摘要 : Double suppression subtractive hybridization was used to isolate DNA from 'Candidatus Phytoplasma prunorum' (GSFY2) propagated on Catharanthus roseus. Among the 11 new non-ribosomal genetic loci characterized, aceF and pnp genes w... 展开 Double suppression subtractive hybridization was used to isolate DNA from 'Candidatus Phytoplasma prunorum' (GSFY2) propagated on Catharanthus roseus. Among the 11 new non-ribosomal genetic loci characterized, aceF and pnp genes were selected as targets for detection and sequence typing. PCR primers chosen on aceF and pnp genes allowed to amplify the expected PCR products of 797 bp and 549 bp from the GSFY2 isolate as well as the homologous genetic loci from reference phytoplasma isolates of the group 16SrX. Sequences of aceF PCR products revealed a 13.7-15.5% variation between 'Ca. P. prunorum', 'Ca. P. pyri' and 'Ca. P. mali', which could be distinguished by specific sequence insertions or deletions. Four different groups of 'Ca. P. prunorum' isolates could be detected and discriminated in France according to their ace F sequence. 'Ca. P. prunorum' isolates B7, E22, PVCLA8 and PVCLA9, known to be associated with low level of symptom expression and formerly shown to provide cross protection to inoculated trees or peach seedlings against virulent isolates, had the same aceF sequence, which was one and two nucleotides different from the aceF sequence of the B6, GSFY, G32 and ECAM200 virulent isolates. A 'Ca. P. prunorum' plum isolate detected in Azerbaijan was much more different than the isolates detected in France (10-11 nucleotide changes). The greater variability in aceF relative to pnp makes aceF a better target for monitoring the variability among phytoplasmas infecting temperate fruit trees in Europe. 收起