Serological characterization of papaya ringspot virus isolates in Taiwan

Twenty-seven isolates of papaya ringspot virus (PRSV) were obtained from Ta iwan. Differences in symptoms were observed. In addition to such isolates a s necrotic severe mottle (SMN), severe mottle (SM) and mild mottle (M), ano ther mottle type with deformation (DF) was isolated. Ail the isolates of PR SV and PRSV-W (PRSV type W) examined were serologically indistinguishable a s determined by polyclonal antibodies-rabbit antisera to PRSV, but were con sistently distinguishable with monoclonal antibodies (MAbs). Those isolates were raised against the PRSV. The virus isolates that reacted with the MAb s to PRSV were selected and applied to compare the antigenic specificity of the PRSV strain. Moreover, the immunoreactivities of the MAbs were compare d with polyclonal rabbit serum to detect PRSV in foliar tissue by enzyme-li nked immunosorbent assay (ELISA). Eleven selected MAbs were differentiated into five sero-groups according to sere-reaction patterns of ELISA index wi th 27 isolates of PRSV and PRSV-W. It was assumed that at least five antige nic epitopes were identified. Distinct results were obtained in application of MAb to ELISA for detecting PRSV strains in cucurbitaceous plants.