HIGH SIMILARITY AMONG THE TOMATO YELLOW LEAF CURL VIRUS ISOLATES FROMTHE WEST MEDITERRANEAN BASIN - THE NUCLEOTIDE-SEQUENCE OF AN INFECTIOUS CLONE FROM SPAIN

An isolate of tomato yellow leaf curl geminivirus, from the first epid emic outbreaks that occurred in Murcia, Spain (TYLCV-M) in 1992, was c loned and its nucleotide sequence was determined. The circular single stranded DNA consisted of 2777 nucleotides. The genome organization re sembled that of other TYLCV sequenced so far; regulatory signal sequen ces for bidirectional transcription and for polyadenylation of the tra nscripts were localized in the sequence. Infectivity of the cloned DNA was demonstrated by subcloning a 1.8 mer of TYLCV-M in pBin19 and agr oinoculating it into tomato and Nicotiana benthamiana plants. Symptoms and viral DNA forms in agroinfected plants did not differ from those of field infected ones. Sequence comparisons with other TYLCV isolates show a high homogeneity between isolates from the West Mediterranean Basin, suggesting the presence of a geographical cluster.