Plant Pathology (2011) 60, 1069-1076

A. Pérez-Sierra, L.A. Álvarez, A. Vercauteren, K. Heungens and P. Abad-Campos (2011)
Genetic diversity, sensitivity to phenylamide fungicides and aggressiveness of Phytophthora ramorum on Camellia, Rhododendron and Viburnum plants in Spain
Plant Pathology 60 (6), 1069-1076
Abstract: Phytophthora ramorum has been detected in official plant health surveys on Rhododendron, Viburnum and Camellia in ornamental nurseries in northern Spain since 2003. A collection of 94 isolates of P. ramorum was obtained from 2003 to 2008 from plants with symptoms at different geographical locations. Isolates were identified based on morphology and sequence of the rDNA ITS region. Mating type, genetic variation, sensitivity to phenylamide fungicides and aggressiveness of these isolates were determined. All isolates belonged to the A1 mating type, ruling out the possibility of genetic recombination. Seven microsatellite markers were used to study genetic diversity; three out of the seven microsatellite markers were polymorphic within the Spanish population of P. ramorum. This study confirms that all Spanish isolates of P. ramorum belonged to the EU1 lineage. Twelve intralineage genotypes were detected, five that are unique to Spain (EU1MG38, EU1MG41, EU1MG37, EU1MG39 and EU1MG40) and seven that are also present in at least one other European country (EU1MG1, EU1MG29, EU1MG22, EU1MG13, EU1MG2, EU1MG18 and EU1MG26). Genotypes EU1MG37, EU1MG39 and EU1MG40 were isolated from Rhododendron from one region; EU1MG38 and EU1MG41 were isolated from Camellia from two different regions. Isolates of genotype EU1MG38 were resistant to metalaxyl and mefenoxam. The level of genetic diversity within the Spanish population of P. ramorum is limited and indicates a relatively recent clonal expansion.
(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): Luis Armando Alvarez, Kurt Heungens

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Phytophthora ramorum	Camellia (other species)	Spain (continental)
	Phytophthora ramorum	Rhododendron (crop)	Spain (continental)
	Phytophthora ramorum	Viburnum (crop)	Spain (continental)