RAPD and ISSR markers for molecular characterization of Grewia optiva: an important fodder tree of north western Himalayas

Abstract

RAPD (random amplified polymorphic DNA) and ISSR (inter simple sequence repeats) markers were used to study DNA polymorphism of thirty Grewia optiva genotypes raised from seeds collected from various districts of Himachal Pradesh (India) and selected on the basis of morphological parameters. In general, the genotypes exhibited a very high level of molecular diversity and DNA polymorphism. Using 25 RAPD and 18 ISSR primers molecular diversity based on Jaccard’s similarity coefficients among 30 genotypes ranged from 0.17-0.83 in RAPD assay and 0.30-0.84 in ISSR assay. RAPD primers amplified more loci than ISSR primers. RAPD and ISSR primers amplified 96.31 and 91.72% polymorphic loci, respectively. The dendrogram derived using the unweighted pair-group method with arithmetic averaging (UPGMA) clustered the genotypes into different groups reflecting geographical sub-structuring of the genetic diversity. Genotype SO-12 (Kasauli) was found to be the most divergent genotype which could be used for number of combinations to be established in the seed orchards and as a parent in hybridization programme.