Bean leafroll virus

Bean Leafroll Virus (BLRV) is a plant pathogenic virus that primarily affects legume crops, notably beans. It is a member of the genus Luteovirus, within the family Luteoviridae. BLRV is responsible for causing the disease known as bean leafroll, which can lead to significant yield losses in affected crops. The virus is transmitted by aphids in a persistent, circulative non-propagative manner, meaning the aphids can carry the virus for life but the virus does not multiply within the aphid.

A healthy bean plant, unaffected by Bean Leafroll Virus.

Symptoms

The symptoms of bean leafroll virus include:

• Stunting of plant growth
• Rolling and curling of leaves
• Chlorosis (yellowing) of foliage, particularly along the veins
• Reduced pod size and number
• Delayed maturity

Transmission

BLRV is transmitted by several species of aphids, with the pea aphid (Acyrthosiphon pisum) being the most efficient vector. The virus is acquired by the aphid after feeding on an infected plant for a period of time and can then be transmitted to other plants after a latent period. The virus is not transmitted through seed or mechanical damage.

Management

Management of bean leafroll virus focuses on controlling the aphid vectors and planting resistant varieties when available. Strategies include:

• Monitoring aphid populations and applying insecticides when necessary
• Using reflective mulches to deter aphids
• Implementing crop rotation and removing weeds that can serve as alternative hosts
• Planting certified virus-free seeds

Economic Impact

The economic impact of BLRV can be significant, particularly in regions where beans are a major crop. Yield losses can vary depending on the level of infection and environmental conditions, with severe cases leading to substantial reductions in both yield and quality.

Research

Ongoing research on bean leafroll virus includes the development of resistant bean varieties, understanding the virus's interaction with its host plants and vectors, and improving management practices to reduce its spread and impact.

See Also

• Plant pathology
• Virus transmission by aphids
• Legumes
• Agricultural pest management