Identification and Fine Mapping of QTLs Conferring Clubroot Resistance in Brassica oleracea

  • Okazaki, K. (Graduate School of Science and Technology, Niigata University) ;
  • Kawamura, K. (Graduate School of Science and Technology, Niigata University) ;
  • Kodama, T. (Graduate School of Science and Technology, Niigata University) ;
  • Shimizu, S. (Graduate School of Science and Technology, Niigata University) ;
  • Tomita, H. (Graduate School of Science and Technology, Niigata University) ;
  • Doullah, M.A.U. (Department of Plant Pathology and Seed Science, Sylhet Agricultural University) ;
  • Fukai, E. (Graduate School of Science and Technology, Niigata University)
  • Published : 2015.05.13

Abstract

Throughout the world, clubroot disease is one of the most damaging diseases affecting Brassica oleracea. In order to perform QTL analysis of CR (clubroot resistance) loci in B. oleracea, we constructed a map, and analyzed CR-QTLs using the mean phenotypes of F3 progenies from the cross of a resistant double-haploid cabbage line (Anju) with a susceptible double-haploid broccoli line (GC). We identified one major QTL, pb-Bo(Anju)1 in C2 from Anju and four minor QTLs; pb-Bo(GC)1 in O5 from GC, pb-Bo(Anju)2, -3, -4 in C2, C3, and C7 from Anju, respectively. Additionally, we found that the accumulation of Pb-Bo(Anju)1 allele and the minor CR-QTLs is essential for resistance against various six isolates. Our finding markers closely linked to the CR-QTLs will help marker-assisted selection for CR. At present, we are undergoing toward map-based cloning for Pb-Bo(Anju)1 gene. The preliminary experiment delimited Pb-Bo(Anju)1 locus, encompassing among 450kB.

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