Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 6/10/2005
Publication Date: 8/1/2006
Citation: Liu, Z.H., Friesen, T.L., Ling, H., Meinhardt, S.W., Rasmussen, J.B., Faris, J.D. 2006. Genomic mapping of toxin sensitivity and quantitative trait loci for seedling resistance to stagonospora nodorum in wheat. Phytopathology. 95:S62
Technical Abstract: Stagonospora nodorum blotch (SNB) is an economically important foliar and glume disease of wheat worldwide. We previously identified a host-selective toxin (SnTox1) produced by the isolate Sn2000 of S. nodorum and mapped the gene (Snn1) conditioning sensitivity to chromosome 1BS in the International Triticeae Mapping Initiative (ITMI) population. Here, we evaluated SnTox1 sensitivity and resistance to SNB caused by Sn2000 in a population of recombinant inbred lines derived from a cross between Grandin (toxin sensitive and disease susceptible) and BR34 (insensitive and resistant). In this population, sensitivity to partially purified SnTox1 mapped to chromosome 5BL. The 5BL locus underlied a major quantitative trait locus (QTL) for resistance to SNB and explained 62% of the phenotypic variation indicating that SnTox1 plays an important role in causing disease. In addition, minor QTL on chromosomes 1BS, 5AL, 5BL, and 6AS, and an interaction were detected. A multiple regression model explained 77% of phenotypic variation.