Detection and identification of Pear blister canker viroid occurring in pear trees in Canada

A survey was conducted in Canada for the presence of Pear blister canker viroid (PBCVd) in pear trees of different origin. A total of 118 pear samples were tested and only two (Anjou Euwer and Clapp's Favorite Starkrimson) tested clearly positive, as also confirmed by RT-PCR with specific primers and sequencing of amplified products. Infection by Apple scar skin viroid and/or Apple dimple fruit viroid in all the tested samples was ruled out the basis of TPH hybridization tests with specific probes. This is the first documented report of PBCVd in Canada.