Introduction
Phytophthora idaei D.
M. Kenn. (1995)
Phytophthora idaei
was isolated from rotting raspberry (Rubus
idaeus) in the
Cultural Characteristics
The optimum temperature for growth is 20–22°C. Colonies have limited aerial mycelium.
Reproductive Structures
Asexual Structures
Sporangiophores:
Sporangiophores are simple and in a lax
sympodium.
Sporangia:
Sporangia are
papillate and predominantly spherical to ovoid.
Sporangia are
29.2–43.7 × 41–55 µm
(mean 34.4 × 48 µm) (Figs. 1, 2.2, and 2.3).
Sporangia are persistent and noncaducous.
Sporangia predominately germinate indirectly by zoospores.
Chlamydospores and
Hyphal Swellings:
No chlamydospores or hyphal swellings are formed.
Sexual Structures
P. idaei is
homothallic.
Antheridia:
Antheridia are predominantly
paragynous and occasionally
amphigynous and are club shaped.
Oogonia:
Oogonia are smooth, spherical, and 26 × 38 µm.
Oospores:
Oospores are aplerotic and 22.8–31.2 µm (average 27 µm) (Fig. 2.4). Oospores form readily in the roots of raspberry.
Host Range and Distribution
Host |
Common Name |
Disease |
Geographical Distribution |
Rubus idaeus |
Raspberry |
Root rot |
|
Symptoms
The pathogen has a limited host range and primarily infects the fine roots of
Rubus species. It does not infect the
aboveground portion of the plant.
References
Cline, E. T., Farr,
D. F., and Rossman, A. Y. 2008. A
synopsis of Phytophthora with accurate scientific names, host range, and
geographic distribution. Plant Health Progress
doi:10.1094/PHP-2008-0318-01-RS.
Erwin, D. C., and Ribeiro, O. K.
1996.
Phytophthora Diseases Worldwide. American Phytopathological Society,
Kennedy, D. M., and Duncan, J. M. 1995. A
papillate Phytophthora species
with specificity to Rubus. Mycol.
Res. 99:57-68.
Stamps, D. J., Newhook, F. J., Waterhouse, G. M., and Hall, G. S. 1990. Revised
tabular key to the species of
Phytophthora de Bary.
Mycol. Pap. 162.
CAB International, Wallingford, United Kingdom; Commonwealth Mycological
Institute, Kew,
Waterhouse, G. M. 1963. Key to the species of
Phytophthora de Bary. Mycol. Pap. 92.
CAB International, Wallingford, United Kingdom; Commonwealth Mycological
Institute, Kew,
Young, V., Cooke, D., Barker, H., and Dolan, A. 2007. Does Phytophthora idaei pose a treat to the raspberry crop? Scottish Crop Research Institute, Invergowrie, Dundee, Scotland. www.scri.ac.uk/webfm_send/658.