title: The inheritance of resistance to Verticillium wilt caused by race 1 isolates of Verticillium dahliae in the lettuce cultivar La Brillante.
abstract: Verticillium wilt of lettuce caused by Verticillium dahliae can cause severe economic damage to lettuce producers. Complete resistance to race 1 isolates is available in Lactuca sativa cultivar (cv.) La Brillante and understanding the genetic basis of this resistance will aid development of new resistant cultivars. F(1) and F(2) families from crosses between La Brillante and three iceberg cultivars as well as a recombinant inbred line population derived from L. sativa cv. Salinas 88 × La Brillante were evaluated for disease incidence and disease severity in replicated greenhouse and field experiments. One hundred and six molecular markers were used to generate a genetic map from Salinas 88 × La Brillante and for detection of quantitative trait loci. Segregation was consistent with a single dominant gene of major effect which we are naming Verticillium resistance 1 (Vr1). The gene described large portions of the phenotypic variance (R(2) = 0.49-0.68) and was mapped to linkage group 9 coincident with an expressed sequence tag marker (QGD8I16.yg.ab1) that has sequence similarity with the Ve gene that confers resistance to V. dahliae race 1 in tomato. The simple inheritance of resistance indicates that breeding procedures designed for single genes will be applicable for developing resistant cultivars. QGD8I16.yg.ab1 is a good candidate for functional analysis and development of markers suitable for marker-assisted selection.
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Crop Improvement and Protection Unit, Salinas, CA 93905, USA. Ryan.Hayes@ars.usda.gov
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Hayes
authors.forename: Leah K
authors.initials: LK
authors.lastname: McHale
authors.forename: Gary E
authors.initials: GE
authors.lastname: Vallad
authors.forename: Maria Jose
authors.initials: MJ
authors.lastname: Truco
authors.forename: Richard W
authors.initials: RW
authors.lastname: Michelmore
authors.forename: Steve J
authors.initials: SJ
authors.lastname: Klosterman
authors.forename: Karunakaran
authors.initials: K
authors.lastname: Maruthachalam
authors.forename: Krishna V
authors.initials: KV
authors.lastname: Subbarao
mesh_terms: D020090:Chromosome Segregation / Q000235:genetics; D003433:Crosses, Genetic; D060467:Disease Resistance; D020224:Expressed Sequence Tags; D017343:Genes, Plant; D005819:Genetic Markers; D018545:Lactuca / Q000235:genetics*; D010641:Phenotype; D010935:Plant Diseases / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D057865:Plant Immunity / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D017422:Sequence Analysis, DNA; D020172:Verticillium / Q000254:growth & development / Q000472:pathogenicity*
chemical_list: D005819:Genetic Markers