title: Localization of a new gene for bitterness in cucumber.
abstract: Bitterness in cucumber fruit and foliage is due to the presence of cucurbitacins. Several genes have been described that control the trait, with bi (bi-1) making fruit and foliage bitter free and Bt (Bt-1) making the fruit highly bitter. Previous studies have reported the inheritance and molecular markers linked to bi-1 or Bt-1, but we were interested in studying the inheritance of fruit bitterness in the progeny of 2 nonbitter fruit inbred lines. The objective was to determine the inheritance of cucumber fruit and foliage bitterness and to locate them on a current linkage map using a recombinant inbred lines (RILs) population derived by crossing 9110Gt and 9930. It was concluded from the inheritance analysis that there were 2 loci controlling fruit bitterness in the population. One locus was in the same position as the location previously identified for bi-1, and another locus was for bi-3. Using a simple sequence repeat (SSR) linkage map, 2 loci for fruit bitterness in this RILs population were mapped. The locus of bi-1 was located at the region between SSR0004 and SSR02309 within the genetic distance of 5.2 cM on chromosome 6. The locus of bi-3 was placed in the region of SSR00116-SSR05321 within the genetic distance of 6.3 cM on chromosome 5. The physical distances for the regions of bi-1 and bi-3 were 11,430.94 Kb with 160 predicted genes and 1528.23 Kb with 198 predicted genes, respectively. Among 160 predicted genes for bi-1, there is a terpene synthase gene named Csa008595, which was speculated as the candidate gene of bi-1.
authors.affiliation: Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 10081, China.
authors.forename: Shengping
authors.initials: S
authors.lastname: Zhang
authors.forename: Han
authors.initials: H
authors.lastname: Miao
authors.forename: Rifei
authors.initials: R
authors.lastname: Sun
authors.forename: Xiaowu
authors.initials: X
authors.lastname: Wang
authors.forename: Sanwen
authors.initials: S
authors.lastname: Huang
authors.forename: Todd C
authors.initials: TC
authors.lastname: Wehner
authors.forename: Xingfang
authors.initials: X
authors.lastname: Gu
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics; D002874:Chromosome Mapping; D019295:Computational Biology; D003433:Crosses, Genetic; D018553:Cucumis sativus / Q000737:chemistry / Q000235:genetics*; D054728:Cucurbitacins / Q000032:analysis / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D005638:Fruit / Q000235:genetics*; D017343:Genes, Plant / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D008126:Lod Score; D018895:Microsatellite Repeats / Q000235:genetics; D058977:Molecular Sequence Annotation; D018515:Plant Leaves / Q000235:genetics*; D040641:Quantitative Trait Loci / Q000235:genetics
chemical_list: D017931:DNA Primers; D005819:Genetic Markers; D054728:Cucurbitacins; D019883:Alkyl and Aryl Transferases; C108877:terpene synthase