Development and characterization of wheat-Ae. searsii Robertsonian translocations and a recombinant chromosome conferring resistance to stem rust
The emergence of a new highly virulent race of stem rust (Puccinia graminis tritici), Ug99, rapid evolution of new Ug99 derivative races overcoming resistance of widely deployed genes, and spread towards important wheat growing areas now potentially threaten world food security. Exploiting novel genes effective against Ug99 from wild relatives of wheat is one of the most promising strategies for the protection of the wheat crop. A new source of resistance to Ug99 was identified in the short arm of the Aegilops searsii chromosome 3Ss by screening wheat- Ae. searsii introgression libraries available as individual chromosome and chromosome arm additions to the wheat genome. For transferring this resistance gene into common wheat, we produced three double-monosomic chromosome populations (3A/3Ss, 3B/3Ss and 3D/3Ss) and then applied integrated stem rust screening, molecular maker analysis, and cytogenetic analysis to identify resistant wheat-Ae. searsii Robertsonian translocation. Three Robertsonian translocations (T3AL·3SsS, T3BL·3SsS and T3DL·3SsS) and one recombinant (T3DS-3SsS·3SsL) with stem rust resistance were identified and confirmed to be genetically compensating on the basis of genomic in situ hybridization, analysis of 3A, 3B, 3D and 3SsS-specific SSR/STS-PCR markers, and C-banding. In addition, nine SSR/STS-PCR markers of 3SsS-specific were developed for marker-assisted selection of the resistant gene. Efforts to reduce potential linkage drag associated with 3SsS of Ae. searsii are currently under way.
KeywordsStem Rust Infection Type Substitution Line Translocation Line Robertsonian Translocation
This research was part of the project “Durable Rust Resistance in Wheat” supported by Bill and Melinda Gates Foundation and a special USDA-CSREES grant to the Wheat Genetic and Genomic Resources Center at Kansas State University. We thank W. John Raupp for critical editorial review of the manuscript and Shuangye Wu for her technical assistance. This is contribution number 11-148-J from the Kansas Agricultural Experiment Station, Kansas State University, Manhattan, KS 66506-5502, USA.
- Feldman M, Strauss I, Vardi A (1979) Chromosome pairing and fertility of F1 hybrids of Aegilops longissima and Ae. searsii. Can J Genet Cytol 21:261–272Google Scholar
- Jin Y, Szabo LJ, Pretorius ZA (2008a) Virulence variation within the Ug99 lineage. In: Appels R, Eastwood R, Lagudah E, Langridge P, Mackay M, McIntye L, Sharp P (eds) Proceedings of 11th International Wheat Genet Symposium Sydney University Press, Sydney, Australia, pp 4–6Google Scholar
- Jin Y, Rouse M, Olivera PD, Steffenson BJ. (2009b) Progress and prospects in discovery and use of novel sources of stem rust resistance. In: Borlaug Global Rust Initiative 2009 Technical Workshop, Obregón, Sonora, Mexico, p 28Google Scholar
- McIntosh RA, Amazaki YY, Dubcovsky J, Rogers J, Morris C, Somers DJ, Appels R, Devos KM (2008) Catalogue of gene symbols for wheat, http://www.shigen.nig.ac.jp/wheat/komugi/genes/download.jsp
- Singh RP, Hodson DP, Jin Y, Huerta-Espino J, Kinyua M, Wanyera R, Njau P, Ward RW (2006) Current status, likely migration and strategies to mitigate the threat to wheat production from race UG99 (TTKS) of stem rust pathogen. CAB Reviews: Perspec Agric Vet Sci Nat Res 54:1–13Google Scholar
- Singh RP, Huerta-Espino JH, Jin Y, Herrera-Foessel S, Njau P, Wanyera R, Ward RW (2008b) Current resistance sources and breeding strategies to mitigate Ug99 threat. In: Appels R, Eastwood R, Lagudah E, Langridge P, Mackay M, McIntye L, Sharp P (eds) Proceedings of 11th International Wheat Genet Symposium Sydney University Press, Sydney, Australia, pp 7–9Google Scholar
- Singh D, Girma B, Njau P, Wanyera R, Badebo A, Bhavani S, Singh RP, Huerta-Espino J, Woldeab G and Ward R (2009) Screening for stem rust resistance in East Africa. In: Borlaug Global Rust Initiative: 2009 Technical Workshop Obregón, Sonora, Mexico, pp 33–38Google Scholar
- Sourdille P, Singh S, Cadalen T, Brown-Guedira GL, Gay G, Qi L, Gill BS, Dufour P, Murigneux A, Bernard M (2004) Microsatellite based deletion bin system for the establishment of genetic-physical map relationships in wheat (Triticum aestivum L.). Funct Integr Genomics 4:12–25PubMedCrossRefGoogle Scholar
- Xu SS, Dundas IS, Pumphrey MO, Jin Y, Faris JD, Cai X, Qi LL, Friebe BR, Gill BS (2008) Chromosome engineering to enhance utility of alien-derived stem rust resistance. In: Appels R, Eastwood R, Lagudah E, Langridge P, Mackay M, McIntye L, Sharp P (eds) Proceedings of 11th International Wheat Genet Symposium Sydney University Press, Sydney, Australia, pp 12–14Google Scholar