Beet curly top virus
Beet curly top virus | |
---|---|
Beet plant infected with BCTV | |
Virus classification | |
(unranked): | Virus |
Realm: | Monodnaviria |
Kingdom: | Shotokuvirae |
Phylum: | Cressdnaviricota |
Class: | Repensiviricetes |
Order: | Geplafuvirales |
Family: | Geminiviridae |
Genus: | Curtovirus |
Species: | Beet curly top virus
|
Synonyms[2] | |
|
Beet curly top virus (BCTV) is a
History
Beet curly top virus was first discovered in 1888 in the Western parts of the United States. The virus wasn't fully recognized until 1907 when people started to realize that the virus was affecting their crops which led to increasing yield loss.[7] As the BCTV began to surface and multiply within the United States, it affected many states (California, Idaho, Utah, and Washington) located in the Western area. According to the Environmental Protection Agency (EPA), many crops were destroyed from the disease and led to a considerable economic loss.[3] The BCTV has also been known to affect other countries including Mexico, South America, and the Old World (the Mediterranean basin and the Middle East).[5]
Structure
BCTV contains a single-stranded circular DNA that is encapsulated in a twinned
Transmission
BCTV is transmitted to
Hosts
BCTV has been known to affect more than 300 plant
Symptoms
Plants that are infected will tend to display early symptoms within 5 days.[12] The BCTV causes many symptoms including:[5][6][11][13]
- Vein swelling (the earliest and most common symptom)
- Leaf curling
- Yellowing of leaves with purple veins
- Necrosis and hyperplasia of the phloem
- Fruit deformation
- Premature fruit ripening
- Reduced fruit quality and yield
- Stunting
- Death of young seedlings
Environment
The beet leafhopper is commonly found in tropical and subtropical countries that have warm climates.
Environmental impacts
The BCTV caused many problems for farmers. When the virus was first recognized in 1907, California farmers were detrimentally affected and had a large yield loss in crops.[7] Other states including Idaho were also greatly affected by the virus. The BCTV nearly wiped out Idaho's sugar beet industry until they effectively developed sugar beets that were resistant to the virus in 1935.[10] From the early 1900s till now, farmers are still having difficulties in containing this virus. In 2001, the Central Valley located in California had an enormous loss in crops valuing up to millions of dollars. In 2002, the bean production located in the Columbian basin of Washington State was also afflicted with the virus and encountered many losses.[5]
Treatment and management
As the BCTV became more difficult to manage, many methods were developed to help contain this virus. Methods included breeding curly top virus resistant crops, planting earlier or later in the year, the use of insecticides, and weed management.
In 1918, the first project known to produce resistant sugar beets was established. After developing their first curly top resistant sugar beets in 1926, researchers determined the plants were unable to fully resist the virus and were still susceptible to infection.[12]
Due to the increasing number of curly top virus outbreaks in California, many groups joined in the development of curly top resistant
Many states which were afflicted with the BCTV soon began using insecticides to reduce the number of BCTV outbreaks. In 1943, California adopted the BCTV management program, which is still running today. This program focuses on the use of insecticides to reduce the amount of beet leafhoppers by spraying chemicals in non-crop areas where the beet leafhoppers reside. Killing the beet leafhoppers before they invade susceptible host crops leads to fewer crops being infected. Slowly, the use of insecticides was questioned due to its effects on the environment, non-target organisms, and endangered species.[7][12] As the number of beet leafhoppers continued to rise, the EPA ordered the use of clothianidin to help control the insects in 2006, 2007 and 2008.[3]
In 1949, another curly top management program was developed in southern Idaho. It focused on the use of insecticides and specific planting times to control the virus. The method of specific planting dates was inconsistent and led to an unsuccessful management of the virus. In 1969, the program was eliminated due to the increase in urbanization and shortage of funds available to keep the program running.[10]
In Arizona, field observations indicated that a delay in planting until late October to November may help decrease BCTV incidence; however, changing the planting dates may not always be successful because the movements of beet leafhoppers are inconsistent and unpredictable.[10] Many weeds are also host for the beet leafhoppers; therefore, proper weed control can help decrease the incidence of BCTV.[6]
References
- ^ ICTV 7th Report van Regenmortel, M.H.V., Fauquet, C.M., Bishop, D.H.L., Carstens, E.B., Estes, M.K., Lemon, S.M., Maniloff, J., Mayo, M.A., McGeoch, D.J., Pringle, C.R. and Wickner, R.B. (2000). Virus taxonomy. Seventh report of the International Committee on Taxonomy of Viruses. Academic Press, San Diego. p.291 https://ictv.global/ictv/proposals/ICTV%207th%20Report.pdf
- ^ "Curtovirus-Becurtovirus Group Test". agida. agdia. Retrieved 27 August 2020.
- ^ PMID 18943410.
- ^ "Virus Taxonomy: 2018b Release". International Committee on Taxonomy of Viruses (ICTV). March 2019. Retrieved 17 July 2019.
- ^ PMID 30754401.
- ^ a b c d "ag.arizona.edu" (PDF).
- ^ PMID 30845586.
- ^ PMID 21473892.
- PMID 18943410.
- ^ PMID 30780973.
- ^ a b c "NMSU: Curly Top Virus".
- ^ PMID 30781144.
- ISSN 0960-7412.
- ^ "Show DPV and Refs in Frame".