Mungbean yellow mosaic virus

Mungbean yellow mosaic virus (MYMV) is a significant plant pathogen belonging to the genus Begomovirus within the Geminiviridae family. Characterized by a single-stranded DNA genome, this virus causes severe yellow mosaic diseases in various legume crops, leading to significant yield losses and threatening food security in many regions of the world.

The virus primarily affects mung bean, black gram, common bean, soybean, and pigeon pea. The disease manifests through chlorosis, patchy yellow mosaic patterns on leaves, stunted plant growth, and reduced flower and pod formation. Severe infections can result in total crop failure, as the plant becomes unable to synthesize nutrients effectively due to chlorotic leaf tissue.

The biological cycle of MYMV is tightly coupled with its primary vector, the whitefly (Bemisia tabaci). The transmission is persistent and circulative; the insect acquires the virus while feeding on infected sap and remains infectious for the remainder of its life. This makes the whitefly a highly efficient long-distance vector, contributing to rapid disease spread.

Environmental conditions play a crucial role in the dissemination of the virus. Warm temperatures and high humidity promote the rapid population growth of Bemisia tabaci, leading to explosive outbreaks of the mosaic disease. During the off-season, the virus survives in various weed hosts or volunteer crops, which serve as primary inoculum sources for the next growing season.

Management strategies focus on a multi-faceted approach to limit the impact of the virus. Key tactics include the development and cultivation of MYMV-resistant crop varieties, which remains the most sustainable solution. Additionally, farmers should employ chemical control of the whitefly population during the early stages of crop growth, remove weed hosts, and implement strict phytosanitary practices to disrupt the viral cycle.