Botryosphaeriaceae species associated with cankers and dieback of grapevine and other woody hosts in agricultural and forestry ecosystems

Species of Botryosphaeriaceae have a cosmopolitan distribution and are known to cause serious diseases with dramatic economic implications in both agricultural and forestry ecosystems. In recent years, epidemic attacks of Diplodia and Neofusicoccum species have gradually increased in Sardinia on different hosts such as holm oak, cork oak and Juniper. Considering the plurivorous nature of many Botryosphaeriaceae species and the little information available on their geographic distribution, host range and genetic variability in Sardinia, it was considered appropriate in this PhD thesis to expand knowledge on five patho-systems by studying taxonomy, morphology, phylogeny and pathogenicity of the main species associated with plant cankers and dieback. Results obtained highlight that more than twenty Botryosphaeriaceae species occur on declining plants in both agricultural and forestry ecosystems. Among these, three species Diplodia subglobosa, Lasiodiplodia exigua and Lasiodiplodia mediterranea, morphologically and phylogenetically (ITS and EF1-α sequences data) distinct from all other known species, are described and illustrated herein. Finally, this study showed that species belonging to the Botryosphaeriaceae family currently represent a serious threat to the biodiversity of Sardinian natural ecosystems and can strongly affect the quality and quantity of the produce yielded.