Pea seed-borne mosaic virus

The Pea seed-borne mosaic virus (PSbMV) is a plant pathogenic virus belonging to the genus Potyvirus and the family Potyviridae.

This virus consists of flexuous filamentous particles. Its most critical feature is the high efficiency of transmission via seeds, which facilitates its international spread and establishment in various agricultural regions.

PSbMV primarily infects plants within the Fabaceae family, including pea (Pisum sativum), lentil, chickpea, and faba bean, as well as several wild legume species.

The virus is primarily transmitted by aphids in a non-persistent manner, as well as through infected seeds, which serve as the main reservoir for the virus to survive between growing seasons.

Due to its high genetic variability, several strains of the virus exist, varying in host range and symptom severity, which complicates the development of universal control strategies.

The damage caused by PSbMV includes reduced seed quality, lower yield, and significant losses in plant vigor. Infected plants often exhibit stunted growth and reduced biomass.

The virus impacts the reproductive success of the plant, leading to deformed pods, fewer seeds per pod, and lower germination rates in progeny seeds.

Economic losses are particularly high in seed production fields, as contaminated batches must be discarded or require extensive processing to meet certification standards.

In addition to direct losses, the weakened state of infected plants makes them more susceptible to opportunistic pathogens, further exacerbating the decline in yield.

The virus can also lead to widespread failure in breeding programs by destroying the viability of specific germplasm and disrupting genetic improvement cycles.

Symptoms of PSbMV infection vary significantly depending on the cultivar and environmental conditions. Early signs in seedlings typically manifest as leaf mosaic and curling.

Characteristic symptoms include vein clearing, light green to yellow mosaic patterns on leaves, and leaf deformation. Stunted plants with shortened internodes are common indicators of infection.

Pods may show symptoms such as mosaic patterns, light green mottling, or white lines along the seams. In severe cases, blossom drop and pod abortion occur.

Seed transmission leads to severe symptoms appearing as early as the first true leaves, often showing crinkled leaf edges and stunted growth compared to healthy plants.

• Distinct mosaic or mottle on foliage.
• Leaf distortion and curling.
• Reduced plant height (stunting).
• Mottling or mosaic patterns on pods.
• Delayed plant maturity and pod development.

The primary control measure is the use of virus-free, certified seeds. Testing via ELISA or PCR is essential to ensure that seed lots are free from PSbMV.

Implementing spatial isolation between pea production fields and perennial legume crops reduces the chances of aphid-mediated virus spread from local reservoirs.

Effective management of aphid populations using targeted insecticide applications during the peak migration periods can help decrease the secondary spread of the virus within the field.

Strict sanitation protocols, including the removal of volunteer legumes and susceptible weeds in and around fields, help eliminate potential viral inoculum sources.

Developing and planting resistant or tolerant pea varieties is the most sustainable and efficient long-term method for mitigating the risks posed by this virus.