Variation between Turnip mosaic virus Isolates in Zhejiang Province, China and Evidence for Recombination

The 3¢-terminal sequences (c. 1700 nt) of the RNA genome of 10 Turnip mosaic virus (TuMV) isolates from different hosts in Zhejiang province, China, were determined. Phylogenetic analysis of the coat protein nucleotide sequences revealed that most TuMV sequences fell into two distinct clusters. The Chinese isolates B1-B4 (from Brassica spp.) were similar and placed in the largest group (Group 1), while the isolates R1-R6 (from Raphanus) were usually placed in a distinct but smaller group (Group 2). There were only approximately 90% identical nucleotides between the two groups. However, one isolate (R5) showed evidence of recombination in that the region between nucleotides 430 and 450, from the start of the coat protein gene and its 3¢-terminus, was a Group 1 type.