Nomenclatural standards and genetic passports of potato cultivars bred at the Leningrad Research Institute for Agriculture “Belogorka”

In the present paper, the potato cultivars bred at the Leningrad Research Institute for Agriculture “Belogorka”, were taken as an example for demonstrating the results of elaboration of methodological approaches that are currently developed at the N.I. Vavilov Institute of Plant Genetic Resources (VIR) for the preparing of nomenclatural standards and their genotyping. In 2018, joint research of VIR scientists and breeders from the Leningrad Research Institute for Agriculture “Belogorka” began in the field of preparing nomenclatural standards for potato cultivars bred at this institute. Nomenclatural standards were prepared according to the ‘International Code of Nomenclature for Cultivated Plants’. Plant material for herbarium specimens was collected in the experimental field of the “Belogorka” Institute in 2018 by cultivar authors and handed over to the VIR Herbarium of cultivated plants, their wild relatives and weeds (WIR). The plant material included stems with inflorescences and later - tubers of 21 cultivars which were bred at the “Belogorka” Institute. Two precultivars undergoing State variety testing and three breeding clones were also included in this study. Just before herbarium preparation, the obtained plant material was photographed, plant morphological characters described, and the results compared with the description given in such official documents as the “Cultivar Questionnaireˮ and “Description of selection achievementˮ. The nomenclatural standards of 21 cultivars registered in the VIR Herbarium Database and transferred for conservation to the VIR herbarium, are published in this paper. Before herbarium preparation, the plant material was sampled for DNA extraction and subsequent genotyping and molecular screening. The genetic passports include information about the polymorphism of 10 chromosome-specific microsatellite loci, as well as the data on the presence/absence of diagnostic fragments of 12 markers of the 11 R-genes conferring resistance to diseases and pests, and for some cultivars – the information about their cytoplasm type. These genetic passports are valuable not only because different types of DNA markers were used in their preparing (SSR, SCAR and CAPS markers of the R genes; markers specific to different loci of the nuclear and organelle genomes), but first of all because of the material itself, as the DNA samples were isolated from the plants with the assigned status of nomenclatural standard for each particular cultivar. Based on the genetic passports data, trueness to type of the “Belogorka” cultivar samples obtained from various sources was verified.