气条件下桃树净光合速率（Pn）及主要环境因子并分析日变化特征，通过相关分析、逐步多元回归等方法探讨Pn与环境因子的关系。结果表明：①2种天气条件下，设施桃树光合日变化差异较大，晴天‘中油5号’油桃光合日变化为不对称双峰曲线且第1个峰值较小，沙尘暴天气的光合日变化曲线为单峰型且全天Pn平均值仅为晴天的50%左右。②晴天，影响设施桃Pn的主要环境因子及大小顺序为光合有效辐射（PAR）＞相对湿度（RH）＞温度（Ta）＞CO2体积分数（Ca），沙尘暴天气，影响设施桃Pn的主要环境因子及大小顺序为PAR＞Ta。沙尘暴天气使光照极度减弱，导致设施内环境因子大幅改变，影响桃树的光合日变化。2种天气条件下，光照通过直接或间接作用成为影响设施桃树光合作用最重要的环境因子。
During fruit development of peach trees under protected cultivation,TPS-2 portable photosynthesis analysis system was used to determine diurnal variation of photosynthesis and environment factors in fair weather and sand-dust weather,relative analysis and stepwise multi-regression were also used to discuss the relationship of environment factors and diurnal changes of photosynthetic rate. The results showed that:①There was great difference among the diurnal variation of Pn in two kinds of weather conditions,the diurnal variation of Pn was the bimodal curve in fair weather and the first peak was small,the diurnal variation of Pn was the unimodal curve in sand-dust weather and the average value of photosynthetic rate was only about half of which in fair weather during a whole day. ②In fair weather ,the main environment factors which affected Pn and the order of effecting ability was PAR＞RH＞Ta＞Ca;in sand-dust weather,PAR＞Ta. Light extremely weakened in sand-dust weather and it rised to a dramatic change of environment factors affected the diurnal variation of Pn. Under this two kinds of weather conditions,light was the most important environment factor which directly or indirectly affected photosynthesis of peach tree under protected cultivation .