First Report of Cowpea Mild Mottle Virus on Bean and Mung Bean in Tanzania. G. I. Mink, Irrigated Agriculture Research and Extension Center, Washington State University, Prosser 99350. C. L. Keswani, Plant Protection Research Institute, Causeway, Zimbabwe. Plant Dis. 71:557. Accepted for publication 23 March 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0557F.

Using indirect enzyme-linked immunosorbent assay and an antiserum provided by A. Brunt, we detected cowpea mild mottle virus (CMMV), a carlavirus, in leaf tissue from three bean (Phaseolus vulgaris L.) and two mung bean (P. mungo L.) plants collected on the Sokoine University research farm located near Morogoro, Tanzania. Typical carlavirus particles with modal lengths of 600-650 nm were observed in leaf-dip preparations from infected bean and mung bean tissues. Mild but distinct veinclearing and mottle were observed on both infected mung bean plants. No symptom attributable to CMMV was found on the three infected bean plants. CMMV was not detected in over 100 bean leaf samples tested from private farms and research stations in other areas of Tanzania and Kenya. Occurrence of CM MV only in and near plots of imported germ plasm suggested that the virus was introduced into the area through infected mung bean seed lots from India and subsequently spread to a few nearby bean plants. No residual mung bean seed was available.