Construction of new genomes of columnar apple trees in the Russian research institute of fruit crop breeding

Abstract

Relevance. The article presents data on the creation of new genotypes of columnar apple trees based on interval crossings of the 2x × 4x type using traditional breeding methods and elements of accelerated assessment of hybrid forms using cytoembryological and molecular genetic methods.Results. Cytological assessment of seedlings obtained from the studied interval crossings of six columnar apple varieties and the selected columnar form 29-35-123 with tetraploid forms 30-47-88 and 25-37-45, which are donors of diploid gametes, showed that seedlings with a triple set of chromosomes prevail and their share is 83.0%. The share of diploids accounts for 17.0%. A comparative assessment of the ploidy of offspring showed that the difference between the yield of triploid seedlings in the offspring of families where different donors of diploid gametes (25-37-45 and 30-47-88) were taken as paternal forms is insignificant. From the tetraploid 30-47-88, 81.7% of triploid offspring were obtained, from 25-37-45 — 91.3%.The data of molecular genetic analysis confirm that in combinations where both parents have the scab immunity gene, the yield of immune seedlings is high (70,7%) and corresponds to the splitting on this basis in a ratio of 3:1. n families where only one of the parents carries the Rvi6 gene in its genotype (Garland × 25-37-45, 29-35-123 × 25-37-45, Moscow necklace × 30-47-88 and Constellation × 25-37-45) immune seedlings were less common (52%). A unique combination of columnarity, the Rvi6 gene and a triple set of chromosomes in one genotype is characteristic of 23.1% of seedlings.