Analysis of polymorphism of strawberry genotypes (Fragaria L.) according to the strawberry red root spot resistance gene RPF1 for identification of strawberry forms promising for breeding and horticulture

Abstract

Red root spot (Phytophthora fragariae var. fragariae Hickman) is one of the most important strawberry diseases in the temperate climate zone. Identification of forms, carrying resistance genes, is an important stage in breeding programs aimed at obtaining red root spot resistant strawberry varieties. Diagnostic DNA markers of target genes will increase reliability of identification and efficiency of strawberry breeding for the creation of resistant genotypes. The purpose of this study is analysis of polymorphism of wild species of Fragaria L. genus and strawberry varieties (F. × ananassa Duch.) according to the strawberry red root spot resistance gene Rpf1 using molecular markers. The research sunjects were the wild species F. orientalis Los., F. moschata Duch., F. ovalis Rydb., F. virginiana Duch. ssp. platypetala and strawberry varieties (F. × ananassa Duch.) of different ecological and geographic origin. Total genomic DNA of strawberry was extracted from the fresh leaves using the Puchooa method. To assess the allelic state of Rpf1 gene, SCAR-R1A marker (linked to the Rpf1 dominant allele) and OPO-16C marker (linked to the rpf1 recessive allele) have been used. SCAR-R1A marker was identified in wild species F. virginiana Duch. ssp. platypetala (vegetation region: British Columbia, Canada), pineapple strawberry varieties Bylinnaya and promising selected forms 62-41 (Bylinnaya × Feyyerverk), 65-17 and 65-24 (Olimpiyskaya nadezhda × Bylinnaya). These genotypes are characterized by heterozygous Rpf1rpf1 genotype according to Rpf1 gene (both markers are present in genotype) and can be used as red root spot resistance source in marker-assisted selection. In the remaining studied genotypes of strawberry, SCAR-R1A marker was not detected, which presumably indicated their homozygous recessive genotype rpf1rpf1 according to Rpf1 gene. The research results can be useful for breeders of strawberry and researchers of plant biodiversity of p. Fragaria.