抗黑胫病烟草种质的遗传多样性分析

为了从分子水平上了解种质库抗黑胫病种质的遗传多样性，为拓宽黑胫病种质的遗传多样性、提高黑胫病抗性种质的利用率提供理论和技术支持，利用筛选出来的34对烟草多态性引物，对取自国家烟草种质资源库的73份抗黑胫病烟草种质进行遗传多样性分析，根据材料类型将其中的68份普通烟草种质分为烤烟和晾晒烟2个群体。结果表明：这34对引物共扩增出88多态性条带，每对引物平均扩增出2.6个变异位点，其中有效变异占94.12%。遗传多样性指数(Nei’s)为0.4200，Shanno’s指数为0.6803，种质间遗传相似系数变异范围在0.5140~0.9818的占63.57%，表明烟草抗黑胫病种质遗传多样性较差，其遗传多样性与栽培类型没有必然联系。加大对抗性野生烟的利用，对拓宽烟草抗黑胫病种质资源的遗传多样性有重要意义。

Genetic Diversity Analysis on Resistant Tobacco Germplasm to Black Shank Disease

To understand the genetic diversity of germplasm in the germplasm bank against black shank from the molecular level, and to afford theoretical and technical support for broadening the genetic diversity of germplasm against black shank and enhancing the utilization rate of the germplasm, genetic diversity of 73 resistant tobacco germplasm to black shank disease, including two Nicotiana tabacum population (flue-cured tobacco and sun-cured tobacco), came from national storage of tobacco germplsam was evaluated based on 34 selective polymorphic primer pairs. Results showed that 88 bands, all of which were polymorphic, were amplified using 34 SSR primers, with an average of 2.6 variable sites per primer pair. A high level of genetic differentiation among populations was detected based on Nei’s genetic diversity analysis (0.4200), Shannon’s information index analysis (0.6803). The percent of tobacco varieties, with a genetic similarity coefficients ranged from 0.5410 to 0.9818, was 63.57%. This indicated that there was a low genetic diversity among the resistant tobacco germplasm to black shank disease in China, and had no significant relationship whit its cultivated type. It had a significant meaning to widen the genetic base of the resistance tobacco varieties to black shank disease through exploring the applying of the wild tobacco.