Location: Cereal Disease Laboratory
Title: Development of a molecular assay system for the rapid detection and identification of Ug99 and related races of Puccinia graminis Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 1, 2012
Publication Date: August 28, 2012
Citation: Szabo, L.J., Crouch, J. 2012. Development of a molecular assay system for the rapid detection and identification of Ug99 and related races of Puccinia graminis. Meeting Abstract. p. 238. Technical Abstract: In the last decade the complexity and distribution of the Ug99 race group of Puccinia graminis f. sp. tritici has dramatically expanded. In order to provide rapid tools, a two-stage molecular assay system has been developed using real-time polymerase chain reaction methodologies and TaqMan probes. Stage-1 uses a suite of four assays to identify samples belonging to the Ug99 race group. An internal control, based on the actin gene, is included to control for false negatives. Only samples from the Ug99 race group are positive for all four of the assays. The stage-2 assay uses a suite of ten allele-specific SNP markers to predict the specific race phenotype of the sample within the Ug99 race group. A worldwide collection of over 400 samples has been used to validate this assay system. The assay performed reliably with a range of samples including pure fungal tissue, infected plant tissue and ethanol-killed infected wheat stem tissue. This assay system provides a rapid and accurate method for diagnosis of Ug99 race group and provides new tools for monitoring the movement Ug99 and related races of the wheat stem rust fungus.