Endophytic bacteria from grapevines: A potential for biocontrol of trunk diseases

Grapevine trunk diseases (GTDs) have an economic impact in all grape growing regions worldwide, causing dieback, cankers, wood decay, death of vines and affecting the sustainability and productivity of vineyards (Figure 1,see page 54). Eutypa dieback (ED)and botryosphaeria dieback (BD)caused by several Diatrypaceae and Botryosphaeriaceae species,respectively, are two major GTDs responsible for grapevine decline in Australia (Highet & Wicks 1998, Pittet al. 2010). These diseases persist in affected vines from season to season causing a reduction in productivity and threatening the Australian wine industry.Current management of GTDs relies mainly on remedial surgery and fungicide treatment of pruning wounds.Only a limited number of effective fungicides are available for GTDs, and some only offer short term protection.Thus, there is an increasing pressure to find alternative solutions to combat these diseases in vineyards. Recent studies of beneficial endophytes have shown they have the potential to act as biological control agents against many plant diseases including GTDs. Endophytes are microorganisms that reside within plant tissues and can be beneficial, harmless or pathogenic to their plant hosts (Hardoim et al. 2015, Brader et al. 2017). The use of beneficial endophytes for the control of plant disease has gained popularity as the application of fungicides continues to raise concerns with human and environmental safety