Mungbean yellow mosaic virus

Mungbean Yellow Mosaic Virus (MYMV) is a significant plant pathogen that affects leguminous crops, particularly mungbeans (Vigna radiata) and other related species. This virus is responsible for causing the yellow mosaic disease, which is characterized by yellowing of the leaves, reduced leaf size, and stunted growth, leading to significant yield losses. MYMV belongs to the genus Begomovirus and is transmitted by whiteflies (Bemisia tabaci), making its management challenging in regions with high whitefly populations.

Symptoms

The primary symptoms of MYMV include:

• Yellowing of the leaves, which may display a mosaic pattern.
• Reduction in leaf size.
• Stunted plant growth.
• In severe cases, affected plants may produce fewer and smaller pods, leading to significant yield losses.

Transmission

MYMV is transmitted by the whitefly Bemisia tabaci in a persistent manner. The virus can also spread through infected seeds, which contributes to its dissemination across different geographical regions.

Management

Management of MYMV involves an integrated approach:

• Cultural Practices: Removal and destruction of infected plants to reduce virus sources.
• Resistant Varieties: Use of resistant or tolerant mungbean varieties, when available, is the most effective control measure.
• Chemical Control: Judicious use of insecticides to control whitefly populations. However, reliance on chemical control should be minimized to avoid the development of insecticide resistance.
• Biological Control: Encouragement of natural enemies of the whitefly, such as lady beetles and lacewings.

Economic Impact

MYMV poses a significant threat to the cultivation of mungbeans and related legumes, especially in South and Southeast Asia. The virus can cause substantial yield losses, which directly affect the income of farmers and can lead to food security issues in affected regions.

Research

Ongoing research on MYMV focuses on understanding the virus's genetics, developing resistant mungbean varieties through conventional breeding and biotechnological approaches, and improving integrated pest management strategies to control the whitefly vector.