优良杨树品种夏秋二季净光合速率及生态因子的日变化

目的:研究自然条件下中南地区的杨树优良品种(中潜3)的光合作用日进程以及生态因子对它的影响.方法:采用LI-6200测定净光合速率与生态因子,用Origin 6.1制图,用DPS数据处理系统进行逐步多元回归和通径分析.结果:夏季晴天阳叶净光合速率日进程呈现“单峰“曲线变化,秋季为“双峰“型,光合效率明显降低.应用逐步多元回归方法,得到净光合速率日变化的最优方程,夏季晴天为:Y=-8.536 1 0.013 1X_1-0.608 8X_3 0.076 3X_4(复相关系数R=0.950 4,F=6.225 9,显著水平p=0.141 5).秋季晴天为:Y=-10.012 3 0.203 0X_2 0.409 1X_3-0.014 1X_4(复相关系数R=0.809 2,F=1.897 5,显著水平p=0.306 0).偏相关分析和通径分析表明:夏季光合有效辐射(X_1)与净光合速率(Y)的日变化有着显著的相关关系

Diurnal Variation of Net Photosynthetic Rate and Ecological Factors of A Fine Poplar Variety in Summer and Fall

The diurnal variation of photosynthesis of a fine Poplar variety (Zhongqian3) leaves under natural conditions and the effect of ecological factors were studied.The curves of diurnal variation of net photosynthetic rate (Pn) in sunnyleaf have one peak and two peaks respectively during the clear day of Summer and September, and Pn is obviously reduced in September.The best equation for the diurnal variation of Pn is obtained by the method of stepwise multiple regression as follows;Y=-8.536 1 0.013 1X_1-0.608 8X_3 0.076 3X_4 (Summer;R =0.9504,F=6.225 9,p=0.1415).Y=-10.012 3 0.203 0X_2 0.409 1X_3-0.014 1X_4.Fail;R=0.809 2, F=1.897 5,p=0.306 0).The analysis of partial correlation and path on Pn and factors shows that the diurnal variation of Pn has significant correlation with photosynthetically active radiation (PAR) in Summer.