1997 Volume 63 Issue 2 Pages 89-94
A viroid was detected from European pears cultivated in Fukushima and Yamagata prefectures, Japan. Nucleotide sequence analysis of each of the Fukushima and Yamagata isolates revealed that they were isolates of pear blister canker viroid (PBCVd) reported in France. The Fukushima isolate consisted of 312 nucleotides, whereas the Yamagata isolate had 313 nucleotides. The only difference between the consensus sequence of the two isolates was an additional A residue in the Yamagata isolate at the site between no. 54 and 55 of the Fukushima isolate. The Fukushima isolate differed from the French isolate P2098T (Hernandez et al., 1992) at 26 sites in the sequence, the Yamagata isolate at 27 sites. These changes included 17 base exchanges and six deletions for both isolates, with three insertions for the Fukushima isolate and four insertions for Yamagata. PBCVd was detected from six of twelve (50%) European rough bark (Sohi-byo in Japanese) pear samples in Fukushima prefecture and three out of eight (37.5%) dimple pit (Kubomika-byo in Japanese) samples in Yamagata, as opposed to none of nine European and eight Japanese symptomless pears.