Evaluation of allelic polymorphism of apple tree resistance genes to scab

Abstract

The article presents the data of molecular genetic analysis for several genes of the Rvi system of resistance to Venturia inaequalis (Cooke) G. Winter (Rvi1, Rvi6, Rvi8, Rvi9, Rvi11, Rvi14, Rvi16, Rvi17) of the collection and new breeding material of the apple tree (Malus ? domestica Borkh.) of different ploidy, ecological, geographic and genetic origin. We used the CTAB method, which was previously modified in FSBSI NCFSCHVW for more complete purification of DNA samples during extraction. SSR-markers and SCAR-markers linked to the desired 9 genes were used: Rvi1 – CH01D03; Rvi4 – CH02c02a; Rvi6 – CH-Vf1, VfC; Rvi8 – OPL19; Rvi9, Rvi11 – CH05e03; Rvi14 – HB09; Rvi16 – NH030a; Rvi17 – CH-Vf1. The experiment was carried out with the participation of 53 apple samples, including: 17 varieties, 4 elite and 32 hybrid forms of domestic breeding. According to the data obtained, the following genes were classified as quite rare in the studied sample of samples: Rvi9, Rvi16; the presence of genes has not been established: Rvi8, Rvi11, Rvi17. Revealed that among the new breeding material of the apple tree, the Rvi6 gene is the most common, its frequency of occurrence is 62.5%. The study of the allelic polymorphism of several target genes of the Rvi set made it possible to identify promising apple samples for breeding use – carriers of 2–3 resistance genes to Venturia inaequalis (Cooke) G. Winter. According to the DNA marking data, varieties and forms of domestic breeding were selected: Zarya Stavropol'ya, Nika, 12/2-20-75, 17/1-6-72 (carriers of the Rvi1, Rvi6, Rvi14 genes) as promising donors to enhance the efficiency of apple breeding technology for long-term resistance to scab. The data obtained are important for the formation of an identified collection of Malus Mill., the selection of new valuable donors to optimize a number of key stages of the breeding process for long-term resistance to the pathogen by pyramiding the target genes.