Summary of taxonomy changes ratified by the International Committee on Taxonomy of Viruses (ICTV) from the Fungal and Protist Viruses Subcommittee, 2025.

The Fungal and Protist Viruses Subcommittee (SC) of the International Committee on Taxonomy of Viruses (ICTV) has received a total of eight taxonomic proposals for the 2024 annual cycle. The extent of proposed changes varied, including nomenclatural updates, creation of new taxa and reorganization of established taxa. Following the ICTV procedures, all proposals were reviewed and voted upon by the members of the Executive Committee with ratification in March 2025.

Annual (2024) taxonomic update of RNA-directed RNA polymerase-encoding negative-sense RNA viruses (realm : kingdom : phylum ).

In April 2024, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum was expanded by 1 new order, 1 new family, 6 new subfamilies, 34 new genera and 270 new species. One class, two orders and six species were renamed. Seven families and 12 genera were moved; ten species were renamed and moved; and nine species were abolished.

Reexamining the Mycovirome of spp.

species cause gray mold disease in more than 200 crops worldwide. To control this disease, chemical fungicides are usually applied. However, more sustainable control alternatives should be explored, such as the use of hypovirulent mycovirus-infected fungal strains.

ICTV Virus Taxonomy Profile: 2023.

is a family of capsidless viruses with positive-sense RNA genomes of 7.3-18.3 kb that possess either a single large open reading frame (ORF) or two ORFs.

Mycoviruses as a part of the global virome: Diversity, evolutionary links and lifestyle.

Knowledge of mycovirus diversity, evolution, horizontal gene transfer and shared ancestry with viruses infecting distantly related hosts, such as plants and arthropods, has increased vastly during the last few years due to advances in the high throughput sequencing methodologies. This also has enabled the discovery of novel mycoviruses with previously unknown genome types, mainly new positive and negative single-stranded RNA mycoviruses ((+) ssRNA and (-) ssRNA) and single-stranded DNA mycoviruses (ssDNA), and has increased our knowledge of double-stranded RNA mycoviruses (dsRNA), which in the past were thought to be the most common viruses infecting fungi. Fungi and oomycetes (Stramenopila) share similar lifestyles and also have similar viromes.

ICTV Virus Taxonomy Profile: 2022.

Typical members of the family produce filamentous, enveloped virions containing a single molecule of linear, negative-sense RNA of about about 10 kb, but some may not produce any virions. The family includes several genera, some with multiple species. Mymonavirids usually infect filamentous fungi, but a few have been identified associated with insects, oomycetes or plants.

Construction and Characterization of a Botrytis Virus F Infectious Clone.

Botrytis virus F (BVF) is a positive-sense, single-stranded RNA (+ssRNA) virus within the family of the plant-pathogenic fungus . In this study, the complete sequence of a BVF strain isolated from collected from grapevine fields in Spain was analyzed. This virus, in this work BVF-V448, has a genome of 6827 nt in length, excluding the poly(A) tail, with two open reading frames encoding an RNA dependent RNA polymerase (RdRP) and a coat protein (CP).

Going Viral: Virus-Based Biological Control Agents for Plant Protection.

The most economically important biotic stresses in crop production are caused by fungi, oomycetes, insects, viruses, and bacteria. Often chemical control is still the most commonly used method to manage them. However, the development of resistance in the different pathogens/pests, the putative damage on the natural ecosystem, the toxic residues in the field, and, thus, the contamination of the environment have stimulated the search for saferalternatives such as the use of biological control agents (BCAs).

Novel Mycoviruses Discovered in the Mycovirome of a Necrotrophic Fungus.

is one of the most important plant-pathogenic fungus. Products based on microorganisms can be used in biocontrol strategies alternative to chemical control, and mycoviruses have been explored as putative biological agents in such approaches. Here, we have explored the mycovirome of isolates from grapevine of Italy and Spain to increase the knowledge about mycoviral diversity and evolution, and to search for new widely distributed mycoviruses that could be active ingredients in biological products to control this hazardous fungus.

ICTV Virus Taxonomy Profile: .

The family includes viruses infecting plants and filamentous fungi containing a positive-sense, ssRNA genome that can be mono- or multi-segmented. Genera in the family include: (plant viruses), and , and (fungal viruses). This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the family , which is available at ictv.

ICTV Virus Taxonomy Profile: .

Members of the family produce filamentous, enveloped virions containing a single molecule of linear, negative-sense RNA of ≈10 kb. The family currently includes a single genus, . Mymonaviruses usually infect filamentous fungi, and one virus, Sclerotinia sclerotiorum negative-stranded RNA virus 1, induces hypovirulence in the fungal host.

Taxonomy of the order Mononegavirales: update 2019.

In February 2019, following the annual taxon ratification vote, the order Mononegavirales was amended by the addition of four new subfamilies and 12 new genera and the creation of 28 novel species. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV).