Phytophthora has been rebuilt to fix security-related problems and to restore GIS tools. These tools allow users to visualize the geospatial, temporal, and environmental contexts of Phytophthora discoveries. The next phase is to update species information and add data derived from large-scale surveys. If you have suggestions and requests to make the database better, please contact Seogchan Kang (sxk55@psu.edu).
Genus wide phylogeny for Phytophthora using four mitochondrial loci (cox2, nad9, rps10 and secY; 2,373 nucleotides). Maximum likelihood branch lengths shown. Numbers on nodes represent bootstrap support values for maximum likelihood (top), maximum parsimony (middle) and Bayesian posterior probabilities as percentages (bottom). Nodes receiving significant support (>95%) in all analysis are marked with an asterisk (*). Scale bar indicates number of substitutions per site.(Martin, Blair and Coffey, unpublished).
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Phytophthora europaea E.M. Hansen & T. Jung 2002 (Oomycetes, Pythiales)
Distribution: Europe (France, Germany), North America (USA).
Substrate: Soil.
Disease Note: Not associated with symptoms of oak decline; weakly aggressive to seedlings (Jung et al. 2002).
Host: Quercus spp. (Fagaceae).
Supporting Literature:
Jung, T., Hansen, E.M., Winton, L., Obwald, W. , and Delatour, C. 2002. Three new species of Phytophthora from European oak forests. Mycol. Res. 106: 397-411
Updated on Jun 26, 2006
1. Sporangia
Sporangia are non-papillate, ellipsoid, ovoid and obpyriform with a broad exit pore. Dimensions average 46 ± 10.7 x 32 ± 5.4 µm; length/breadth ratio is about 1.4. Sporangia form on long, sparingly branched sporangiophores. Sporangial proliferation is usually internal, often nested, but occasionally sympodial.
Irregular, mostly elongated hyphal swellings are produced by most isolates in liquid culture.
2. Chlamydospores
Never observed
3. Sex Organs
P. europaea is homothallic. Oogonia from six isolates averaged 33 ± 4.6 µm. Antheridia are paragynous, about 12 ± 2.2 x 9 ± 1.7 µm, and attached near the stalk. Oogonia usually exhibit a tapering, often curved base. Oospores nearly fill the oogonia, and average 29 ± 4.5 µm diam. The oospore wall is about 2 ± 0.5 µm diam, often turning golden-brown when ageing.
4. Growth temperatures
P. europaea shows a moderately slow growth at 20°C on CMA (radial growth about 4 mm/day), V8A (5-6 mm/day) and MEA (3.7mm/day). On CMA the growth optimum ranged from 21 to 25°C (4-4.3mm/day).
5. Growth Characteristics in Culture Media
Colonies were loosely aerial with no pattern on CMA, striate pattern on V8A and MEA with a dense central mound of aerial hyphae. On potato dextrose agar, colonies produced dense, felt-like mycelia, often with a central mound of aerial hyphae.
6. Distinguishing Characteristics
It belongs to the group V of the morphological classification system of Waterhouse (Waterhouse 1963). DNA sequences indicates P. europaea belongs to clade 7 (Jaime Blair et al., unpublished data). P. europaea shares many morphological and growth features with members within this clade, howver, it is distinguished by its combination of vegetative, sexual and physiological characters and DNA sequences.
Morphologically the most characteristic feature is his oogonia with a tapered, curved base.
In artificial inoculation studies it was shown to aggressively infect the roots of Q. robur (Jung et al. 2002) and to the stem of Q. alba Q. rubra and Q. velutina (Balci et al. 2006)
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Nomenclature information was provided by the Systematic Botany and Mycology Laboratory in USDA-ARS. Other information was provided by Dr. Yilmaz Balci at West Virginia University.
Isolate list