Location: Cereal Crops ResearchTitle: Genomic analysis and tools for the Septoria nodorum blotch susceptibility gene Snn2 in wheat
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/14/2016
Publication Date: 11/2/2016
Citation: Seneviratne, S., Friesen, T.L., Faris, J.D. 2016. Genomic analysis and tools for the Septoria nodorum blotch susceptibility gene Snn2 in wheat [abstract]. Durable Wheat Resistance Meeting, November 2-3, 2016, Minneapolis, MN.
Technical Abstract: Septoria nodorum blotch of wheat is caused by Parastagonospora nodorum and leads to significant yield losses as well as reductions in grain quality and grain weight. The wheat Snn2 gene confers sensitivity to the necrotrophic effector SnTox2 of P. nodorum. A compatible Snn2-SnTox2 interaction is important in conferring both seedling and adult plant susceptibility. The objective of this study is to develop the tools and resources necessary to clone and characterize the Snn2 gene. A saturated genetic linkage map was developed using a segregating population of 164 F7:8 recombinant inbred lines derived from a cross between the SnTox2-insensitive wheat line BR34 and the SnTox2-sensitive line Grandin. Markers were identified by SNP genotyping using the 90K iSelect wheat SNP chip and previously mapped simple sequence repeat markers. New markers were developed based on whole-genome sequence scaffolds and wheat survey sequences identified using SNP contextual sequences. These efforts allowed us to delineate Snn2 to a genetic interval of 1.5 cM and a physical segment of 1.7 Mb. A high resolution mapping population consisting of at least 3,000 F2 plants will be screened to refine the Snn2 region. In addition, we have developed an ethyl methanesulfonate-induced mutant population to identify Snn2-disrupted mutants for purposes of functional analyses and for conducting RenSeq. Results of this study will increase our knowledge of wheat-P. nodorum interactions, which will help to develop better host resistance through genetic manipulation.