In marker-assisted breeding for bacterial blight(BB) resistance in rice, three major resistance genes, viz., Xa21, xa13 and xa5, are routinely deployed either singly or in combinations. As efficient and functional mar...In marker-assisted breeding for bacterial blight(BB) resistance in rice, three major resistance genes, viz., Xa21, xa13 and xa5, are routinely deployed either singly or in combinations. As efficient and functional markers are yet to be developed for xa13 and xa5, we have developed simple PCR-based functional markers for both the genes. For xa13, we designed a functional PCR-based marker, xa13-prom targeting the In Del polymorphism in the promoter of candidate gene Os8N3 located on chromosome 8 of rice. With respect to xa5, a multiplex-PCR based functional marker system, named xa5 FM, consisting of two sets of primer pairs targeting the 2-bp functional nucleotide polymorphism in the exon II of the gene TFIIA5(candidate for xa5), has been developed. Both xa13-prom and xa5 FM can differentiate the resistant and susceptible alleles for xa13 and xa5, respectively, in a co-dominant fashion. Using these two functional markers along with the already reported functional PCR-based marker for Xa21(p TA248), we designed a single-tube multiplex PCR based assay for simultaneous detection of all the three major resistance genes and demonstrated the utility of the multiplex marker system in a segregating population.展开更多
In recent years,the strong virulence pathotype Ⅴ of rice bacterial blight grew up quickly in Southern China,which has become a major population and spread to the rice regions of Jiangsu and Zhejiang provinces in Sout...In recent years,the strong virulence pathotype Ⅴ of rice bacterial blight grew up quickly in Southern China,which has become a major population and spread to the rice regions of Jiangsu and Zhejiang provinces in Southern China.Since pathotype Ⅴ caused serious bacterial blight disease in rice production regions,it is urgent to breed and promote resistant varieties against pathotype Ⅴ.The most economic and effective measure to control rice bacterial blight is to breed resistant cultivars for widely planting using resistance genes.The Institute of Plant Protection,Guangdong Academy of Agricultural Sciences,and Agricultural Science Research Institute of Panyu District of Guangzhou used IRBB5 carrying the recessive xa5 gene from IRRI that is resistant to pathotype Ⅴ to breed resistant varieties with rice blast resistance source,through hybridization,multiple cross,pedigree selection and synchronous resistance evaluation.We successfully bred series of new resistant rice varieties such as Baijiangzhan,Baijingzhan and Baisizhan,which showed resistance to strong virulence pathotype Ⅴ(grade 1-3)of bacterial blight and rice blast(mediate to high resistance),good grain quality(level 3 of rice quality of Guangdong),and yield equivalent to major cultivars(compared with region trial control cultivars of Guangdong).These new resistant varieties were promoted and planted in the strong virulence pathotype Ⅴ region along the west coast of Guangdong,which showed favorable superiority and wide application prospect in controlling rice bacterial blight with resistance varieties.展开更多
Rice xa5 gene provides recessive, race-specific resistance to bacterial blight disease caused by the pathogen Xanthomonas oryzae pv. oryzae and has great value for re-search and breeding. In an effort to clone xa5, an...Rice xa5 gene provides recessive, race-specific resistance to bacterial blight disease caused by the pathogen Xanthomonas oryzae pv. oryzae and has great value for re-search and breeding. In an effort to clone xa5, an F2 popula-tion of 4892 individuals was developed from the xa5 near isogenic lines, IR24 and IRBB5. A fine mapping procedure was conducted and tightly linked RFLP markers were used to screen a BAC library of IRBB56, a resistant rice line con-taining the xa5 gene. A 213 kb contig covering the xa5 locus was constructed. According to the sequences from the Inter-national Rice Genome Sequening Project (IRGSP), the Chi-nese Superhybrid Rice Genome Project (SRGP) and some sub-clones of the contig, twelve SSLP and CAPS markers were developed for fine mapping. The xa5 gene was mapped to a 0.3 cM interval between markers K5 and T4, which spanned an interval of approximately 24 kb, co-segregating with marker T2. Sequence analysis of the 24 kb region re-vealed that an ABC transporter and a basal transcription factor (TFIIa) were potential candidates for the xa5 resis-tance gene product. The molecular mechanism by which the xa5 gene provides recessive, race-specific resistance to bacte-rial blight will be elucidated by the functional tests of the 24 kb DNA and the candidate genes.展开更多
基金the funding support provided by the Department of Biotechnology(DBT),Government of India(Grant Nos.BT/AB/FG-2 (PH-II)/2009 and BT/PR11705/AGR/02/646/2008)
文摘In marker-assisted breeding for bacterial blight(BB) resistance in rice, three major resistance genes, viz., Xa21, xa13 and xa5, are routinely deployed either singly or in combinations. As efficient and functional markers are yet to be developed for xa13 and xa5, we have developed simple PCR-based functional markers for both the genes. For xa13, we designed a functional PCR-based marker, xa13-prom targeting the In Del polymorphism in the promoter of candidate gene Os8N3 located on chromosome 8 of rice. With respect to xa5, a multiplex-PCR based functional marker system, named xa5 FM, consisting of two sets of primer pairs targeting the 2-bp functional nucleotide polymorphism in the exon II of the gene TFIIA5(candidate for xa5), has been developed. Both xa13-prom and xa5 FM can differentiate the resistant and susceptible alleles for xa13 and xa5, respectively, in a co-dominant fashion. Using these two functional markers along with the already reported functional PCR-based marker for Xa21(p TA248), we designed a single-tube multiplex PCR based assay for simultaneous detection of all the three major resistance genes and demonstrated the utility of the multiplex marker system in a segregating population.
