Genetic Diversity of the Collection of Far Eastern Actinidia spp. Revealed by RAD Sequencing Technology

More than ten species of the <i>Actinidia</i> Lindl. genus bear edible fruits rich in biologically active compounds, which are essential and beneficial for human health. The most popular cultivars today are the large-fruited <i>Actinidia</i> species, <i>A. deliciosa</i> and <i>A. chinensis</i>, commonly known as kiwi. However, small-fruited kiwi cultivars are gaining prominence due to their high nutritional value, superior cold resistance, and suitability for temperate climates. In Russia, these are represented by Far Eastern species: <i>A. arguta</i>, <i>A. kolomikta</i>, and <i>A. polygama</i>. Despite increasing consumer interest, Russian <i>Actinidia</i> cultivars remain little studied, with fragmented genetic data available for breeding purposes. Our objective was to analyze the <i>Actinidia</i> collection at the Federal Horticultural Center for Breeding, Agrotechnology, and Nursery and the N.V. Tsitsin Main Botanical Garden (MBG RAS, Moscow), which includes samples from four species, <i>A. kolomikta</i>, <i>A. arguta</i>, <i>A. polygama</i>, <i>A. purpurea</i>, interspecific hybrids, and derived varieties, using RAD sequencing. We assessed the genetic variability of all species, identified population groups within <i>A. kolomikta</i> and <i>A. arguta</i> based on origin, determined ploidy levels across the collection, and identified a set of SNP markers associated with valuable agronomic traits.