Stripe rust and powdery mildew are both devastating diseases for durum and common wheat.Pyramiding of genes conferring resistance to one or more diseases in a single cultivar is an important breeding approach to provi...Stripe rust and powdery mildew are both devastating diseases for durum and common wheat.Pyramiding of genes conferring resistance to one or more diseases in a single cultivar is an important breeding approach to provide broader spectra of resistances in wheat improvement. A new powdery mildew resistance gene originating from wild emmer(Triticum turgidum var.dicoccoides) backcrossed into common wheat(T. aestivum) line WE35 was identified. It conferred an intermediate level of resistance to Blumeria graminis f. sp. tritici isolate E09 at the seedling stage and a high level of resistance at the adult plant stage. Genetic analysis showed that the powdery mildew resistance in WE35 was controlled by a dominant gene designated Pm64. Bulked segregant analysis(BSA) and molecular mapping indicated that Pm64 was located in chromosome bin 2 BL4-0.50–0.89. Polymorphic markers were developed from the corresponding genomic regions of Chinese Spring wheat and wild emmer accession Zavitan to delimit Pm64 to a 0.55 cM genetic interval between markers WGGBH1364 and WGGBH612, corresponding to a 15 Mb genomic region on Chinese Spring and Zavitan 2 BL, respectively. The genetic linkage map of Pm64 is critical for fine mapping and cloning. Pm64 was completely linked in repulsion with stripe rust resistance gene Yr5. Analysis of a larger segregating population might identify a recombinant line with both genes as a valuable resource in breeding for resistance to powdery mildew and stripe rust.展开更多
Wild emmer wheat(Triticum dicoccoides,WEW)is an immediate progenitor of both the cultivated tetraploid and hexaploid wheats and it harbors rich genetic diversity against powdery mildew caused by Blumeria graminis f.sp...Wild emmer wheat(Triticum dicoccoides,WEW)is an immediate progenitor of both the cultivated tetraploid and hexaploid wheats and it harbors rich genetic diversity against powdery mildew caused by Blumeria graminis f.sp.tritici(Bgt).A powdery mildew resistance gene Ml I^(W172)originated from WEW accession I^(W172)(G-797-M)is fine mapped in a 0.048 centimorgan(c M)genetic interval on 7 AL,corresponding to a genomic region spanning 233 kb,1 Mb and 800 kb in Chinese Spring,WEW Zavitan,and T.urartu G1812,respectively.Ml I^(W172)encodes a typical NLR protein NLRI^(W172)and physically locates in an NBS-LRR gene cluster.NLRI^(W172)is subsequently identified as a new allele of Pm60,and its function is validated by EMS mutagenesis and transgenic complementation.Haplotype analysis of the Pm60 alleles reveals diversifications in sequence variation in the locus and presence and absence variations(PAV)in WEW populations.Four common single nucleotide variations(SNV)are detected between the Pm60 alleles from WEW and T.urartu,indicative of speciation divergence between the two different wheat progenitors.The newly identified Pm60 alleles and haplotypes in WEW are anticipated to be valuable for breeding powdery mildew resistance wheat cultivars via marker-assisted selection.展开更多
Many species of Triticeae display a glaucous phenotype. In wheat, glaucousness/waxiness on spikes, leaves and shoots is controlled by wax production genes(W loci) and epistatic inhibitors(Iw loci). In this study, a su...Many species of Triticeae display a glaucous phenotype. In wheat, glaucousness/waxiness on spikes, leaves and shoots is controlled by wax production genes(W loci) and epistatic inhibitors(Iw loci). In this study, a suppressor of glaucousness from wild emmer wheat(Triticum turgidum ssp. dicoccoides) accession "PI 481521" was investigated in a pair of durum(T. turgidum ssp. durum cv. "Langdon", LDN)—wild emmer wheat chromosome substitution lines, LDN and "LDNDIC521-2B". Genetic analysis revealed that the non-glaucous phenotype of LDNDIC521-2Bwas controlled by the dominant glaucous suppressor Iw1 on the short arm of chromosome 2B. In total, 371 2B-specific marker differences were identified between LDN and LDNDIC521-2B. The location of the Iw1 gene was mapped using an F2 population that stemmed from LDN and LDNDIC521-2B, generating a partial linkage map that included 19 simple sequence repeats(SSR) and ten gene-based markers. On the current map, the Iw1 gene was located within the Xgwm614–BE498111 interval, and cosegregated with BQ788707,CD893659, CD927782, CD938589, and Xbarc35. Mapping of Iw1 in LDNDIC521-2B, a publically accessible and widely distributed line, will provide valuable information for marker-assisted selection of the agronomically important trait of glaucousness.展开更多
