title: Comparative mapping of Raphanus sativus genome using Brassica markers and quantitative trait loci analysis for the Fusarium wilt resistance trait.
abstract: Fusarium wilt (FW), caused by the soil-borne fungal pathogen Fusarium oxysporum is a serious disease in cruciferous plants, including the radish (Raphanus sativus). To identify quantitative trait loci (QTL) or gene(s) conferring resistance to FW, we constructed a genetic map of R. sativus using an F2 mapping population derived by crossing the inbred lines '835' (susceptible) and 'B2' (resistant). A total of 220 markers distributed in 9 linkage groups (LGs) were mapped in the Raphanus genome, covering a distance of 1,041.5 cM with an average distance between adjacent markers of 4.7 cM. Comparative analysis of the R. sativus genome with that of Arabidopsis thaliana and Brassica rapa revealed 21 and 22 conserved syntenic regions, respectively. QTL mapping detected a total of 8 loci conferring FW resistance that were distributed on 4 LGs, namely, 2, 3, 6, and 7 of the Raphanus genome. Of the detected QTL, 3 QTLs (2 on LG 3 and 1 on LG 7) were constitutively detected throughout the 2-year experiment. QTL analysis of LG 3, flanked by ACMP0609 and cnu_mBRPGM0085, showed a comparatively higher logarithm of the odds (LOD) value and percentage of phenotypic variation. Synteny analysis using the linked markers to this QTL showed homology to A. thaliana chromosome 3, which contains disease-resistance gene clusters, suggesting conservation of resistance genes between them.
authors.affiliation: Molecular Genetics and Genomics Laboratory, Department of Horticulture, Chungnam National University, Daejeon, 305-764, Republic of Korea.
authors.forename: Xiaona
authors.initials: X
authors.lastname: Yu
authors.forename: Su Ryun
authors.initials: SR
authors.lastname: Choi
authors.forename: Nirala
authors.initials: N
authors.lastname: Ramchiary
authors.forename: Xinyang
authors.initials: X
authors.lastname: Miao
authors.forename: Su Hee
authors.initials: SH
authors.lastname: Lee
authors.forename: Hae Jeong
authors.initials: HJ
authors.lastname: Sun
authors.forename: Sunggil
authors.initials: S
authors.lastname: Kim
authors.forename: Chun Hee
authors.initials: CH
authors.lastname: Ahn
authors.forename: Yong Pyo
authors.initials: YP
authors.lastname: Lim
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D001937:Brassica / Q000235:genetics*; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D060467:Disease Resistance / Q000235:genetics* / Q000276:immunology; D005670:Fusarium / Q000502:physiology*; D005819:Genetic Markers; D018745:Genome, Plant / Q000235:genetics*; D010935:Plant Diseases / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D040641:Quantitative Trait Loci / Q000235:genetics*; D019655:Quantitative Trait, Heritable; D031224:Raphanus / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D026801:Synteny / Q000235:genetics
chemical_list: D005819:Genetic Markers