Assessment of the genetic diversity of exotic mulberry germplasm collections
Mulberry belongs to the fig family Moraceae under the order Urticales that is considered to be an advanced in the woody flowering plants. Widening of gene pool as well as development of superior genotypes is a continuous process for mulberry improvement. In the present study, 26 SSR markers were employed to assess genetic relatedness among 20 exotic mulberry accessions conserved at CSRTI, Mysuru. Among the 26 SSR markers, 6 were polymorphic, generating 32 scorable loci. The size of the fragments ranged from 180 to 350 bp with an average of 1.4 fragments per primer. The highest dissimilarity of 12.37 was observed between Moreti and ACC.165 followed by 12.33 in Acc. 165 and Australia, Acc.165. Similarly, highest similarity was observed in BR-2 and BR-8, BR-8 and Thailand Lobe. Clustering of the genotypes was done with unweight pair group method using arithmetic average (UPGMA) which generated 2 clades (I and II). Interestingly, Clade II has only one accession SRDC-3 and was highly divergent. The genetic diversity in exotic accessions will be useful for mulberry hybridization programme to develop superior varieties suitable for specific zones, providing opportunity for plant breeders to develop new and improved cultivars with desirable characteristics, which include yield potential, pest and disease resistance.
Keywords: germplasm, genetic diversity, marker, exotic, mulberry