Phenotypic and genetic study of seedlessness in grape varieties

The phenomenon of seedlessness in grapes is a special form of sterility and it is characterized by the complete absence of seeds in the berry or the presence of their primordia. A phenotypic and genetic studies of 20 varieties of seedless grape growing at the Anapa ampelographic collection were carried out. The manifestation of the degree of seedlessness may depend on growing conditions and climatic peculiarities during crop formation. In the weather and climate conditions of 2019, which were characterized by an increased temperature regime, the degree of seedless berries of the studied varieties was determined. Genetic studies were performed on the basis of polymerase chain reaction (PCR) with the separation of reaction products by capillary electrophoresis using the automatic genetic analyzer ABI Prism 3130. The DNA-marker p3-VvAGL11, closely linked to the VvAGL11 locus, which influences to the formation of seedlessness in grapes, was used in the work. The mass of rudiments was determined by extracting seed primordia from berries and their dehydration in a drying cabinet to final unchanged mass of rudiments. In the varieties Kishmish Sogdiana, Remaily Seedless and Kishmish Kruglyi rudiments were practically absent. The greatest mass of rudiments in the berry (over 14.1 mg) was observed in the varieties Pamyati Smirnova, Yangi Yer, Vanessa Seedless, Kishmish Luchistyi. In addition to the degree of development of seed rudiments, in seedless table grape varieties, an important indicator is the size of the berry, which generally affects the consumer choice of a particular variety. By the average weight of the berry, Kishmish Luchistyi variety (5.05 g) was distinguished. The smallest mass of berries observed in varieties Rozovyi Biser, Kishmish Siyekh, Kishmish Kruglyi, Kishmish Krupnyi, Bessemyannyi Ranniy (less than 1.5 g). DNA analysis using the p3-VvAGL11 marker revealed in all genotypes the presence of a PCR-product with a size of 198 nucleotide pairs, which corresponds to published data on the correlation of this size of the PCR-product with seedless berries.