VIEW ARTICLE

Etiology

Isolation of Anastomosis Group 5 of Rhizoctonia solani from Potato Field Soils in Maine. B. P. Bandy, Research assistant, Department of Botany and Plant Pathology, University of Maine, Orono 04469; D. H. Zanzinger(2), and S. M. Tavantzis(3). (2)(3)Graduate research assistant, and assistant professor, Department of Botany and Plant Pathology, University of Maine, Orono 04469. Phytopathology 74:1220-1224. Accepted for publication 6 April 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/Phyto-74-1220.

Nine of 50 isolates of Rhizoctonia solani obtained from potato field soils in Maine were found to be members of anastomosis group (AG) 5. All nine isolates anastomosed readily with the tester for AG 5. No hyphal fusion was observed between these isolates and any of the testers for AGs 1, 2, 3, or 4. In pathogenicity trials under greenhouse conditions, eight of the nine AG 5 isolates tested produced sunken brown lesions on cultivar Katahdin potato stems; the ninth isolate appeared to be nonpathogenic.