关键词: 木荷, 生长性状, 多元线性回归, 反向逐步剔除法

Abstract: Twenty open-pollinated families of Schima superba progenies in Dongjiang Forest Farm and Meinan Forest Farm in Guangdong province were selected for testing growth traits. The height (H), diameter-at-breast-height (D)/collar diameter (C) and individual stock volume (V) were analyzed at ages of 3, 6, 9 and 11 years. Highly significant differences in 9 growth traits were observed among families and between two testing sites, and significant interactions were detected between families and planting sites. To explicitly reveal the linear relationships among growth traits, the V at age of 11 years was taken as dependent variable for the construction of multiple linear regression equations on the basis of taking height and D/C at ages of 3 to 9 years as independent variables. Sixty-three regression equations were established by using backward stepwise elimination method for total population and 20 individual families at single-site and across-site testing. All equations were highly significant on the whole, but each equation displayed obvious differentiation in intercept and independent variable component, amount, regression coefficient and determining coefficient, suggesting that it was appropriate to separately construct a multiple linear regression equation of S. superb for each family at single site. In terms of predicting V11 of S. superb, common precision could be achieved by using single-site or multiple-site regression model from population analysis, whereas higher precision was achievable using single-site regression model of each individual family.

Key words: Schima superba, growth trait, multiple linear regression, backward stepwise elimination