Assessment of the Genetic Diversity of Apple (Malus × domestica Borkh.) Cultivars Grown in the Kashmir Valley using Microsatellite Markers

Abstract

The diverse germplasm of any crop species represents an important genetic resource for mining genes or alleles necessary to meet future nutritional and disease resistance needs. A total of 29 SSR markers were used to elucidate genetic diversity among nineteen apple cultivars for the first time in the Kashmir valley. Different parameters like polymorphic information content, resolving power and marker index were calculated. A total of 218 polymorphic fragments were obtained. A high level of genetic diversity was observed in these 19 cultivars with 218 polymorphic fragments, between three and 14 alleles per primer pair, averaging 7.51 alleles per SSR. Cultivars differentiated through mutations like Oregon Spur, Reeka Red and Siliver Spur were also used as experimental cultivars in the present study and had identical allelic compositions at all loci. The cluster dendrogram and principal component analysis partitioned the cultivars into two main clusters based on Jaccard’s similarity coefficient. These findings will have impact on apple breeding and conservation programs as the present sample of apple cultivars are commercially very important at national and international level. So their characterization at morphological, biochemical, cytological and molecular level will help the apple breeders to use these in apple breeding. Keywords: Apple germplasm, Genetic diversity, Kashmir Valley, SSR markers