A tissue printing hybridization (TPH) method for
detecting pome fruit viroids was developed and used for
a survey in Bosnia and Herzegovina. A total of 310 samples,
representative of 65 apple and 51 pear cultivars
and of several rootstocks were tested for the presence of
Apple scar skin viroid (ASSVd), Apple dimple fruit viroid
(ADFVd) and Pear blister canker viroid (PBCVd).
Whereas ASSVd and ADFVd were not found, 13% of
the pear samples tested by TPH gave positive signals for
PBCVd that were confirmed by dot-blot and northernblot
hybridization assays. These data show for the first
time that PBCVd infects pear trees (belonging to at
least 10 different cultivars) in Bosnia and Herzegovina
and validate the use of TPH for surveys of viroid infections
in pome fruit trees. Molecular characterization of
the PBCVd population infecting the native pear cv Rancica
identified five new polymorphic positions in the viroid
genome, two of which are shared by all the sequenced
variants of this Bosnian isolate. Apple cv Spy
227 was shown to be an experimental host of PBCVd
