New disorder of chestnut found in Marche region (Italy)
In Italy, a new disorder of chestnut has recently been reported by the Plant Protection Service of the region Marche. This disorder was observed on Castanea sativa growing within the National Park ‘Gran Sasso’, on the commune of Acquasanta Terme (province of Ascoli Piceno). The outbreak covered approximately 15 ha. Affected trees showed leaf yellowing, distortion, chlorosis followed by marginal necrosis and production of fruits was drastically reduced. Among cultivars present in the affected area, cv. ‘Marone di Acquasanta Terme’ was particularly susceptible. It is suspected that a pathogen is involved in this disorder as it was possible to transmit the disease by grafting. However, in preliminary studies, it was not possible to detect viral dsRNA in symptomatic samples.
Interestingly, it can be recalled that in 1996, a similar disorder called ‘chestnut yellows’ was reported by Mittempergher and Sfalanga in Emilia-Romagna and Toscana (see EPPO RS 99/044). Similar symptoms (yellowing, distortion, marginal necrosis) and severe reduction of fruit production were reported. Tree decline and death were also mentioned. At that time, phytoplasmas were suspected but PCR tests failed to detect them. The etiology of the disease remained unknown. The disease was included on the EPPO Alert List but was subsequently deleted in the absence of any information about its etiology. Further studies are needed on the etiology of these disorders of chestnut and their possible relationships.
Sources
NPPO of Italy, 2006-02.
Mittempergher L, Sfalanga A (1998) Chestnut yellows: a new disease for Europe. Phytopathologia Mediterranea 37(3), 143-145.