Leaf rust(LR) and stripe rust(YR) are important diseases in wheat producing areas worldwide and cause severe yield losses under favorable environmental conditions when susceptible varieties are grown. We determined th...Leaf rust(LR) and stripe rust(YR) are important diseases in wheat producing areas worldwide and cause severe yield losses under favorable environmental conditions when susceptible varieties are grown. We determined the genetic basis of resistance to LR and YR in variety Borlaug 100 by developing and phenotyping a population of 198 F6 recombinant inbred lines derived from a cross with the susceptible parent Apav#1. LR and YR phenotyping were conducted for 4 and 3 seasons, respectively, at CIMMYT research stations in Mexico under artificial epidemics. Mendelian segregation analyses indicated that 3–5 LR and 2 YR genes conferred resistance in Borlaug 100. Lr46/Yr29(1 BL), Yr17(2 AS) and Yr30(3 BS) were present in the resistant parent and segregated in the RIL population based on characterization by molecular markers linked to these genes. When present alone, Lr46/Yr29 caused average 13% and 16% reductions in LR and YR severities, respectively, in RILs. Similarly, Yr17 and Yr30 reduced YR severities by 57% and 11%, respectively. The Yr30 and the Yr17 translocation were also associated with 27% and 14% reductions, respectively, in LR severity, indicating that the 3 BS and 2 AS chromosomal regions likely carry new slow rusting LR resistance genes, temporarily designated as Lr B1 and Lr B2, respectively. Additive effects of Yr30*Yr17, Yr29*Yr17 and Yr29*Yr30 on YR and LR were significant and reduced YR severities by 56%,55%, and 45%, respectively, and LR severities by 34%, 40%, and 45%, respectively. Furthermore, interaction between the three genes was also significant, with mean reductions of 70% for YR and 54% for LR severities. Borlaug 100, or any one of the 21 lines with variable agronomic traits but carrying all three colocated resistance loci, can be used as resistance sources in wheat breeding programs.展开更多
Dear Editor,Wheat leaf rust,caused by Puccinia triticina(Pt),is a destructive fungal disease of wheat globally.Host resistance(R)genes are widely studied as a means to combat disease.Lr13 is regarded as one of the mos...Dear Editor,Wheat leaf rust,caused by Puccinia triticina(Pt),is a destructive fungal disease of wheat globally.Host resistance(R)genes are widely studied as a means to combat disease.Lr13 is regarded as one of the most widely distributed leaf rust R genes in wheat(McIntosh et al.,1995).Researchers observed that lines carrying Lr13 consistently gave hybrid necrosis in specific crosses.展开更多
基金supported by the International Cooperation and Exchange of the National Natural Science Foundation of China(31861143010)Huazhong Agricultural University Scientific&Technological Self-innovation Foundation+3 种基金Australian Grains Research and Development Corporation(GRDC)with funding to the Australian Cereal Rust Control Program(ACRCP)CGIAR Research Program WHEAT(CRP-WHEAT)the Open Project of Qinghai Provincial Key Laboratory of Crop Molecular Breeding(2021-ZJ-Y05)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA24030102)。
文摘Leaf rust(LR) and stripe rust(YR) are important diseases in wheat producing areas worldwide and cause severe yield losses under favorable environmental conditions when susceptible varieties are grown. We determined the genetic basis of resistance to LR and YR in variety Borlaug 100 by developing and phenotyping a population of 198 F6 recombinant inbred lines derived from a cross with the susceptible parent Apav#1. LR and YR phenotyping were conducted for 4 and 3 seasons, respectively, at CIMMYT research stations in Mexico under artificial epidemics. Mendelian segregation analyses indicated that 3–5 LR and 2 YR genes conferred resistance in Borlaug 100. Lr46/Yr29(1 BL), Yr17(2 AS) and Yr30(3 BS) were present in the resistant parent and segregated in the RIL population based on characterization by molecular markers linked to these genes. When present alone, Lr46/Yr29 caused average 13% and 16% reductions in LR and YR severities, respectively, in RILs. Similarly, Yr17 and Yr30 reduced YR severities by 57% and 11%, respectively. The Yr30 and the Yr17 translocation were also associated with 27% and 14% reductions, respectively, in LR severity, indicating that the 3 BS and 2 AS chromosomal regions likely carry new slow rusting LR resistance genes, temporarily designated as Lr B1 and Lr B2, respectively. Additive effects of Yr30*Yr17, Yr29*Yr17 and Yr29*Yr30 on YR and LR were significant and reduced YR severities by 56%,55%, and 45%, respectively, and LR severities by 34%, 40%, and 45%, respectively. Furthermore, interaction between the three genes was also significant, with mean reductions of 70% for YR and 54% for LR severities. Borlaug 100, or any one of the 21 lines with variable agronomic traits but carrying all three colocated resistance loci, can be used as resistance sources in wheat breeding programs.
文摘Dear Editor,Wheat leaf rust,caused by Puccinia triticina(Pt),is a destructive fungal disease of wheat globally.Host resistance(R)genes are widely studied as a means to combat disease.Lr13 is regarded as one of the most widely distributed leaf rust R genes in wheat(McIntosh et al.,1995).Researchers observed that lines carrying Lr13 consistently gave hybrid necrosis in specific crosses.
