抗黑胫病地方烟草品种遗传多样性分析与评价

为了拓宽黑胫病抗性育种亲本材料的遗传背景以及充分发掘和利用地方品种的抗病基因资源,本研究利用筛选获得的25对SSR引物对35份抗黑胫病地方烟草品种进行了亲缘关系聚类分析和遗传多样性分析。结果表明:(1) 25对SSR引物共检测到85个多态性位点,聚类分析结果表明35份地方烟草品种的遗传相似性系数分布范围为0.57~0.87;(2)在遗传相似性系数为0.57时,可以将35份抗黑胫病地方烟草品种分成两个类群,A类包括20份烤烟品种,B类包括15份晒烟品种。在遗传相似系数0.62烤烟分为2个类群,晒烟分为3分类群;(3)在抗黑胫病地方烟草品种中观测等位基因数的平均值为3.32个;有效等位基因数的平均值为2.651;观测杂合度的平均值为0.395;期望杂合度的平均值为0.596。平均Nei’s基因多样性指数(H)为0.558,平均Shannon’s指数(I)为1.020。不同地方的抗黑胫病烟草品种间具有一定的遗传差异,品种之间具有较高的遗传多样性,且品种间的亲缘关系和品种的地理来源之间具有一定的相关性。

Genetic Diversity Analysis and Evaluation of Resistant to Black Shank Disease Local Tobacco Varieties

The objective of this study was to broaden the genetic background of black shank disease resistance breeding parents and fully exploit and utilize the resistance gene resources of local varieties. 35 local tobacco varieties which resistant to black shank disease were analyzed by genetic cluster analysis and genetic diversity analysis using 25 pairs of SSR primers. The results showed that:(1) 85 polymorphic loci were detected by 25 pairs of SSR primers, and cluster analysis showed that the variation range of genetic similarity coefficient was 0.57~0.87;(2)When the genetic similarity coefficient was 0.57, 35 local tobacco varieties resistant to black shank disease could be divided into two groups. Category A included 20 flue-cured tobacco varieties and Category B included 15 sun-cured tobacco varieties. At genetic similarity coefficient 0.62, flue-cured tobacco was divided into two groups and sun-cured tobacco was divided into three groups;(3) The average values of observed allele number was 3.32. The effective allele number was 2.651. The observed heterozygosity was 0.395 and the expected heterozygosity was0.596. The average Nei’s gene diversity index(H) was 0.558 and the average Shannon’s index(I) was 1.020. There are certain genetic differences am ong tobacco varieties resistant to black shank disease in different places, and there is a high genetic diversity among varieties, and there is a certain correlation between the genetic relationship among varieties and the geographical origin of varieties.