Tomato yellow leaf curl disease (TYLCD), caused by tomato yellow leaf curl virus (TYLCV), is one of the most important viral diseases of tomato (Solanum lycopersicum L.). The disease was first reported in Sudan and the Middle East in 1932 (Yassin and Nour, 1965), but it was only in the 1960s that TYLCV was identified as the virus responsible for TYLCD (Mabvakure et al., 2016). The virus occurs epidemically in tomato crops in tropical and subtropical regions of several countries around the world and has caused significant economic losses (Cao et al., 2024; Prasad et al., 2020; Yan et al., 2021). In South America, TYLCD had only been reported in Venezuela (Prasad et al., 2020; Yan et al., 2021). TYLCV belongs to the species Begomovirus coheni (genus Begomovirus, family Geminiviridae), and the whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is a vector (Brown et al., 2015). In December 2024, tomato plants were found in commercial fields in the municipality of Faxinal (24°01’18.4”S, 51°19’10.9”W), Paraná state, Brazil, with symptoms similar to those described for TYLCV infections. Samples from symptomatic plants were collected and taken to the Virology Laboratory of the Institute for Rural Development of Paraná/IAPAR-Emater – IDR-Paraná for analyses. Describe the symptoms leaves was extracted (ABARSHI et al. 2012) and subjected to polymerase chain reaction (PCR) using the primers PAL1v1978' (5' GCA-TCT-GCA-GGC-CCA-CAT-YGT-CTT-YCC-NGT 3') and 'PAR1c496' (5' CAT-GCT-GCA-GTA-CAT-YGG-CCT-YTT-DAC-CC 3'), specific to begomoviruses (ROJAS et al., 1993). DNA amplicons of the expected 1.1 kbp in size were directly Sanger sequenced (Applied Biosystems ABI 3730XL DNA Analyzer, Foster City, CA, USA). The sequences of the amplified DNA fragments were analyzed using the BLASTn algorithm on the NCBI platform (https://blast.ncbi.nlm.nih.gov/). Nucleotide sequences confirmed the presence of TYLCV isolates with 96%-97.8% identities with TYLCV isolate Sinaloa (FJ012359). Furthermore, multiple sequence alignments with ClustalW (Thompson et al., 1994) and a maximum likelihood tree constructed using MEGA X (Kumar et al., 2018) confirmed the clustering of the Brazilian isolate with isolate Sinaloa. The TYLCV sequences obtained in our study were deposited in NCBI GenBank as accessions PX443927 (RM2) and PX443928 (RM3). Additionally, the whole genome of the TYLCV strain PX443927 (RM2), was amplified by the RCA assay using the TempliPhi 100 amplification kit (Cytiva, Marlborough, MA, USA), following a previously reported protocol optimized for the amplification of a double stranded viral DNA genome (Rector et al., 2004). The entire nucleotide the full-length sequence of Brazilian isolate RM2 was obtained through primer walking and direct Sanger sequencing of the RCA product. The complete genomic sequence of the TYLCV strain PX443927 (RM2), from Brazil was deposited in GenBank as accession number PX513837. Finally, the presence of TYLCV in commercial tomato fields was observed in at least seven municipalities in the state of Paraná, Brazil. This is the first report confirming the occurrence of TYLCV infecting tomato plants in Brazil.
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