Rhynchosia yellow mosaic India virus

Begomovirus rhynchosiaindiaense is a viral pathogen classified within the genus Begomovirus and the family Geminiviridae. This virus possesses a circular single-stranded DNA genome and causes significant systemic infections in susceptible hosts. It is a major concern in tropical agriculture, particularly where specific host species are cultivated on a large scale.

The host range of this virus primarily includes legumes, such as various species of Vigna and Phaseolus. The virus is named after Rhynchosia minima, an initial host plant where the pathogen was described. In agricultural settings, the virus impacts productivity by infecting crops during their most vulnerable growth stages, leading to economic losses.

Symptoms typically manifest as yellow mosaic patterns on leaves, leaf curling, stunted plant growth, and general chlorosis. The intensity of symptoms often depends on the host cultivar and the timing of the initial infection. Severe cases result in a drastic reduction in biomass and the failure of flowers to develop into mature pods.

The transmission of the virus is strictly mediated by the whitefly Bemisia tabaci in a circulative, non-propagative manner. The efficiency of transmission is highly dependent on the population density of the insect vector and ambient environmental conditions, such as high temperature and humidity, which favor the proliferation of whitefly populations.

Strategic management of this viral disease focuses on limiting the exposure of crops to vectors and reducing the source of inoculum:

• Implementation of integrated pest management (IPM) to control whitefly populations.
• Utilization of resistant or tolerant crop varieties.
• Removal and destruction of infected plant debris to limit reservoir populations.
• Application of protective screens in greenhouse environments.
• Strategic timing of planting to avoid peak whitefly migration periods.