鹅掌楸种源遗传变异和选择评价

在中国鹅掌楸全分布区内抽样15个种源，于长江中下游5省区按统一试验设计营造种源试验林，7年生时全面测定其树高（H）、胸径（DBH）、冠幅（RC）等主要生长性状，进行遗传6变异分析，结果表明：中国鹅掌楸生长性状在种源间存在显著的遗传差异，地点间差异极显著，种源对环境反映灵敏，种源与地点间存在明显的交互作用，H、DBH和材积（V）的广义遗传力分别为0.503、0.526、0.521，受较强的遗传控制；RC受遗传控制程度相对较低（H^2=0.301)。相继进行了遗传稳定性、生长适应性分析和幼成龄相关分析，分析结果为种源选择和评价提供了理论依据，多点综合选择选出黎平、伤痛永两个优良种源，遗传增益11.8%。单点选择分别选出1-3个丰产种源，遗传增益达15.4%-51.5%。

Genetic Variation and Provenance Selection of Chinese Tuliptree

Fifteen provenances were sampled in the dis tribution areas of Chinese Tuliptree(Liriodendron chinense) and the trial plantations were simultaneously established in 5 sites along t he middle and lower reaches of Yangtze River in 1991. The main growth characteri stics, including height (H), diameter at breast height ( DBH) and range of tree crown (RC ) were all measured respectively when in the seventh year and the variance analy sis were conducted. The results showed that there were significant differences a mong provenances (FH＝29.5,FDBH＝10.02,FRC＝4.1),which indicated potentia lity of selection and genetic improvement, and there were significant difference s among sites, which indicated Chinese Tuliptree was sensitive to environment, a nd there were also significant differences among mutual actions of provenances a nd sites. The heritabilities of height, DBH and volume f or provenance are all more than 0.5 which shows a strongly genetic control in gr owth characteristics and a good genetic gain can be acquired by provenance selec tion. The analysis of genetic stability, growth andaptability and correlation be tween juvenile and mature were conducted, which provided bases for provenance se lection and evaluation. The provenance selection and evaluation were conducted i n multi-sites' and single-site's way respectively. Liping and Xuyong provenanc es were picked out from all five sites in multi-sites selection and the genetic gain was 11.8%, and one to three provenances were respectively picked out for e ach site in single-site's selection and the genetic gain was 15.4%～51.5% highe r than multi-sites'.