Diversity assessment of the gene bank collection of the genus <i>Campsis</i> representatives based on the phenotypic and molecular genetic analysis data

The genus Campsis is of great interest as a valuable ornamental plant that blooms for a long period in the hot and dry months of June to September. The economic and biological qualities of Campsis enable different uses of this plant: as a liana for vertical soft landscaping, as compact and beautifully flowering shrubs formed with the help of heavy pruning, and as a standard plant. In the ornamental horticulture of the southern regions of Russia, the potential of the crop has not been fully unlocked. Moreover, there is no scientifically substantiated assortment; no breeding is being performed. Since 2014, the North Caucasus Federal Scientific Center for Horticulture, Viticulture, Winemaking (Krasnodar) has been introducing and forming a collection of the genus Campsis representatives. Specimens enter the collection from various sources. In the process of studying them, we address issues of the cultivar identity clarification of the introduced plants. ISSR genotyping of representatives of the genus Campsis makes it possible to form an idea of the available genetic diversity of the collection and select the most promising markers for further work. Using phenotypic and molecular genetic analysis, the research aims to study the diversity of the genus Campsis in the genetic bank collection of the North Caucasus Federal Scientific Center for Horticulture, Viticulture, Winemaking. The study was conducted on 13 specimens of the genus Campsis which are the basis for the emerging collection in the South of Russia. Phenotypic assessment was carried out from 2020 to 2022 on 11 specimens; it included the analysis of 4 morphological and 4 economic-biological characteristics. 8 ISSR markers were employed to perform genotyping of 13 representatives of the genus. The genotypes of Catalpa, Chitalpa, and Paulownia species were added as an outgroup. Specimen clustering according to phenotypic and genotypic characteristics was conducted using the UPGMA method. The results obtained by combining phenotypic assessment and ISSR genotyping made it possible to correct the specimen collection of the genus Campsis . The study confirmed the commonality of two genotypes of C. x tagliabuana (Madam Galen) and two genotypes of C. radicans (Flava). A new genotype of C. x tagliabuana , previously erroneously attributed to the hybrid ‘Madam Galen’, has been determined. In this regard, it is necessary to clarify the cultivar identification of the genotype. Hybrid forms of Campsis No. 1 and Campsis No. 2 are also subject to further study and genotype identification. An assumption was made that they belong to the species C. grandiflora . The position of the Campsis specimens relative to the genotypes represented in the outgroup corresponds to the current systematic position of this genus. The use of ISSR markers in assessing the core of the emerging genetic collection of the genus Campsis has demonstrated that they are a simple and convenient tool for genetic analysis.