Keywords: 
• Piper nigrum L. /
• Cucumber mosaic virus /
• Hainan isolates /
• nucleotide /
• complete sequence analysis

Abstract: The full-length c DNA sequences of genomic RNAs of CMV-WN1,DA and FT isolates from the leaves of black pepper（ Piper nigrum L.） infected with cucumber mosaic virus in Hainan Province were determined by using RT-PCR and sequence analysis. The RNA1 of the CMV-WN1,DA and FT consisted of 3361,3360 and3359 nucleotides（ nt）,respectively,and encoded protein 1a. The RNA2 consisted of 3044,3048 and 3046 nt,respectively,and encoded protein 2a and 2b. The RNA3 contained 2217,2224 and 2216 nt,respectively,and encoded protein 3a and CP. The CMV-WN1,DA and FT isolates had the highest similarity in the sequences of RNA 1,RNA2 and RNA3 with the CMV-SD strain,and their amino acid sequences of all encoding proteins were also most highly similar with that of the CMV-Strain,of which the amino acid sequence of all the proteins had a93. 5% similarity with that of the CMV-SD except that 2b amino acid sequence shared a similarity of 90% or less. Analysis of the 5’NTR structure of RNA3,the phylogenetic tree analyses of 5’NTR nucleotide sequences of RNA3 and CP amino acid sequences showed that the CMV-WN1,DA and FT isolates were classified into CMV IB subgroup. The phylogenetic tree analyses of CP amino acid sequences also showed that CMV-WN1,CMV-FT and the isolate of the black pepper in Yunnan,CMV-YNP,were clustered into the same group while the CMVDA and the isolate of the black pepper in Hainan,CMV-HNP,were clustered into another separate group.