Susceptibility of Some Strawberry Cultivars to Tomato Ringspot Virus as Determined by ELISA. R. H. Converse, USDA-ARS Horticultural Crops Research Unit, Department of Botany and Plant Pathology, Oregon State University, Corvallis 97331. Plant Dis. 70: 369-371. Accepted for publication 26 September 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, 1986. DOI: 10.1094/PD-70-369.

The susceptibility of 52 strawberry cultivars to graft infection by an isolate of tomato ringspot virus (TmRSV) from strawberry was determined by leaflet-graft inoculations and subsequent detection by enzyme-linked immunosorbent assay (ELISA). In 18 cultivars, TmRSV was readily detected by ELISA, whereas in 21 cultivars, it was infrequently detected and then usually at low levels. In 13 cultivars, TmRSV was not detected. In preliminary inoculation tests of three susceptible cultivars, leaflet grafts were found by ELISA to transmit virus only 42% of the time. This level of reliability requires that 10 of 10 grafted plants of a given cultivar must test negative for TmRSV by ELISA to state with a confidence level of P = 0.996 that the cultivar did not contain ELISA-detectable TmRSV. Therefore, in this study, at least 10 separate graft inoculations of a given cultivar were tested for TmRSV before determining that no ELISA-detectable virus was present.