Location: Cereal Disease LabTitle: Genetics of leaf rust resistance in the hard red winter wheat cultivars Santa Fe and Duster Author
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/24/2017
Publication Date: 9/15/2017
Citation: Kolmer, J.A. 2017. Genetics of leaf rust resistance in the hard red winter wheat cultivars Santa Fe and Duster. Crop Science. 57:2500-2505. Interpretive Summary: Leaf rust caused by Puccinia triticina occurs regularly in the Great Plains and can cause significant losses in wheat in years that are favorable for the rust fungus to increase quickly. Genetic resistance in hard red winter wheat cultivars is the most economical method to reduce yield losses due to leaf rust. In this study the genetics of leaf rust resistance in two wheat cultivars that have had good durable resistance to leaf rust was examined. The cultivar Santa Fe was determined to have the resistance genes Lr3a, Lr37 on the 2NS/2AS A. ventricosa-wheat translocation, and an unknown adult plant resistance gene that was highly effective in field plot tests. The cultivar Duster was determined to have Lr3a, Lr11, Lr34, and an unknown adult plant resistance gene that was highly effective in field plots. Santa Fe and Duster are excellent sources of leaf rust resistance for the wheat breeding projects in the Southern Great Plains.
Technical Abstract: Leaf rust caused by Puccinia triticina is a common and important disease of hard red winter wheat in the Great Plains of the United States. The hard red winter wheat cultivars 'Santa Fe' and 'Duster' have had effective leaf rust resistance since their release in 2003 and 2006, respectively. Both cultivars were vernalized and crossed with the susceptible spring wheat 'Thatcher', and F1 plants were backcrossed to Thatcher and 90 backcross (BC) F1 plants from each cross were grown out to develop BC1F2 families. Seedlings of the Thatcher*/Santa Fe F2 families segregated for the same two genes to races BBBDB and SBDGG. Resistance to both races was completely correlated with the presence of the 2AS/2NS translocation from Aegilops ventricosa. In field plots the BC1F2 families segregated for a single gene that was independent of the 2AS/2NS translocation. Seedlings of the Thatcher*2/Duster F2 families segregated for two genes to races BBBDB and SBDGG, and for one gene to race KFBJG. In field plots the BC1F2 families segregated for two genes. Selected BC1F3 lines were tested with different races of P. triticina to postulate identity of the segregating seedling resistance genes. Santa Fe was determined to have Lr3a, the 2NS translocation that has Lr37, and an additional adult plant resistance gene. Duster was determined to have Lr3a and Lr11 for seedling resistance, and Lr34 plus another adult plant resistance gene for field resistance. Santa Fe and Duster are valuable sources of leaf rust resistance for the southern Great Plains region.