Phylum:Oomycota >> Class: Oomycetes >>  Order: Pythiales 
 BCRC Number NO BCRC Number!  
 Scientific Name: Pythium aphanidermatum

Pythium aphanidermatum (Edson) Fitzp, Mycologia 15: 168. 1923.

 Description: Colonies on cornmeal agar with cottony aerial mycelium. Main hyphae up to 10 μm wide. Sporangia consisting of terminal complexes of swollen hyphal branches of varying length and up to 20 μm wide. Zoospores formed at 25-30℃. Encysted zoospores about 12 μm diam. Oogonia terminal, globose, smooth, 22-24 μm diam. Antheridia mostly intercalary, sometimes terminal, broadly sac-shapes, 10-14 μm wide. Antheridium 1 per oogonium, monoclinous or diclinous, oospores aplerotic, 20-22 μm diam, wall 1-2 μm thick.

Taiwan, Sinshe: Momordica, 12 Sep 1998, P50. Taiwan, Jhongli: Brassica, 12 Oct 1997, Pa-3-r1. Taiwan, Taichung: Amaranthus, 23 Sep 1997, Pa-2-r15; Cucumis, 23 Sep 1997, Pa-2-r13.

 Habitat: soil, water, plant



Plaats-Niterink, AJ van der. 1981.


P. H. Wang

 Note: P. aphanidermatum belongs to a group of species characterized by the possession of inflated filamentous sporangia, often intercalary antheridia and aplerotic oospores. P. deliense is similar to P. aphanidermatum but differs from their oogonial stalks which curve towards the antheridium. P. aphanidermatum is a typical plant parasite of warm regions, it can cause root-rot and damping-off, stalk and rhizome rot, soft rot, fruit rot or cottony blight of many plants. Temperature of 30-35℃ are most favorable for infection, while at lower temperature it is less or negligible.