Strawberry breeding for disease resistance and fruit quality traits is a challenging process due to its complex octoploid genetics. The use of marker-assisted selection (MAS) in plant breeding programs can significantly improve the selection of genotypes through linkage mapping and the identification of quantitative trait loci (QTL) approaches. The success rate of marker development for MAS depends on the complexity, stability and the nature of the QTL, and marker-trait combinations being utilized. In this study, work will be carried out to understand how different complex traits are correlated in the octoploid strawberry at the phenotypic and genotypic level and to investigate how this affects the deployment of markers in breeding. The discovery of the best and easiest traits to phenotype and developing simple ways of capturing phenotypic data in an automated fashion will speed up the development of novel breeding approaches, first through MAS and then genomic selection (GS). A particular focus of current research is on two suites of traits, disease resistance and fruit quality. Work is underway to characterize the nature of Verticillium wilt disease resistance and to uncover and map molecular markers linked to key fruit quality traits such as firmness, sugar levels, fruit size and shape in cultivated strawberry using QTL mapping. An octoploid strawberry mapping population (‘Redgauntlet’ × ‘Hapil’) containing a total of 122 seedlings was used for phenotyping flower-related traits, root architecture and plant characteristics. The existing SSR-based linkage map (‘Redgauntlet’ × ‘Hapil’) will be used for locating genes of interest for MAS and to identify QTLs associated with phenotyped traits.
