Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2003
Publication Date: 1/14/2004
Citation: Adhikari, T., Cavaletto, J.R., Hu, X., Shaner, G., Goodwin, S.B. 2004. Molecular mapping of the septoria tritici blotch resistance gene stb1 in wheat (abstract). Plant and Animal Genome XII. Abstract No. P454.
Technical Abstract: Septoria tritici blotch (STB), caused by the ascomycete Mycosphaerella graminicola (anamorph Septoria tritici), was the most destructive disease of wheat in Indiana and adjacent states before the deployment of the resistance gene Stb1 during the early 1970s. Since then, Stb1 has provided durable protection against STB losses in widely grown wheat cultivars. However, its chromosomal location is not known, so the molecular mapping of Stb1 is of great interest. Genetic studies were performed by analysis of 106 F6 recombinant-inbred lines (RILs) derived from the cross between the resistant line 72626E2-12-9-1 and the susceptible cultivar Arthur. Bulked segregant analysis (BSA) using amplified fragment length polymorphism (AFLP) and microsatellite or simple-sequence repeat (SSR) markers was conducted to identify the molecular markers putatively linked to the Stb1 gene. Segregation analysis confirmed that Stb1 is a single dominant gene that controls the resistance to M. graminicola. The most closely linked marker was SSR Xbarc74 at a distance of 2.8 cM proximal to Stb1. Microsatellite loci Xgwm 335 and Xgwm 213 also were proximal to Stb1 at distances of 7.4 and 8.3 cM, respectively. The flanking AFLP marker, EcoRI-AGC/MseI-CTA-1, was 8.4 cM distal to Stb1. Linkage analysis positioned the Stb1 locus on the long arm of wheat chromosome 5B. The molecular markers closely linked to Stb1 could be useful for maker-assisted selection and for pyramiding of Stb1 with other genes for resistance to M. graminicola in wheat.