Rhynchosia yellow mosaic virus

Rhynchosia yellow mosaic virus (RhYMV) is a viral pathogen classified within the genus Begomovirus, family Geminiviridae. It contains a single-stranded circular DNA genome. The virus causes systemic mosaic disease in susceptible plants, significantly disrupting the host's physiological pathways and photosynthetic efficiency.

The virus primarily affects plant species belonging to the Fabaceae family. While it is named after the wild host Rhynchosia aurea, it poses a notable threat to agricultural legumes, including common beans and soybeans, acting as a limiting factor in yield stability in regions where the virus is endemic.

Clinical signs of infection include chlorotic mosaic patterns on the leaves, which can become severe as the disease progresses. Infected plants often exhibit stunted growth, leaf curling, distorted development, and a marked reduction in the number of pods or seeds, leading to substantial economic losses for farmers.

Transmission of this begomovirus is mediated primarily by the whitefly Bemisia tabaci in a circulative, non-propagative manner. The insect acquires the virus while feeding on infected plants and transmits it during subsequent feeding events on healthy plants, facilitating rapid spread across agricultural fields during favorable weather conditions.

Effective disease management relies on an integrated pest management (IPM) approach. This includes the utilization of resistant plant varieties, the application of insecticides to reduce whitefly populations, and rigorous sanitation practices, such as removing weeds that act as virus reservoirs. Furthermore, crop rotation and spatial isolation are crucial strategies for mitigation.