RESUMEN
Wheat yellow (stripe) rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating diseases of wheat worldwide. Pst populations are composed of multiple genetic groups, each carrying one or more races characterized by different avirulence/virulence combinations. Since the severe epidemics in 2017, yellow rust has become the most economically important wheat foliar disease in Uruguay. A set of 124 Pst isolates collected from wheat fields in Uruguay between 2017 and 2021 were characterized phenotypically, and 27 of those isolates were subsequently investigated in-depth by additional molecular genotyping and race phenotyping analyses. Three genetic groups were identified, PstS7, PstS10, and PstS13, with the latter being the most prevalent. Two races previously reported in Europe, Warrior (PstS7) and Benchmark (PstS10), were detected in four and two isolates, respectively. A third race, known as Triticale2015 (PstS13), that was first detected in Europe in 2015 and in Argentina in 2017 was detected at several locations. Additional virulence to Yr3, Yr17, Yr25, Yr27, or Yr32 was detected in three new race variants within PstS13. The identification of these new races, which have not been reported outside South America, provides strong evidence of the local evolution of virulence in Pst during the recent epidemic years.
Asunto(s)
Enfermedades de las Plantas , Puccinia , Triticum , Virulencia/genética , Enfermedades de las Plantas/microbiología , Puccinia/patogenicidad , Puccinia/genética , Triticum/microbiología , Uruguay , Genotipo , Evolución Biológica , Fenotipo , Basidiomycota/genética , Basidiomycota/patogenicidad , Basidiomycota/clasificación , Basidiomycota/fisiologíaRESUMEN
Understanding the genetic basis of rust resistance in elite CIMMYT wheat germplasm enhances breeding and deployment of durable resistance globally. "Mokue#1", released in 2023 in Pakistan as TARNAB Gandum-1, has exhibited high levels of resistance to stripe rust, leaf rust, and stem rust pathotypes present at multiple environments in Mexico and Kenya at different times. To determine the genetic basis of resistance, a F5 recombinant inbred line (RIL) mapping population consisting of 261 lines was developed and phenotyped for multiple years at field sites in Mexico and Kenya under the conditions of artificially created rust epidemics. DArTSeq genotyping was performed, and a linkage map was constructed using 7892 informative polymorphic markers. Composite interval mapping identified three significant and consistent loci contributed by Mokue: QLrYr.cim-1BL and QLrYr.cim-2AS on chromosome 1BL and 2AS, respectively associated with stripe rust and leaf rust resistance, and QLrSr.cim-2DS on chromosome 2DS for leaf rust and stem rust resistance. The QTL on 1BL was confirmed to be the Lr46/Yr29 locus, whereas the QTL on 2AS represented the Yr17/Lr37 region on the 2NS/2AS translocation. The QTL on 2DS was a unique locus conferring leaf rust resistance in Mexico and stem rust resistance in Kenya. In addition to these pleiotropic loci, four minor QTLs were also identified on chromosomes 2DL and 6BS associated with stripe rust, and 3AL and 6AS for stem rust, respectively, using the Kenya disease severity data. Significant decreases in disease severities were also demonstrated due to additive effects of QTLs when present in combinations.
Asunto(s)
Basidiomycota , Triticum , Triticum/genética , Resistencia a la Enfermedad/genética , Enfermedades de las Plantas/genética , Fitomejoramiento , GenómicaRESUMEN
Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important diseases of wheat worldwide. To understand the worldwide distribution of its molecular groups, as well as the diversity, differentiation, and migration of the Pst populations, 567 isolates collected from nine countries (China, Pakistan, Italy, Egypt, Ethiopia, Canada, Mexico, Ecuador, and the U.S.) in 2010-2018 were genotyped using 14 codominant simple sequence repeat markers. A total of 433, including 333 new multi-locus genotypes (MLGs), were identified, which were clustered into ten molecular groups (MGs). The MGs and country-wise populations differed in genetic diversity, heterozygosity, and correlation coefficient between the marker and virulence data. Many isolates from different countries, especially the isolates from Mexico, Ecuador, and the U.S., were found to be identical or closely related MLGs, and some of the MGs were present in all countries, indicating Pst migrations among different countries. The analysis of molecular variance revealed 78% variation among isolates, 12% variation among countries, and 10% variation within countries. Only low levels of differentiation were found by the pairwise comparisons of country populations. Of the 10 MGs, 5 were found to be involved in sexual and/or somatic recombination. Identical and closely related MLGs identified from different countries indicated international migrations. The study provides information on the distributions of various Pst genetic groups in different countries and evidence for the global migrations, which should be useful in understanding the pathogen evolution and in stressing the need for continual monitoring of the disease and pathogen populations at the global scale.
