title: Fine mapping and identification of blast resistance gene Pi-hk1 in a broad-spectrum resistant japonica rice landrace.
abstract: One Japonica rice landrace, Heikezijing, from the Taihu Lake region of China, exhibits broad-spectrum resistance to rice blast. As characterized in our previous research, a main-effect resistance (R) gene, Pi-hk1, in Heikezijing against five isolates (GD10-279a, JS2004-141-1, JS2004-185, JS90-78, and Hoku1) was roughly mapped on the long arm of chromosome 11. To fine map Pi-hk1, one recombinant inbred line (RIL), RIL72 (F2:8), from the cross between Heikezijing and blast-susceptible variety Suyunuo, was further crossed and backcrossed with Suyunuo to produce a BC1F2 population of 477 individuals. Inoculation experiments with the representative isolate Hoku 1 indicated that RIL72 carries a single dominant R gene for blast resistance. With the help of advanced BC1F3 (915 plants), BC1F4 (4,459 plants), and BC1F5 (2,000 plants) mapping populations, Pi-hk1 was finally mapped to a 107-kb region between molecular markers P3586 and ILP3, and co-segregated with the markers P4098, RM7654, and P4099. By sequence analysis of Heikezijing bacterial artificial chromosome clones covering Pi-hk1 region, 16 predicted genes were identified within this region, including three nucleotide-binding site leucine-rich repeat candidate genes. These results provide essential information for cloning of Pi-hk1 and its application in rice breeding for broad-spectrum blast resistance by marker-assisted selection.
authors.forename: Yunyu
authors.initials: Y
authors.lastname: Wu
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Bao
authors.forename: Liujie
authors.initials: L
authors.lastname: Xie
authors.forename: Yunyun
authors.initials: Y
authors.lastname: Su
authors.forename: Ruizhen
authors.initials: R
authors.lastname: Chu
authors.forename: Wanwan
authors.initials: W
authors.lastname: He
authors.forename: Ji
authors.initials: J
authors.lastname: Huang
authors.forename: Jianfei
authors.initials: J
authors.lastname: Wang
authors.forename: Hongsheng
authors.initials: H
authors.lastname: Zhang
mesh_terms: D001947:Breeding; D002681:China; D002874:Chromosome Mapping; D022202:Chromosomes, Artificial, Bacterial; D060467:Disease Resistance / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D020082:Magnaporthe / Q000472:pathogenicity*; D012275:Oryza / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics*
chemical_list: D010940:Plant Proteins