Phytopathology (2016) 106, 372-379

R.P. Naegele, L.M. Quesada-Ocampo, J.D. Kurjan, C. Saude and M.K. Hausbeck (2016)
Regional and temporal population structure of Pseudoperonospora cubensis in Michigan and Ontario
Phytopathology 106 (4), 372-379
Abstract: Cucurbit downy mildew (CDM), caused by the oomycete pathogen Pseudoperonospora cubensis, is a devastating disease that affects cucurbit species worldwide. This obligate, wind-dispersed pathogen does not overwinter in Michigan or other northern regions and new isolates can enter the state throughout the growing season. To evaluate the regional and temporal population structure of P. cubensis, sporangia from CDM lesions were collected from cucurbit foliage grown in Michigan and Ontario field locations in 2011. Population structure and genetic diversity were assessed in 257 isolates using nine simple sequence repeat markers. Genetic diversity was high for isolates from Michigan and Canada (0.6627 and 0.6131, respectively). Five genetic clusters were detected and changes in population structure varied by site and sampling date within a growing season. The Michigan and Canada populations were significantly differentiated, and a unique genetic cluster was detected in Michigan.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Mary K. Hausbeck

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Pseudoperonospora cubensis		Canada (east)
	Pseudoperonospora cubensis		U.S.A. (NE)