Identification Of Subgroup Of A Cucumber Mosaic Virus Isolate From Capsicum Chinense In Hainan

An isolate of Cucumber mosaic virus (HN-Cc) was isolated from Capsicum chinense leaves whose tip showed necrosis, and maintained in Nicotiana tabacum. Electron microscope study revealed that the purified virus particle was a kind of spherical virus particles whose dimeter about 28-30nm, the cytopathological ultrastructure included the particles approached and attached to the cell walls, then entered the sensitive cell through the plasmodesma, and some swell and disintegration chloroplast were observed. 1'he study of host responses to virus infection suggested that the HN-Cc could infect plants of 11 species from 4 families, and was transmitted by Myzus persicae and the seed of the disease host, while it could not be transmitted by the soil. It showed positive reaction that the HN-Cc was detected with the CMV antiserum by ELISA. The molecular weight of the coat protein (CP) subunit was about 28kDa as evaluated by SDS-PAGE. The CP gene was amplified by RT-PCR using the genomic RNA as template and a pair of primers specific to CMV. Sequencing results showed that the CP gene of the HN-Cc consists of 657 nucleotides which could encode the protein of 218 amino acids. The nucleotide sequences and amino acid sequences of the HN-Cc shared over 92.1% and 96.3% homology with other isolates belonging to the subgroup I of CMV, respectively, while they shared under 77.3% and 80.7% homology with orther isolates belonging to the subgroup , respectively. According to these results, the HN-Cc was indentified as an isolate of CMV, belonging to the subgroup I .