Rhizoctonia solani

Rhizoctonia solani (teleomorph: Thanatephorus cucumeris) is a plant pathogen with a wide host range and worldwide distribution. It is one cause of the condition known as damping off, which is a cause of death of seedlings in agriculture.

Identification
Rhizoctonai solani does not produce spores hence it is identified only from mycelial characteristics. Its hyphal cells are multinucleate. Also, it produces white to deep brown mycelium when grown on artifical medium. The hypae are 4-15 μm wide and tend to branch at righat angles. A septum near each hyphal branch and a slight constriction at the branch are diagnostic.R. solani is subdivided into anastomosis groups (AG) based on hyphal fusion between compatible strains.

The teleomorph of R. solani is Thanatephorus cucumeris It forms club-shaped basidia and four apical sterigmata on which oval, hyaline sporidia are borne.