关键词: 欧美杨杂交种&lsquo, 中嘉8&rsquo, 光合速率, 生态因子, 多元逐步回归, 通径分析

Abstract: To analysis the correlation between net photosynthetic rate and ecological factors, using the methods of stepwise regression and analysis of path is much better than correlation analysis of duality variable.By the methods of stepwise regression and analysis of path, this paper studied the diurnal changes of zhongjia8, a crossbreed from Occident Poplar, during early summer and autumn.The results indicated that the diurnal changes of Pn showed a single-peak curve in early summer, the major factor affecting it was PAR (X₁), and PAR had extremely significant correlation with Pn.The optimum equation of Pn was attained as follows:Y=17.8271+0.0108 X₁-0.2185 X₂(multiple correlated coefficient R=0.9954, F=215.4439, significance level p=0.0001, Pn-Y, PAR-X₁, RH-X₂).But in September, Pn showed a two-peak curve, the major factor affecting it was Ca(X₄).The optimum equation was attained as follows:Y=5.2915-0.0030X₁+0.3414X₃-0.0216X₄ (multiple correlated coefficient R=0.8962, F=4.0823, significance level p=0.1391, Pn-Y, PAR-X₁, RH-X₂, Tleaf-X₃, Ca-X₄).

Key words: Populus deltoides CL.‘Zhongjia 8’, photosynthetic rate, ecological factor, stepwise multiple regression, analysis of path