Evaluation of new DNA markers for powdery mildew resistance in the garden strawberry cultivar collection bred at the Federal Horticultural Center for Breeding, Agrotechnology and Nursery (FSBSO ARHCBAN)

Abstract

Powdery mildew is a particularly damaging disease of garden strawberries grown both in open fi elds and under protected conditions, as it can reduce plant productivity and adversely aff ect fruit quality. Therefore, an important objective of strawberry breeding is the identifi cation and development of genotypes resistant to this disease. The present study aimed to screen a collection of garden strawberry cultivars and selected breeding forms for the presence of Pair1PM DNA marker linked to the FaRPa1C locus, which is associated with resistance to powdery mildew. The study was conducted using cultivars and selected forms of garden strawberries bred at the Federal Horticultural Center for Breeding, Agrotechnology and Nursery (FSBSO ARHCBAN). High-resolution melting (HRM) analysis was used to classify the studied accessions into three groups based on the melting temperature of the amplifi cation products and their putative allelic states: stable homozygous genotypes C/C, heterozygous genotypes T/C, and unstable homozygous genotypes T/T. Among the studied cultivar accessions, the stable homozygous genotype C/C predominated (42.9 %), whereas heterozygotes and nonresistant homozygotes T/T account for 35.7 and 21.4%, respectively. The distribution was nonuniform, which may indicate a selection preference for the C allele among the studied accessions. The stable homozygous haplotype identifi ed in the cultivars Vostorg, Bereginya, Nashe Podmoskovie, and Tsaritsa, as well as in the selected breeding forms 3-5-1 and 3-731-3, makes these accessions promising for further breeding. The selected form 3-5-1 (Divnaya × open pollination) demonstrated the presence of a stable homozygous genotype for the Pair1PM marker. The Divnaya cultivar should be genotyped using the same marker to clarify its resistance status and probable routes of inheritance. Another breeding form of interest is 3-731-3 (3-387-20 × Barynya). One or both of its parental forms presumably carry a polymorphism at the FaRPa1C locus associated with resistance to powdery mildew. Both parental forms should be analyzed in future studies to identify the donor of this gene. Thus, the obtained results demonstrate the potential of molecular genetic methods in selecting source material for breeding garden strawberries resistant to powdery mildew.