|Grunwald, Niklaus - Nik|
Submitted to: Mycological Society of America
Publication Type: Abstract only
Publication Acceptance Date: 4/6/2006
Publication Date: 8/1/2006
Citation: Grunwald, N.J., Prospero, S., Hansen, E., Tyler, B., Lamour, K. 2006. Population divergence in Phytophthora ramorum. Mycological Society of America Abstracts. p.197. Interpretive Summary:
Technical Abstract: Phytophthora ramorum, causal agent of Sudden Oak Death on oaks and Ramorum blight on ornamentals such as rhododendron, is an emerging pathogen with significant impact on both natural oak forest ecosystems and the nursery industry. The pathogen was simultaneously discovered in Germany and California. Recent studies based on AFLP established that the US population was clonal. We screened the genome of P. ramorum for simple sequence repeat and single nucleotide polymorphisms loci. While trinucloeotide loci only distinguished between the EU and U.S. clones, tetranucleotide repeats were found to be highly informative for locally evolving populations. We also developed an Affymetrix microarray with 880 SNPs. These assays were applied to the U.S. and EU populations as well as recently discovered novel clones. SNP and SSR discovery is ongoing. All these markers indicate that both the European and North American populations are reproductively isolated and have gone through a bottleneck. There currently is no evidence for sexual recombination. Novel genotypes detected in the U.S. likely originated through migration.