Detection of Tomato yellow leaf curl virus in imported tomato fruit in northern Europe

Imported tomato fruits infected with Tomato yellow leaf curl virus (TYLCV) were identified on the market in northern Europe using paper-based FTA Classic Cards (Whatman), polymerase chain reaction (PCR) and partial DNA sequence analysis. Trade tomatoes originating from southern Europe, Africa and the Middle East were sampled in Estonia and Sweden, and tested for infection with begomoviruses. Out of 100 batches analysed with five fruits sampled in each batch (58 batches from Estonia and 42 from Sweden), 20 batches were positive (16 from Estonia and four from Sweden). Rolling circle amplification (RCA) and full-length genome sequence analysis of one isolate collected in Estonia and one isolate in Sweden, revealed highest nucleotide sequence identity at 99% to TYLCV-IL for the Estonian isolate and at 97% to TYLCV-Mld for the Swedish isolate. In this study, TYLCV was identified for the first time in imported tomato fruits on the market in northern Europe. FTA cards proved to be an effective means to collect, extract and store begomovirus DNA from tomato fruits and the subsequent molecular analysis.