Powdery mildew(PM),caused by Blumeria graminis f.sp.tritici(Bgt),is one of the destructive wheat diseases worldwide.Wild emmer wheat(Triticum turgidum ssp.dicoccoides,WEW),a tetraploid progenitor of common wheat,is a ...Powdery mildew(PM),caused by Blumeria graminis f.sp.tritici(Bgt),is one of the destructive wheat diseases worldwide.Wild emmer wheat(Triticum turgidum ssp.dicoccoides,WEW),a tetraploid progenitor of common wheat,is a valuable genetic resource for wheat disease resistance breeding programs.We developed three hexaploid pre-breeding lines with PM resistance genes derived from three WEW accessions.These resistant pre-breeding lines were crossed with susceptible common wheat accessions.Segregations in the F2populations were 3 resistant:1 susceptible,suggesting a single dominant allele in each resistant parent.Mapping of the resistance gene in each line indicated a single locus on the long arm of chromosome 7A,at the approximate location of previously cloned Pm60 from T.urartu.Sanger sequencing revealed three different Pm60 haplotypes(Hap 3,Hap 5,and Hap 6).Co-segregating diagnostic markers were developed for identification and selection of each haplotype.The resistance function of each haplotype was verified by the virus-induced gene silencing(VIGS).Common wheat lines carrying each of these Pm60 haplotypes were resistant to most Bgt isolates and differences in the response arrays suggested allelic variation in response.展开更多
Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici （Pst）, is a devastating disease that can cause severe yield losses. Identification and utilization of stripe rust resistance genes are essential for e...Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici （Pst）, is a devastating disease that can cause severe yield losses. Identification and utilization of stripe rust resistance genes are essential for effective breeding against the disease. Wild emmer accession TZ-2, originally collected from Mount Hermon, Israel, confers near-immunity resistance against several prevailing Pst races in China. A set of 200 F6：7 recombinant inbred lines （RILs） derived from a cross between susceptible durum wheat cultivar Langdon and TZ-2 was used for stripe rust evaluation. Genetic analysis indicated that the stripe rust resistance of TZ-2 to Pst race CYR34 was controlled by a single dominant gene, temporarily designated YrTZ2. Through bulked segregant analysis （BSA） with SSR markers, YrTZ2 was located on chromosome arm 1BS flanked by Xwmc230 and Xgwm413 with genetic distance of 0.8 cM （distal） and 0.3 cM （proximal）, respectively. By applying wheat 90K iSelect SNP genotyping assay, 11 polymorphic loci （consisting of 250 SNP markers） closely linked to YrTZ2 were identified. YrTZ2 was further delimited into a 0.8-cM genetic interval between SNP marker IWB19368 and SSR marker Xgwm413, and cosegregated with SNP marker IWB28744 （co-segregated with 28 SNP）. Comparative genomics analyses revealed high level of collinearity between the YrTZ2 genomic region and the orthologous region of Aegilops tauschii 1DS. The genomic region between loci IWB19368 and IWB31649 harboring YrTZ2 is orthologous to a 24.5-Mb genomic region between AT1D0112 and AT1D0150, spanning 15 contigs on chromosome 1DS. The genetic and comparative maps of YrTZ2 rovide a framework for map-based cloning and marker-assisted selection of YrTZ2.展开更多
基金supported by the National Key Research and Development Program of China (2017YFD0101004)the Science and Technology Service Network Initiative of Chinese Academy of Sciences (KFJ-STS-ZDTP-024)
