Genotype identification and inference of genetic relatedness among different purpose grape varieties and rootstocks using microsatellite markers

Twenty-seven (27) grape genotypes representing different grape groups namely table, wine, juice grapes and rootstocks with present or potential future importance for sub-tropical viticulture were characterized with 29 microsatellite markers spanning over 15 linkage groups of ‘Syrah’ x ‘Grenache’ linkage map. The objective of the investigation was to establish the unique molecular identity of the promising genotypes and to know the diversity status among them. The study revealed that most of the markers were highly informative and polymorphism information content (PIC) of 21 out of total 29 markers was ≥ 0.8. The use of two simple sequence repeat (SSR) markers was sufficient enough to resolve the differences among all the grape genotypes. The unweighted Neighbour-Joining tree generated using DARwin 5.0 software classified the germplasm into three different clusters. The grouping of the different genotypes in the tree had distinct order. Genotypes derived from the same species were in one group, while the genotypes having both or one parents common in their pedigree formed separate group. Likewise, the rootstocks were clearly differentiated from grape varieties. However, the varieties could not be differentiated into table, juice and wine types. The findings of the study will be helpful in authentication of the genotypes and their use in the future grape breeding programmes. Keywords : Vitis species, table, juice, wine varieties, rootstocks, DNA fingerprinting, diversity analysis African Journal of Biotechnology Vol. 12(2), pp. 134-141