Introduction
Phytophthora
ipomoeae
Flier & Grünwald (2002)
Phytophthora ipomoeae
was first described on morning glory in
Cultural Characteristics
Mycelium grows well on
Reproductive Structures
Asexual Structures
Sporangiophores:
Sporangiophores are aerial and have compound sympodial and intermediate
branches, with swellings where sporangia emerge.
Sporangia:
Sporangia are
semipapillate and ellipsoid or semiovoid with caducous short pedicels.
Sporangia are 35–47.5 µm long (average 39 µm). The length–breadth ratio is
1.9:1 (Fig. 2). Sporangia germinate
directly with germ tubes or indirectly with zoospores.
Chlamydospores:
Chlamydospores have not been reported for P. ipomoeae.
Hyphae:
Hyphae are nonseptate, freely branching, and 4–7.5 µm in diameter. Hyphal
swellings have not been reported for P.
ipomoeae
Sexual
Structures
P. ipomoeae is homothallic.
Antheridia:
Antheridia are
amphigynous and 19 µm long.
Oogonia:
Oogonia are smooth walled and 32.5 µm in diameter.
Oospores:
Oospores are smooth walled, colorless, and 28.8 µm in diameter (Fig. 3).
Host Range and Distribution
Host |
Common Name |
Disease |
Geographical Distribution |
Ipomoea longipedunculata |
Morning glory |
Leaf blight |
|
Ipomoea purpurea |
Morning glory |
Leaf blight |
|
Symptoms
Symptoms include blight on the leaves and stems of morning glory and other
members of the family Convolvulaceae
(Fig. 4).
References
Cooke, D. E. L., Drenth, A.,
Erwin, D. C., and Ribeiro, O. K. 1996.
Phytophthora
Diseases Worldwide. American Phytopathological Society,
Flier, W. G., Grunwald, N. J., Kroon, L. P. N. M., van den Bosch, B. M.,
Garay-Serrano, E., Lozoya-Saldana, H., Bonants, P. J. M., and Turkensteen, L. J.
2002.
Phytophthora ipomoeae
sp. nov., a new
homothallic species causing leaf blight on
Ipomoea longipedunculata in the
Kroon, L. P. N. M., Bakker, F. T., van den Bosch, G. B. M., Bonants, P. J. M.,
and Flier, W. G.
2004. Phylogenetic
analysis of
Phytophthora species based on mitochondrial and nuclear DNA
sequences. Fungal Genet. Biol. 41:766-782.
Stamps, D. J., Waterhouse, G. M., Newhook, F. J., 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, Surrey, England.
Waterhouse, G. M. 1963. Key to the species of Phytophthora de Bary. Mycol. Pap. 92. CAB International, Wallingford, United Kingdom; Commonwealth Mycological Institute, Kew, Surrey, England.