| Groundnut rosette virus | |
|---|---|
Virus classification  | |
| (unranked): | Virus |
| Realm: | Riboviria |
| Kingdom: | Orthornavirae |
| Phylum: | Kitrinoviricota |
| Class: | Tolucaviricetes |
| Order: | Tolivirales |
| Family: | Tombusviridae |
| Genus: | Umbravirus |
| Species: | Groundnut rosette virus |
| Synonyms | |
| |
Groundnut rosette virus (GRV) is a peanut pathogenic virus found in Sub-Saharan Africa. It is transmitted between plants by insect vectors such as the groundnut aphid (Aphis craccivora). [1]
The groundnut (Arachis hypogaea) originated in South America where it has long been domesticated. More recently it has been cultivated in other parts of the world and is an important subsistence crop in Sub-Saharan Africa. Groundnut rosette virus was first described in Africa in 1907 and causes serious damage to groundnut crops on that continent. In 1939 it was reported to infect 80 to 90% of plants in the Belgian Congo causing major losses in yield. The virus can spread rapidly through a crop. In a study in Tanzania, the first affected plants were seen six days after the first aphids were observed. Aphid numbers built up rapidly and the disease increased tenfold in two weeks with 65% of the crop plants affected three weeks later. [1]
Research has shown that plants infected by groundnut rosette virus alone show little or no effect, but that the symptoms of the disease are caused by a satellite RNA co-infection, a subviral agent. Groundnut plants affected take on a bushy appearance due to stunting and distortion of the growing shoots. There is a yellowing or mottling of the foliage. Plants affected when young may produce no nuts. [1]
There are three main types of symptoms:
The chlorotic and green types are caused by two variants of the satellite RNA while the mosaic type is caused by infection with a mixture of both variants. [3] Further research has shown that another virus, groundnut rosette assistor virus (GRAV), is also involved in infection. Some groundnut varieties that are resistant to rosette disease have been demonstrated to be highly resistant to GRV and its satellite RNA but fully susceptible to GRAV. [4]
The main vector for groundnut rosette virus is the groundnut aphid (Aphis craccivora). [5] When it sucks the sap of an infected plant it receives groundnut rosette virus and satellite RNA, packaged together within a coating of groundnut rosette assistor virus. The disease is epidemic in nature and there is a seasonal cycle of infection, but the origins of this virus are unknown. In Africa, the groundnut aphid feeds on as many as 142 different species of plant, many of them in the family Fabaceae, and the groundnut rosette virus is presumed to have originated among these. Research has shown that although other host plants exist for GRV, GRAV and satellite RNA individually, the only known natural host plant for all parts of the complex is the groundnut. [5]
Virus resistant varieties of groundnut have been discovered but mostly have a long growing period (five to six months rather than three to four for other varieties) and may therefore be more susceptible to drought. A breeding programme has been established in Malawi focussing on disease resistance, early maturity and high yield. [5]
Lettuce mosaic virus (LMV) is a typical potyvirus, which causes one of the major virus diseases of lettuce crops worldwide.
Citrus tristeza virus (CTV) is a viral species of the genus Closterovirus that causes the most economically damaging disease to its namesake plant genus, Citrus. The disease has led to the death of millions of Citrus trees all over the world and has rendered millions of others useless for production. Farmers in Brazil and other South American countries gave it the name "tristeza", meaning sadness in Portuguese and Spanish, referring to the devastation produced by the disease in the 1930s. The virus is transmitted most efficiently by the brown citrus aphid.
Cassava mosaic virus is the common name used to refer to any of eleven different species of plant pathogenic virus in the genus Begomovirus. African cassava mosaic virus (ACMV), East African cassava mosaic virus (EACMV), and South African cassava mosaic virus (SACMV) are distinct species of circular single-stranded DNA viruses which are transmitted by whiteflies and primarily infect cassava plants; these have thus far only been reported from Africa. Related species of viruses are found in India and neighbouring islands, though cassava is cultivated in Latin America as well as Southeast Asia. Nine species of cassava-infecting geminiviruses have been identified between Africa and India based on genomic sequencing and phylogenetic analysis. This number is likely to grow due to a high rate of natural transformation associated with CMV.
Cucumber mosaic virus (CMV) is a plant pathogenic virus in the family Bromoviridae. This virus has a worldwide distribution and a very wide host range, having the reputation of the widest host range of any known plant virus. It can be transmitted from plant to plant both mechanically by sap and by aphids in a stylet-borne fashion. It can also be transmitted in seeds and by the parasitic weeds, Cuscuta sp. (dodder).
Sunn-hemp mosaic virus (SHMV) is a pathogenic plant virus. It is known by many names, including bean strain of tobacco mosaic virus and Sunn-hemp rosette virus. SHMV is an intracellular parasite that infects plants. It can be seen only through an electron microscope. It is a positive-sense single-stranded RNA virus that causes physical characteristics of spotting and/or discoloration. The Sunn-hemp mosaic virus is listed as a species within the genus Tobamovirus and the virus family Virgaviridae by the International Committee on the Taxonomy of Viruses, who renamed it from "Sunnhemp" to "Sunn-hemp" in 1991.
Indian cassava mosaic virus(ICMV) is a plant pathogenic virus of the family Geminiviridae. It affects cassava (Manihot esculenta) in India and certain other countries. It is considered to be an invasive species.
