First report of Tomato yellow leaf curl Sardinia virus (TYLCSV) infecting tomato crops in Greece

Abstract

Tomato yellow leaf curl virus (TYLCV) and Tomato yellow leaf curl Sardinia virus (TYLCSV) are two viruses of the genus Begomovirus (family Geminiviridae) causing yellow leaf curl disease of tomato ( Lycopersicon esculentum ) crops in the Mediterranean basin (Accotto et al ., 2000) and other regions of the world (Czosneck & Laterrot, 1997). In Greece, tomato yellow leaf curl disease was first reported in 2000, causing heavy losses in greenhouse and open field tomatoes in Crete (Avgelis et al ., 2001). During the summer of 2005, a high percentage of greenhouse tomato crops in southern Peloponnese and Crete exhibited severe stunting, reduced leaf size and curling, yellowing, shortened internodes and a bushy appearance; symptoms that could easily be attributed to tomato yellow leaf curl disease. High populations of the whitefly vector Bemisia tabaci were present in greenhouse and open field tomato crops. Plants with symptoms were collected from the areas of Glykovrysi, Agios Ioannis, Neapoli (Peloponnese) and Mires, Tympaki, Ierapetra (Crete). DNA was extracted from leaves of 48 of these plants and a 580 bp of the coat protein (CP) gene was amplified by polymerase chain reaction (PCR) using the TY(+) and TY(–) primer pair (Accotto et al ., 2000). Restriction fragment length polymorphism (RFLP) analysis (using restriction endonuclease Ava II) of the PCR product produced a 360, 150 and 68 bp pattern from 26 isolates collected from all sampling areas in Peloponnese and from two areas in Crete (Mires, Tympaki), indicating the presence of TYLCSV. All 22 isolates from Ierapetra (Crete) produced a TYLCV pattern (302 and 277 bp). The amplified DNA from six TYLCSV isolates was cloned and sequenced. All six sequences were identical (EMBL accession no. AM 259652) and showed 100% nucleotide identity to a TYLCSV isolate from Sicily (EMBL accession no. Z28390). These results show that both TYLCV and TYLCSV species co-exist in Crete, whereas in Pelloponese only TYLCSV was found. This is the first report of TYLCSV in Greece.