Formation and storage of lettuce (Lactuca sativa L.) collection at Ustymivka experimental station of plant production

Aim. To preserve the existing genetic diversity of lettuce, to introduce new domestic and foreign accessions, to evaluate valuable economic traits, to register individual accessions with valuable traits in the National Center for Plant Genetic Resources of Ukraine. Results and Discussion. Issues of formation, investigation and storage of collection lettuce accessions were considered. The lettuce collection comprises 284 accessions originating from 30 countries worldwide. By biological status, the lettuce collection was divided into the following groups: 227 accessions (80%) are breeding varieties, including 31 Ukrainian varieties; 34 accessions (12%) are breeding and research material, including 16 Ukrainian accessions; 23 accessions (8%) are landraces and ancient varieties, including 9 Ukrainian ones. Major valuable economic characteristics were assessed and, according to them, 8 accessions were selected: Zolotyi Shar, Spalakh, Lollo Rossa, American Brown, Red Pick, Marysienka, Krimson, and Azart. Based on the study results, a romaine (Romana rorogorana) accession with valuable economic characteristics was registered in the National Center for Plant Genetic Resources of Ukraine. Conclusions. The lettuce collection comprising 284 accessions was formed. The collection of cutting lettuce was divided into several different groups: leaf lettuce (or looseleaf), head lettuce (crispleaf lettuce), romaine (cos), and stem lettuce (uysun). The assortment of collection lettuce varieties, which was built up at Ustymivka Experimental Station of Plant Production, allows for provision of breeding and educational institutions with various gene pool accessions and information about the existing germplpasm. Our work is mainly focused on search for and introduction of new lettuce accessions as well as on their further screening for a set of characteristics and, on this basis, on formation and registration of core, trait, educational and other collections of accessions with valuable characteristics.