Maize dwarf mosaic virus
| Maize dwarf mosaic virus (MDMV) | |
|---|---|
| Virus classification | |
| Group: | IV: (+)sense RNA Viruses |
| Family: | Potyviridae |
| Genus: | Potyvirus |
| Species: | Maize dwarf mosaic virus |
| Synonyms | |
|
MDMV-A | |
Maize dwarf mosaic virus (MDMV) is a plant pathogenic 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.
Transmission
Maize Dwarf Mosaic Virus is spread by seed, by infected leaves rubbing on non-infected leaves and perhaps most commonly, via aphids (Lipps & Mills, n.d.). These aphids become carriers after they feed on plants such as Johnson grass, corn or sorghum, or other grass species that are infected with MDMV. Broadleaf plants do not become infected with MDMV (The CIMMYT Maize Program). Aphids transmit Maize Dwarf Mosaic Virus disease effectively fifteen to thirty minutes after feeding on infected plants when by spreading the virus to the susceptible plants after they have flown or are blown onto a nearby corn crop and will start to feed (“Maize Dwarf Mosaic Virus,” n.d.).
Symptoms
When looking for symptoms of MDMV in corn, one must also be aware of the plant’s growth stage as symptoms may affect the plant differently at various stages. Young leaves, may experience chlorotic spotting which may eventually turn into a mosaic or mottle pattern (“Maize Dwarf Mosaic Virus,” n.d.). Later in the growing season, the mosaic pattern may bleed into a general yellowing of the leaf and eventually areas of red streaks or blotches may appear if night time temperatures are consistently around 60 degrees Fahrenheit (Lipps & Mills, n.d.). Plants affected later in their reproductive cycle may experience a slowing in ear development (“Maize Dwarf Mosaic Virus,” n.d.), while some plants may even become barren (Lipps & Mills, n.d.). It is not uncommon for plants to have shortened upper internodes or an increase in tiller number (“Maize Dwarf Mosaic Virus,” n.d.).
Control
Maize Dwarf Mosaic Virus can be managed in several ways. One way is the removal of the local population of Johnson grass as this can harbor the disease. It is best if all producers (farmers) in the area participate in this practice or the disease can remain in sporadic plant populations and be spread in the ways described above (Lipps & Mills, n.d.). Another way to help avoid MDMV is by selecting corn varieties that are tolerant of the virus and by planting corn crops earlier in the season to help seedlings avoid key aphid population times (Lipps & Mills, n.d.).
References
The CIMMYT Maize Program. 2004. Maize Diseases: A Guide for Field Identification. 4th edition. Mexico, D.F.: CIMMYT.
Lipps, P.E., & Mills, D.R. Maize Dwarf Mosaic, Maize Chlorotic Dwarf Diseases of Corn. Retrieved from http://ohioline.osu.edu/ac-fact/0024.html.
Maize Dwarf Mosaic Virus. Retrieved from http://cropdisease.cropsci.illinois.edu/corn/maizedwarfmosaicvirus.html.