The family Closteroviridae includes viruses causing economic losses in different agricultural crops worldwide, including citrus, grapevine and vegetables.
Presently, control of viral diseases consists of prophylactic measures to limit virus dispersion and the use of resistant cultivars obtained by plant breeding or genetic engineering. However, viruses have a great potential for rapid evolution and they often overcome the disease control methods.
Characterization of the genetic diversity of viral populations provides relevant information on the processes involved in virus evolution and epidemiology and it is crucial for designing reliable diagnostic tools and developing efficient and durable disease control strategies.
In this review by Luis Rubio and colleagues, analyses of the genetic variability of closteroviruses showed a risk of emergence of new diseases produced by: A) generation of new genotypes by genome recombination, or adaptation to new hosts or insect vectors, B) introduction of new genotypes by long distance transport of infected propagative plant material, and C) increased virulence resulting from interaction between different viruses of viral genotypes.
On the other hand, genetic stability provided by strong negative selection in some closteroviruses could be exploited for crop protection based on genetic engineering.