Genetic Diversity of Sichuan Sun-Cured Tobacco Cultivars by ISSR

Genetic diversity of 70 Sichuan sun-cured tobacco cultivars was analyzed by inter simple sequence repeats(ISSR).107 bands were identified using agarose gel electrophoresis.The average number of amplified DNA bands was 8.23 per primer,and the rate of polymorphic bands was 90.37%.Genetic similarity ranged from 0.46 to 0.87 through cluster analysis with UPGMA,which suggested the genetic diversity among these germplasms not obvious,and the average genetic similarity index was 0.646.Genetic similarity index between Hong maoliu and Ba maoliu was 0.87,indicating that their genetic diversity was similar,but genetic similarity index between Tu yan from Da zhou and Hei niupi from Xin du was 0.46,showing more difference of their genetic diversity.Cluster analysis and principal component analysis(PCA) were carried out.The results showed that the 70 Sichuan sun-cured tobacco cultivars were divided into five groups,deeply associated with their geographical distribution.ISSR analysis was suitable for variety identification and the research on genetic diversity of tobacco germplasm.