Viral DNA extraction was conducted using the Viral Gene-spin Viral DNA/RNA Extraction Kit (iNtRON Biotechnology, Seongnam, Korea) from tissue samples following manufacturer’s protocol. PCR analysis was done with 1× AccuPower PCR Master Mix (Bioneer, Daejeon, Korea) and TYLCV-specific primer set, whose target is TYLCV partial sequence for intergenic region (IR) and V2 gene (5′-GATGGCCGCGCCTTTTCCTTTTATGTGG-3′, 5′-GCTGCTGTATGGGCTGTCGAAGTTCAG-3′) (Kil et al., 2016 (link)). Amplification was carried out under the following conditions: preheating at 94°C (3 min), then 35 cycles of 30 s at 94°C, 30 s at 58°C and 1 min at 72°C, followed by a final extension at 72°C (5 min). PCR products were visualized in 1% agarose gel electrophoresis.