CANDIDATUS PHYTOPLASMA PYRI INFECTIONS IN PEAR ORCHARDS IN TUNISIA
M. Ben Khalifa, M. Marrakchi, H. Fakhfakh
Samples from apparently healthy European pears (Pyrus communis) from Tunisian orchards and from trees showing symptoms recalling those of the “slow decline” form of pear decline, i.e. reduced growth, production of fewer and smaller leaves that turn reddish and drop early in autumn, were analyzed by polymerase chain reaction (PCR) using the universal phytoplasma primers P1/P7. A band with the expected size (1.8 kbp) was obtained from samples collected from symptomatic trees only. PCR products were used for restriction fragment length polymorphism (RFLP) analysis after digestion with the endonucleases AluI, RsaI and SspI. RFLP patterns obtained were consistent with those reported for Candidatus Phytoplasma pyri, thus providing evidence of the occurrence in Tunisia of this hitherto unrecorded pathogen.