Molecular Characterization of Two <i>Triticum speltoides</i> Interstitial Translocations Carrying Leaf Rust and Greenbug Resistance Genes

Dubcovsky, Jorge; Lukaszewski, Adam J.; Echaide, Mercedes; Antonelli, E. F.; Porter, D. R.

doi:10.2135/cropsci1998.0011183x003800060040x

“…Bread wheat line T7AS-7S#1S-7AS·7AL carrying the T. speltoides 7 S interstitial translocation in the short arm of chromosome 7 A (Dubcovsky et al 1998) was the source of DNA for the T. speltoides sequences and the source of Lr47 for the marker-assisted selection program. T. speltoides accessions DV562 and DV563 were kindly provided by Dr. J. Dvorak (University of California Davis, Calif., USA).…”

Section: Plant Materialsmentioning

confidence: 99%

“…The utilization of these genes has minimized the application of fungicides, contributing to reduce both environmental contamination and production costs. Therefore, it is not surprising that rust resistance genes were frequent targets in restriction fragment length polymorphism (RFLP) mapping studies in wheat (Schachermayr et al 1994(Schachermayr et al , 1995Autrique et al 1995;Dedryver et al 1996;Nelson et al 1997;Sun et al 1997;Dubcovsky et al 1998).…”

Section: Introductionmentioning

confidence: 99%

“…Any of the RFLP markers located within the 7S#1 chromosome segment can be used to monitor the introgression of Lr47 because homoeologous chromosomes do not recombine in polyploid wheat in the presence of the wild-type Ph1 locus (Riley and Chapman 1958). This is a valuable breeding objective because this gene confers resistance to a wide spectrum of leaf rust strains (Dubcovsky et al 1998).…”

Section: Introductionmentioning

confidence: 99%

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Development of PCR markers for the wheat leaf rust resistance gene Lr47

Helguera¹,

Khan²,

Dubcovsky³

2000

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The leaf rust resistance gene Lr47 confers resistance to a wide spectrum of leaf rust strains. This gene was recently transferred from chromosome 7 S of Triticum speltoides to chromosome 7 A of hexaploid wheat Triticum aestivum. To facilitate the transfer of Lr47 to commercial varieties, the completely linked restriction fragment length polymorphism (RFLP) locus Xabc465 was converted into a PCR-based marker. Barley clone ABC465 is orthologous to the type-I wheat sucrose synthase gene and primers were designed for the conserved regions between the two sequences. These conserved primers were used to amplify, clone and sequence different alleles from T. speltoides and T. aestivum. This sequence information was then used to identify the T. speltoides sequence, detect allele-specific mutations, and design specific primers. Cosegregation of the PCR product of these primers and the T. speltoides chromosome segment was confirmed in four backcross-populations. To complement this dominant marker, a cleavage amplified polymorphic sequence (CAPS) was developed for the 7 A allele of Xabc465. This CAPS marker is useful to select homozygous Lr47 plants from F 2 or backcross-F 2 segregating populations, and in combination with the T. speltoides-specific primers is expected to facilitate the deployment of Lr47 in new bread wheat varieties.

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“…Important wheat leaf rust resistance genes have been located on specific wheat chromosomes since Sears introduced this mapping method approximately 70 years ago (Sears, 1939). These genes include Lr18 on chromosome 1A (Bai et al, 1998); Lr45 on chromosome 2A (McIntosh et al, 1995); genes resistant to P. triticina, P. graminis, P. striiformis, and Erysiphe graminis on chromosome 2A (Bariana and McIntosh, 1993); 2 inserted chromosomal segments carrying resistance genes to leaf rust and greenbug initially located on chromosome 7S of Triticum speltoides and then transferred to chromosome 7A of hexaploid wheat (Dubcovsky et al, 1998), and Lr39 introgressed from Aegilops tauschii on chromosome 2D (Raupp et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Monosomic and molecular mapping of adult plant leaf rust resistance genes in the Brazilian wheat cultivar Toropi

