Oomycetes in the genus Phytophthora are among the most damaging plant pathogens worldwide. Two important species are Phytophthora cinnamomi, which causes root rot in thousands of native and agricultural plants, and Phytophthora agathidicida, which causes kauri dieback disease in New Zealand. As is the case for other Phytophthora species, management options for these two pathogens are limited. H...

The recent incidence of Ramorum blight, caused by Phytophthora ramorum, on many nursery crops has focused attention on improving management strategies against Phytophthora diseases in nurseries. We evaluated several chemical agents that target Oomycete pathogens for their capacity to inhibit infection of rhododendron or lilac leaves by P. ramorum (both NA strain 2027 mating type A2 and European...

Phytophthora infestans is a devastating phytopathogenic oomycete that causes late blight on tomato and potato. Recent genome sequencing efforts of P. infestans and other Phytophthora species are generating vast amounts of sequence data providing opportunities to unlock the complex nature of pathogenesis. However, accurate annotation of Phytophthora genomes will be a significant challenge. Most ...

Sixteen streams in middle and eastern Tennessee were surveyed for the sudden oak-death pathogen Phytophthora ramorum 2010-2012. Surveys were conducted in the spring and fall using healthy Rhododendron leaves, and a total of 354 oomycete isolates were recovered. Sequence analysis of the ITS region provisionally identified 151 Phytophthora, 200 Pythium, two Halophytophthora and one Phytopythium. ...

A comprehensive phylogeny representing 142 described and 43 provisionally named Phytophthora species is reported here for this rapidly expanding genus. This phylogeny features signature sequences of 114 ex-types and numerous authentic isolates that were designated as representative isolates by the originators of the respective species. Multiple new subclades were assigned in clades 2, 6, 7, and...

In July 2000, the fi nger of blame for a mysterious mass killer of Californian oak trees came to rest on a previously undescribed plant pathogen. From the initial identifi cation of Phytophthora ramorum, it took less than four years to produce a draft sequence of its genome, one of the fastest-ever discovery-to-sequence stories for a complex pathogen. This achievement was a United States initia...

There are more than 60 species in the genus Phytophthora (94), and most are destructive plant pathogens. Extensive efforts are directed at the control of Phytophthora diseases each year, yet they still cause serious crop losses. For example, more than $200 million in lost production annually is attributed to Phytophthora diseases in Australia alone (47). Late blight, caused by P. infestans, pro...

Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis), a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI) as barcode genes, one of the two taxa was pro...

There are more than 60 species in the genus Phytophthora (94), and most are destructive plant pathogens. Extensive efforts are directed at the control of Phytophthora diseases each year, yet they still cause serious crop losses. For example, more than $200 million in lost production annually is attributed to Phytophthora diseases in Australia alone (47). Late blight, caused by P. infestans, pro...

Microsatellites were evaluated as genetic markers for the mitochondrial genome (mtDNA) of Phytophthora cinnamomi for population studies. Two (A)n microsatellite loci were cloned from the mtDNA of P. cinnamomi. Amplification products from these loci showed little polymorphism among Phytophthora isolates due to their location in coding regions of mtDNA. A further three (A)n microsatellite loci ob...