Pea seed-borne mosaic virus

Pea seed-borne mosaic virus (PSbMV) is a significant plant pathogen belonging to the Potyvirus genus within the Potyviridae family. It is recognized as one of the most economically important viruses affecting legume crops worldwide, primarily because it is efficiently transmitted through infected seed material.

The virus infects a range of legumes, including peas, lentils, and chickpeas. The disease manifests through various symptoms, such as mosaic patterns on the leaves, leaf rolling, plant stunting, and reduced internode length. In more severe cases, pods may appear deformed, and seeds can show necrotic spotting or growth abnormalities, significantly affecting crop quality.

The biology of the virus is centered around seed transmission, where the virus is maintained within the embryo of the seed. Once infected seedlings emerge, they act as primary reservoirs. Secondary spread within the field occurs via aphid vectors in a non-persistent manner. Aphids acquire the virus during brief feeding sessions on infected plants and transmit it rapidly to healthy neighboring plants.

Environmental conditions that favor aphid population growth, such as mild and warm temperatures, accelerate the spread of PSbMV. During the off-season, the virus survives within contaminated seeds and in perennial legume weeds that serve as alternative hosts, ensuring a continuous cycle of infection from one growing season to the next.

The economic impact of PSbMV is substantial, often resulting in significant yield losses. Infected crops produce fewer pods and smaller, low-quality seeds. Furthermore, poor seed germination rates in infected lots create management challenges for farmers. The combination of reduced yield and impaired seed quality makes it a critical concern for agricultural production.

Effective control strategies focus on integrated pest management. The primary defense is the use of certified virus-free seeds, which eliminates the initial inoculum. Additionally, monitoring and controlling aphid populations with systemic insecticides can limit secondary spread. Strict weed management and planting resistant cultivars are also essential components of a successful control program.