Study Of Genetic Diversity And Phylogenetic Relationship For23Sun-Cured Tobacco Germplasm Resources In Jilin Province

23sun-cured tobacco in Jilin Province were used as materials to analyzes the genetic diversity and phylogenetic relationship with morphological markers and SSR molecular marker and two flue-cured tobacco as a control. The major results were as follows:1. The results of morphological markers:The Euclidean distance between the23sun-cured tobacco material was1.11-8.29, the varieties could be clearly clustered into two groups(Ⅰ1, Ⅰ2) at the first level, and all the sun-cured tobacco (Ⅰ2) could be furthe clustered into two sub-groups(Ⅱ1,Ⅱ2) at the second level, Ⅱ1sub-groups include:yanjizilaihong, yanjiqiancengta, zhongchengwushiye, jilinhupoxiang, honghuaaizi and mengshancao, Ⅱ2sub-groups include the other17sun-cured tobacco varieties. Overall, the genetic relationship of the tested sun-cured tobacco was relatively narrow.2. An optimized SSR-PCR reaction system of sun-cured tobacco was established. Optimum concentrations of each components in20μl reaction system were as follows:2μl10x PCR buffer,20ng template DNA,0.25μmol/L forward primers,0.25μmol/L reverse primers,1.5mmol/L Mg2+,0.2mmol/L dNTPs,1.5U Taq enzyme and10.1μl ddH2O.3. Among the92pairs of SSR primers combinations,10polymorphic primers were selected and used to amplify for all the tested materials by PCR,52amplification bands were detected in the molecular weight of200bp-1000bp. Of which,8fragments were common, that revealed the homology between tobacco germplasm in a certain extent, of which44fragments were polymorphic, and the average percentage polymorphic bands was85.4. In SSR molecular markers, the similarity coefficient of genetic among23sun-cured tobacco ranged from0.531to0.980, average similarity was0.744, which descripted that they had a large genetic similarity and a recent phylogenetic relationship, the genetic distance of2flue-cured tobacco and23sun-cured tobacco was relatively far, average is0.627. The clustering results:sub-group (Ⅱ1) included9varieties:honghuaaizi, zhongchengwushiye, taixingyan, mengshancao, mudanyihao, songchuan(guandong201), yanshaiyihao,8107and yanbianhong, the genetic similarity coefficient in groups is0.698-0.898. Sub-group (Ⅱ2) included the other14sun-cured tobacco, the genetic similarity coefficient in groups is0.726-0.980. The first sub-group (Ⅱ1) was divided into two small sub-groups (Ⅲ1, Ⅲ2) under the unchanged results of second level, in which, yanshaiyihao,8107and yanbianhong is belong to Ⅲ2and the other6varieties is belong to Ⅲ1.5. The morphology of Euclidean distance and SSR genetic similarity coefficient were analysed by SPSS, the correlation coefficient was r=-0.383, reached highly significant level. To determine the degree of consistency of genetic differences in different varieties, the morphological Euclidean distance and SSR genetic similarity coefficient were further discussed. The correlation on chemical composition and Agronomic Traits Euclidean distance and SSR genetic similarity coefficient were respectively analysed, all the results showed highly significant negative correlation, the correlation coefficients were r=-0.366and r=-0.265.