Characteristics of Varieties and Hybrids of Potato on Fertility

Most cultivars and hybrids of potato are sterile or have low fertility due to their complex interspecific origin. Information on the fertility of cultivars and hybrids used as initial parent forms is need to form and implement breeding programs. Searching for effective pollinators among cultivars and hybrids using traditional breeding tools in combination with marker-assisted selection is the purpose of the present study. In our study, the results of various types of intervarietal crosses carried out in 2008–2020 were analyzed. Among potato cultivars and hybrids, twenty-nine genotypes were identified as pollinators with a complex of agronomic traits, such as resistance to pathogens, suitability for processing, etc. These genotypes can be used as perspective parental forms for different directions of breeding work. Correlation analysis between the main indicators of fertility showed that the most reliable characteristics of pollinators are the number of formed berries and the number of seeds per pollinated flower. The index of fertility was calculated using these indicators. Genotypes identified among potato cultivars and hybrids as pollinators were separated by their fertility index into conditional groups. Two interspecific hybrids, 88.16/20 and 88.34/14, in the origin of which the autotetraploid S. garciae K2727 (VIR), which is resistant to potato virus Y was used, were selected among the most effective pollinators along with cultivars. Since male sterility in potatoes is associated with a specific type of cytoplasmic genome, information on the type of cytoplasm can been considered as one of the indicators of sterility/fertility of cultivars and hybrids. The genetic diversity of the cytoplasmic genome of 207 potato genotypes, including cultivars of Russian and foreign selection, backcross hybrids, and samples of species Solanum, was determined with specific molecular markers. Among the 207 studied samples of potato, 48% had T (T/β) type cytoplasm, 28% had the D-type cytoplasm, and 24% had the W (W/α, W/β, W/γ)-type cytoplasm. Among foreign varieties of potato and selected pollinators, T-type cytoplasm predominated, while the largest number of genotypes had D-type cytoplasm among the Russian cultivars of potato. The rare subtype cytoplasms W/α and W/β were found in interspecific hybrids and Solanum species and were absent in potato cultivars. The molecular marker YES3-3A of the Ryₛₜₒ gene was found not only in genotypes with the W/γ-type of the cytoplasmic genome.