Pythium aphanidermatum

Pythium aphanidermatum is a plant pathogen that belongs to the Oomycetes class of organisms, often referred to as water molds. It is a member of the genus Pythium, which comprises several species known for causing diseases in plants.

Taxonomy

The species name aphanidermatum is derived from the Greek words 'aphanes' (invisible) and 'derma' (skin), referring to the organism's ability to infect plant roots without visible symptoms initially. It belongs to the kingdom Stramenopiles, which includes many important plant pathogens.

Morphology

Pythium aphanidermatum is characterized by its coenocytic (non-septate) hyphae and the production of asexual spores known as zoospores. These zoospores are biflagellate, meaning they have two flagella that aid in movement, especially in water.

Pathogenicity

Pythium aphanidermatum is a soil-borne pathogen that primarily affects the root systems of plants, causing diseases such as root rot and damping-off. It is particularly problematic in hydroponic systems and nurseries where conditions are often ideal for the pathogen's growth and spread. Crops commonly affected include cucumbers, lettuce, peppers, and various ornamental species.

Management

Management of Pythium aphanidermatum involves a combination of cultural practices, chemical treatments, and biological control methods. Cultural practices include crop rotation and sanitation measures to reduce pathogen populations in the soil. Chemical treatments often involve the use of fungicides, while biological control methods include the use of beneficial microorganisms that can suppress the pathogen.

See also

• Pythium
• Oomycetes
• Plant Pathology