Pea seed-borne mosaic virus

Pea seed-borne mosaic virus (PSbMV) is a significant plant pathogen belonging to the Potyviridae family, genus Potyvirus. As the name suggests, it is primarily transmitted via infected seeds, making it a critical concern for pea production and international seed trade. This RNA virus is classified as a seed-borne pathogen of major economic importance.

The virus mainly infects legumes, including common pea, lentils, and chickpeas. Symptoms of the infection include leaf mosaic patterns, vein clearing, severe plant stunting, and deformation of pods. In some cases, the seeds themselves may show symptoms such as cracking or discoloration, significantly affecting the quality of the harvested produce.

The biological cycle begins when an infected seed germinates, leading to a systemically infected plant. The virus then spreads throughout the field primarily through aphid vectors in a non-persistent manner. This means that aphids can acquire the virus after feeding on an infected plant for a short time and immediately transmit it to healthy ones during subsequent feeding sessions.

Environmental conditions that favor aphid population growth, such as mild temperatures and dry spells, significantly increase the rate of virus spread. High mobility of aphid vectors in late spring and early summer often leads to widespread outbreaks. The lack of natural immunity in many commercial pea cultivars allows the virus to persist in the ecosystem for several seasons.

The economic impact of PSbMV includes reduced yields, impaired seed germination, and lower nutritional quality of the crop. To control the pathogen, farmers should implement the following strategies:

• Ensure the use of virus-free seeds certified through laboratory testing.
• Monitor and control aphid populations using targeted insecticide applications.
• Implement proper crop rotation to break the cycle of viral persistence.
• Remove weeds that act as alternate hosts for the virus and aphid vectors.
• Deploy resistant varieties if available for the specific growing region.