Diversity of Botryosphaeriaceae species associated with grapevine and other woody hosts in Italy, Algeria and Tunisia, with descriptions of Lasiodiplodia exigua and Lasiodiplodia mediterranea sp. nov.
The diversity of Botryosphaeriaceae species associated with "Botryosphaeria dieback" of grapevine was investigated in 18 vineyards in Sardinia, Italy. Lasiodiplodia isolates obtained from different woody hosts including holm oak, sweet orange and broom bush in Italy, Algeria and Tunisia were also characterized. Morphological and cultural characteristics as well as ITS and EF1-α sequence data were used to identify the fungal isolates. Forty-eight botryosphaeriaceous isolates were obtained from 113 symptomatic grapevine samples, from which ten species were identified. Diplodia seriata was the dominant species (25% of isolates), followed by Neofusicoccum parvum (21.7%). Two species, Diplodia olivarum and D. africana are reported for the first time on grapevine. In addition, two new species namely Lasiodiplodia mediterranea sp. nov. from grapevine, holm oak and sweet orange and Lasiodiplodia exigua sp. nov. from broom bush are described. In artificial inoculation experiments conducted on excised green grapevine shoots and lignified canes as well as holm oak seedlings, L. mediterranea was shown to be an aggressive pathogen.