ARS | Publication request: Quantitative TaqMan real-time PCR assay for Stenocarpella maydis, the causal agent of Diplodia ear and stalk rot of maize

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 4, 2007
Publication Date: August 1, 2007
Citation: Fessehaie, A., Block, C.C., Shepherd, L.M., Misra, M.K. 2007. Quantitative TaqMan real-time PCR assay for Stenocarpella maydis, the causal agent of Diplodia ear and stalk rot of maize [abstract]. American Phytopathological Society Annual Meeting. 97:S35.

Technical Abstract: Stenocarpella maydis (syn. Diplodia maydis), the causal organism of Diplodia ear rot and stalk rot of maize, is increasing in incidence across the Midwestern U.S., likely associated with changes in farming practices where conservation tillage and continuous corn are becoming more common. Rapid detection techniques such as PCR would assist in phytosanitary testing of seed lots for S. maydis infection. To develop a TaqMan real-time PCR assay, primers and DNA probe were designed from the internal transcribed spacers (ITS) within the nuclear rRNA genes. An optimal PCR reaction was achieved with 300nM of each primer and 200nM probe. Specificity and sensitivity of the TaqMan assay was tested using purified DNA from 30 strains of S. maydis obtained from across the Midwest. The detection limit of the assay for purified S. maydis DNA was 2fg. This TaqMan real-time PCR assay is highly specific and sensitive and provides a simple, rapid alternative to other methods for identification and quantitative detection of S. maydis isolated from maize seed.