Tomato chlorotic spot virus, an emerging tospovirus threatening vegetable production in the United States

Authors: ZHANG, SHOUAN - University Of Florida; Ling, Kai-Shu; SEAL, DASHINA - University Of Florida; POUDEL, BINDU - University Of Florida; MCGRATH, MARGARET - Cornell University; WANG, QINGREN - University Of Florida; MCAVOY, GENE - University Of Florida

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 5/31/2018
Publication Date: 10/1/2018
Citation: Zhang, S., Ling, K., Seal, D., Poudel, B., McGrath, M., Wang, Q., McAvoy, G. 2018. Tomato chlorotic spot virus, an emerging tospovirus threatening vegetable production in the United States. Phytopathology. 108(10S):S1.190. https://doi.org/10.1094/phyto-108-10-s1.1.
DOI: https://doi.org/10.1094/phyto-108-10-s1.1

Interpretive Summary:

Technical Abstract: Tomato chlorotic spot virus (TCSV) is a tospovirus first detected in tomato and bell pepper in south Florida in 2012. Subsequently, TCSV was confirmed in tomato in Ohio and New York. Since 2014, TCSV has caused significant losses to tomato and bell pepper growers in south Florida. Under field condition, TCSV is efficiently transmitted by thrips, especially western flower thrips (Frankliniella occidentalis), which is abundant in many parts of the U.S. Initial symptoms of TCSV in tomato begin to appear approximately three weeks after transplanting, primarily on top leaves, as blemishes and tiny necrotic lesions. Within one week, the symptoms quickly expand to cause wilting, bronzing, necrosis, deformation of leaves, and terminal stem and leaf death. In bell pepper TCSV causes chlorosis on top leaves, and necrosis over time. TCSV results in severe stunting and eventually death of the plant if plants are infected at an early stage. Infected tomato plants produce few if any fruit with necrotic rings rendering them unmarketable. Field survey of tomato fields conducted in Miami-Dade County, Florida in 2016 to 2017 indicated that TCSV has become the dominant tospovirus in south Florida. In 2017, TCSV was also detected in snap bean in a research greenhouse and in purslane, a common weed, in Homestead, Florida. A method of reverse transcription loop-mediated isothermal amplification (RT-LAMP) was developed for rapid and accurate detection of TCSV from tomato plants. Results of field trials indicate that tomato cultivars carrying sw-5 gene are resistant or tolerant to TCSV. Applying insecticides are not highly effective in reducing TCSV incidence, but can minimize secondary of TCSV by its thrips vectors.