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

Publication Type:

Journal Article

Authors:

Tooley, Paul W.; Carras, Marie M.

Source:

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

URL:

http://dx.doi.org/10.1111/j.1439-0434.2011.01810.x

Keywords:

chlamydospore, ramorum blight

Abstract:

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.