Comparison of serological and molecular techniques for detection of Tomato yellow leaf curl begomovirus*

Tomato yellow leaf curl begomovirus (TYLCV) causes severe damage to tomato crops. The virus is not considered as established in France, although a single outbreak (subjected to eradication measures) occurred in 1999. Since the vector of TYLCV, the whitefly Bemisia tabaci, is already present in France and the virus is present in several neighbouring Mediterranean countries, there is a high risk of introduction into France. To prevent spread of the disease, systematic detection is essential. Samples of tomato and Eustoma grandiflorum were tested, and different methods were compared to determine which is the best for regular tests. Classical serological methods (TAS‐ELISA and immuno‐printing) were compared with molecular hybridization (which is specially suitable for the single‐stranded DNA genome of Geminiviridae), and PCR. Tissue‐printing methods, which avoid time‐consuming sample preparation, gave consistent results with hybridization. In contrast, immunoprinting detection confirmed only 61 % of samples found positive with TAS‐ELISA. Furthermore, a comparison of signal intensities obtained with TYLCV‐IL or TYLCV‐Sar probes provided indications on viral strain(s) detected. The efficiency, reliability and feasibility of serological and molecular techniques for routine official testing are discussed.