Asunto(s)
Puccinia/genética , Puccinia/metabolismo , Canadá , China , Ecuador , Egipto , Etiopía , Evolución Molecular , Variación Genética/genética , Genética de Población , Genotipo , Italia , México , Pakistán , Fenotipo , Enfermedades de las Plantas/genética , Puccinia/patogenicidad , Triticum/genética , Triticum/metabolismo , Estados Unidos , VirulenciaRESUMEN
Leaf and stripe rust are major threats to wheat production worldwide. The effective, multiple rust resistances present in the Brazilian cultivar Toropi makes it an excellent choice for a genetic study of rust resistance. Testing of DNA from different seed lots of Toropi with 2,194 polymorphic 90K iSelect single nucleotide polymorphism markers identified significant genetic divergence, with as much as 35% dissimilarity between seed lots. As a result, further work was conducted with a single plant line derived from Toropi variant Toropi-6.4. A double haploid population with 168 lines derived from the cross Toropi-6.4 × Thatcher was phenotyped over multiple years and locations in Canada, New Zealand, and Kenya, with a total of seven field trials undertaken for leaf rust and nine for stripe rust. Genotyping with the 90K iSelect array, simple sequence repeat and Kompetitive allele-specific polymerase chain reaction markers resulted in a genetic map of 3,043 cM, containing 1,208 nonredundant markers. Significant quantitative trait loci (QTL) derived from Toropi-6.4 were identified in multiple environments on chromosomes 1B (QLr.crc-1BL/QYr.crc-1BL), 3B (QLr.crc-3BS), 4B (QYr.crc-4BL), 5A (QLr.crc-5AL and QYr.crc-5AL), and 5D (QLr.crc-5DS). The QTL QLr.crc-1BL/QYr.crc-1BL colocated with the multi-rust resistance locus Lr46/Yr29, while the QTL QLr.crc-5DS located to the Lr78 locus previously found in a wheat backcross population derived from Toropi. Comparisons of QTL combinations showed QLr.crc-1BL to contribute a significantly enhanced leaf rust resistance when combined with QLr.crc-5AL or QLr.crc-5DS, more so than when QLr.crc-5AL and QLr.crc-5DS were combined. A strong additive effect was also seen when the stripe rust resistance QTL QYr.crc-1BL and QYr.crc-5AL were combined.
Asunto(s)
Basidiomycota , Resistencia a la Enfermedad , Triticum , Brasil , Canadá , Mapeo Cromosómico , Resistencia a la Enfermedad/genética , Genotipo , Kenia , Nueva Zelanda , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Sitios de Carácter Cuantitativo/genética , Triticum/genética , Triticum/microbiologíaRESUMEN
Stripe rust, caused by Puccinia striiformis is one of the most destructive diseases of wheat worldwide. CH5389 is a wheat-Thinopyrum intermedium derived line conferring stripe rust resistance. Genetic analyses of seedlings of F2 populations and F2:3 families developed by crossing CH5389 and susceptible common wheat revealed that stripe rust resistance in CH5389 was controlled by a single dominant gene that was designated YrCH5389. Eight SSR and EST-PCR polymorphic markers on chromosome 3AL were identified in F2 population of CH5389/Taichung29. The YrCH5389 was flanked by EST marker BE405348 and SSR marker Xwmc388 on chromosome 3AL with genetic distances of 2.2 and 4.6 cM, respectively. Comparative genomic analysis demonstrated that the orthologous genomic region of YrCH5389 covered 990 kb in rice, 640 kb in Brachypodium, and 890 kb in sorghum. Based on the locations of the markers, the resistance gene was located to chromosome deletion bin 3AL-0.85-1.00. Because there are no officially named stripe rust resistance genes on the 3AL chromosome, the YrCH5389 should be designated as a new resistance gene. These linkage markers could be useful for marker-assisted selection in wheat resistance breeding.(AU)
A ferrugem linear causada por Puccinia striiformis é uma das doenças mais destrutivas do trigo no mundo. A linhagem CH5389 é derivada do cruzamento de trigo com Thinopyrum intermedium e confere resistência a ferrugem linear. Análises genéticas de indivíduos da população F2 e família F2:3 obtida a partir do cruzamento entre CH5389 e trigo comum suscetível revelaram que a resistência à ferrugem linear na linhagem CH5389 foi controlada por um único gene dominante, designado YrCH5389. Oito marcadores polimórficos SSR e EST-PCR no cromossomo 3AL foram identificados na população F2 de CH5389/Taichung29. O gene YrCH5389 foi delimitado pelos marcadores EST BE405348 e SSR Xwmc388 no cromossomo 3AL com distâncias genéticas de 2,2 e 4,6 cM, respectivamente. Análises genômicas comparativas demonstraram que regiões genômicas ortólogas do gene YrCH5389 compreendem 990 kb em arroz, 640 kb em braquipódio e 890 kb em sorgo. Com base nas localizações dos marcadores, o gene de resistência foi localizado no cromossomo 3AL-0.85-1.00. Como não há genes oficialmente nomeados de resistência à ferrugem linear no cromossomo 3AL, o YrCH5389 deve ser designado como um gene novo de resistência. Esses marcadores de ligação podem ser úteis para a seleção assistida de genótipos de trigo resistentes a ferrugem linear.(AU)
