Phytophthora ramorum is a phytopathogen that has large impacts on the Californian native ecosystem and has been isolated from 6 European countries in mainly nursery settings or non-native vegetation. The pathogen has the potential to be a worldwide problem.
Symptomatic leaf material from a wide range of plants growing on the university campus and the botanical garden were sampled for PCR analysis. The garden contains over 13,238 plant taxas from around the world, many of which are rare or endangered. It provides an opportunity to investigate the extent of plants that are susceptible to the pathogen.
Twenty-four plants were PCR positive for P. ramorum and included shrubs and trees from America (South and North), Asia, Australia, and Europe. Of the 13 different plant families identified as potential hosts, 10 plants were Ericaceous. Eight different Rhododendron spp. were positive for P. ramorum. Koch's Postulates will be fulfilled for all plants identified by PCR analysis as potential hosts.
