Molecular Plant-Microbe Interactions (2018) 31, 614-622

Javier F. Tabima, Michael D. Coffey, Inga A. Zazada and Niklaus J. Grünwald (2018)
Populations of Phytophthora rubi show little differentiation and high rates of migration among states in the western United States
Molecular Plant-Microbe Interactions 31 (6), 614-622
Abstract: Population genetics is a powerful tool to understand patterns and evolutionary processes that are involved in plant-pathogen emergence and adaptation to agricultural ecosystems. We are interested in studying the population dynamics of Phytophthora rubi, the causal agent of Phytophthora root rot in raspberry. P. rubi is found in the western United States, where most of the fresh and processed raspberries are produced. We used genotyping-by-sequencing to characterize genetic diversity in populations of P. rubi sampled in the United States and other countries. Our results confirm that P. rubi is a monophyletic species with complete lineage sorting from its sister taxon P. fragariae. Overall, populations of P. rubi show low genetic diversity across the western United States. Demographic analyses suggest that populations of P. rubi from the western United States are the source of pathogen migration to Europe. We found no evidence for population differentiation at a global or regional (western United States) level. Finally, our results provide evidence of migration from California and Oregon into Washington. This report provides new insights into the evolution and structure of global and western United States populations of the raspberry pathogen P. rubi, indicating that human activity might be involved in moving the pathogen among regions and fields.
(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): Niklaus J. Grünwald, Michael D. Coffey

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Phytophthora rubi	Raspberry/blackberry (Rubus)	U.S.A. (SW)
	Phytophthora rubi	Raspberry/blackberry (Rubus)	U.S.A. (NW)