【作者】 李世峰；

【导师】 潘惠新；

【作者基本信息】 南京林业大学 ， 林木遗传育种， 2003， 硕士

【摘要】 本文从表型与分子两个层次上对南京林业大学建立的美洲黑杨种质资源库中的11个家系，145个无性系进行遗传变异研究，为将来杨树育种提供科学的依据。主要结果如下： 1．11个家系及各个家系内无性系间在树高、胸径和材积等生长性状上差异达极显著水平，总遗传变异中平均家系变异占总遗传变异的17％，家系内无性系间的变异占总遗传变异41％。三个性状三年的平均遗传力和遗传变异系数分别为64.48％、62.78％、60.59％和11.26％、11.49％、28.42％，处于中等遗传控制水平。 2．采用12对SSR引物对137个样品进行遗传变异分析，共得到了103个等位基因，平均每对引物得到8.6个等位基因(2～14)，其有效等位基因平均数(Ne)为5.37个(8.79～1.57)。12个引物观测杂合度(Ho)为0.39(0.14～0.50)，基因多样度(He)平均值为0.75(0.37～0.89)显示了美洲黑杨种质资源库存在着丰富的遗传变异。 各家系的遗传多样性没有明显的差异，遗传相似度从0.2735～0.7272之间，平均相似系数为0.4814。遗传分化系数(Gst)平均值为0.22，表明在总的遗传变异中有22％的变异存在于家系之间，78％存在于家系内。经聚类分析，11个家系分为两大类，第一类的4个家系均来自于路易斯安娜州，第二类的7个家系均来自于密西西比州。 3．对SSR位点与生长性状进行相关分析，有3个位点对一个或几个性状有显著或极显著影响。在这些位点附近可能存在着控制某个性状的QTL。更多还原

【Abstract】 Genetic variation of 11 sib-families (145 clones) from Populus deltoides germplasm established by Nanjing Forestry University was analyzed on phenotype and molecular level, which provided the base for the polar breeding in future. The main results as follows:1. The results indicated that significant difference in height, DBH and volume characters exited among 11 sib-families and clones-within families. About 17% of the genetic diversity resulted from differentiation among families with remaining 41% residing within families. Height, DBH and volume characters of P.deltoides were middle genetically controlled with the average broad-hereditary of 3 years of 64.48%, 62.78%, 60.58%, respectively, and the average coefficient of genetic variance of 3 years of 11.26%, 11.49%,28.42%.2. A total of 103 alleles were detected using 12 SSR loci in 137 P.deltoides clones, with an average allele number of 8.6 per locus (range : 2-14) , effective allele number of 5.4 (1.6-8.8). Except for PMGC2408 and PMGC2522, all other SSR markers showed on a high value of gene diversity ranging from 0.37 to 0.89 with a mean of 0.75.The results showed that genetic diversity of families had no significant difference . 11 sib-families showed a high value of genetic identity ranging from 0.2735 to 0.7272 with a mean of 0.4814.The average coefficient of genetic differentiation (Gst) was 0.22, which showed 22% of genetic diversity resulted from differentiation among families with remaining 78% residing within families. UPMGA cluster analysis showed that 11 sib-families could be classified into two distinct classes at genetic distance 0.61. 7 sib-families that come from Mississippi were classed into class one, and class two only had 4 sib-families, coming from Louisiana. The average genetic distance was 0.61, which showed abundant genetic variation exited among 11 sib-families.3. Effect of 12 SSR loci on growth traits of P.deltoides were analyzed with PROC GLM of SAS. Results showed that 3 loci had significant effect on growth traits of P.deltoids. It appeared that some QTLs exited near of these locis.更多还原