Oomycota

fungal-like organisms • plant diseases • pests-diseases-weeds

smooth-walled oogonium of Phytophthora alni with oospore and amphigynous antheridium (click on image to enlarge it)
Author(s): Thomas Jung
Source: IPM Images

Oomycota - plant pathogenic oomycetes

The Oomycota are a group of fungal-like, multicellular organisms which have been classified under the "fungi" for many years. In fact, they are unrelated to the true fungi, but have some relationship to the brown algae and some other groups like the plant pathogenic Labyrinthulomycetes. They belong to the Heterokonta group of organisms which is characterised by having two differently shaped flagella. Oomycota have biflagellate zoospores.

Oomycota are characterized by the formation of thick-walled sexual oospores and their close association with water. They typically disperse through running water or rain splashes.

For details see the respective page in Wikipedia.

Note:
This page only deals with plant pathogens. For other groups of oomycetes in the system see

• Oomycota (antagonists)
• Oomycota (entomopathogens)
• Oomycota (weed pathogens)

The system currently includes the following orders of plant pathogenic Oomycota:

• Peronosporales
• Pythiales
• Saprolegniales
• Sclerosporales