Marker-assisted screening of apple genotypes with immunity to scab

Abstract

Monogenic scab resistance is important breeding trait of apple. To this moment, there were identified 20 genes determined resistances to apple scab of different races. The use of molecular markers allows in the early stages of ontogenesis to determine with high reliability the presence of the necessary genes in the genome, significantly reduce the level of complexity and reduce the amount of financial costs and to reduce the time of the selection process. The purpose of the study is to identify variety samples with the presence of monogenic resistance to scab in the collection of Apple trees of various ecological and geographical origins. The tasks of the research were to determine the genotypic structure of varieties and hybrid seedlings according to the Rvi6 gene, to identify genotypes carrying target alleles of monogenic resistance to scab genes, including those with dominant homozygous genotype (Rvi6Rvi6). Research carried out in 2015-2018 years on the basis of the gene-pool of the I.V. Michurin Federal scientific center in Michurinsk-Naukograd of the Tambov region, numbering about 6 thousand genotypes with different quality characteristics as the fruits and of the plants themselves. The article presents the results of scientific research on screening of apple genotypes for the presence of genes of monogenic resistance to scab. Molecular genetic analysis allowed us to select some samples of M. domestica Borkh, which contain the Rvi6 gene, providing absolute resistance to the Venturia inaequalis (Juice) Wiht.). The selected genotypes are of interest for further breeding programs, which are aimed at creating varieties that combine in their genotype the "pyramid" of genes that provide economically valuable traits of the phenotype.