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 Scale bar indicates number of substitutions per site.(Martin, Blair and Coffey, unpublished).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 hibernalis Carne 1925 (Oomycetes, Pythiales)
Notes: Phytophthora hibernalis was considered by Tucker (1931) to be synonymous with Phytophthora syringae, but they are now considered distinct species (Erwin & Ribeiro 1996).
Distribution: Africa (South Africa); Asia (Israel); Australasia; Europe; North America (USA: CA); Central America Caribbean; South America (Agentina Brazil Venezuela).
Substrate: Fruits, leaves, twigs.
Disease Note: Brown rot of fruit; leaf and twig blight.
Host: Primarily Citrus spp. (Rutaceae); on 11 genera in 9 families.
Supporting Literature:
Erwin, D.C., and Ribeiro, O.K. 1996. Phytophthora Diseases Worldwide. APS Press, St. Paul, Minnesota, 562 pages.
Tucker, C.M. 1931. Taxonomy of the genus Phytophthora de Bary. Univ. Missouri Agric. Exp. Sta. Bull. 153: 1-208
Waterhouse, G.M., and Waterston, J.M. 1964. Phytophthora hibernalis. C.M.I. Descript. Pathog. Fungi Bact. 31: 1-2
Updated on Jun 07, 2006
P. hibernalis was described briefly by Waterhouse and Waterston (1964a) and Holliday (1980) and is classified in group IV (Stamps et al 1990). Ho and Jong (1993) reported a comprehensive comparison of P. hibernalis and P. syringae, which had erroneously been considered to be conspecific (Tucker 1931). See Tables 4.2 and 4.3 in Phytophthora Diseases Worldwide (Erwin and Ribeiro 1996) for tabular keys of Phytophthora species. Morphology is shown in Figure 1.
1. Sporangia
Sporangia are elongate, ellipsoid, ovoid, or obovoid, often with the broadest point near the apex; 29 to 53 µm long x 14 to 22 µm wide (average 40 x 19 µm); caducous (pedicel 23 to 73 µm long); and semipapillate. Sporangiophores are unbranched or formed as long, lateral branches in an irregular sympodium.
2. Chlamydospores
Neither hyphal swellings nor chlamydospores are formed. According to Ho and Jong (1993), the chainlike \'chlamydospores\' observed by Nadel-Schiffman (1947) were most likely monilioid hyphal swellings.
3. Sex Organs
P. hibernalis is homothallic; antheridia are mostly amphigynous but occasionally are paragynous; oogonia are 22 to 56 µm in diameter (average 35 µm); oospores are 22 to 45.6 µm in diameter (average 30 µm) and plerotic.
4. Growth Temperatures
Minimum temperature for growth is <5oC, optimum 15oC, and maximum <25oC.
5. Distinguishing Characteristics
P. hibernalis is distinguished from P. syringae by production of elongate, caducous sporangia with long pedicels and of mostly amphigynous antheridia (Waterhouse and Waterston 1964a). P. syringae (Chapter 60 in Erwin and Ribeiro (1996, Phytophthora Diseases Worldwide)) produces noncaducous sporangia and mostly paragynous antheridia. See Ho and Jong (1993) for a comprehensive literature review and results of a comparative study of both species.
Nomenclature information was provided by the the Systematic Botany and Mycology Laboratory in USDA-ARS.
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