A new Phytophthora species was detected (i) in the USA, infecting foliage of Kalmia latifolia, (ii) in substrate underneath Pieris, and (iii) in Germany in soil samples underneath Aesculus hippocastanum showing disease symptoms. The new species Phytophthora obscura sp. nov. is formally named based on phylogenetic analysis, host range, Kochs...
Tanoak (Lithocarpus densiflorus (Hook. and Arn.) Rehder) is highly susceptible to sudden oak death, a disease caused by the oomycete Phytophthora ramorum Werres, De Cock & Man in’t Veld. Symptoms include a dying crown, bleeding cankers, and, eventually, death of infected trees. The cause of mortality is not well understood,...
Nurseries are an important part of the agriculture industry of the United States. The nursery industry provides ornamental, forest, restoration and specialty products to many markets in N. America. The disease sudden oak death, caused by Phytophthora ramorum, has devastating environmental and economic impacts on forested land, the urban-forest interface,...
The phytopathogen Phytophthora ramorum (Werres, DeCock & Man in't Veld), causal agent of Sudden Oak Death (SOD) of oaks (Quercus spp.) and tanoaks (Notholithocarpus densiflorus syn. Lithocarpus densiflorus), is established in coastal forests of the western United States. Since the discovery of SOD in the Douglas-fir / tanoak forests of...
Research on the population genetics of microbial organisms requires the use of specialized analyses designed for clonal organisms to avoid violating the assumptions of traditional population genetic models. The tools necessary for performing these analyses existed as a set of unrelated software with non-overlapping capabilities and did not cover all...
The chlamydospore is a survival spore produced by 35 of the 75 described species of Phytophthora. Phytophthora ramorum Werres, de Cock & Man in't Veld, the causal agent of Sudden Oak Death (SOD), produces abundant chlamydospores in artificial culture and plant tissue. The chlamydospore is likely the most important survival...
Isolation, detection with diagnostic polymerase chain reaction (PCR), and microscopy demonstrated the presence of Phytophthora ramorum in the sapwood of mature, naturally infected tanoak (Lithocarpus densiflorus) trees. The pathogen was strongly associated with discolored sapwood (P < 0.001), and was recovered or detected from 83% of discolored sapwood tissue samples....
Pythium species are important soilborne pathogens occurring in the forest nursery industry of the Pacific Northwest. However, little is known about their genetic diversity or population structure and it is suspected that isolates are moved among forest nurseries on seedling stock and shared field equipment. In order to address these...
Full Text:
E. Weiland, Patricia Garrido, Zhian N. Kamvar, Andrés S. Espı́ndola, Stephen M. Marek,
Niklaus J
Sudden Oak Death (SOD) is a forest disease caused by the oomycete pathogen Phytophthora ramorum, and infects trees in the Western United States and Europe. This generalist pathogen can infect over 130 species of plants, and causes rapid mortality in tree species in the Fagaceae. Sexual reproduction is thought to...
Des séquences entières ou partielles de génomes deviennent de plus en plus accessibles. En ce qui concerne plusieurs systèmes plante-agent
pathogène, nous abordons l’ère du recéquençage du génome. Les premiers génomes de Phytophthora, P. ramorum et P. sojae, ont été
disponibles à partir de 2004, suivis de près par celui...