Introduction of the Exotic Tomato yellow leaf curl virus-Israel in Tomato to Puerto Rico

Abstract

Thirty-five-day-old tomato plants (cultivar Florasette) exhibited yellow leaf curling, stunting, and extremely reduced fruit set in spring 2001, in Guanica, Puerto Rico (PR). Twenty percent disease incidence was observed in this field and, 8 weeks later, 75% of the plants showed symptoms. These symptoms were distinct from those caused by other tomato-infecting begomoviruses reported previously from PR, namely Merremia mosaic virus, Tomato mottle virus (ToMoV), and Potato yellow mosaic virus (1). A colony of the B biotype of Bemisia tabaci (Genn.) was used to transmit the suspect virus from symptomatic plants collected in the field and established in the greenhouse in Rio Piedras, PR. The suspect virus was transmitted readily to tomato cultivar Roma (10 of 10 plants), and symptoms were like those observed in the field. Symptoms also were reminiscent of those described for several Old World begomoviruses, referred to as Tomato yellow leaf curl virus (TYLCV). Total nucleic acids were isolated from three symptomatic field samples and three greenhouse-inoculated tomato plants showing typical disease symptoms. Extracts were analyzed by polymerase chain reaction (PCR) with primers AV2466 and AC1145 to amplify a begomoviral fragment (approximately 1.1 bp) that contains a portion of the intergenic region and the viral coat protein gene (CP) (2). Amplicons were cloned, and their nucleotide sequences were determined. A comparison of CP with other well-studied begomoviral nucleotide sequences revealed that the CP sequences for field isolates 1 to 6 shared 99.7 to 100% identity with each other and 99.9 to 100% identity with TYLCV from Israel (TYLCV-IL; accession no. X76319) as well as TYLCV-IL isolates discovered in the Dominican Republic (DO; accession no. AF024715) and, subsequently, in Florida. TYLCV-specific PCR primers (forward) 5′-GAATTCCGCCTTTAA-TTTG-3′ and (reverse) 5′-GAATTCCCACTATCTTTCTC-3′ were used to amplify the complete viral genome form a PR field isolate. An expected-sized amplicon of approximately 2.8 kb was obtained, and the nucleotide sequence of two cloned amplicons was determined. Genome organization revealed a predicted precoat open reading frame of 351 bp, which is characteristic of other Old World begomoviruses, including TYLCV-IL. Nucleotide comparisons indicated that the PR isolate shared 99% nucleotide sequence identity with TYLCV-IL (first reported from Israel) and introduced TYLCV-IL isolates in DO and Florida, thereby confirming the introduction of TYLCV-IL into PR. TYLCV-IL was first identified several years ago in the Western Hemisphere, and the virus has been reported in five offshore locations and three continental U.S. states since its initial introduction into the DO in the early 1990s. Considering the extreme virulence of TYLCV-IL compared with most New World tomato-infecting begomoviruses, this introduction, which likely occurred from a nearby Caribbean country or Florida, has the potential to destroy the fresh-market tomato industry in PR, which supplies tomatoes to the continental United States during the winter months. There is compelling evidence for the routine movement of tomato seedlings from the continental United States to this location in PR throughout the last 10 years, including the previous introduction of ToMoV (1). These incidences and others indicate the need for those in infected areas to take precautions to avoid further spread of this highly damaging virus in and adjacent to the Caribbean region. References: (1) A. M. Idris et al. Phytopathology 88:S42, 1998. (2) A. M. Idris and J. K. Brown, Phytopathology 88:648, 1998.

Ongoing geographical spread of Tomato yellow leaf curl virus

“…Other independent introductions of TYLCV into the Caribbean likely occurred when TYLCV-IL moved from East-Asia between 2006 and 2011 (Figs. 1-3), and TYLCV-Mld arrived there from the Western Mediterranean between 1990 and 2009 (Bird et al, 2001;Mcglashan et al, 1994;Roye et al, 1999;Zambrano et al, 2007).…”

Tomato yellow leaf curl disease and plant-virus vector interactions

“…Based on these markers several "biotypes" were described based on biology and using the esterase morphotypes. The Q biotype of B. tabaci was first described as native to the Mediterranean Basin in 1997 (Guirao et al, 1997) and one year later TYLCV was first described on the United States east coast and Yucatan Peninsula (Ascencio-Ibáñez et al, 1999), then into Mexico (Brown and Idris, 2006) and Puerto Rico (Bird et al, 2001), and TYLCV displaced tomato yellow leaf curl sardinia virus (another virus species associated with TYLCD) in Spain. By this time reports also described the replacement of the B biotype in Spain by the Q biotype (Moya et al, 2001).…”

First Report of Tomato Yellow Leaf Curl Virus in Greenhouse Tomatoes in Kentucky

“…In the United States it was introduced into Florida in late 1996 or early 1997 (14) and has since then been detected in the continental US in the following states: Georgia in 1998 (12); Louisiana in 2000 (17); Mississippi (9) and North Carolina in 2001 (15); South Carolina (11) and Alabama in 2005 (1); Arizona (8) and Texas in 2006 (10); and California in 2007 (16). TYLCV was reported in Puerto Rico in 2001 (2). TYLCV has been found in the US in field and greenhouse tomato-production systems and may have spread by the movement of infected tomato transplants.…”