Asunto(s)
Enfermedades de las Plantas/genética , Triticum/genética , Micosis/diagnóstico , Micosis/genéticaRESUMEN
Stripe rust, caused by Puccinia striiformis is one of the most destructive diseases of wheat worldwide. CH5389 is a wheat-Thinopyrum intermedium derived line conferring stripe rust resistance. Genetic analyses of seedlings of F2 populations and F2:3 families developed by crossing CH5389 and susceptible common wheat revealed that stripe rust resistance in CH5389 was controlled by a single dominant gene that was designated YrCH5389. Eight SSR and EST-PCR polymorphic markers on chromosome 3AL were identified in F2 population of CH5389/Taichung29. The YrCH5389 was flanked by EST marker BE405348 and SSR marker Xwmc388 on chromosome 3AL with genetic distances of 2.2 and 4.6 cM, respectively. Comparative genomic analysis demonstrated that the orthologous genomic region of YrCH5389 covered 990 kb in rice, 640 kb in Brachypodium, and 890 kb in sorghum. Based on the locations of the markers, the resistance gene was located to chromosome deletion bin 3AL-0.85-1.00. Because there are no officially named stripe rust resistance genes on the 3AL chromosome, the YrCH5389 should be designated as a new resistance gene. These linkage markers could be useful for marker-assisted selection in wheat resistance breeding.
A ferrugem linear causada por Puccinia striiformis é uma das doenças mais destrutivas do trigo no mundo. A linhagem CH5389 é derivada do cruzamento de trigo com Thinopyrum intermedium e confere resistência a ferrugem linear. Análises genéticas de indivíduos da população F2 e família F2:3 obtida a partir do cruzamento entre CH5389 e trigo comum suscetível revelaram que a resistência à ferrugem linear na linhagem CH5389 foi controlada por um único gene dominante, designado YrCH5389. Oito marcadores polimórficos SSR e EST-PCR no cromossomo 3AL foram identificados na população F2 de CH5389/Taichung29. O gene YrCH5389 foi delimitado pelos marcadores EST BE405348 e SSR Xwmc388 no cromossomo 3AL com distâncias genéticas de 2,2 e 4,6 cM, respectivamente. Análises genômicas comparativas demonstraram que regiões genômicas ortólogas do gene YrCH5389 compreendem 990 kb em arroz, 640 kb em braquipódio e 890 kb em sorgo. Com base nas localizações dos marcadores, o gene de resistência foi localizado no cromossomo 3AL-0.85-1.00. Como não há genes oficialmente nomeados de resistência à ferrugem linear no cromossomo 3AL, o YrCH5389 deve ser designado como um gene novo de resistência. Esses marcadores de ligação podem ser úteis para a seleção assistida de genótipos de trigo resistentes a ferrugem linear.
Asunto(s)
Enfermedades de las Plantas/genética , Micosis/diagnóstico , Micosis/genética , Triticum/genéticaRESUMEN
ABSTRACT: Stripe rust, caused by Puccinia striiformis is one of the most destructive diseases of wheat worldwide. CH5389 is a wheat-Thinopyrum intermedium derived line conferring stripe rust resistance. Genetic analyses of seedlings of F2 populations and F2:3 families developed by crossing CH5389 and susceptible common wheat revealed that stripe rust resistance in CH5389 was controlled by a single dominant gene that was designated YrCH5389. Eight SSR and EST-PCR polymorphic markers on chromosome 3AL were identified in F2 population of CH5389/Taichung29. The YrCH5389 was flanked by EST marker BE405348 and SSR marker Xwmc388 on chromosome 3AL with genetic distances of 2.2 and 4.6 cM, respectively. Comparative genomic analysis demonstrated that the orthologous genomic region of YrCH5389 covered 990 kb in rice, 640 kb in Brachypodium, and 890 kb in sorghum. Based on the locations of the markers, the resistance gene was located to chromosome deletion bin 3AL-0.85-1.00. Because there are no officially named stripe rust resistance genes on the 3AL chromosome, the YrCH5389 should be designated as a new resistance gene. These linkage markers could be useful for marker-assisted selection in wheat resistance breeding.