Maize dwarf mosaic virus (MDMV) is a pathogenic plant virus of the family Potyviridae. Depending on the corn plant’s growth stage, the virus can have severe implications to the corn plant’s development which can also result in economic consequences to the producer of the crop.
Panicum mosaic virus (PMV) is a positive-sense single-stranded RNA viral pathogen that infects plant species in the panicoid tribe of the grass family, Poaceae. The pathogen was first identified in Kansas in 1953 and most commonly causes disease on select cultivars of turf grass, switchgrass, and millet. The disease most commonly associated with the panicum mosaic virus pathogen is St. Augustine Decline Syndrome, which infects species of turf grass and causes chlorotic mottling. In addition to St. Augustine Decline, panicum mosaic virus is responsible for chlorotic streaking and mild green mosaicking in select cultivars of switchgrass and millet.
Peanut stunt virus (PSV) is a plant pathogenic virus in the family Bromoviridae. It is a member of the genus Cucumovirus. The members of this genus are positive-stranded RNA viruses with a multipartite genome. The virus particles have an isometric or spherical shape.
Potato virus Y (PVY) is a plant pathogenic virus of the family Potyviridae, and one of the most important plant viruses affecting potato production.
Soil-borne wheat mosaic virus is a rod-shaped plant pathogen that can cause severe stunting and mosaic in susceptible wheat, barley and rye cultivars. The disease has often been misdiagnosed as a nutritional problem, but this has actually allowed in part for the fortuitous visual selection by breeding programs of resistant genotypes. Soil-borne wheat mosaic virus is part of the genus Furovirus. Members of this genus are characterized by rigid rod-shaped particles and positive sense RNA genomes consisting of two molecules that are packaged into separate particles that code for either replication, mobility, structure or defense against the host. The virus is spread by a fungal-like protist, Polymyxa graminis, whose asexual secondary and sexual primary cycles help the virus spread. The disease produces secondary symptoms from the root cell infection. The disease is a serious contributor to loss in crop yield.
Soybean mosaic virus (SMV) is a member of the plant virus genus Potyvirus. It infects mainly plants belonging to the family Fabaceae but has also been found infecting other economically important crops. SMV is the cause of soybean mosaic disease that occurs in all the soybean production areas of the world. Soybean is one of the most important sources of edible oil and proteins and pathogenic infections are responsible for annual yield losses of about $4 billion in the United States. Among these pathogens, SMV is the most important and prevalent viral pathogen in soybean production worldwide. It causes yield reductions of about 8% to 35%, but losses as high as 94% have been reported.
Strawberry vein banding virus (SVBV) is a plant pathogenic virus and a member of the family Caulimoviridae.
Orthotospovirus is a genus of negative-strand RNA viruses, in the family Tospoviridae of the order Bunyavirales, which infects plants. Tospoviruses take their name from the species Tomato spotted wilt orthotospovirus (TSWV) which was discovered in Australia in 1919. TSWV remained the only known member of the family until the early 1990s when genetic characterisation of plant viruses became more common. There are now at least twenty species in the genus with more being discovered on a regular basis. Member viruses infect over eight hundred plant species from 82 different families.
Watermelon mosaic virus (WMV) also known as Marrow mosaic virus, Melon mosaic virus, and until recently Watermelon mosaic virus type 2 (WMV-2), is a plant pathogenic virus that causes viral infection in many different plants. The virus itself is referred to as Watermelon Mosaic Virus II or WMV-2 and is an isolate of the U.S. WMV-2 is a ssRNA positive strand virus that is part of the Potyviridae or Potyvirus clade. Like all RNA viruses, it contains a protein capsid which protects the inner viral RNA. First described on squash in Florida, WMV arose from a unique recombination of genetic material contributed by Soybean mosaic virus (SMV) and Bean common mosaic virus (BCMV) along with Peanut Stripe virus (PSV).
Aphis craccivora, variously known as the cowpea aphid, groundnut aphid or black legume aphid, is a true bug in the family Aphididae. Originally of probable Palearctic origin, it is now an invasive species of cosmopolitan distribution.
Maize lethal necrosis disease is a viral disease affecting maize (corn) predominantly in East Africa, Southeast Asia and South America, which was recognised in 2010. It is caused by simultaneous infection with two viruses, MCMoV and any of several Potyviridae.
Cocoa necrosis virus (CoNV) is a plant pathogenic virus of the genus nepovirus that infects Theobroma cacao en natura causing cacao necrosis disease. CoNV is considered synonymous with Strain S of cacao swollen shoot virus. Unlike Cacao swollen shoot virus, it is not transmitted by mealybugs nor vectored by aphids, beetles, or leafhoppers that also commonly infest cacao. It is serologically, distantly related to Tomato black ring virus and very distantly related to Grapevine chrome mosaic virus.
The cardamom mosaic virus (CdMV) is a mosaic virus that affects the production of green cardamom (E. cardamomum). It is a member of the genus Macluravirus (recognized under the family Potyviridae by ICTV in 1988), and is transmitted through aphids (P.caladii) and infected rhizomes, the former in a non-persistent manner.
Carrot virus Y (CarVY) is a (+)ss-RNA virus that affects crops of the carrot family (Apiaceae), such as carrots, anise, chervil, coriander, cumin, dill and parsnip. Carrots are the only known crop to be infected in the field. Infection by the virus leads to deformed roots and discolored or mottled leaves. The virus is spread through insect vectors, and is currently only found in Australia.