Silva¹,

Brammer²,

Guerra³

et al. 2012

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ABSTRACT. Leaf rust is one of the most destructive diseases affecting wheat worldwide. The most effective way to control it is to use resistant cultivars. Resistance based on slow-rusting adult plant resistance (APR) genes has proven to be the best method for developing cultivars with durable resistance. A source of slow-rusting APR for leaf rust is the Brazilian wheat cultivar Toropi. The Toropi/IAC 13 F 2 and F 7 recombinant inbred lines (RILs) were developed in previous studies. Phenotypic analysis of the F 2 and F 7 RILs showed that 2 recessive genes that were temporarily named trp-1 and trp-2 conferred APR in Toropi. In the present study, we used monosomic families and amplified fragment length polymorphism (AFLP), sequence-tagged site, and simple sequence repeat (SSR) markers to map trp-1 and trp-2 on wheat chromosomes. Analysis of the F 2 monosomic RIL showed that trp-1 and trp-2 were located on chromosomes 1A and 4D, respectively. AFLP analysis of the F 7 RIL identified 2 independent AFLP markers, XPacgMcac3 and XPacgMcac6, which were associated with Toropi APR. These markers explained 71.5% of the variation in the phenotypic data in a multiple linear regression model. The AFLP markers XPacg/ Mcac3 and XPacg/Mcac6 were anchored by SSR markers previously mapped on the short arms of chromosomes 1A (1AS) and 4D (4DS), respectively. The trp-2 gene is the first leaf rust resistance gene mapped on wheat chromosome 4DS. The mapping of trp-1 and trp-2 provides novel and valuable information that could be used in future studies involving the fine mapping of these genes, as well as in the identification of molecular markers that are closely related to these genes for markerassisted selection of this important trait in wheat.

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“…This gene is located within an interstitial segment of Triticum speltoides (Taush) Gren. chromosome 7S#1 (Friebe et al 1996) transferred to the short arm of chromosome 7 A of bread wheat translocation line T7AS-7S#1S-7AS·7AL (Dubcovsky et al 1998). From telomere to centromere, the short arm of chromosome 7 A from this translocation line has a 40-cM segment of 7AS, a 20-30-cM interstitial segment of the short arm of chromosome 7S#1, and a 2-10-cM segment of chromosome 7AS.…”

Section: Introductionmentioning

confidence: 99%

Development of PCR markers for wheat leaf rust resistance gene Lr47

Helguera¹,

Khan²,

Dubcovsky³

2000

Self Cite

View full text Add to dashboard Cite

The leaf rust resistance gene Lr47 confers resistance to a wide spectrum of leaf rust strains. This gene was recently transferred from chromosome 7 S of Triticum speltoides to chromosome 7 A of hexaploid wheat Triticum aestivum. To facilitate the transfer of Lr47 to commercial varieties, the completely linked restriction fragment length polymorphism (RFLP) locus Xabc465 was converted into a PCR-based marker. Barley clone ABC465 is orthologous to the type-I wheat sucrose synthase gene and primers were designed for the conserved regions between the two sequences. These conserved primers were used to amplify, clone and sequence different alleles from T. speltoides and T. aestivum. This sequence information was then used to identify the T. speltoides sequence, detect allele-specific mutations, and design specific primers. Cosegregation of the PCR product of these primers and the T. speltoides chromosome segment was confirmed in four backcross-populations. To complement this dominant marker, a cleavage amplified polymorphic sequence (CAPS) was developed for the 7 A allele of Xabc465. This CAPS marker is useful to select homozygous Lr47 plants from F 2 or backcross-F 2 segregating populations, and in combination with the T. speltoides-specific primers is expected to facilitate the deployment of Lr47 in new bread wheat varieties.

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Molecular Characterization of Two Triticum speltoides Interstitial Translocations Carrying Leaf Rust and Greenbug Resistance Genes

Cited by 97 publications

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Development of PCR markers for the wheat leaf rust resistance gene Lr47

Development of PCR markers for the wheat leaf rust resistance gene Lr47

Monosomic and molecular mapping of adult plant leaf rust resistance genes in the Brazilian wheat cultivar Toropi

Development of PCR markers for wheat leaf rust resistance gene Lr47

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