Summary

 Taro(Colocasia esculenta Schott) originated in India and adjacent areas of southeast Asia and is now widely cultivated in Asia and Oceania. In some Pacific Coast countries, this crop is one of the main sources of starchy food. In Korea, the crop has been cultivated constantly over 4,000 tons/year. In this study, Dasheen mosaic virus(DsMV-Kr), causing mosaic symptoms was isolated from taro, and its properties were characterized.

The local lesion symptom was found in inoculated leaves of Tetragonia expansa and systemic mosaic symptoms on Zantedeschia aethiopica, while 11 species of indicator plants did not infect. In an electron microscope, DasMV particles were long filamentous type, with about 34 kDa in SDS-PAGE. Gel double diffusion test revealed that DsMV was not serologically related to Zantedechia mosaic virus(ZaMV) which has been reported an Araceae-infecting another potyviruses.

The coat protein(CP) gene of DsMV(-Kr) wsa cloned and their nucleotide sequences was determined. The sequence of the 3-terminal 1,199 nucleotides, which consisted of the 3-terminus of the partial nuclear inclusion body(NIb), coat protein(CP) gene and 3-non coding region. Similartiy at the nucletide and amino acid levels of CP and 3-NCR were from 51.0 ti 91.5% and from49.1 to 93.9%, respectively, when compared with those of other potyviruses.

Phylogenetic analysis of selected potyviral CP sequences indicated that the virus is an isolate of DsMV and distinguishable from other potyviruses. These results indicatd a new strain of DsMV, and the name Kr strain of DsMV is hereby proposed.