Enhanced recovery of Phytophthora ramorum from soil following 30 Days of storage at 4°C

Publication Type:

Journal Article


Journal of Phytopathology, Blackwell Publishing Ltd, p.no–no (2011)




chlamydospore, ramorum blight


Chlamydospores of Phytophthora ramorum were used to infest field soil at densities ranging from 0.2 to 42 chlamydospores/cm3 soil. Recovery was determined by baiting with rhododendron leaf discs and dilution plating at time 0 and after 30 days of storage at 4°C, as recommended by USDA-APHIS. Baiting was slightly more sensitive than dilution plating in recovering P. ramorum immediately following infestation of soil and allowed detection from samples infested with as little as 0.2 chlamydospores/cm3 compared with 1 chlamydospore/cm3 for dilution plating. After 30 days of infested soil storage at 4°C, P. ramorum was detected at significantly (P = 0.05) higher levels than at time 0 with both recovery methods. The results indicate that storage of P. ramorum-infested soil at 4°C may allow for pathogen activity, such as sporangia production, which may enhance recovery from soil.