EVALUATION OF MOLECULAR GENETIC VARIABILITY AMONG IDENTIFIED NATU TOBACCO ( NICOTIANA TABACUM ) GERMPLASM

Abstract

Genetic diversity among Natu tobacco varieties and landraces was studied by RAPD, SSR and isozyme markers. A total of 78 amplified fragments were produced by 10 RAPD primers with 42.3% polymorphism. A total of 45 amplicons were common to all accessions indicating the conserved nature of genome among Natu tobacco. Sixteen SSR primers produced 83 amplified fragments with 44.5% polymorphism. Isoenzymes of polyphenol oxidase showed 7 loci with maximum variability among the accessions. The genetic similarity among the cultivars and land- races of Natu tobacco based on RAPD, SSR and isozymes varied from 73 to 97%, 58 to 93% and 50 to 92%, respectively. The clustering pattern based on UPGMA was nearly similar with three types of markers with respect to the varieties but differed in sub-clustering. The RAPD markers showed higher per cent of average genetic similarity when compared to SSR markers. SSR markers showed more variety/land race specific markers. The higher genetic variability existing among the Natu tobacco genotypes can be utilized in the breeding programme for the development of varieties with required yield and quality traits.