Assessment of genetic diversity and relationships among some grape varieties using ISSR markers

Abstract: As a result of large-scale introduction, the origin and authenticity of many grape varieties is unclear and the subject of some controversy. This has led to confusion regarding their correct identification. Molecular markers have proved to be useful to analyze the genetic relationships as well as diversity between different grape varieties. In the present study, 34 grape varieties have been characterized using Inter Simple Sequence Repeat (ISSR) markers. Out of 93 ISSR primers screened initially, 11 showed good polymorphism. Total 174 bands were obtained, out of which 145 were polymorphic. The pair wise similarity indices were calculated from the band data. Cluster analysis of the varieties resulted in the formation of two main clusters, one belonging to Vitis vinifera and other to V. labrusca. Varieties belonging to V. vinifera appeared more diverse and formed distinct sub-clusters based on their colour, flavour and seeds. Out of 34 varieties screened, 10 varieties with green/yellow berries were grouped together in one subcluster and 15 with red/black berries in the other. Three varieties with green/ yellow berries, Italia, Queen of Vineyard and Thompson seedless were grouped with the varieties with red/black berries. The cluster of labrusca varieties showed homogeneity and had five varieties except Dakh, which belongs to vinifera. Concord separates initially from all other varieties. Incidentally, Concord is a pure selection from V. labrusca, while other varieties like Bangalore Blue, Black Muscat, Catawba and Muzzafar Nagar in labrusca group, may be the hybrids of V. abrusca x V. vinifera. The current study thus revealed that genetic relationships among grape cultivars could be assessed using ISSR markers.