Soil-borne wheat mosaic virus

Soil-borne wheat mosaic virus (SBWMV) is a plant pathogen that specifically targets wheat (Triticum spp.), causing significant yield losses in affected crops. This virus is of particular concern in major wheat-producing regions around the world due to its ability to spread and persist in soil, making management and control challenging.

Overview

SBWMV is a member of the genus Furovirus, within the family Virgaviridae. The virus is transmitted by the soil-inhabiting fungus Polymyxa graminis, which acts as its vector. The disease cycle is closely linked to the life cycle of this plasmodiophorid, with the virus being taken up by wheat roots during periods of cool, moist conditions, typically in the spring or autumn.

Symptoms

Infected wheat plants exhibit a range of symptoms, which can vary depending on the wheat variety, the virus strain, and environmental conditions. Common symptoms include:

• Mosaic patterning on leaves, characterized by alternating light and dark green patches
• Stunting of plant growth
• Distortion of leaf shape
• Reduced tillering
• Premature senescence and death in severe cases

Transmission and Spread

SBWMV is primarily spread through the movement of infected soil and plant debris, as well as through the vector Polymyxa graminis. The virus can persist in the soil for several years, even in the absence of susceptible wheat crops, due to its association with the resting spores of the vector. This persistence poses a significant challenge for disease management and control.

Management

Effective management of SBWMV involves an integrated approach, including:

• Crop rotation with non-host crops to reduce the population of Polymyxa graminis in the soil
• Use of resistant wheat varieties, where available
• Avoidance of planting wheat in fields known to be infested with SBWMV
• Timely planting to avoid peak periods of vector activity
• Good field hygiene to minimize the spread of infected soil and plant material

Economic Impact

The economic impact of SBWMV can be considerable, with significant yield losses reported in heavily infested fields. The cost of managing the disease, through the use of resistant varieties and other control measures, also contributes to the economic burden on wheat producers.

Research

Ongoing research into SBWMV is focused on understanding the virus-vector relationship, developing and deploying resistant wheat varieties, and improving management practices to reduce the impact of the disease. Advances in molecular biology and genetics offer promising avenues for enhancing resistance to SBWMV in wheat.

See Also

• Wheat
• Plant pathology
• Crop rotation
• Genetic resistance

External Links

• American Phytopathological Society - Provides resources and information on plant diseases, including SBWMV.
• Food and Agriculture Organization of the United Nations - Offers information on crop diseases and management strategies.