文摘Stripe rust and powdery mildew are both devastating diseases for durum and common wheat.Pyramiding of genes conferring resistance to one or more diseases in a single cultivar is an important breeding approach to provide broader spectra of resistances in wheat improvement. A new powdery mildew resistance gene originating from wild emmer(Triticum turgidum var.dicoccoides) backcrossed into common wheat(T. aestivum) line WE35 was identified. It conferred an intermediate level of resistance to Blumeria graminis f. sp. tritici isolate E09 at the seedling stage and a high level of resistance at the adult plant stage. Genetic analysis showed that the powdery mildew resistance in WE35 was controlled by a dominant gene designated Pm64. Bulked segregant analysis(BSA) and molecular mapping indicated that Pm64 was located in chromosome bin 2 BL4-0.50–0.89. Polymorphic markers were developed from the corresponding genomic regions of Chinese Spring wheat and wild emmer accession Zavitan to delimit Pm64 to a 0.55 cM genetic interval between markers WGGBH1364 and WGGBH612, corresponding to a 15 Mb genomic region on Chinese Spring and Zavitan 2 BL, respectively. The genetic linkage map of Pm64 is critical for fine mapping and cloning. Pm64 was completely linked in repulsion with stripe rust resistance gene Yr5. Analysis of a larger segregating population might identify a recombinant line with both genes as a valuable resource in breeding for resistance to powdery mildew and stripe rust.
基金financially supported by National Science Foundation of China (31971876, U21A20224)Scientific Research Project of Beijing Municipal Commission of Education (KM201910020014)
文摘Wild emmer wheat(Triticum dicoccoides,WEW)is an immediate progenitor of both the cultivated tetraploid and hexaploid wheats and it harbors rich genetic diversity against powdery mildew caused by Blumeria graminis f.sp.tritici(Bgt).A powdery mildew resistance gene Ml I^(W172)originated from WEW accession I^(W172)(G-797-M)is fine mapped in a 0.048 centimorgan(c M)genetic interval on 7 AL,corresponding to a genomic region spanning 233 kb,1 Mb and 800 kb in Chinese Spring,WEW Zavitan,and T.urartu G1812,respectively.Ml I^(W172)encodes a typical NLR protein NLRI^(W172)and physically locates in an NBS-LRR gene cluster.NLRI^(W172)is subsequently identified as a new allele of Pm60,and its function is validated by EMS mutagenesis and transgenic complementation.Haplotype analysis of the Pm60 alleles reveals diversifications in sequence variation in the locus and presence and absence variations(PAV)in WEW populations.Four common single nucleotide variations(SNV)are detected between the Pm60 alleles from WEW and T.urartu,indicative of speciation divergence between the two different wheat progenitors.The newly identified Pm60 alleles and haplotypes in WEW are anticipated to be valuable for breeding powdery mildew resistance wheat cultivars via marker-assisted selection.
基金supported by the Natural Science Foundation of Shandong Province, China (JQ201107)the National Natural Science Foundation of China (31110103917)the Cooperative Innovation Center of Efficient Production with High Annual Yield of Wheat and Corn, Shandong Province, China
文摘Many species of Triticeae display a glaucous phenotype. In wheat, glaucousness/waxiness on spikes, leaves and shoots is controlled by wax production genes(W loci) and epistatic inhibitors(Iw loci). In this study, a suppressor of glaucousness from wild emmer wheat(Triticum turgidum ssp. dicoccoides) accession "PI 481521" was investigated in a pair of durum(T. turgidum ssp. durum cv. "Langdon", LDN)—wild emmer wheat chromosome substitution lines, LDN and "LDNDIC521-2B". Genetic analysis revealed that the non-glaucous phenotype of LDNDIC521-2Bwas controlled by the dominant glaucous suppressor Iw1 on the short arm of chromosome 2B. In total, 371 2B-specific marker differences were identified between LDN and LDNDIC521-2B. The location of the Iw1 gene was mapped using an F2 population that stemmed from LDN and LDNDIC521-2B, generating a partial linkage map that included 19 simple sequence repeats(SSR) and ten gene-based markers. On the current map, the Iw1 gene was located within the Xgwm614–BE498111 interval, and cosegregated with BQ788707,CD893659, CD927782, CD938589, and Xbarc35. Mapping of Iw1 in LDNDIC521-2B, a publically accessible and widely distributed line, will provide valuable information for marker-assisted selection of the agronomically important trait of glaucousness.
