Skip to Main Content
Due to a lapse in federal funding, this USDA website will not be actively updated. Once funding has been reestablished, online operations will continue.
Clonal expansion of the Belgian Phytophthora ramorum populations based on new microsatellite markersAuthor(s): A. Vercauteren; I. De Dobbelaere; N. J. Grünwald; P. Bonants; E. Van Bockstaele; M. Maes; K. Heungens
Source: Molecular Ecology 19(1): 92-107
Publication Series: Scientific Journal (JRNL)
Station: Pacific Southwest Research Station
View PDF (267.86 KB)
DescriptionCo-existence of both mating types A1 and A2 within the EU1 lineage of Phytophthora ramorum has only been observed in Belgium, which begs the question whether sexual reproduction is occurring. A collection of 411 Belgian P. ramorum isolates was established during a 7-year survey. Our main objectives were genetic characterization of this population to test for sexual reproduction, determination of population structure, evolution and spread, and evaluation of the effectiveness and impact of control measures. Novel, polymorphic simple sequence repeat (SSR) markers were developed after screening 149 candidate loci. Eighty isolates of P. ramorum, broadly representing the Belgian population, were analyzed using four previously described and three newly identified polymorphic microsatellite loci as well as amplified fragment length polymorphisms. SSR analysis was most informative and was used to screen the entire Belgian population. Thirty multilocus genotypes were identified, but 68% of the isolates belonged to the main genotype EU1MG1. Although accumulated mutation events were detected, the overall level of genetic diversity within the Belgian isolates of P. ramorum appears to be limited, indicating a relatively recent clonal expansion. Based on our SSR analysis there is no evidence of sexual recombination in the Belgian population of P. ramorum. Metalaxyl use decreased the genetic diversity of P. ramorum until 2005, when the majority of the isolates had become resistant. Most genotypes were site-specific and despite systematic removal of symptomatic and neighbouring plants, some genotypes were detected over a period of several years at a single site, sometimes discontinuously, indicating (latent) survival of the pathogen at those sites.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationVercauteren, A.; De Dobbelaere, I.; Grünwald, N. J.; Bonants, P.; Van Bockstaele, E.; Maes, M.; and Heungens, K. 2010. Clonal expansion of the Belgian Phytophthora ramorum populations based on new microsatellite markers. Mol. Ecology 19(1) 92-107. DOI 10.1111/j.1365-294X.2009.04444.x
Keywordsmetalaxyl resistance, nurseries, oomycetes, population genetics, Sudden Oak Death, universal labelling
- Genetic diversity of Phytophthora ramorum in Belgium
- Identification of new polymorphic microsatellite markers in the NA1 and NA2 lineages of Phytophthora ramorum
- Use of microsatellite markers derived from whole genome sequence data for identifying polymorphism in Phytophthora ramorum
XML: View XML