Outbreak of tomato fruit blotch virus in the most relevant tomato greenhouse production area of Sicily

Abstract

Tomato (Solanum lycopersicum L.) is threatened by several viral diseases. In autumn 2018, tomato fruit blotch virus - ToFBV (Blunervirus genus, Kitaviridae family), was isolated for the first time from symptomatic tomato plants in Italy (Latina, Lazio) (Ciuffo et al. 2020). The ToFBV genome has four polyadenylated single-stranded RNA(+) segments, RNA1 (5,790 nucleotides) and RNA2 (3,621 nt) contain a single open reading frame (ORF), while RNA3 (2,842 nt) and RNA4 (1,924 nt) encode five and two ORFs, respectively. In December 2023, tomato plants cultivated in different greenhouses located in Ragusa province (Sicily, Italy) showed circular or irregular chlorotic blotches in tomato fruit, while no symptoms were observed in young or middle leaves. Twenty symptomatic tomato plants were collected for molecular analysis, and an asymptomatic plant was used as negative control. To identify the disease causal agent, samples were tested for pepino mosaic virus (PepMV) by RT-PCR, for tomato mottle mosaic virus (ToMMV) and tomato brown rugose fruit virus (ToBRFV) by real time RTPCR. All samples tested negative for PepMV, ToMMV and ToBRFV. Subsequently, symptomatic samples were analyzed by end point RT-PCR for ToFBV using the Bluner1F/ Bluner1R primer pair (Nakasu et al. 2022). All symptomatic samples tested positive for ToFBV