SUMMARY

The sequences of the N-terminal 132 nucleotides of the coat protein genes of eleven Portuguese isolates of Zucchini yellow mosaic virus (ZYMV) were determined. The nucleotide sequence similarities among the eleven isolates suggested two groups, based on different codon usage for the amino acid residues in seven positions. Comparisons among the encoded amino acid sequences and those previously reported indicated that in this re-gion the Portuguese isolates were identical to isolate