Archivio Journal of Plant Pathology

Abstract:

In March 2017, severe infections of tomato were observed in heated plastic tunnels in the South of Tunisia. Symptoms consisted of chlorotic mottling and vein distortion on middle leaves, as well as severe leaf curling and stunting. Based on the symptoms and the presence of Bemisia tabaci, a begomovirus infection was suspected. Genomic DNA was purified from leaf samples of six symptomatic and two asymptomatic tomato plants and used in PCR to identify tomato yellow leaf curl virus (TYLCV), tomato yellow leaf curl Sardinia virus (TYLCSV) or recombinant species with the amplification of fragments ca. 570 bp for TYLCV and Rec A, and ca. 800 bp for TYLCSV and Rec B (Davino et al., 2008). Two of six tomato samples resulted infected with TYLCV Rec A. To identify the virus species present in PCR-negative samples, PCR was performed using specific primers MA2061 and MA2062 for tomato leaf curl New Dehli virus (ToLCNDV) (Ruiz et al., 2015). An amplicon of approximately 890 bp was obtained from four tomato samples tested, but not from symptomless plants. Sequencing two PCR amplicons showed 99.9% nucleotide sequences identity. The ToLCNDV nucleotide sequences (GenBank accession Nos. MF784758 and MF784759) shared 99.7 to 99.5% nucleotide identity with partial nuclear shuttle protein gene sequences of ToLCNDV from zucchini and tomato in Spain respectively (KF749227 and KM977734). ToLCNDV, a bipartite begomovirus, was first reported on Solanaceous and Cucurbitacae crops in India and neighboring countries, and more recently on zucchini and tomato in Spain (Juárez et al., 2014; Ruiz et al., 2015), and on cucurbits in Tunisia (Mnari-Hattab et al., 2015). To the best of our knowledge, this is the first report of ToLCNDV on tomato in Tunisia.