Genetic diversity in Indian chewing tobacco (Nicotiana tabacum) as revealed by RAPD and SSR markers

Abstract

Randomly amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) markers were employed to assess genetic diversity among released varieties of chewing tobacco cultivars grown in Tamil Nadu and Bihar. In RAPD, 15 out of 25 primers amplified 79 fragments of which 43 (54.43%) were polymorphic. Twelve SSR primers amplified 52 fragments of which 35 (67.3%) were polymorphic. Pair-wise genetic similarity based on RAPD assay ranged from 0.48 to 0.94 with an average of 0.71 while it ranged from 0.37 to 0.95 with a mean of 0.66 based on SSR marker assay. From the cluster analysis based on RAPD and SSR markers, the chewing tobacco varieties grown in these two states were found genetically divergent. The clustering pattern of the cultivars corresponded more with parentage. SSR markers were more efficient than RAPD markers in differentiating chewing tobacco cultivars and could be used for development of markers for various traits. The SSR primers TbM 27 and TbM 29 produced variety-specific markers.