Phytophthora species in forest streams in Oregon and Alaska

Abstract

Eighteen Phytophthora species and one species of Halophytophthora were identified in 113 forest streams in Alaska, western Oregon, and southwestern Oregon that were sampled by baiting or filtration of stream water with isolation on selective media. Species were identified by morphology and DNA characterization using single strand conformational polymorphism, COX spacer sequence, and ITS sequence. ITS Clade 6 species were most abundant overall, but only four species, P. gonapodyides (37% of all isolates), P. taxon Salixsoil, P. taxon Oaksoil, and P. pseudosyringae, were found in all three regions. The species assemblages were similar in the two Oregon regions, but P. taxon Pgchlamydo was absent in Alaska and one new species present in Alaska was absent in the Oregon streams. The number of Phytophthora propagules in Oregon streams varied by season and in SW Oregon, where sampling continued year round, P. taxon Salixsoil, P. nemorosa and P. siskiyouensis were only recovered in some seasons.

Citation

Reeser, Paul ; Wendy Sutton, Everett M. Hansen, Philippe Remigi and Gerard C. Adams. 2010. Phytophthora species in forest streams in Oregon and Alaska. Mycologia 2010 0: 10-013 .doi: 10.3852/10-013