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.