Location: Cereal Crops ResearchTitle: Chromosome engineering for alien gene introgression in wheat: Progress and prospective) Author
|Rouse, Matthew - Matt|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/14/2013
Publication Date: 9/14/2013
Citation: Xu, S.S., Niu, Z., Klindworth, D.L., Zhang, Q.J., Chao, S., Friesen, T.L., Jin, Y., Rouse, M.N., Faris, J.D., Cai, X. 2013. Chromosome engineering for alien gene introgression in wheat: Progress and prospective. Triticeae Cytogenetics: Past, Present and Future, September 15-16, 2013, Kyoto, Japan. p. 24-25. Interpretive Summary:
Technical Abstract: Chromosome engineering is a useful strategy for introgression of desirable genes from wild relatives into cultivated wheat. However, it has been a challenge to transfer a small amount of alien chromatin containing the gene of interest from one genome to another non-homologous genome through classical chromosome engineering. Only a small number of useful alien genes have been isolated from large alien chromosomal segments and successfully used in wheat breeding and production. In an effort to utilize wild species-derived genes for controlling the newly-emerged Ug99 stem rust races, we initiated this research to reduce or eliminate linkage drag associated with four Ug99-resistance genes (Sr37 from Triticum timopheevii, Sr39 and Sr47 from Aegilops speltoides, and Sr43 from Thinopyrum ponticum) and to transfer novel Sr genes from several wheat-alien species (Ae. markgrafii, Th. intermedium, and Th. junceum) disomic addition lines into the wheat genome. To minimize linkage drag, we utilized a new scheme of chromosome engineering to reduce alien chromatin surrounding the Sr genes. In this procedure, we first developed a large homoeologous recombinant population using the ph1b mutant in hexaploid wheat and a Ph1-deficient cytogenetic stock in tetraploid wheat. Homoeologous recombinants carrying the Sr genes on reduced alien chromosomal segments were identified using high-throughput phenotyping and genotyping, robust DNA markers, and genomic in situ hybridization. By using this procedure, we developed wheat germplasm carrying the four Sr genes (Sr37, Sr39, Sr43, and Sr47) on small alien chromosomal segments. To transfer novel Sr genes from the wheat-alien species addition lines, we used 'Chinese Spring' Ph1 inhibitor or monosomics to induce recombination between wheat chromosomes and their homoeologs carrying the Sr genes from alien species. New wheat lines containing four novel Sr genes on translocated alien chromosome segments were developed from the crosses of the wheat-alien species addition lines with the Ph1 inhibitor or monosomics. The new wheat lines developed in this study provide useful resources for the ongoing global breeding efforts to combat Ug99. We are currently applying these procedures to transfer other novel genes for resistance to stem rust, leaf rust, and Hessian fly from wild species into wheat. References (1) Klindworth DL, Niu Z, Chao S, Friesen TL, Jin Y, Faris JD, Cai X, Xu SS. Introgression and characterization of a goatgrass gene for a high level of resistance to Ug99 stem rust in tetraploid wheat, Genes, Genomes, Genetics 2:665-673 (2012). (2) Niu ZX, Klindworth DL, Friesen TL, Chao S, Jin Y, Cai X, Xu SS. Targeted introgression of a wheat stem rust resistance gene by DNA marker-assisted chromosome engineering. Genetics 187:1011–1021 (2011). (3) Xu SS, Jin Y, Klindworth DL, Wang RR-C, and Cai X. Evaluation and characterization of seedling resistance to stem rust Ug99 races in wheat-alien species derivatives. Crop Sci. 49:2167–2175 (2009).