Emergence ofGroundnut ringspot virusandTomato chlorotic spot virusin Vegetables in Florida and the Southeastern United States

Abstract

Groundnut ringspot virus (GRSV) and Tomato chlorotic spot virus (TCSV) are two emerging tospoviruses in Florida. In a survey of the southeastern United States, GRSV and TCSV were frequently detected in solanaceous crops and weeds with tospovirus-like symptoms in south Florida, and occurred sympatrically with Tomato spotted wilt virus (TSWV) in tomato and pepper in south Florida. TSWV was the only tospovirus detected in other survey locations, with the exceptions of GRSV from tomato (Solanum lycopersicum) in South Carolina and New York, both of which are first reports. Impatiens (Impatiens walleriana) and lettuce (Lactuca sativa) were the only non-solanaceous GRSV and/or TCSV hosts identified in experimental host range studies. Little genetic diversity was observed in GRSV and TCSV sequences, likely due to the recent introductions of both viruses. All GRSV isolates characterized were reassortants with the TCSV M RNA. In laboratory transmission studies, Frankliniella schultzei was a more efficient vector of GRSV than F. occidentalis. TCSV was acquired more efficiently than GRSV by F. occidentalis but upon acquisition, transmission frequencies were similar. Further spread of GRSV and TCSV in the United States is possible and detection of mixed infections highlights the opportunity for additional reassortment of tospovirus genomic RNAs.

Resistance to Tospoviruses in Vegetable Crops: Epidemiological and Molecular Aspects

“…Interestingly, Melon yellow spot virus (MYSV), formerly reported only in Asia, has for the first time been found outside Asia, in Ecuador (94). Furthermore, in Florida in 2012 (66), the first occurrence of a natural interspecific reassortant Groundnut ringspot virus (GRSV)-Tomato chlorotic spot virus (TCSV) in tomato fields has been reported (144) and its parental TCSV species identified. Another study performed with a number of TSWV isolates showed that reassortment among isolates within a species seems to be a common evolutionary strategy (136), and, in one case, a resistance-breaking (RB) isolate was shown to originate through reassortment (73).…”

“…In addition to RB isolates (4, 22, 23, 62, 106), unique tospovirus isolates have been identified, arisen from genome reassortment during mixed infections (144,145). The ecological and evolutionary significance of such reassortant events, as well as the risk these resulting new viruses may pose on the durability of genetic resistance genes, remain to be elucidated.…”

First report of Tomato chlorotic spot virus on Mirabilis jalapa

“…South American isolates formed a separate monophyletic group to those from Central and North America. Webster et al (2015) reported that the RNAs of TCSV isolates from Florida (USA), Puerto Rico, and the Dominican Republic all share high levels of nucleotide identity with the corresponding RNAs of TCSV isolates from South America. With regard to Brazilian TCSV, the isolate from M. jalapa (TCSV-Mir-BR07, GenBank number KP276236) formed a monophyletic group with isolates from the states of Rio Grande do Sul (JQ034525) and Minas Gerais (AF282982), as well as Argentina (U49709), in the maximum-likelihood tree.…”

Dissecting the Mode of Maize Chlorotic Mottle Virus Transmission (Tombusviridae: Machlomovirus) by <I>Frankliniella williamsi</I> (Thysanoptera: Thripidae)

“…In Florida, thrips feeding damage has been associated with post-bloom fruit drop in citrus, fruit bronzing in strawberry, leaf distortion in pepper and other crops, and stippling in tomato (Frantz & Mellinger 1990;Childers 1999;Dŏgramaci et al 2011;Smith & Whidden 2014). Viruses in Florida transmitted by thrips include Tomato spotted wilt virus (TSWV), Tomato chlorotic spot virus (TCSV), Iris necrotic spot virus (INSV), and Groundnut ringspot virus (GRSV) (Baker et al 2007;Webster et al 2011Webster et al , 2015. Thrips species in Florida that have quarantine status elsewhere include F. occidentalis, Thrips hawaiiensis (Morgan), T.…”