A SOUTH-AFRICAN ISOLATE OF RYEGRASS MOSAIC-VIRUS

An isolate of ryegrass mosaic virus (RMV-SA) was found in Italian ryeg rass plants in two areas in South Africa. Preliminary characterization indicated that the virus exhibited the same symptoms and host range a s RMV strains previously found in Canada and the UK. The virus was tra nsmitted by the eriophyid mite Abacarus hystrix. Particle structure an d size were comparable to the USA and UK strains. The coat protein and RNA were found to be slightly larger than previously reported, being 32 kDa and 2.8 x 10(6), respectively. The virus exhibited serological cross-reactivity with antisera to RMV-Wales and RMV-Canada but was not serologically related to other Rymovirus members.