Assessment of genetic diversity and population structure in a selected germplasm collection of 292 jute genotypes by microsatellite (SSR) markers

Abstract

Genetic diversity within the available jute germplasm has not been characterised in detail. Therefore, using 172 SSRs developed in our laboratory, we assessed genetic diversity and population structure in 292 genotypes (including both indigenous and exotic accessions) of two cultivated species (C. capsularis L. and C. olitorius L.). Altogether, as many as 596 alleles (3.46 alleles per locus) were detected. The average values of PIC calculated over all the loci did not differ significantly in the two species (0.198 in C. capsularis and 0.203 in C. olitorius). In C. capsularis, 112 markers (2.55 alleles per locus) and in C. olitorius 140 markers (2.75 alleles per locus) were polymorphic. During both distance based cluster analyses and model based structure analyses, most of the indigenous and exotic genotypes of the two species clearly delineated into separate groups. Basic statistics (Ne, I and He) revealed that the exotic genotypes were slightly more diverse than the indigenous genotypes in C. olitorius while the reverse was true in case of C. capsularis. In each of the two species, low level of population differentiation (Fst) was observed between the indigenous and exotic genotypes, which are also congruent with the results of AMOVA and Nei’s genetic distance, suggesting incidence of gene flow through germplasm exchange across countries. Seven pairs of most divergent genotypes of the two species were identified by pair-wise genetic distance analysis which could be useful for development of jute genotypes with improved fibre yield and fibre quality traits.