03160nas a2200229 4500008004100000022001300041245012000054210006900174260001100243300001400254490000800268520234900276100001702625700001902642700002202661700002202683700002102705700002502726700002102751700002102772856013702793 2003 eng d a0953756200aPhytophthora pseudosyringae sp. nov., a new species causing root and collar rot of deciduous tree species in Europe0 aPhytophthora pseudosyringae sp nov a new species causing root an c7/2003 a772 - 7890 v1073 a

In several studies of oak decline in Europe, a semi-papillate homothallic Phytophthora taxon was consistently isolated, together with other Phytophthora species, from rhizosphere soil samples. It was also found associated with necrotic fine roots and stem necroses of Fagus sylvatica and Alnus glutinosa. Due to morphological and physiological similarities, the semi-papillate isolates were previously identified as P. syringae by various authors. The morphology, physiology and pathogenicity against fine roots of Quercus robur, Q. petraea and F. sylvatica, bark of A. glutinosa, leaves of Ilex aquifolium and apple fruits of this Phytophthora species are described and compared with those of related and similar Phytophthora species, namely P. ilicis, P. psychrophila, P. quercina, P. citricola and P. syringae. The phylogenetic placement on the basis of ITS and mtDNA sequence data was also examined. Isolates of this taxon produce colonies with stellate to rosaceous growth patterns and limited aerial mycelium on various agar media. Antheridia are predominantly paragynous. In water culture catenulate hyphal swellings and semi-papillate caducous sporangia, that are usually limoniform, ellipsoid or ovoid, are formed abundandly, mostly in lax or dense sympodia. This taxon is a moderately slow growing, low temperature species with optimum and maximum temperatures around 20 and 25 °C, respectively. Tested isolates are moderately aggressive to fine roots of oaks and beech, highly aggressive to holly leaves and apple fruits, and slightly pathogenic to alder bark. Thirteen tested isolates had an identical and distinct ITS sequence which was more similar to that of P. ilicis and P. psychrophila than any other known taxa. On the basis of their unique combination of morphological characters, colony growth patterns, cardinal temperatures for growth, growth rates, pathogenicity to oaks, beech, alder, apple and holly, their host range, and ITS and mtDNA sequences the semi-papillate caducous Phytophthora isolates from oaks, beech and alder are clearly separated from related and similar Phytophthora spp., and described as a new species, P. pseudosyringae sp. nov.

1 aJung, Thomas1 aNechwatal, Jan1 aCooke, David, E L1 aHartmann, ünther1 aBlaschke, Markus1 aOßwald, Wolfgang, F1 aDuncan, James, M1 aDelatour, Claude uhttps://forestphytophthoras.org/references/phytophthora-pseudosyringae-sp-nov-new-species-causing-root-and-collar-rot-deciduous-tree02261nas a2200157 4500008004100000022001300041245012600054210006900180260001200249300001600261490000800277520164800285100001701933700001901950856013401969 2008 eng d a0953756200aPhytophthora gallica sp. nov., a new species from rhizosphere soil of declining oak and reed stands in France and Germany0 aPhytophthora gallica sp nov a new species from rhizosphere soil  c10/2008 a1195 - 12050 v1123 a

A non-papillate, slow-growing Phytophthora species, which could not be assigned to any existing taxon, was isolated from rhizosphere soil of a declining oak in Northeast France, and from the rhizosphere of Phragmites australis at Lake Constance in south-west Germany in 1998 and 2004, respectively. We describe this species, previously informally designated Phytophthora taxon ‘G’, as Phytophthora gallica sp. nov. Morphology, growth rates, and pathogenicity against cuttings of riparian tree species and leaves of reed are described and compared with those of morphologically and phylogenetically similar Phytophthora species. P. gallica produces colonies with limited aerial mycelium and variable growth patterns. Gametangia are not formed in single or mixed cultures with tester strains of known mating types. P. gallica produces globose and elongated irregular chlamydospores, of which a high proportion is abortive. In water culture irregular hyphal swellings and non-papillate persistent sporangia are formed abundantly. P. gallica is moderately aggressive to Alnus glutinosa and Fagus sylvatica, weakly aggressive to Quercus robur and Salix alba and non-pathogenic to Fraxinus excelsior and Phragmites australis. According to ITS and mtDNA sequence data P. gallica belongs to a distinct Phytophthora clade, with P. boehmeriae and P. kernoviae being the closest relatives. The origin of P. gallica and its ecological role in wet ecosystems remain unclear.

1 aJung, Thomas1 aNechwatal, Jan uhttps://forestphytophthoras.org/references/phytophthora-gallica-sp-nov-new-species-rhizosphere-soil-declining-oak-and-reed-stands