Further molecular characterisation of potyviruses infecting aroid plants for medicinal use in China.

Degenerate primers were used to detect and amplify 3'-terminal genome fragments of potyviruses from medicinal aroid plants growing at 16 sites in China. Virus was detected in 7 samples of which six, all of Pinellia ternata, contained a strain of soybean mosaic virus (SMV) similar to that previously reported from this host in China. The complete sequence of one isolate and the P1 protein coding region of the other isolates were also sequenced. In all cases, the P1 proteins resembled isolates of Dasheen mosaic virus (DsMV) more closely than SMV, confirming earlier suggestions of recombination in this region. In a phylogenetic analysis of SMV, DsMV and related sequences, the aroid sequences of SMV formed a distinct group which also included a sequence published as Zantedeschia symptomless virus (AF469171). One of the P. ternata samples was also infected with a second potyvirus, the 3'-terminal sequence of which was similar to DsMV and to some sequences published as Vanilla mosaic virus. The seventh infected sample was Typhonium flagelliforme and the virus from it was identified from its sequence as zantedeschia mosaic virus (ZaMV), providing the first report of this virus from mainland China.