Genetic diversity, population structure and genetic relationships in apricot (Prunus armeniaca L.) germplasm of Jammu and Kashmir, India using ISSR markers

The collection and characterization of apricot germplasm is an important step for its utilization, conservation, and breeding programs. In the present study, the genetic diversity and population structure of 106 accessions of apricot including 82 indigenous and 24 exotic accessions collected from various geographical locations of Jammu and Kashmir, India were evaluated using 14 inter simple sequence repeat markers. The PCR amplification produced 365 loci of which 356 (97.53%) were polymorphic. The average number of alleles, effective number of alleles, expected heterozygosity, Shannon's information index indicated high level of genetic diversity in the collected apricot accessions, and the polymorphism information content (0.82) revealed that these markers were highly polymorphic. The results of UPGMA dendrogram and model-based STRUCTURE analysis clearly divided the 106 apricot accessions into two main groups; one group included the 78 accessions of Kashmir province and the other included 28 accessions of Jammu province indicating the distinction of two genetic pools of apricot in the region. Nonetheless, PCoA also revealed a similar grouping of accessions except few exotic accessions that formed a small separate group. Moreover, analysis of molecular variance showed high genetic variation within the population (67%) and low among the population (33%). To our knowledge, this study represents the first comprehensive report on the ISSR based genetic diversity, relationship, and the structure of apricot accessions of Jammu and Kashmir. Further, the results of the present study will assist in efficient utilization, conservation, and MAS based breeding programs of apricot.