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Title: Genomic dissection of nonhost resistance to wheat stem rust in Brachypodium distachyon

item COLETTA, RAFAEL DELLA - Universidade De Campinas (UNICAMP)
item HIRSCH, CANDICE - University Of Minnesota
item LORENZ, AARON - University Of Minnesota
item Rouse, Matthew
item Garvin, David

Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/18/2017
Publication Date: 1/16/2018
Citation: Coletta, R., Hirsch, C., Lorenz, A., Rouse, M.N., Garvin, D.F. 2018. Genomic dissection of nonhost resistance to wheat stem rust in Brachypodium distachyon. Plant and Animal Genome Conference Proceedings. January 13-17, 2018. San Diego, CA.

Interpretive Summary:

Technical Abstract: Wheat stem rust caused by the fungus Puccinia graminis f.sp. tritici (Pgt) is a devastating disease that has largely been controlled for decades by the deployment of resistance genes. However, new races of this pathogen have emerged that overcome many important wheat stem rust resistance genes used by breeding programs, and their spread toward major wheat production areas poses a threat to global wheat production. Nonhost resistance in plants, which provides durable and broad-spectrum resistance to non-adapted pathogens, holds great promise for helping to control wheat stem rust, but the genetic and molecular basis of nonhost resistance is poorly understood. This study employed the model plant Brachypodium distachyon (Brachypodium), a nonhost of Pgt, to genetically dissect nonhost resistance to wheat stem rust. Using bulked segregant analysis, next-generation sequencing, cumulative allele frequency differences and statistical analysis, seven quantitative trait loci (QTL) that contribute to stem rust resistance were identified in a recombinant inbred population derived from a cross between two Brachypodium genotypes with differing levels of resistance. The QTL effects vary in their magnitude, and act both additively and in some cases interact, indicating that the resistance is genetically complex. The delineation of regions of the Brachypodium genome that harbor these QTLs will guide future research aiming to identify genes essential to the nonhost resistance response and their mechanisms of action.