Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 5/18/2006
Publication Date: 7/29/2006
Citation: Barnes, C.W., Szabo, L.J., Johnson, J.L., Nguyen, K.P., Floyd, C.M., Kurle, J.E. 2006. Detection of Phakopsora pachyrhizi dna in rain using qpcr and a portable rain collector [abstract]. Phytopathology. 96:59.
Technical Abstract: Long-distance transport of rust fungus spores in rain has been monitored since the 1960’s using various methods of spore detection. Rust spores have been identified on the basis of morphological characteristics, but the accuracy of this method is problematic. In this study, a nested real-time PCR assay was used to detect Phakopsora pachyrhizi DNA isolated from rust spores collected on filters in an inexpensive, portable rain collector. Assay sensitivity was increased through the use of a DNA extraction kit developed for use with soil samples. The collector directly filtered particulate matter deposited in rain. Samples from the collector contained a significant amount of debris deposited by both wet and dry deposition. Thirty collectors were located adjacent to soybean sentinel plots during the period of early June through mid September 2005. A total of 265 filters were assayed, with 58 (22%) testing positive for P. pachyrhizi DNA. Positive samples were collected from 25 of the 27 Minnesota counties where collectors were located in 2005. Most of the positive samples were found on filters from the southern part of the state. DNA sequence analysis of the amplicon for selected positive samples was used for verification. Preliminary assay results of 2006 samples for P. pachyrhizi DNA as well as additional rust fungi will be presented. Annual Meeting of APS. Quebec City, Quebec Canada, July 29 - August 02, 2006.