A study of genetic profiles of grape plants preserved under the name of Dagestan variety ‘Khatmi’

Background. Traditionally, the description of grape varieties is a task of ampelographic studies. However, several different grape cultivars have similar phenotypic traits. Molecular genetic characterization is the most accurate tool for cultivar identification. The development of DNA fingerprinting of varieties is the first step in this direction. An extensive database of DNA profiles of grape genotypes makes it possible to determine the varietal affiliation of unknown forms, confirm or refute the varietal correspondence of planting material. ‘Khatmi’ is an autochthonous grape variety from Dagestan. The profile of ‘Khatmi’ is presented in the VIVC international database of DNA fingerprints for grape varieties. However, an application of DNA analysis methods in grape variety studies has determined that several ancient varieties were cultivated under one name, while for others a certain variability of genotypes was observed. The objectives of the work were to study samples of ‘Khatmi’ plants from different places of growth in Dagestan by standard microsatellite loci used for grape genotyping, to assess the level of genetic similarity of the samples, and to refine the DNA profile of ‘Khatmi’. Materials and methods. Molecular genetic study was carried out on 10 samples from different ‘Khatmi’ populations. The material was picked from the collection sites of Dagestan breeding experimental station of viticulture and vegetable growing and the Dagestan Experiment Station of VIR, as well as from production plantations. DNA was extracted from herbarium specimens of young grape shoot tips by the CTAB method. The samples were genotyped by polymerase chain reaction using a standard set of primers for 9 microsatellite markers VVS2, VVMD5, VVMD7, VVMD25, VVMD27, VVMD28, VVMD32, VrZAG62 and VrZAG79 recommended by the International Organization of Grapes and Wine (OIV) for grapevine DNA fingerprinting. Amplification products were separated, and their sizes were assessed using capillary electrophoresis on an ABI Prism 3130 genetic analyzer. Results. Genotyping was done for 10 samples of grapes growing in Dagestan under the name ‘Khatmi’, including samples from different collections and places of industrial cultivation, as well as clonal variations of this variety and putative clonal variations. The two base pair differences within one of the loci distinguished the DNA profiles of the analyzed samples from that of ‘Khatmi’ presented in the international grape varieties database VIVC. It was determined that the sample under the name ‘Khatmi krupnoyagodnyi’ is closely related to ‘Khatmi’ variety by its genotype, but probably represents a clonal variation of ‘Koz uzyum’, another local variety of Dagestan. Conclusion. The DNA profile of the local Dagestan grape variety ‘Khatmi’ has been refined.