Assessing the genetic diversity of tobacco (Nicotiana tabacum L.) varieties

The genetic diversity of ۴۰ tobacco (Nicotiana tabacum L.) cultivars was analyzed using ۱۲ ISSR primers. Thecultivars were evaluated for ۱۴ traits using a simple lattice design (۷×۷) with two replications. Of ۱۴۹ amplified bands, ۱۴۲ (۹۵.۳%) were polymorphic. Maximum and minimum bands were generated by primers UBC۸۲۵ (۱۷ bands and ۹۴.۱۱% polymorphic) and UBC۸۲۴ (۷ bands and ۱۰۰% polymorphic), respectively. Of the studied primers, UBC۸۲۴ showed maximum Polymorphism Information Content (PIC) (۰.۴۳) and the highest genetic diversity, and thus could be used in future genetic diversity studies. In principal coordinate analysis using a similarity matrix, the first two coordinates, which are the main coordinates, explained ۴۱.۹۷% of the total variance. Cluster analysis was performed to determine the genetic relationship of tobacco cultivars using the un-weighted pair-group method with arithmetic average (UPGMA) based onmorphological traits and ISSR markers separately. Plant genotypes were divided into nine main groups of flue-cured tobacco cultivars, and a cophenetic correlation coefficient was calculated (r = ۰.۹), indicating the usefulness of the UPGMA method for clustering plant genotypes. Cluster analysis based on morphological traits divided the studied genotypes into five groups using the UPGMA method. Results of canonical discriminate function analysis using the Fisher Linear method showed that the UPGMA method separated the genotypes with ۱۰۰% accuracy. Both clusters were consistent with the geographical origins of the cultivars.

کلیدواژه ها:

cluster analysis ، molecular marker ، morphological traits ، Nicotiana tabacum ، polymorphism information content (PIC)