Il Deperimento della componente arborea e arbustiva nell’isola di Caprera: caratterizzazione della sindrome e studi eziologici

Species ofBotryosphaeriaceaeare well known as endophytes and pathogens of woody plants world-wide. Beginning in 2008, a field survey was conducted to study species ofBotryosphaeriaceaethat occur on declining trees and shrubs of Mediterranean maquis on Caprera Island (Sardinia, Italy). Fungal isolates from symptomatic plants were identified on the basis of morphological features, as well as DNA-based techniques. Eight species were constantly isolated from diseased plants:Diplodia corticola,Diplodia seriata,Fusicoccum aesculiandNeofusicoccum parvum(from holm oak),Diplodia africana,Neofusiccocum australeandNeofusicoccum luteum(phoenicean juniper),Diplodia scrobiculata(strawberry tree). Pathogenicity of all fungal species was verified by stem inoculation on seedlings of the same hosts from which they were isolated, under controlled laboratory conditions. All fungal species, were shown to be pathogens. The results obtained emphasize that several species ofBotryosphaeriaceaemay represent a serious threat for Mediterranean trees and shrubs. In particular suggest thatD. corticolais an important contributing factor in the onset of long-term oak decline. Moreover, our findings have contributed to improving the knowledge ofD. africanaandD. scrobiculataby expanding their host range that includes now phoenicean juniper and strawberry tree, respectively.