title: High-density linkage mapping revealed suppression of recombination at the sex determination locus in papaya.
abstract: A high-density genetic map of papaya (Carica papaya L.) was constructed using 54 F(2) plants derived from cultivars Kapoho and SunUp with 1501 markers, including 1498 amplified fragment length polymorphism (AFLP) markers, the papaya ringspot virus coat protein marker, morphological sex type, and fruit flesh color. These markers were mapped into 12 linkage groups at a LOD score of 5.0 and recombination frequency of 0.25. The 12 major linkage groups covered a total length of 3294.2 cM, with an average distance of 2.2 cM between adjacent markers. This map revealed severe suppression of recombination around the sex determination locus with a total of 225 markers cosegregating with sex types. The cytosine bases were highly methylated in this region on the basis of the distribution of methylation-sensitive and -insensitive markers. This high-density genetic map is essential for cloning of specific genes of interest such as the sex determination gene and for the integration of genetic and physical maps of papaya.
authors.affiliation: Department of Molecular Biosciences and Bioengineering, University of Hawaii, Honolulu, Hawaii 96822, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Ma
authors.forename: Paul H
authors.initials: PH
authors.lastname: Moore
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Liu
authors.forename: Minna S
authors.initials: MS
authors.lastname: Kim
authors.forename: Qingyi
authors.initials: Q
authors.lastname: Yu
authors.forename: Maureen M M
authors.initials: MM
authors.lastname: Fitch
authors.forename: Terry
authors.initials: T
authors.lastname: Sekioka
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Paterson
authors.forename: Ray
authors.initials: R
authors.lastname: Ming
mesh_terms: D001482:Base Composition; D029441:Carica / Q000235:genetics*; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D019175:DNA Methylation; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D017343:Genes, Plant; D018745:Genome, Plant; D011110:Polymorphism, Genetic; D011995:Recombination, Genetic; D019849:Sex Determination Processes; D013489:Suppression, Genetic
chemical_list: D018744:DNA, Plant