基金supported by grants from the National Key Research and Development Program of China(2023YFF1000404,2022YFF10001501)the National Natural Science Foundation of China(32171971)。
文摘Powdery mildew(PM),caused by Blumeria graminis f.sp.tritici(Bgt),is one of the destructive wheat diseases worldwide.Wild emmer wheat(Triticum turgidum ssp.dicoccoides,WEW),a tetraploid progenitor of common wheat,is a valuable genetic resource for wheat disease resistance breeding programs.We developed three hexaploid pre-breeding lines with PM resistance genes derived from three WEW accessions.These resistant pre-breeding lines were crossed with susceptible common wheat accessions.Segregations in the F2populations were 3 resistant:1 susceptible,suggesting a single dominant allele in each resistant parent.Mapping of the resistance gene in each line indicated a single locus on the long arm of chromosome 7A,at the approximate location of previously cloned Pm60 from T.urartu.Sanger sequencing revealed three different Pm60 haplotypes(Hap 3,Hap 5,and Hap 6).Co-segregating diagnostic markers were developed for identification and selection of each haplotype.The resistance function of each haplotype was verified by the virus-induced gene silencing(VIGS).Common wheat lines carrying each of these Pm60 haplotypes were resistant to most Bgt isolates and differences in the response arrays suggested allelic variation in response.
基金financially supported by the Science and Technology Service Network Initiative of Chinese Academy of Sciences(KFJ-STS-ZDTP-024)
文摘Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici （Pst）, is a devastating disease that can cause severe yield losses. Identification and utilization of stripe rust resistance genes are essential for effective breeding against the disease. Wild emmer accession TZ-2, originally collected from Mount Hermon, Israel, confers near-immunity resistance against several prevailing Pst races in China. A set of 200 F6：7 recombinant inbred lines （RILs） derived from a cross between susceptible durum wheat cultivar Langdon and TZ-2 was used for stripe rust evaluation. Genetic analysis indicated that the stripe rust resistance of TZ-2 to Pst race CYR34 was controlled by a single dominant gene, temporarily designated YrTZ2. Through bulked segregant analysis （BSA） with SSR markers, YrTZ2 was located on chromosome arm 1BS flanked by Xwmc230 and Xgwm413 with genetic distance of 0.8 cM （distal） and 0.3 cM （proximal）, respectively. By applying wheat 90K iSelect SNP genotyping assay, 11 polymorphic loci （consisting of 250 SNP markers） closely linked to YrTZ2 were identified. YrTZ2 was further delimited into a 0.8-cM genetic interval between SNP marker IWB19368 and SSR marker Xgwm413, and cosegregated with SNP marker IWB28744 （co-segregated with 28 SNP）. Comparative genomics analyses revealed high level of collinearity between the YrTZ2 genomic region and the orthologous region of Aegilops tauschii 1DS. The genomic region between loci IWB19368 and IWB31649 harboring YrTZ2 is orthologous to a 24.5-Mb genomic region between AT1D0112 and AT1D0150, spanning 15 contigs on chromosome 1DS. The genetic and comparative maps of YrTZ2 rovide a framework for map-based cloning and marker-assisted selection of YrTZ2.
