Rapid Detection of Phytophthora cinnamomi using PCR with Primers derived from the Lpv putative storage protein genes

摘要

Phytophthora cinnamomi is an ecologically and economically important pathogen.In this study,PCR assays wee developed with primer pair LPV2 or LPV3 for arapid detection and identification of this organism.Both primer pairs were selected from putative storage protein genes.The specificity of these primer pairs was evaluated against 49 isolates of P.cinnamomi,102 isolates from 30 other Phytophthora spp.,17 isolates from nine Pythium spp.and 43 isolates of other water moulds bacteria and true fungi.PCR with both primer pairs amplified the DNAS from all isolates of P.cinnamomi regardless of origin.The LPV3 primers showed adequate specificity among all other species tested.The LPV2 primers cross-reacted with some species of Pythium and true fungi,but not with any other Phytophthora species.PCR with the LPV3 primers detected the pathogen at levels of a single chlamydospore or 10 zoospores in repeated tests.The PCR assay was at least 10 times more sensitive than the plaating method for detection of the pathogen for artificially infested soilless medium,and,ato a lesser extent,from naturaly infected plants.PCR with LPV3 primers can be a useful tool for detecting P.cinnamomi from soillesss media and planat tissues at ornamental nurseries,whereas the LPV2 primers can be an effective alternative for identification of this apecies from pure culture.Applications of these assays for detection of P.cinnamomi in other environments were also discussed.