利用RAPD和ISSR标记分析烤烟品种间遗传关系

Assessment of Genetic Relationships between the Flue-cured Tobacco Varieties by RAPD and ISSR Markers

利用RAPD和ISSR标记对22份烤烟（Nicotiana tabacum L．）品种进行了遗传关系研究。在RAPD分析中筛选到13个引物，共扩增出167条带，其中多态性带50条，多态性比率为29．9％；在ISSR分析中筛选出7个引物，共扩增出96条带，其中多态性带44条，多态性比率为45．8％。两种标记相结合估算出的品种间遗传相似系数在0．881-0．979之间，平均为0．933。单独基于RAPD标记和ISSR标记的聚类结果有一定差异；两种标记结合起来的聚类分析结果与系谱信息吻合程度更高。定向选择可能对烤烟品种间遗传关系有较大影响；国外引进品种与国内育成品种并未完全分开，表明分子水平的遗传关系和地理来源间缺乏必然联系。

The genetic relationships between 22 flue-cured tobacco varieties were assessed by RAPD and ISSR markers. For RAPD analysis, 13 random primers were identified with polymorphism among the entries. In total 167 bands were produced, of which 50 bands were polymorphic. Percentage of polymorphic bands was 29.9%. For ISSR analysis,7 primers were identified with polymorphism among the entries. In total 96 bands were produced, of which 44 bands were polymorphic. Percentage of polymorphic bands was 45. 8%. Pairwise similarity coefficients combining both RAPD and ISSR markers ranged between O. 881 and O. 979, with an average of 0. 933. Clustering of genotypes had some differences when RAPD- and IS- SR- derived dendrograms were compared. The den rable to the information on pedigree. The selection drogram combining both two markers was more compapressure had great effects on the genetic relationships between varieties. The fact that the introduced varieties from abroad were not separated from the developed varieties in China implied that the genetic relationships based on the molecular marker data did not correspond well with the geographic sources.