Purification and partial nucleic acid characterization of Melilotus Alba virus: A report submitted in partial fulfilment of the requirements for the Degree of Bachelor of Science with Honours in the University of Canterbury

Abstract

Multipartite plant viruses are viruses in which the genetic material is located in two or more particles. Such viruses may be the rule rather the exception. Examples of viruses with genomes packaged into two particles include Tobacco rattle virus and Cowpea mosaic virus. Alfalfa mosaic virus consists of four or five particles, of which at least three are necessary for infection to give complete virus synthesis. The most probable advantage of such a system is increased genetic flexibility, by allowing selection and reassortment to occur during virus replication, transmission, entry into the cell and movement through the plant. However, the probability of successful infection is reduced, as two or more particles must co-operate by infecting the same, or very 1 close cells. This may be overcome by the fact that all known multipartite viruses reach high concentrations in infected plants. A preliminary examination by J.W. Ashby (D.S.I.R., Lincoln), suggested that a virus isolated from Melilotus alba (clover) might be multipartite. A pilot report on some of the properties of this virus is presented in this study.