‘Candidatus Phytoplasma mali’ identified in Prunus avium, P. armeniaca and P. domestica
Apple proliferation is caused by ‘Candidatus Phytoplasma mali’ (EPPO A2 List). In addition to apple (Malus domestica) which is the main host, the presence of this phytoplasma has been detected in hazelnut (Corylus avellana), pear (Pyrus communis) and Japanese plum (Prunus salicina). In 2004, in south-western Slovenia, symptoms of wilting, decline, floral and phloem necrosis were observed on cherry trees (P. avium). Phytoplasmas could not be found in leaves or phloem from 40 tested trees, but were detected in roots of 3 symptomatic trees and 1 asymptomatic tree (DAPI and electronic microscopy). These phytoplasmas were then identified as ‘Ca. Phytoplasma mali’ with molecular techniques (PCR assays, RFLP, sequencing). This phytoplasma was also identified in 2 out of 29 apricot trees showing stem necrosis and leaf wilting, and in 1 out of 34 plum trees showing late flowering. According to the authors, this is the first time that ‘Ca. Phytoplasma mali’ has been detected in cherry, apricot or European plum. But it is underlined that although the infected trees tested negative for other pathogenic bacteria, further experiments are needed to verify whether ‘Ca. Phytoplasma mali’ caused the observed symptoms.
New Disease Reports. BSPP website (last retrieved 2007-04).
Mehle N, Brzin J, Boben J, Hren M, Frank J, Petrovič N, Gruden K, Dreo T, Žežlina I, Seljak G, Ravnikar M (2007) First report of ‘Candidatus Phytoplasma mali’ in Prunus avium, P. armeniaca and P. domestica http://www.bspp.org.uk/ndr/jan2007/2006-90.asp