基金Special Fund of Agro-scientific Research in Public Interest(201303015)Earmarked Fund for China Agriculture Research System(CARS-01-24,2019KJ105)+1 种基金Science and Technology Planning Project of Guangdong Province(2015A020210081)Special Fund for Science and Technology Innovation Strategy of Guangdong Academy of Agricultural Sciences(R2016PY-JX005,R2016PY-QY009)。
文摘In recent years,the strong virulence pathotype Ⅴ of rice bacterial blight grew up quickly in Southern China,which has become a major population and spread to the rice regions of Jiangsu and Zhejiang provinces in Southern China.Since pathotype Ⅴ caused serious bacterial blight disease in rice production regions,it is urgent to breed and promote resistant varieties against pathotype Ⅴ.The most economic and effective measure to control rice bacterial blight is to breed resistant cultivars for widely planting using resistance genes.The Institute of Plant Protection,Guangdong Academy of Agricultural Sciences,and Agricultural Science Research Institute of Panyu District of Guangzhou used IRBB5 carrying the recessive xa5 gene from IRRI that is resistant to pathotype Ⅴ to breed resistant varieties with rice blast resistance source,through hybridization,multiple cross,pedigree selection and synchronous resistance evaluation.We successfully bred series of new resistant rice varieties such as Baijiangzhan,Baijingzhan and Baisizhan,which showed resistance to strong virulence pathotype Ⅴ(grade 1-3)of bacterial blight and rice blast(mediate to high resistance),good grain quality(level 3 of rice quality of Guangdong),and yield equivalent to major cultivars(compared with region trial control cultivars of Guangdong).These new resistant varieties were promoted and planted in the strong virulence pathotype Ⅴ region along the west coast of Guangdong,which showed favorable superiority and wide application prospect in controlling rice bacterial blight with resistance varieties.
基金supported by the Nationa1 Key Basic Research Program of China(Grant No.G1998010207)the Nationa1 Natural Science Foundation of China(Grant No.30270747)the Nationa1 Special Program on Transgenic plants(Grant No.JY03A0501).
文摘Rice xa5 gene provides recessive, race-specific resistance to bacterial blight disease caused by the pathogen Xanthomonas oryzae pv. oryzae and has great value for re-search and breeding. In an effort to clone xa5, an F2 popula-tion of 4892 individuals was developed from the xa5 near isogenic lines, IR24 and IRBB5. A fine mapping procedure was conducted and tightly linked RFLP markers were used to screen a BAC library of IRBB56, a resistant rice line con-taining the xa5 gene. A 213 kb contig covering the xa5 locus was constructed. According to the sequences from the Inter-national Rice Genome Sequening Project (IRGSP), the Chi-nese Superhybrid Rice Genome Project (SRGP) and some sub-clones of the contig, twelve SSLP and CAPS markers were developed for fine mapping. The xa5 gene was mapped to a 0.3 cM interval between markers K5 and T4, which spanned an interval of approximately 24 kb, co-segregating with marker T2. Sequence analysis of the 24 kb region re-vealed that an ABC transporter and a basal transcription factor (TFIIa) were potential candidates for the xa5 resis-tance gene product. The molecular mechanism by which the xa5 gene provides recessive, race-specific resistance to bacte-rial blight will be elucidated by the functional tests of the 24 kb DNA and the candidate genes.
