Towards molecular detection methods for aphid-borne strawberry viruses

摘要

Intact rhabdovirus particles of strawberry crinkle cytorhabdovirus (SCV) mechanically transmitted from Fragaria vesca UC-S to Physalis pubescens plants were purified. When the particles were used as an immunogen, it was not possible to obtain eithera virus-specific polyclonal antiserum after rabbit immunization or monoclonal antibodies. Each of the major nucleocapsid proteins (N, Ns and M) were therefore purified by means of preparative electrophoresis and injected into mice. The polyclonal mouseantisera raised showed a specific reaction with SCV-infected P. pubescens. Work is in progress to obtain specific monoclonal antibodies. It is also possible to isolate one ssRNA of c. 13 kb from purified particles of SCV. Relatively abundant dsRNA couldbe extracted from Nicotiana occidentalis 37B plants infected with strawberry mottle virus (SMoV). This dsRNA was composed of 2 bands of c. 7.8 and 6.3 kbp which were DNase resistant. They became RNase resistant in the presence of NaCl above 0.5 M. Work is in progress to make a cDNA library from purified dsRNA of SMoV. The need of replacing the leaf-graft indexing of strawberry for the major aphid-borne viruses in relation to the potential offered by the current knowledge on these viruses is discussed.