Tospoviruses: A growing threat to lettuce production in Mexico

Authors: MEJIA QUEVEDO, ISRAEL - University Of Chapingo; HICKS, CHAELA - Former ARS Employee; Hladky, Laura; Hasegawa, Daniel; TLAPAL BOLANOS, BERTHA - University Of Chapingo

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 6/5/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Lettuce is a leafy greens vegetable that is grown throughout the central regions of Mexico. In 2023, total production equaled 341,686.62 tons, which was mostly destined for the export market. Several plant pathogenic viruses can cause issues for lettuce, including tomato spotted wilt virus (TSWV), an orthotospovirus that is transmitted by thrips. However, in recent years, the occurrence of virus infections in lettuce have increased, sometimes resulting in the abandonment of the crop due to high disease incidence. In 2023, lettuce plants from the state of Mexico were tested for the presence of TSWV and a second orthotospovirus, impatiens necrotic spot virus (INSV) using lateral flow serological strips, TAS-ELISA, and Sanger sequencing. Our findings confirmed the presence and predominance of INSV in most of the lettuce plants analyzed. Follow up field surveys near agricultural areas where tospovirus outbreaks occurred identified additional hosts for INSV and TSWV. Samples were tested for INSV and TSWV using a combination of serological and genetic techniques. The results highlight the importance of several weeds and other crops as possible reservoirs of INSV and TSWV. Understanding the host range for these two economically important viruses in the local region enhances our ability to develop management strategies, including tactics to identify and minimize high risk areas that serve as sources of virus inoculum.