Morphological characteristics and infection processes of nematophagous Harposporium with reference to two new species

Harposporium sinense and H. multiformis sp. nov., isolated from soil in Yunnan, China are described and illustrated as endoparasitic parasites of nematodes. The conidia of both species can cause infection of bacterial-feeding nematodes after being ingested. Harposporium sinense produces chlamydospores and typical crescent-shaped, Harposporium-like conidia with a mucus sheath at the basal end. Harposporium multiformis produces four types of spores in pure culture: accessory conidia, arthroconidia, chlamydospores and helicoid infection conidia. The arthroconidia germinate in a peculiar manner to produce Harposporium type phialides and helicoid conidia. The infection processes of both species are described and a key to the known species of Harposporium is provided.