Phytotoxic exopolysaccharides produced by Botryosphaeriaceae spp., involved in grapevine trunk disease in Italy.

Recently, several Botryosphaeriaceae spp. have been associated with grapevine decline symptoms worldwide including dieback, cankers and characteristic wedgeshaped necrosis in arms and trunks. An increasing number of species including Neofusicoccum parvum have been shown to produce phytotoxic secondary metabolites in vitro, both lipophilic low molecular weight compounds and high molecular weight exopolysaccharides (EPSs), some of which appeared structurally different from previously reported botryosphaerans. Preliminary results on the chemical and biological characterization of these EPSs were previously reported and compared with EPSs produced by Phaeomoniella chlamydospora, a fungus associated with grapevine esca complex along with Phaeoacremonium spp. In this communication, the progress on the chemical and biological characterization of EPSs produced by N. parvum and P. chlamydospora will be reported, as well as the results on the characterization of the EPSs produced by N. australe.