01714nas a2200253 4500008004100000022001300041245008800054210006900142300001400211490000700225520092000232653001701152653002701169653001301196653002201209653001101231653003001242653001001272653001901282100001601301700001601317700001601333856011101349 2007 eng d a1437478100aPhytophthora cambivora in Oregon and its pathogenicity to Chrysolepis chrysophylla.0 aPhytophthora cambivora in Oregon and its pathogenicity to Chryso a409 - 4190 v373 a

A new canker disease causing mortality of golden chinquapin trees [Chrysolepis chrysophylla (Dougl.) Hjelmqvist], in Oregon was recently observed. Most of the symptomatic or dead trees were located near roads. The cankers on the lower boles of trees are similar to those caused by species of Phytophthora on other trees in western North America. The cankers in the inner bark were reddish-orange in colour and extended upward from necrotic roots. Phytophthora (Petri) Buisman was isolated from the cankers; identity was confirmed by morphological comparison with known isolates and internal transcribed spacer sequence analysis. Pathogenicity was confirmed by inoculation of chinquapin seedlings and mature trees. Seven of nine isolates from chinquapin were A2 mating type; 27 of 28 isolates from other hosts in Oregon and Washington were A1 mating type.

10aBiodiversity10aCanker (Plant disease)10adiseases10aForests. forestry10aOregon10aPathogenic microorganisms10apests10aPLANT diseases1 aSaavedra, A1 aHansen, E M1 aGoheen, D J uhttp://onlinelibrary.wiley.com.proxy.library.oregonstate.edu/doi/10.1111/j.1439-0329.2007.00515.x/abstract