大叶栎家系水平性状变异及优良家系选择研究

对大叶栎半同胞家系生长性状的遗传变异进行了研究,结果表明:除了冠径比外,树高、胸径、单株材积、冠幅和冠高比家系间差异极显著,且家系遗传力都在0.50以上,说明家系间具有良好的选择潜力;大多性状间的表型相关和遗传相关呈极显著或显著的正相关,有利于对多性状进行综合选择,构建的综合选择指数方程为I=8.9527X1+2.9906X2+2111.6762X3+6.1398X4-9.3236X5;按10％的入选率选出2个优良家系,与家系平均值比较,树高、胸径、材积、冠幅、冠高比和冠径比的平均遗传增益分别为14.18％、23.33％、45.24％、23.25％、6.72％、-0.67％,与对照相比,以上性状的平均遗传增益分别为20.55％、28.89％、48.92％、21.97％、5.16％、-3.91％.

Variation of traits among Castanopsis fissa families and selection of superior families

In this paper, the genetic variation on growth traits of a Castanopsis fisa half-sib family plantation were studied. The results showed that there were extremely significant differences among families on the tree height (H),diameter at breast height (DBH), individual tree volume (V), crown diameter (CD) and the ratio of crown diameter to H(RCDH), except for the ratio of crown diameter to DBH (RCDDBH). The family heritability of all traits were higher than 0.50, it indicated that an extensive selection potential existed among families. For the given traits, many of them had significant positive phenotypic and genetic correlations among each other, which was favorable for the comprehensive selection with multi -traits. On the base of traits-combining selection, a selection index equation was introduced(I=8.9527X1+2.9906X2+2111.6762X3+6.1398X4-9.3236X5). At the selection rate of 10%, two superior families were chosen.Compared the trait mean of two selected families with that of plantation, the expected genetic gains on H, DBH, V, CD,RCDH, and RCDDBH were 14.18%, 23.33%, 45.24%, 23.25%, 6.72, and -0.67%. More genetic gains were expected when compared the trait mean of selected families with that of control (CK), the expected values were 20.55%, 28.89%, 48.92%,21.97%, 5.16%, and -3.91%, respectively.