Solanum rugose yellow leaf virus

Pathogen and disease type: The Solanum rugose yellow leaf virus (SRYLV) is a member of the Begomovirus genus within the Geminiviridae family. It is a viral pathogen characterized by a circular single-stranded DNA genome. The disease is systemic, meaning the virus moves through the phloem of the host plant, causing widespread physiological disruptions.

Host range: The virus primarily infects plants belonging to the Solanaceae family. Economically important crops such as tomatoes (Solanum lycopersicum) and peppers are highly susceptible. Furthermore, many weed species within the nightshade family can act as symptomless reservoirs, perpetuating the viral cycle in the field.

Symptoms and signs: Infected plants exhibit severe leaf rugosity (wrinkling), upward curling, and distinct yellowing or mosaic patterns on the foliage. Stunting is a common and diagnostic feature, often accompanied by shortened internodes. Affected plants produce fewer flowers, and the resulting fruits are usually deformed, smaller in size, and commercially unviable.

Conditions for development and spread: Transmission is mediated by the whitefly Bemisia tabaci in a persistent circulative manner. The virus spreads most rapidly in warm, humid climates where whitefly populations thrive. Once a whitefly acquires the virus, it remains infectious for the remainder of its life, facilitating long-distance and efficient transmission within greenhouses and open fields.

Economic impact and management: This virus causes severe yield losses and reduces the market quality of vegetable crops. Effective management practices include:

• Strict management of whitefly populations through chemical and biological control methods.
• Implementation of physical barriers like insect-proof nets in greenhouse production.
• Sanitation, including the eradication of infected host plants and nearby weed hosts.
• Utilization of virus-resistant or tolerant cultivars where available.