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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Publications at this Location » Publication #370937

Research Project: Management of Pathogens for Strawberry and Vegetable Production Systems

Location: Crop Improvement and Protection Research

Title: Mining genetic diversity in a global population of elite and exotic germplasm to identify novel race-specific Fusarium wilt resistance genes in strawberry

item PINCOT, D - University Of California
item RODGRIGUES, A - University Of California
item COBO, N - University Of California
item Henry, Peter
item HARDIGAN, M - University Of California
item LORANT, A - University Of California
item LEDDA, M - University Of California
item FAMULA, R - University Of California
item GORDON, T - University Of California
item COLE, G - University Of California
item KNAPP, S - University Of California

Submitted to: International Strawberry Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 12/23/2019
Publication Date: 12/23/2019
Citation: Pincot, D.D., Rodgrigues, A., Cobo, N., Henry, P.M., Hardigan, M.A., Lorant, A., Ledda, M., Famula, R.A., Gordon, T.R., Cole, G.S., Knapp, S.J. 2019. Mining genetic diversity in a global population of elite and exotic germplasm to identify novel race-specific Fusarium wilt resistance genes in strawberry. International Strawberry Symposium, May 2-6, 2020, Rimini, Italy.

Interpretive Summary:

Technical Abstract: Fusarium wilt, a soil-borne disease caused by the fungal pathogen Fusarium oxysporum f. sp. fragariae, poses a serious risk to strawberry (Fragaria × ananassa) production in many parts of the world. The pathogen causes wilting, collapse, and death in susceptible genotypes. We previously identified a dominant gene (Fw1) that confers resistance to AMP132, a California race of the pathogen, and hypothesized that race-specific resistance (R) genes were diverse and abundant in strawberry. Here, we report the results of several follow up studies that support this hypothesis and shed further light on the genetics of resistance to Fusarium wilt in strawberry. We identified numerous elite and exotic sources of resistance and confirmed the Mendelian segregation of a dominant R-gene (Fw2) on chromosome 2-4 and large-effect quantitative trait loci (Fw3 and Fw4) on chromosomes 1-4 and 5-2. The Guardian-Fw2 gene is either allelic or tightly linked to Fw1. The phenotypic differences produced by the segregation of the Wiltguard (Fw3) and Del Norte (Fw4) QTL were weaker than those associated with the segregation of the Fw1 or Fw2 loci, thus the QTL designation. Using diversity statistics and AMP132 resistance phenotypes for 1,000 germplasm accessions, 132 were selected and screened to identify host differentials and sources of resistance to Australian, Japanese, and Spanish races. We identified multiple sources of resistance and hypothesize that strawberry harbors a diverse arsenal of race-specific R-genes. We have developed and anticipate expanding a library of sub-genome specific high-throughput DNA markers to accelerate the introgression of novel R-genes into modern cultivars through marker-assisted selection. The diversification of Fusarium wilt resistant cultivars is critical for maximizing the durability of resistance and minimizing the risk posed by the global spread of the pathogen.