Plant viruses are extremely minute infectious particles consisting a protein coat and a core of nucleic acid. They have no means of self-dispersal, but instead rely on various vectors (including humans) to transmit them from infected to healthy plants. Once viruses penetrate into the plant cells they take over the cells’ nucleic acid and protein synthesis systems and ‘hijack’ them to produce more virus.
Viruses are frequently transmitted through propagated material but, depending on the virus, can also be transmitted via insect or mite vectors, pollen, mechanical transfer via contaminated hands and tools, and nematode vectors in the soil. Some viruses can be transmitted via seed, but generally these are a minority and therefore seed propagation is often a useful way to ensure virus-free plant material.
Virus of camellia can all be transmitted to the next generation through propagation procedures. Information on the vectors for newly discovered camellia viruses is still to be obtained. However, from knowledge of the transmission of other viruses in the same taxonomic group it is thought that these viruses may be transmitted by mites, insect vectors and pollen.