04183nas a2200181 4500008004100000022001400041245010600055210006900161260001700230300001400247490000800261520361500269100001703884700001403901700001503915700001903930856005203949 2015 eng d a0027-551400aThe Phytophthora species assemblage and diversity in riparian alder ecosystems of western Oregon, USA0 aPhytophthora species assemblage and diversity in riparian alder  cOctober 2015 a889 - 9020 v1073 a

Phytophthora species were systematically sampled, isolated, identified and compared for presence in streams, soil and roots of alder (Alnus species) dominated riparian ecosystems in western Oregon. We describe the species assemblage and evaluate Phytophthora diversity associated with alder. We recovered 1250 isolates of 20 Phytophthora species. Only three species were recovered from all substrates (streams, soil, alder roots): P. gonapodyides, the informally described “P. taxon Pgchlamydo”, and P. siskiyouensis. P. alni ssp. uniformis along with five other species not previously recovered in Oregon forests are included in the assemblage: P.citricola s.l., P. gregata, P. gallica, P. nicotianae and P. parsiana. Phytophthora species diversity was greatest in down- stream riparian locations. There was no significant difference in species diversity comparing soil and unwashed roots (the rhizosphere) to stream water. There was a difference between the predominating species from the rhizosphere compared to stream water. The most numerous species was the informally described “P. taxon Oaksoil”, which was mainly recovered from, and most predominant in, stream water. The most common species from riparian forest soils and alder root systems was P. gonapodyides.

1 aSims, L., L.1 aSutton, W1 aReeser, P.1 aHansen, E., M. uhttp://www.mycologia.org/cgi/doi/10.3852/14-255