Cowpea aphid-borne mosaic virus

Cowpea aphid-borne mosaic virus (CABMV) is a significant plant pathogen belonging to the genus Potyvirus within the Potyviridae family. This virus is a single-stranded RNA pathogen that causes widespread mosaic disease, particularly affecting legumes, and is considered one of the primary limiting factors for cowpea production in many regions.

The host range of CABMV primarily includes members of the Fabaceae family, such as cowpea (Vigna unguiculata), common bean, soybean, and peanut. Symptoms caused by the infection typically include severe mosaic patterns, chlorosis, vein banding, leaf distortion, and stunted growth. Infected plants often show reduced flower production and smaller, malformed pods, leading to significant yield losses.

The biological cycle of the virus is characterized by non-persistent transmission, primarily through various aphid species, with Aphis craccivora being the most efficient vector. The virus particles adhere to the aphid's stylet during brief probing of plant tissues and are transmitted to healthy plants within seconds. Furthermore, the virus can be seed-borne, which is a critical mechanism for its long-distance dissemination and persistence in the environment.

Environmental conditions that favor aphid population dynamics, such as mild temperatures and the availability of suitable host plants, promote the rapid spread of CABMV. The disease often initiates from infected seedlings grown from contaminated seeds, with subsequent secondary spread facilitated by winged aphid migrations between fields. Early-season infestations are usually the most destructive for crop development.

Effective management and control strategies for CABMV are centered on preventing the initial spread of the virus. Key practices include:

• Utilizing certified virus-free seed stocks.
• Deploying resistant or tolerant crop varieties.
• Managing weed reservoirs that harbor the virus during off-seasons.
• Implementing insecticide programs to reduce aphid vector populations during the early stages of crop growth.
• Utilizing temporal or spatial isolation from heavily infected fields.