A NEW TRANSMISSIBLE SYMPTOMOLOGY ON SWEET CHESTNUT IN ITALY

A new symptomology is spreading on sweet chestnut in Acquasanta Terme in the Marche Region (Italy). Symptoms can be observed at the beginning of the season on leaves that appear distorted and chlorotic. Later in the season, necroses are evident on the youngest leaves and the whole crown appears lighter and sparse. Affected trees drastically reduce fruit production and maturation. On old, grafted marrone trees, symptoms are evident on branches above the graft, while sprouts from the wild rootstock generally appear asymptomatic. Indexing experiments were carried out on grafted marrone seedlings with material collected from symptomatic trees: chlorotic and distorted leaves were observed on re-sprouts. Symptomatic material was tested for phytoplasmas with nested-PCR; no amplification products were obtained with any of the primer combinations used.