Antagonism of Metabolites from Biocontrol Bacteria HT3 and HT5 on Botrytis cinerea

HT3 and HT5 are endophytic bacterium isolated from walnut. To determin their control effect on Botrytis cinerea, we tested the bacteria inhibitive rate on Botrytis cinerea with the mycelium growth rate and spore germination method. The results showed that the metabolites of HT3 and HT5 had significantly inhibited the spores germination, The metabolites of HT3 had strong inhibiting effect on Botrytis cinerea and spore germination inhibition rate was 100%; the metabolites of HT5 led to spores germination deformity and the inhibition rate was 98%. And their metabolites had significantly inhibitory effect on Botrytis cinerea, antibacterial rates 58.69% and63.07% respectively.The mycelial growth inhibition activity of HT3 and HT5 bacterial metabolites mixed with 50% procymidone WP had a synergistic effect, in which the inhibition rate of procymidone : HT3=50∶50,and procymidone: HT5=25∶75 were the highest, 87%and 86% respectively, and both synergism ratios were 1.3.