Evaluation of Red Clover for Resistance to Bean Yellow Mosaic Virus. S. T. Sim, Graduate Research Assistant, USDA-ARS, U.S Regional Pasture Research Laboratory, Department of Plant Pathology, Pennsylvania State University, University Park 16802. K. T. Leath, Research Plant Pathologist, USDA-ARS, U.S Regional Pasture Research Laboratory, and C. P. Romaine, Associate Professor, Department of Plant Pathology, Pennsylvania State University, University Park 16802. Plant Dis. 69:694-696. Accepted for publication 19 February 1985. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1985. DOI: 10.1094/PD-69-694.

A mixed cultivar population of symptomless red clover (Trifolium pratense) plants from 2-, 3-, and 4-yr-old fields and a population of Kenstar red clover plants in the greenhouse were evaluated for resistance to bean yellow mosaic virus (BYMV) strain 204-1 after a series of mechanical inoculations, aphid transmission, and exposure to natural field conditions. Plants were evaluated for resistance by visual inspection for symptom development and by enzyme-linked immunosorbent assay for detection of viral antigen in the leaves. Initial populations of more than 500 plants each were reduced by culling virus-infected plants and general attrition to eight in the field population and seven in the seedling population. These 15 plants were not infected despite repeated mechanical inoculations with standard and concentrated inoculum; exposure for one growing season in a field of aphid-infested, BYMV-infected red clover; and a transmission feeding by viruliferous aphids. These plants were considered resistant to strain 204-1 of BYMV.

Keyword(s): ELISA.