榆林毛乌素沙地樟子松无性系生长性状变异研究

为了解樟子松种子园无性系之间生长性状的变异情况，对其树高、胸径、冠幅的生长量进行调查分析。结果表明：无性系间树高、胸径和冠幅的差异达到极显著水平，无性系内树高、胸径和冠幅的差异不显著，无性系内生长性状平均数的变异较无性系间小得多，说明生长性状主要受遗传控制。重复力估算结果表明：树高为0．399～0．497、胸径为0．132～0．201、冠幅为0．179～0．182，以树高的重复力为最高。依据树高的多重比较对无性系进行排序，一、三区无性系7、9、1、2、10较好，其高生长量超出平均参试无性系平均值的14．41％；五、六区无性系34、7、26、49、51较好，其高生长量超出平均参试无性系平均值的28．65％。

Study on Variations of Growth Traits of Pinus sylvestris Clones in Maowusu Sandland of Yulin Municipality

The height, DBH, crown size growth of the Pinus sylvestris var. monglica clones were investigated and analyzed in order to understand the growth variation among the clones. The variance analysis on growth traits of the clones showed that there were significant differences among clones and insignificant differences within the clones. The variation among the average value for the studied growth traits within clones was much smaller than that of among the clones, which demonstrated that the growth traits were mainly controlled by genetic factors. The re- peatability values of the average height, DBH and crown diameter were 0. 399 -0. 497, 0. 132 -0. 201 and 0. 179 -0. 182 respectively, indicating that the height index had the greatest repeatability. The muhi-comparison of height values showed that the clones No. 7. No. 9, No. 1, No. 2 and No. 10 were superior, the average height of these clones exceeded the mean value of all the Studied clones by 14.41% in the first and third district. The clones No. 34, No. 7, No. 26, No. 49 and No. 51 were even better, the average height value of these clones exceeded the average value of the clones in the fifth and the sixth district by 28.65 %.