RESUMO: A ferrugem linear causada por Puccinia striiformis é uma das doenças mais destrutivas do trigo no mundo. A linhagem CH5389 é derivada do cruzamento de trigo com Thinopyrum intermedium e confere resistência a ferrugem linear. Análises genéticas de indivíduos da população F2 e família F2:3 obtida a partir do cruzamento entre CH5389 e trigo comum suscetível revelaram que a resistência à ferrugem linear na linhagem CH5389 foi controlada por um único gene dominante, designado YrCH5389. Oito marcadores polimórficos SSR e EST-PCR no cromossomo 3AL foram identificados na população F2 de CH5389/Taichung29. O gene YrCH5389 foi delimitado pelos marcadores EST BE405348 e SSR Xwmc388 no cromossomo 3AL com distâncias genéticas de 2,2 e 4,6 cM, respectivamente. Análises genômicas comparativas demonstraram que regiões genômicas ortólogas do gene YrCH5389 compreendem 990 kb em arroz, 640 kb em braquipódio e 890 kb em sorgo. Com base nas localizações dos marcadores, o gene de resistência foi localizado no cromossomo 3AL-0.85-1.00. Como não há genes oficialmente nomeados de resistência à ferrugem linear no cromossomo 3AL, o YrCH5389 deve ser designado como um gene novo de resistência. Esses marcadores de ligação podem ser úteis para a seleção assistida de genótipos de trigo resistentes a ferrugem linear.
RESUMEN
Leaf rust, stripe rust, and stem rust pose a significant threat to global wheat production. Growing rust resistant cultivars is the most efficient and environment friendly method to reduce yield losses. Genetic analysis is undertaken to identify genes and study their roles in conferring rust resistance in a given wheat background. This chapter summarizes the protocol for genetic analysis of rust resistance at both seedling and adult plant stages. Additionally, it examines statistical analysis and related software to characterize quantitative trait loci (QTL) linked with rust resistance.
Asunto(s)
Basidiomycota/fisiología , Mapeo Cromosómico/métodos , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Sitios de Carácter Cuantitativo , Triticum/genética , Triticum/microbiología , Cromosomas de las Plantas , Resistencia a la Enfermedad , Genes de Plantas , Genómica/métodos , Técnicas de Genotipaje/métodos , Fenotipo , Plantones/genética , Plantones/crecimiento & desarrollo , Plantones/microbiología , Programas Informáticos , Triticum/crecimiento & desarrolloRESUMEN
Growing resistant wheat varieties is a key method of minimizing the extent of yield losses caused by the globally important wheat leaf rust (LR) and stripe rust (YR) diseases. In this study, a population of 186 F8 recombinant inbred lines (RILs) derived from a cross between a synthetic wheat derivative (PI610750) and an adapted common wheat line (cv. "UC1110") were phenotyped for LR and YR response at both seedling and adult plant stages over multiple seasons. Using a genetic linkage map consisting of single sequence repeats and diversity arrays technology markers, in combination with inclusive composite interval mapping analysis, we detected a new LR adult plant resistance (APR) locus, QLr.cim-2DS, contributed by UC1110. One co-located resistance locus to both rusts, QLr.cim-3DC/QYr.cim-3DC, and the known seedling resistance gene Lr26 were also mapped. QLr.cim-2DS and QLr.cim-3DC showed a marginally significant interaction for LR resistance in the adult plant stage. In addition, two previously reported YR APR loci, QYr.ucw-3BS and Yr48, were found to exhibit stable performances in rust environments in both Mexico and the United States and showed a highly significant interaction in the field. Yr48 was also observed to confer intermediate seedling resistance against Mexican YR races, thus suggesting it should be re-classified as an all-stage resistance gene. We also identified 5 and 2 RILs that possessed all detected YR and LR resistance loci, respectively. With the closely linked molecular markers reported here, these RILs could be used as donors for multiple resistance loci to both rusts in wheat breeding programs.