Detection of phytoplasmas in alder trees in Southern Italy
During the last few years, declining alder trees (Alnus glutinosa and A. cordata) have been observed in the Agri valley in Basilicata (Southern Italy). Infected trees showed symptoms of yellowing, sparse foliage, premature autumn coloration, sprouting, deliquescent branching, phloem necrosis, dieback and witches' brooms. Phytoplasmas have consistently been found in the phloem of diseased trees, and the authors felt that phytoplasmas are probably the causal agents of this disease. The authors noted that the symptoms observed are similar to those reported on ash affected by phytoplasmas in USA. Previous hybridization studies have indicated that phytoplasmas associated with diseases of alder, elm and ash were genetically related (EPPO RS 95/109).
Sources
Marcone, C.; Firrao, G.; Ragozzino; A.; Locci, R. (1994) Detection of MLOs in declining alder trees in Southern Italy and their characterization by RFLP analysis.
European Journal of Forest Pathology, 24, 217-228.