MOLECULAR SCREENING OF SELECTED STRAWBERRY FORMS (FRAGARIA × ANANASSA DUCH.) FOR RESISTANCE TO POWDERY MILDEW (LOCUS 08 TO-F)

Resistance to fungal pathogens is an important trait of a cultivar’s agrobiological potential. Powdery mildew (Sphaerotheca macularis Mag. f. fragariae Jacz.) is one of the most common fungal diseases of strawberry. Control of the pathogen spreading in strawberry plantations is mainly ensured by synthetic fungicides use. However, the widespread use of chemical plant protection products leads to resistance in some isolates of S. macularis f. fragariae. In this regard, a current research direction is the creation of new strawberry cultivars with genetically determined resistance to powdery mildew. Several large quantitative trait loci (QTLs) for resistance to powdery mildew were identified in strawberry cultivars. For the 08 To-f locus, diagnostic DNA-markers were developed that are suitable for use in marker-assisted selection. The purpose of the research is molecular genetic analysis of strawberry selected forms at the 08 To-f locus to identify promising seedlings with genetically determined resistance to powdery mildew. Over the years of research, 57.9 % of strawberry plants were characterized by the absence of powdery mildew (complex interspecific hybrids 928-12, 932-29, 35-1, 35-5, 35-16; intervarietal hybrids 911-16, 72-71, 69- 29, 62-41, 56-17). Of these, marker IB535110, linked to the resistance locus 08 To-f, was identified in 4 strawberry selected forms of intervarietal origin: 72-71 (‘Privlekatelnaya’ × ‘Bylinnaya’), 69-29 (‘Feyyerverk’ × ‘Bylinnay’a), 62-41 (‘Bylinnaya’ × ‘Feyyerverk’), 56 -17 (‘Gigantella Maxim’ × ‘Privlekatelnaya’). Strawberry selected forms 62-41, 69-29 and 72-71 are additionally characterized by a complex of such valuable agrobiological traits as resistance to abiotic stress factors, resistance to red stele root rot (Rpf1 gene), high productivity and fruit quality. Interspecific hybrids 298-19-9-43, 928-12 and 26-5 (FB2 -FB3 F. orientalis, F. moschata, F. × ananassa) did not inherit the 08 To-f locus from the original wild species. Resistance of these strawberry forms to S. macularis f. fragariae is presumably due to other genetic determinants.