Molecular Characterization and Genetic Relationships of Some Stress Tolerant Grape Rootstock Genotypes as Revealed by ISSR and SSR Markers

Grapevine rootstocks are a complex group of plants; most of them are interspecific hybrids evolved using parent genotypes having inherent tolerance to biotic and abiotic stresses. Fifteen species and interspecific hybrids of grape rootstocks along with three Vitis vinifera cultivars from IARI germplasm unit were analyzed with ten ISSR and seven SSR primers combinations. These ISSR produced 69 scorable bands with band size ranged from 200 to 1500 bp, PIC from 0.66 to 0.86 and primer heterozygosity ranged from 0.71 to 0.88. While, SSR primers detected a total of 24 alleles across 15 genotypes with PIC from 0.43 to 0.78 and primer heterozygosity from 0.49 to 0.81.The genetic similarity among the 15 grape genotypes using ISSR and SSR ranged from 0.27 to 1.00 in ISSR and 0.05 to 1.00 in SSR analysis. The genetic similarity matrices using ISSR analysis ranged from 27.0 to 85.0% and SSR 5.0 to 83.0%, respectively. The Vitis species Dogridge and Salt Creek had the highest similarity coefficient of 85% with ISSR analysis, while the interspecific hybrids 1103 Paulsen and 110 Richtier had the maximum similarity coefficient of 83% as identified by SSR analysis. The two marker systems formed two main clusters which were almost similar to that of PCA values. The principal coordinate analysis further helped in depicting the variability among species and hybrids of grape genotypes in three dimensional modes. In case of ISSRs, the first three coordinates accounted 51.92% for the existing variability, while with SSRs the variability accounted is 59.69%. The results revealed that ISSR and SSR markers could be exploited for genetic diversity analysis among the highly heterozygous grape rootstock species and interspecific hybrids. Plant Tissue Cult. & Biotech. 28(1): 77-90, 2018 (June)