Characterization of Anastomosis Group-10 (Ag-10) of Rhizoctonia Solani

Isolates of R. solani AG-10 have been collected at low frequency from wheat and barley roots in Washington and Oregon, USA. In Western Australia, AG-10 is collected regularly, but at low frequency, from the roots of cereal, lupin and pasture species. In this study all attempts to induce AG-10 to sporulate were unsuccessful. However, earlier studies confirmed that the teleomorph of AG-10 conforms with that of Thanatephorus cucumeris. On potato-dextrose agar, mycelial growth of AG-10 was white to light tan with some isolates displaying a yellowish colouration as cultures aged. White, concentric growth rings formed after 3 or 4 days and the formation of embedded gold, orange-gold or very light tan sclerotia occurred between 14 and 20 days. Sclerotia varied in size from small to large (c. 2-8 mm) and were generally irregular in shape. AG-10 was auxotrophic for thiamine. AG-10 was non-pathogenic on wheat, barley, lupin, vetch and tomato. It may be a weak pathogen on cruciferous hosts. Australasian Plant Pathology 24(4) 252 - 260 Full text doi:10.1071/APP9950252 © CSIRO 1995