The ''Blueberry leaf mottle virus'' (BLMV) is a ''

Nepovirus ''Nepovirus'' is a genus of viruses in the order ''Picornavirales'', in the family ''Secoviridae'', in the subfamily ''Comovirinae''. Plants serve as natural hosts. There are 40 species in this genus. Nepoviruses, unlike the other two genera (' ...

'' that was first discovered in Michigan in 1977. It has also appeared in New York, eastern Canada, Bulgaria, Hungary, and Portugal.

Structure

The BLMV genome is bipartite containing two segmented regions of linear, positive-sense, single stranded RNA. The entire genome of the virus is 14600 nucleotides long, and the RNA-1 has a partially sequenced region that is 7600 nucleotides long. The virus consists of a naked, icosahedral capsid that is 28 nm in diameter. The genome of the virus codes for both structural and non-structural proteins, and the lipids of this virus are unknown.

Strains of the virus

There are currently three known strains of the ''Blueberry leaf mottle virus''. The original strain (BLMV) infects highbush and lowbush varieties in Michigan and eastern Canada. A second strain (BLMV-NY) has only been reported in one case in New York and infected an American grapevine. The third strain was discovered in Bulgarian grapevines and is known as the grapevine ''Bulgarian latent nepovirus''. Grapevines with this strain are asymptomatic.

Hosts

The primary host of BLMV is the highbush blueberry (''

Vaccinium corymbosum ''Vaccinium corymbosum'', the northern highbush blueberry, is a North American species of blueberry which has become a food crop of significant economic importance. It is native to eastern Canada and the eastern and southern United States, from ...

''). Other hosts include lowbush blueberry types ('' V. angustifolium'' and '' V. myrtilloides''), hybrids of highbush and lowbush blueberry types ('' V. corymbosum'' x '' V.angutifolium''), American grapevines (''

Vitis labrusca ''Vitis labrusca'', the fox grape, is a species of grapevines belonging to the ''Vitis'' genus in the flowering plant family Vitaceae. The vines are native to eastern North America and are the source of many grape cultivars, including Catawba, Co ...

''), and Bulgarian grapevines (''

Vitis vinifera ''Vitis vinifera'', the common grape vine, is a species of flowering plant, native to the Mediterranean region, Central Europe, and southwestern Asia, from Morocco and Portugal north to southern Germany and east to northern Iran. There are curre ...

'').

Symptoms

Symptoms of BLMV include malformed, mottled leaves that are pale green in color and have smaller than healthy leaves. The leaves may also have transparent spots that are visible when they are held up to the light. Bushes may be stunted and if bushes are badly infected, they may show dieback of stems with little regrowth. Symptoms do not appear until three to four years after infection.

Transmission

Unlike many nepoviruses, BLMV does not appear to have a

nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...

vector and is instead spread by honeybees during pollination via infected pollen. The virus can also be seedborne in seedlings of an infected bush although this is somewhat rare and has only happened in 1.5% of reported BLMV cases.

Prevention

There is no known treatment for BLMV and prevention is the best method of control. Blueberry bushes should be planted only if they are approved by legitimate virus-testing programs, especially in areas where the virus has been reported. Other blueberry bushes that have already been infected should be identified by

ELISA The enzyme-linked immunosorbent assay (ELISA) (, ) is a commonly used analytical biochemistry assay, first described by Eva Engvall and Peter Perlmann in 1971. The assay uses a solid-phase type of enzyme immunoassay (EIA) to detect the presence ...

and destroyed completely so that they do not grow back and risk infecting other bushes. It is also recommended, since honeybees spread the virus, that all honeybee hives should not be placed anywhere near infected bushes.

References

{{Taxonbar, from=Q18358752 Viral plant pathogens and diseases Nepoviruses