Cynosurus and Cocksfoot Mottle Viruses: a Comparison

Abstract

Summary The biological, physical and chemical properties of New Zealand isolates of cocksfoot mottle (CfMV) and cynosurus mottle (CyMV) viruses were compared. The two viruses could be distinguished by host range differences and serological properties but their physical and chemical properties were similar. The virus particles differed in their buoyant density in CsCl (1.386 g/ml for CfMV; 1.379 g/ml for CyMV) and in their banding behaviour in Cs2SO4 gradients (CfMV formed two bands at pH 5 while CyMV formed only one). Furthermore, CyMV was degraded by low concentrations of SDS at pH 7, while CfMV was resistant except in the presence of EDTA. The viral RNAs were comparable in mol. wt. but differed in their amount of secondary structure and sedimentation values. Molecular hybridization studies using 3H-labelled complementary DNA (cDNA) probes indicated that the RNA genomes of the two viruses had between about 5% and 8% of their base sequences in common. Both viruses were detected in the nuclei of infected cells. However, CfMV, unlike CyMV, formed crystalline arrays in the cytoplasm. It is concluded that although New Zealand isolates of CyMV and CfMV share a number of similar properties they are distinct viruses.