Bean Pod Mottle VIrus
BPMV infected seed courtesy of:
http://www.soydiseases.uiuc.edu/topics/seed_mottle/seed_mot_example.html
Last updated by
Nick Dolezal
on March 19th, 2002
Common Names of Bean Pod Mottle Virus:
-BPMV
-Pod Mottle Virus
Causal Agent:
-Bean Pod Mottle Comovirus
Vector:
Host Range:
16 species of plants can host BPMV, generally these plants are legumes.
Geographical Range:
BPMV was first recorded on soybean plants in Arkansas, North Carolina, and Virginia in 1958 and has since been reported to be widespread in many of the soybean growing areas in the Untied States.
Symptoms:
As seen on the photo on my home page, BPMV can cause leaf discoloration of soybean plant leaves especially during periods of cool weather and rapid growth. Later in the growing season after infected soybean plants have reached maturity, the leaves and pods may turn brown but the plant stems will remain green. When an infected field is harvested, the seed coming from the field may show signs of mottling as the seed coat on some seeds is brown and discolored. See an example of seed mottling at the top of the page. If a field has a large enough infection of BPMV, soybean yields can be reduced by over 50%!
Dissemination:
The plant pathogen is generally carried and vectored into soybean plants by the Bean Leaf Beetle. The Virus can also be spread by contaminated seed. If a farmer doesn't realize that the bean seed he plants is infected he can aid in the spread of the pathogen easily, especially if bean leaf beetles are present in the field later in the season.
Disease Cycle:
The complete disease cycle of BPMV is not yet known at this time. Research is still being conducted to find how the pathogen over winters. Some researchers believe that the virus over winters along with bean leaf beetles and is introduced to new plants in the spring as bean leaf beetles begin feeding. However, bean leaf beetles cannot transmit the virus to its offspring. Other researchers believe that the virus over winters in plant residue which is fed upon by the beetles in the spring and then vectored to new host plants. One final theory is that infected seed which is planted by a farmer may be fed upon by bean leaf beetles and later vectored to other plants.
Control Measures:
Although there are not a lot of options available to farmers to control this pathogen at this time, one of the best methods of control for BPMV is to control the bean leaf beetle. Since this insect is a main vector of primary inoculum for the virus, control of the insect will limit exposure of BPMV to healthy soybeans. Planting uninfected seed will also inhibit the onset of BPMV as one of the quickest ways to introduce the pathogen to a field is to plant bad seed. If some research theories are true, tillage may be an option so as to reduce infected plant residue on the soil surface and preventing bean leaf beetle feeding on infected plants. Late season planting may be an option to some farmers planting early varieties of soybeans. Early season bean leaf beetles will not have an opportunity to colonize a later planted field thus preventing the spread of BPMV. Some varieties may be more resistant to BPMV than are others however, there is not enough research to support this claim and warrant it as a viable method of control at this time.
Recent Research-Summary:
Related Journal Article:
Field,-T.K.; Patterson,-C.A.; Gergerich,-R.C.;
Kim,-K.S. 1994. Fate of viruses in bean leaves after
deposition by Epilachna varivestis, a beetle vector of plant viruses.
84:1346-1350.
The reason for the study performed here was to identify how four different bean viruses spread within a plant after beetle feeding. Of the four viruses used, southern bean mosaic virus (SBMV), bean pod mottle virus (BPMV), tobacco ringspot virus, and tobacco mosaic virus, SBMV and BPMV are beetle transmissible viruses while the other two are non beetle transmissible viruses. Mexican bean beetles were fed the viruses and allowed to feed on soybean plants. A fluorescent antibody was used to detect the virus' progression and spread away from the feeding/infection site. The results of the experiment showed that non beetle transmissible viruses introduced by beetle feeding are moved in plant leaf veins but to a lesser extent than beetle transmissible viruses.
Sources:
Agrios, George N. 1997. Plant Pathology 4 ed. Academic Press.
pp. 513-516.
Laboratory for Soybean Diseases web site.
http://www.soydiseases.uiuc.edu/diseases/bpmv/
Plant Viruses Online web site.
http://image.fs.uidaho.edu/vide/descr073.htm
University of Nebraska. Plant Disease Central Web site
http://pdc.unl.edu/soybean/BPMV/text.html
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