Submitted to: International Congress of Plant Pathology Abstracts and Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/4/2007
Publication Date: 8/15/2008
Citation: Tooley, P.W., Carras, M.M., Sechler, A.J. 2008. Real-time PCR detection of sorghum ergot pathogens Claviceps africana, C. sorghi, and C. sorghicola. International Congress of Plant Pathology Abstracts and Proceedings. Journal of Plant Pathology. Vol. 90 (2, Supplement). 52.312.2008
Technical Abstract: Sorghum ergot is a serious disease that has caused major losses in sorghum growing regions worldwide. C. africana is now the most widely distributed species causing ergot in many countries including the U.S., whereas both C. africana and C. sorghi exist in India. A third species (C. sorghicola) has been described causing sorghum ergot in Japan. As the three species are morphologically very similar, a DNA-based assay is desirable for rapid identification in cases where ergot-infected sorghum is found entering the U.S. and other countries. We designed primers and probes specific for the above three Claviceps species and tested them using purified DNA and ergot samples from the greenhouse and field. Real-time PCR was performed using an ABI Prism 7700 Sequence Detection System in a total volume of 25 microliters. Species-specific primers and probes were developed from the intron 3 region of the B tubulin gene. No amplification was obtained in any of the three ergot species-specific assays when DNA from six other Claviceps species was used as template. The lower limit of detection was 1 pg genomic template DNA in all three assays. A future goal is the development of a multiplex assay using the primers and probes described here. The assays we describe will provide useful tools for detecting sorghum ergot in seed and grain shipments and for determining which species are present in the samples, thereby aiding in the regulatory decision-making process.