鹅掌楸种源遗传变异和选择评价

Genetic Variation and Provenance Selection of Chinese Tuliptree

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 .50 3、0 .52 6、0 .52 1,受较强的遗传控制 ;RC受遗传控制程度相对较低 ( H2 =0 .30 1)。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、叙永两个优良种源 ,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%。

WT5BZ]Fifteen provenances were sampled in the distribution areas of Chinese Tuliptree(Liriodendron chinense) and the trial plantations were simultaneously established in 5 sites along the middle and lower reaches of Yangtze River in 1991. The main growth characteristics, 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 analysis were conducted. The results showed that there were significant differences among provenances (F H=29.5,F DBH =10.02,F RC =4.1),which indicated potentiality of selection and genetic improvement, and there were significant differences among sites, which indicated Chinese Tuliptree was sensitive to environment, and there were also significant differences among mutual actions of provenances and sites. The heritabilities of height, DBH and volume for provenance are all more than 0.5 which shows a strongly genetic control in growth characteristics and a good genetic gain can be acquired by provenance selection. The analysis of genetic stability, growth andaptability and correlation between juvenile and mature were conducted, which provided bases for provenance selection and evaluation. The provenance selection and evaluation were conducted in multi sites' and single site's way respectively. Liping and Xuyong provenances 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 each site in single site's selection and the genetic gain was 15.4%～51.5% higher than multi sites'. [WT5HZ]