First Report of Capsicum chlorosis virus Infecting Tomato in Taiwan

Area of Science:

• Plant Virology
• Molecular Plant Pathology
• Agricultural Science

Background:

• Tomato plants (Solanum lycopersicum cv. Known-you 301) in Taiwan exhibited chlorosis and necrosis.
• Disease incidence was approximately 5% in affected fields.

Purpose of the Study:

• To identify the viral pathogen responsible for the observed symptoms in tomato plants.
• To characterize the identified virus and confirm its pathogenicity.

Main Methods:

• Reverse transcription (RT)-PCR was used with degenerate and specific primers to detect tospoviruses, tobamoviruses, potyviruses, and Cucumber mosaic virus.
• RT-PCR amplified an 816-nt fragment from the L RNA of suspected tospoviruses.
• Virus isolation, sequencing, homology searches, and pathogenicity tests on tomato plants were performed.

Main Results:

• An 816-nt L RNA fragment showed high nucleotide and amino acid identity to Capsicum chlorosis virus (CaCV).
• The isolated virus, TwTom1, was confirmed as a CaCV isolate based on L RNA and nucleocapsid (N) gene sequence analysis.
• Inoculated tomato plants developed symptoms similar to those observed in the field, and CaCV was detected in symptomatic samples.

Conclusions:

• The study confirms Capsicum chlorosis virus (CaCV) as the causative agent of chlorosis and necrosis in tomato plants in Taiwan.
• This is the first documented instance of CaCV naturally infecting a non-ornamental crop, tomato, in Taiwan.
• The findings highlight the potential economic impact of CaCV on tomato production.