VIEW ARTICLE

Nature of the Inhibitory Effect of Bean Pod Mottle Virus on Local Lesion Production by Soybean Mosaic Virus on Bean. Yih- Shyong Lee, Graduate Assistant, Department of Plant Pathology, North Carolina State University, Raleigh, North Carolina 27607; J. P. Ross, Plant Pathologist, Plant Science Research Division, ARS, USDA, P.O. Box 5397, Raleigh, North Carolina 27607. Phytopathology 62:887-889. Accepted for publication 15 February 1972. DOI: 10.1094/Phyto-62-887.

Bean pod mottle virus (BPMV) causes partial inhibition of local lesion production by soybean mosaic virus (SMV) when bean leaves are inoculated with mixtures of the two viruses. Neither zones of SMV lesion inhibition nor a reduction in SMV lesion size was induced by BPMV. The effect of inactivated and infective BPMV and the sequence of virus inoculation on SMV lesion inhibition were studied. Infective BPMV caused more inhibition than BPMV inactivated by heat or ultraviolet irradiation. Sequential inoculations with the two viruses separated by various time intervals indicated that maximum inhibition of SMV lesions occurred when inoculations were simultaneous; SMV lesion inhibition was sharply reduced during the 1st-min interval between inoculations. Inhibition of SMV lesions by BPMV infection may be due to the unilateral competition for infectible sites.