title: [Identification of a resistance gene to bacterial blight (Xanthomonas oryzae pv. oryzae) in a somaclonal mutant HX-3 of indica rice].
abstract: Using the mature embryo of a susceptible rice variety Minghui 63 as the explant, we have obtained a somaclonal mutant HX-3 through selection in vitro, which has showed resistance to bacterial blight. In 8 successive years, the resistance of R1 to R9 generations of HX-3 was identified by ZJ173, a typical bacterial blight strain in Yangtsu River valley, and the results showed that the resistance of HX-3 was stable and heritable. Genetic analysis also indicated that the resistance of HX-3 to bacterial blight was under a dominant gene controlling. Using 32 bacterial blight strains collected in China, Philippines and Japan, the resistance spectrum of HX-3 and other 13 testers with different major dominant resistance genes were tested. Results of 2 years (1999-2000) experiment showed that HX-3 had a broad resistance spectrum, which seemed to be different with those of the other dominant resistance genes identified. Allelic tests were also conducted by crossing HX-3 with IRBB4, IRBB7, CBB12 and IRBB21, and the F2 populations of each of the 4 crosses demonstrated resistant and susceptible plant segregation, indicating that the resistance gene in HX-3 different from Xa-4, Xa-7, Xa-12 and Xa-21. All these results proved that there was a new resistance gene in HX-3. We have designated the new gene as Xa-25(t).
authors.affiliation: Institute of Agricultural Genetics and Phsiology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China. ricebiot@jlonline.com
authors.forename: Dong-Ying
authors.initials: DY
authors.lastname: Gao
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Xu
authors.forename: Zhi-Yi
authors.initials: ZY
authors.lastname: Chen
authors.forename: Li-Hua
authors.initials: LH
authors.lastname: Sun
authors.forename: Qi-Ming
authors.initials: QM
authors.lastname: Sun
authors.forename: Fan
authors.initials: F
authors.lastname: Lu
authors.forename: Bai-Shi
authors.initials: BS
authors.lastname: Hu
authors.forename: Yong-Feng
authors.initials: YF
authors.lastname: Liu
mesh_terms: D004198:Disease Susceptibility / Q000382:microbiology; D017343:Genes, Plant; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006824:Hybridization, Genetic / Q000235:genetics; D009154:Mutation; D012275:Oryza / Q000235:genetics* / Q000382:microbiology; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D030821:Plants, Genetically Modified; D014974:Xanthomonas / Q000235:genetics