PHYTOPLASMA DISEASES OF STONE FRUIT TREES IN POLAND

Symptoms typical for phytoplasma diseases were observed recently on peach, apricot nectarine, and sweet cherry trees growing in experimental orchards in Poland. PCR/RFLP analysis were carried out to identify the causal agents of diseases. Nucleic acid was extracted from phloem tissue. The target DNA were amplified by nested PCR with universal primers R16F2n/R2 and also specific primer pairs R16(I)F1/R1, R16(III)F2/R1, R16(V)F1/R1, and R16(X)F1/R1 followed by P1/P7 primers. Using R16F2n/R2 and R16(V)F1/R1 primer pairs, all samples of DNA extracted from infected trees yielded a nested PCR products of the appropriate size. No PCR products were obtained from healthy trees. RFLP analyses of the R16F2n/R2 amplified fragments revealed that the phytoplasma isolated from the affected peach, nectarine, apricot, and sweet cherry trees is closely related to the elm yellows group (16SrV).