Abstract
The majority of characterized plant viruses have RNA genomes. Genetic variabilityis a fundamental feature of RNA viruses. High mutation rates, recombination andreassortment are the three basic mechanisms that are responsible for the enormousgenetic polymorphism and rapid evolution of RNA viruses. Mutations are mostfrequently introduced into the viral genome during the replication process due tothe low fidelity of RNA-dependent RNA polymerases. Recombination is a widespreadphenomenon described in many plant viruses with both RNA and DNAgenomes and is responsible for more profound changes within the viral genome(sequence deletion or insertion or strand exchange). Reassortment is also an importantmechanism responsible for swapping or introducing a whole genomic segmentof the viral genome, but is limited only to the segmented viruses. However,these three mechanisms are counterbalanced by selection and genetic bottleneckswhich reduce the genetic variation of plant viruses in nature. Recently, geneticbottlenecks have been identified experimentally in plant virus populations duringthe systemic movement within the plant and horizontal transmission from plant.
Original language | English (US) |
---|---|
Title of host publication | Biotechnology and Plant Disease Management |
Publisher | CABI Publishing |
Pages | 109-124 |
Number of pages | 16 |
ISBN (Print) | 9781845932886 |
State | Published - Oct 31 2007 |
All Science Journal Classification (ASJC) codes
- General Environmental Science
- General Biochemistry, Genetics and Molecular Biology
- General Agricultural and Biological Sciences