FIGURE 1.

The beneficial bacterium Bacillus subtilis PTA-271 attenuates the characteristic Botryosphaeria dieback symptoms induced in Chardonnay cuttings by the Neofusicoccum parvum strain Np-Bt67. One month pretreated grapevine cuttings with PTA-271 (Bs, 2 × 10⁸ cfu/g soil) and non-bacteria pretreated ones (Ctl) were inoculated with pathogen mycelium (+Np-Bt67). Non-infected plants were inoculated with sterile medium without pathogen (Control). Compared to PTA-271 treated healthy asymptomatic cuttings (A), the infected symptomatic cuttings showed the typical Botryosphaeria dieback symptoms: dead branch (A,E), stem canker (B,F), stem internal necrosis (C,G), and stem external necrosis (D,H) that were photographed (A–D) and quantified (E–H) at 4 months post-inoculation. Data are means ± standard deviation (SD) for at least three independent experiments with 10 biological replicates per treatment. Vertical bars with different letters are significantly different (Multiple Comparison procedures with Tukey’s test, P < 0.05).