ELVd

Eggplant latent viroid (ELVd) is a plant viroid that infects eggplant (Solanum melongena) and related members of the Solanaceae. In many infections, ELVd remains latent, producing few or no visible symptoms, which can hinder detection and crop management. It is studied as an example of how small, circular RNA pathogens persist in perennial crops without causing obvious disease.

Taxonomy and genome: ELVd is associated with the family Avsunviroidae. Viroids in this group replicate in plastids and possess hammerhead ribozymes. The ELVd genome is a circular, single-stranded RNA and is typically around 240–260 nucleotides in length. Its replication and structure reflect the distinctive features of chloroplast-targeted viroids.

Host range and symptoms: Natural infections are primarily reported in eggplant, with related solanaceous species sometimes investigated under experimental conditions. Because ELVd often causes latent infections, many plants do not display clear symptoms. When symptoms occur, they can include mild mosaic, leaf distortion, or reduced vigor, but such manifestations are not consistently observed.

Transmission and epidemiology: ELVd spreads mainly through infected plant material and during vegetative propagation or grafting. Mechanical transmission via contaminated tools also contributes to spread. Seed transmission is not well established as a common route, and vectors are not routinely implicated in its epidemiology.

Detection and management: Diagnosis relies on molecular methods such as RT-PCR, RT-LAMP, or Northern blot analysis. Management focuses on using certified virus-free planting material, strict sanitation to prevent mechanical spread, quarantine of new material, and removal of infected plants when necessary. Researchers study ELVd to understand viroid biology, particularly chloroplast-based replication and RNA catalysis.

See also: plant viroids, Avsunviroidae, Eggplant diseases.