广西凭祥西南桦种源家系选择试验I. 幼林生长性状的变异

应用25个地理种源400余个家系在广西凭祥进行西南桦种源家系联合筛选试验,对1～4年生幼林进行了生长性状遗传变异分析,结果表明:(1)不同西南桦种源间和家系间的树高和胸径生长均差异极显著;(2)各种源树高和胸径均与其产地经度极显著相关;(3)不同林龄间种源和家系的树高和胸径生长量的相关分析表明,种源选择的可靠性逐年增加;(4)以4年生时生长性状作早期评价,发现大多数优良种源、家系来自广西,可见西南桦种源选择以就近种源较好.

Provenance and Fam ily Tr ia ls for B e tu la a lnoides in Pingx iang, Guangx iI. Early Var ia tion of Growth Tra its

A p rovenance and family trial of B etula alnoides was conducted in Pingxiang of Guangxi, with 25p rovenances and 400 families involved. The genetic variation of growth traitswere analyzed in the first four years. Itwas shown that there were highly significant differences in height (H) and diameter at breast height (DBH) amongp rovenances as well as families, and the height and DBH of p rovenances were remarkably correlated to thelongitudes of their seed sources, respectively. Itwas inferred that p rovenance selection wasmore highly reliable withage of the tree getting older based on the result of correlation analysis on growth performance at different ages, andthe p riority should be given to the p rovenances near the site for p lantation development of this species since mostp rovenances from Guangxi grew the best.