ARS | Publication request: STAGONOSPORA NODORUM BLOTCH AND SEPTORIA TRITICI BLOTCH

Submitted to: Eastern Wheat Workers and Southern Small Grain Workers Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: February 7, 2005
Publication Date: May 9, 2005
Citation: Ohm, Herbert, Goodwin, S.B., Uphaus, J., Breeden, J.D. 2005. Stagonospora nodorum blotch and septoria tritici blotch. [ABSTRACT] Eastern Wheat Workers and Southern Small Grain Workers Conference, Bowling Green, KY, p. 51.

Technical Abstract: We are continuing to identify new sources and genes for resistance, characterize inheritance of resistance, map and identify associated markers, and develop improved germplasm and cultivars that are resistant to Stagonospora nodorum blotch (SNB) and Septoria tritici blotch (STB). Cultivar INW0101, which likely has SNB resistance from two or more of its parent lines Cotipora, Montana 36 and Glory, was developed and released in 2001 by Purdue University. The Purdue line P91193, which derives SNB resistance from Coker 8427, was crossed with INW0101 and a recombinant-inbred (RI) population was developed and phenotyped for resistance to SNB. We identified a SNB resistance quantitative trait locus (QTL) from the parent line P91193 on chromosome 2D near the marker locus Xgwm526. This resistance QTL is different from that of cultivar Arina, which has QSng.sfr-3BS on chromosome 3B. We are developing two RI populations from crosses of SNB-resistant Coker 9663 crossed to two SNB-susceptible wheat lines. The populations will be phenotyped and marker-genotyped to identify SNB resistance QTL. The widely deployed and durable resistance gene Stb 1 was mapped to chromosome 5BL, 2.8 cM distal to SSR Xbarc74. We are pyramiding the resistance genes Stb 1, Stb 2, Stb 4 and Stb 8 by marker-assisted selection into advanced soft winter wheat lines for release as improved germplasm and cultivars. Our objective is to develop a germplasm line with the four genes/QTL in coupling. We have identified by DNA marker genotyping and phenotyping, several lines in which Sr 2 and Qfhs-ndsu-3BS are likely in coupling, and several lines in which QSng.sfr-3BS and Stb 2 are likely in coupling. We are verifying the linkages and plan to combine the two linkage groups into one containing all four resistance traits.