First Report of Red Clover Vein Mosaic Carlavirus Naturally Infecting Lentil

Area of Science:

• Plant Pathology
• Virology
• Agricultural Science

Background:

• Lentil (Lens culinaris Medik.) is a vital legume crop in the Pacific Northwest, susceptible to viruses like pea enation mosaic enamovirus (PEMV) and bean leafroll luteovirus (BLRV), causing significant yield losses.
• Red clover vein mosaic carlavirus (RCVMV) has been experimentally identified in lentil, with transmission by the pea aphid (Acyrthosiphon pisum Harris) noted.
• Monitoring for PEMV and BLRV in lentil crops in 1997 revealed unexpected symptoms, prompting further investigation into other viral agents.

Purpose of the Study:

• To investigate the incidence of various viruses, including RCVMV, in lentil crops exhibiting unusual symptoms in the Pacific Northwest.
• To confirm the presence and prevalence of RCVMV in naturally infected lentil populations.
• To characterize the symptoms and host range of RCVMV in experimentally infected plants.

Main Methods:

• Enzyme-linked immunosorbent assay (ELISA) was employed to test 204 lentil samples for PEMV, RCVMV, BLRV, alfalfa mosaic alfamovirus (AMV), and pea streak carlavirus (PeSV).
• Antiserum for RCVMV was developed, and oligonucleotide primers were designed for polymerase chain reaction (PCR) to verify viral identification.
• Mechanical inoculation of various plant species, including pea, chickpea, faba bean, and lentil, was performed to assess RCVMV's host range and symptoms.

Main Results:

• RCVMV was detected in 76 (34%) of the 204 tested lentil samples.
• A high coinfection rate was observed, with 75 out of 76 RCVMV-positive samples also infected with PEMV.
• Experimental inoculation confirmed RCVMV causes mild mosaic symptoms in pea, chickpea, faba bean, and lentil, with stunting observed in lentil and chickpea.

Conclusions:

• This study reports the first instance of natural infection of lentil by RCVMV in the Pacific Northwest.
• RCVMV is prevalent in the region and frequently coinfects lentil with PEMV, potentially exacerbating yield losses.
• The findings highlight the importance of considering RCVMV in lentil disease management strategies.