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Title: A synopsis of Phytophthora with accurate scientific names, host range, and geographic distribution

item Farr, David
item Rossman, Amy

Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/21/2007
Publication Date: 3/18/2008
Citation: Cline, E., Farr, D.F., Rossman, A.Y. 2008. A synopsis of Phytophthora with accurate scientific names, host range, and geographic distribution. Plant Health Progress.

Interpretive Summary: Fungi and fungal-like organisms cause billions of dollars damage each year to U.S. agriculture and forestry. Most recently, a newly discovered fungal-like organism in the genus Phytophthora was discovered to cause a disease called Sudden Oak Death that has killed numerous forest trees in the western U.S. A related species in this genus was the cause of potato late blight, the organisms that lead to the Irish potato famine in the 1840’s when over one million people immigrated to the U.S. Despite their importance, information about these organisms is often difficult to obtain. This paper provides a summary of reports about all species of Phytophthora including their accurate scientific name, on which plants they have been reported to occur, and all the places in the world where each species is known along with important literature. About half of the known species of Phytophthora are not known to occur in the United States. This paper will allow scientists and policy makers to be more aware of the species of Phytophthora that threaten U.S. agriculture and forestry in order to take steps to prevent the entry of these destructive organisms.

Technical Abstract: The genus Phytophthora includes species such as Phytophthora infestans, causing late blight of potato, and P. ramorum, causing sudden oak death, that have proven capable of inflicting considerable financial and ecological damage. Within Phytophthora there are 78 accepted species and seven infraspecific taxa. Of these, 22 species have been described in the last decade, and an additional 10 species have been proposed but not yet described, underscoring the need for a complete and up-to-date account of Phytophthora. After compiling all available taxonomy and plant pathology literature, we note that 37 species and seven infraspecific taxa or about one-half of the known taxa have not been reported to occur in the United States. Accurate information about the host range and geographic distribution of these species is critical in protecting the United States from the introduction of potentially devastating exotic pathogens.