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 Scale bar indicates number of substitutions per site.(Martin, Blair and Coffey, unpublished).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 cinnamomi var. parvispora Krober & Marwitz 1993 (Oomycetes, Pythiales)
Distribution: Europe (Germany).
Substrate: Stems.
Disease Note: Stem rot.
Host: Beaucarnea sp. (Agavaceae).
Supporting Literature:
Erwin, D.C., and Ribeiro, O.K. 1996. Phytophthora Diseases Worldwide. APS Press, St. Paul, Minnesota, 562 pages.
Kroeber, H., and Marwitz, R. 1993. [Phytophthora tentaculata sp. nov. and Phytophthora cinnamomi var. parvispora var. nov., two new fungi from ornamental plants in Germany. Z. Pflanzenkrankh. Pflanzenschutz. 100: 250-258.
Updated on Jun 06, 2006
The following description is reproduced by permission of the Journal of Phytopathology, courtesy Krober and Marwitz (1993):
Mycelium on carrot agar hyaline; in strands; transparent; only a few downy airmycelia.
Hyphal swellings abundant; mostly side twigs coralloidly blown up, sometimes allantoid or tailshaped, in part several times constricted, or spherical.
Chlamydospores abundant; spherical; terminal; intercalary, rarely lateral, sometimes in clusters on short side stalks; thin-walled; 16-43 (27.1) μm.
Zoosporangia without papilla; ovoid, ellipsoidal, obpyriform or rarely irregularly shaped; single or several in succession with internal proliferation, sometimes nest-shaped; 14-83 x 13-43 (36.9 x 25.5) μm, l/b = 1.45/1.
Generative organs only when complementary strains grown together in intraspecific mating or with P. cinnamomi or P. cryptogea in interspecific mating.
Oogonia in intraspecific mating culture abundant; spherical; 23-41 (31.9) μm.
Antheridia 1 per oogonium; amphigynous; spherical, broad ellipsoidal; relatively large.
Oospores spherical; with a moderately thick wall; hyaline; generally almost plerotic; 22-36 (28.1) μm.
Minimum 10-11, optimum 26-32, maximum 36-37oC; growth rate 10-14 mm/24 hr at optimum temperatures.
Isolated from stem bases of Beaucarnea spec.; Germany (in greenhouses), 1990.
P. cinnamomi var. parvispora is in [sic] some extent closely connected with P. cryptogea Pethybridge et Lafferty and P. drechsleri Tucker but nearest with P. cinnamomi Rands. But it is clearly distinct even from this fungus by considerably smaller chlamydospores and zoosporangia and it has a higher demand of temperature.
Distinguishing Characteristics
Krober and Marwitz (1993) state that P. cinnamomi var. parvispora differs from P. cinnamomi because it produces smaller chlamydospores (27.1 μm in diameter) than P. cinnamomi (41 μm) (Rands 1922). They also state that sporangia are smaller, a statement that is borne out by sporangial size data shown in Table 15A.1 in Phytophthora Diseases Worldwide (Erwin and Ribeiro 1996). Nonetheless, since sporangial size is influenced by so many factors (see Chapter 3 in Phytophthora Diseases Worldwide (Erwin and Ribeiro 1996), the size of P. cinnamomi var. parvispora sporangia might simply be within the range of normal variability.
A higher maximum temperature for growth of P. cinnamomi var. parvispora (36-37oC) is also cited as a difference; however, Table 4 in Zentmyer (1980) lists maximum temperatures from various reports on P. cinnamomi as 30-36oC.
Since DNA RFLP technology has become such a useful tool in determining genetic differences between species, it will be of interest to determine how P. cinnamomi var. parvispora compares with other isolates of P. cinnamomi and/or P. cryptogea that Krober and Marwitz (1993) say it resembles. Oudemans and Coffey (1991a) showed that isozyme patterns of P. cinnamomi isolates from a worldwide collection differed distinctly from those of P. cryptogea. The various isolates of P. cinnamomi were relatively uniform; however, eight electrophoretic types could be distinguished.
*Phytophthora Diseases Worldwide