Genome-wide prediction of powdery mildew resistance in the octoploid strawberry

Powdery mildew (PM) caused by Podosphaera aphanis is a major fungal disease in cultivated strawberry.
Characterization of resistance loci has been challenging for breeders and geneticists due to the complex and polygenic nature of resistance.
Genome-wide prediction (GWP) utilizes genome-wide markers to predict the performance of individuals and accelerate genetic gains for polygenic traits.
In the present study, we implemented GWP models using six pedigree-connected full-sib families from crosses among four University of Florida advanced selections.
These families were evaluated in a replicated field trial, and 250 to 9,000 polymorphic single nucleotide polymorphism (SNP) markers were chosen based on genome coverage and polymorphism.
Half-sibs were used as a training population to rank seedlings within each cross (full-sib family). The highest predictive abilities using Bayes B, GBLUP and RKHS methods were 0.36, 0.38 and 0.38, respectively.
The three methods had comparable parent selection efficiencies, and within-family genetic gains were at least 10% over the family mean when selecting the top 10% of seedlings ranked by GWP. As few as 500 SNP markers were sufficient to achieve comparable results.
Overall, this study demonstrates the potential for application of within-family GWP for rapid genetic improvement of powdery mildew resistance in strawberry seedling families.

IX International Strawberry Symposium

R. Tapia, L.F. Osorio, S. Verma, S. Lee, V.M. Whitaker

powdery mildew, polygenic inheritance, genome-wide selection, strawberry

https://doi.org/10.17660/ActaHortic.2021.1309.16