title: Mapping Resistance to Alternaria cucumerina in Cucumis melo.
abstract: Infection with Alternaria cucumerina causes Alternaria leaf blight (ALB), a disease characterized by lesion formation on leaves, leading to substantial yield and quality losses in Cucumis melo (melon). Although fungicides are effective against ALB, reduction in the frequency of application would be economically and environmentally beneficial. Resistant melon lines have been identified but the genetic basis of this resistance has not been determined. A saturated melon genetic map was constructed with markers developed through genotyping by sequencing of a recombinant inbred line population (F6to F10; n = 82) derived from single-seed descent of a F2population from a cross between the ALB-resistant parent MR-1 and the ALB-susceptible parent Ananas Yokneum. The population was evaluated for A. cucumerina resistance with an augmented block greenhouse study using inoculation with the wounded-leaf method. Multiple quantitative trait loci (QTL) mapping identified two QTL that explained 33.9% of variation in lesion area. Several candidate genes within range of these QTL were identified using the C. melo v3.5 genome. Markers linked to these QTL will be used to accelerate efforts to breed melon cultivars resistant to ALB.
authors.affiliation: First and fourth authors: Clemson University, Coastal Research and Education Center, Charleston, SC 29414; and second, third, and fifth authors: United States Department of Agriculture-Agricultural Research Service, U.S. Vegetable Laboratory, Charleston, SC 29414.
authors.forename: James
authors.initials: J
authors.lastname: Daley
authors.affiliation: First and fourth authors: Clemson University, Coastal Research and Education Center, Charleston, SC 29414; and second, third, and fifth authors: United States Department of Agriculture-Agricultural Research Service, U.S. Vegetable Laboratory, Charleston, SC 29414.
authors.forename: Sandra
authors.initials: S
authors.lastname: Branham
authors.affiliation: First and fourth authors: Clemson University, Coastal Research and Education Center, Charleston, SC 29414; and second, third, and fifth authors: United States Department of Agriculture-Agricultural Research Service, U.S. Vegetable Laboratory, Charleston, SC 29414.
authors.forename: Amnon
authors.initials: A
authors.lastname: Levi
authors.affiliation: First and fourth authors: Clemson University, Coastal Research and Education Center, Charleston, SC 29414; and second, third, and fifth authors: United States Department of Agriculture-Agricultural Research Service, U.S. Vegetable Laboratory, Charleston, SC 29414.
authors.forename: Richard
authors.initials: R
authors.lastname: Hassell
authors.affiliation: First and fourth authors: Clemson University, Coastal Research and Education Center, Charleston, SC 29414; and second, third, and fifth authors: United States Department of Agriculture-Agricultural Research Service, U.S. Vegetable Laboratory, Charleston, SC 29414.
authors.forename: Patrick
authors.initials: P
authors.lastname: Wechter
mesh_terms: D000528:Alternaria / Q000502:physiology*; D002874:Chromosome Mapping; D028463:Cucumis melo / Q000235:genetics* / Q000276:immunology; D060467:Disease Resistance / Q000235:genetics*; D008040:Genetic Linkage; D005838:Genotype; D007178:Inbreeding; D010641:Phenotype; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D018515:Plant Leaves / Q000276:immunology / Q000382:microbiology; D040641:Quantitative Trait Loci / Q000235:genetics*; D017422:Sequence Analysis, DNA