Mycoviruses: Environmental Variables, Vector-Mediated Transmission and Use as a Biocontrol

Mycoviruses, or fungal viruses, are widespread throughout the fungal kingdom. This study aimed to identify environmental factors associated with mycoviruses, explore their transmission mechanisms, including vector-mediated transmission, and assess their potential practical applications. A systematic, retrospective, and cross-sectional bibliographic review was conducted. These viruses are closely linked to their fungal hosts, thus developing a symbiotic relationship. Among environmental variables, temperature appears to play a more significant role in limiting fungal virulence than other factors, such as relative humidity or ultraviolet radiation. Most mycoviruses are generally asymptomatic RNA viruses, rarely affecting the host's phenotype, and are transmitted intracellularly, primarily through vertical transmission via spores or horizontally through hyphal anastomosis; therefore, their life cycle typically lacks an extracellular phase. Mycoviruses remain understudied, particularly their role in vector-borne transmission and their influence on pathogen structure and behavior. Transmission can be persistent, where the virus replicates in insect vectors and is passed to offspring via infected eggs or feces, or non-persistent and indirect, facilitated by vectors without replication. Understanding the biology and ecology of mycoviruses is essential for advancing their potential use in the biocontrol of pathogens, including phytopathogens, representing a promising area of applied research.