Novel fusarium wilt resistance genes uncovered in natural and cultivated strawberry populations are found on three non-homoeologous chromosomes

Fusarium wilt, a soilborne disease caused by Fusarium oxysporum f. sp.
fragariae, poses a significant threat to strawberry (Fragaria x ananassa)
production in many parts of the world. This pathogen causes wilting,
collapse, and death in susceptible genotypes. We previously identified a
dominant gene (FW1) on chromosome 2B that confers resistance to race 1 of
the pathogen, and hypothesized that gene-for-gene resistance to Fusarium
wilt was widespread in strawberry. To explore this, a genetically diverse
collection of heirloom and modern cultivars and octoploid ecotypes were
screened for resistance to Fusarium wilt races 1 and 2. Here we show that
resistance to both races is widespread in natural and domesticated
populations and that resistance to race 1 is conferred by partially to
completely dominant alleles among loci (FW1, FW2, FW3, FW4, and FW5) found
on three non-homoeologous chromosomes (1A, 2B, and 6B). The underlying
genes have not yet been cloned and functionally characterized; however,
plausible candidates were identified that encode pattern recognition
receptor or other proteins known to confer gene-for-gene resistance in
plants. High-throughput genotyping assays for SNPs in linkage
disequilibrium with FW1-FW5 were developed to facilitate marker-assisted
selection and accelerate the development of race 1 resistant cultivars.
This study laid the foundation for identifying the genes encoded by
FW1-FW5, in addition to exploring the genetics of resistance to race 2 and
other races of the pathogen, as a precaution to averting a Fusarium wilt
pandemic.