First report of Tomato yellow leaf curl virus in tomato in Guadeloupe [Texte intégral]

In September 2001, symptoms of stunting and chlorotic curled leaves of reduced size were observed on tomato plants in Guadeloupe. These symptoms were different from those described for Potato yellow mosaic virus, which has been present since 1993, but similar to those described for Tomato yellow leaf curl virus (TYLCV). Samples from symptomatic plants were collected and analyzed by polymerase chain reaction (PCR). Primers PC1 (5'-TGACTATGTCGAAGCGACCAGG-3') and PC2 (5'CGACATTACAGCCTCAGACTGG-3') were designed to amplify a 950-bp fragment within the coat protein gene (CP) of TYLCV-IL species (2). Primer pair MP16/MP82 (3) amplified a 550-bp fragment from the conserved nonanucleotide sequence (TAATATTAC) to the 5' end of the CP gene. Products of expected sizes were obtained with both pairs of primers from all symptomatic samples but not from uninfected samples. A 950-bp and a 550-bp PCR product were cloned into a pGEM-T Easy Vector (Promega, Madison, WI) and sequenced with plasmid specific primers (SP6 and T7). Sequences were compared with those available in the NCBI database using BlastN. Fifteen of the sequences that gave the highest score with BlastN were aligned with the Guadeloupe sequences using Clustal W. The nucleotide sequence of the 950-bp fragment (GenBank Accession No. AY319645) shared at least 97% sequence identity with that of TYLCV from Israel (EMBL Accession No. X15656), Puerto Rico (GenBank Accession No. AY134494), Cuba (EMBL Accession No. AJ223505), and the Dominican Republic (GenBank Accession No. AF024715). Similar percentages of identity were obtained with the 550-bp sequence (GenBank Accession No. AY319646). These results confirm that a begomovirus belonging to the species TYLCV-Israel is infecting tomato in Guadeloupe. To our knowledge, this is the first report of TYLCV in this region of the Caribbean. Puerto Rico is the closest location from which TYLCV was previously reported (1). In May 2002, typical TYLCV symptoms were observed in all tomato production areas at an incidence of 80 to 100%. (Texte intégral)