黄梁木幼林家系主要性状的观测与优良家系的初步选择

Main traits observation of young growth family and superior family selection of Neolamarckia cadamba

2011年从云南、广西、广东等地选择黄梁木幼树40株,2014年5月在广东雷州开展了家系造林对比试验,2015年1月的调查结果表明:树高、地径、冠幅、枝下高、冠高比、冠径比等生长性状在家系间差异极显著,性状家系遗传力均达到0.5以上,家系间选择潜力大;根据性状相关分析和回归检验判断,地径、树高、枝下高对材积指数的影响最大,在此基础上,构建了材积指数主要性状指数方程。以10%的入选率选出4个优良家系,4个优良家系的地径、树高、材积指数、枝下高、冠径比和冠高比的平均遗传增益分别为20.15%、20.49%、46.20%、9.98%、2.45%和-8.95%。

Forty trees of Neolamarckia cadamba were chosen from ~unnan, Guangxi and Guangdong province in 2011, and then contrast test was performed through family afforestation in May 2014. The results from survey in Jan 2015 showed that there were extremely significant differences among families on the tree height （ H ） , ground diameter （ GD ）, individual tree volume （ V ）, height under branch （ BH ）, crown diameter （ CD ） , the ratio of crown diameter to ground diameter （ RCDGD ） , and the ratio of height to height under branch （ RHBH ） . The family heritability of all traits were higher than 0.50, which indicated that an extensive selection potential existed among families. For the given traits, many of them had significant positive phenotypic and genetic correlations with each other, which were favorable for the comprehensive selection with multi-traits. On the base of traits -combining selection, a selection index equation was constructed. Under 10% selection pressure, four superior families were chosen. Compared with the trait mean of control （ CK ） , the expected genetic gains on H, GD, V, BH, CD, RCDGD and RHBH of the four selected families were 17.34%, 20.49%, 46.20%, 20.39%, 13.47%, 2.45% and -8.95%, respectively.