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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Publications at this Location » Publication #339893

Research Project: Genetic Enhancement of Lettuce, Spinach, Melon, and Related Species

Location: Crop Improvement and Protection Research

Title: Genetic characterization of resistance to Sclerotinia in lettuce cultivar Eruption

Author
item Mamo, Bullo - University Of California
item Hayes, Ryan
item Truco, Maria-jose - University Of California
item Michelmore, Richard - University Of California
item Subbarao, Krishna - University Of California
item Simko, Ivan

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 3/24/2017
Publication Date: 8/8/2017
Citation: Mamo, B.E., Hayes, R.J., Truco, M.J., Michelmore, R., Subbarao, K.V., Simko, I. 2017. Genetic characterization of resistance to Sclerotinia in lettuce cultivar Eruption. American Phytopathological Society Annual Meeting, August 5-9, 2017, San Antonio, Texas.

Interpretive Summary:

Technical Abstract: Lettuce drop caused by the fungal pathogens Sclerotinia minor and S. sclerotiorum is a serious disease of lettuce. The use of genetic resistance as part of an integrated lettuce drop management strategy should have a significant economic advantage in mitigating yield loss. Sclerotinia resistance is often confounded with morphological traits, primarily premature bolting. As such, previous attempts of identifying Sclerotinia resistance in lettuce were largely unsuccessful. Recently, high level of resistance to S. minor and S. sclerotiorum independent of plant morphology has been identified in the slow-bolting red Latin type cultivar Eruption (ERN). To characterize the inheritance of resistance to Sclerotinia in Eruption, a cross was made to the susceptible lettuce cv. Batavia Reine des Glaces (BRG). One hundred sixty F6:7 recombinant inbred lines (RILs) were evaluated for lettuce drop resistance and bolting in a field infested with S. minor; genotyped by sequencing (GBS) identified 840 single nucleotide polymorphism (SNP) markers. The variation in the phenotypic data indicates the presence of quantitative resistance in Eruption. QTL analysis identified one resistance QTL on each of lettuce chromosomes 1 and 5, explaining 12% and 12-25% of the variation, respectively. These genomic locations are not associated with bolting in Eruption. The SNP markers identified may be useful in marker-assisted introgression of lettuce drop resistance into breeding materials.