Abstract:
To understand the colonization ability in cucumber plant and biocontrol mechanism of
Bacillus subtilis YN201490, plate confrontation was proceeded to test the inhibitory effect of the strain on different pathogens and the method of drenching root was used to study the colonization ability in cucumber, and the isolation and activity of the fermentation suspension was tested by inhibiting spore germination. Antagonistic activity of YN201490 against
Typhula incarnata,
Fusarium oxysporum f. sp.
lycopersici,
Alternaria alternata,
F.
verticillioides,
Pestalotiopsis theae and
Sarocladium oryzae was confirmed by the confrontation test and a GFP-labeled strain respectively, YN90-P43GFPmut3a was obtained to analyze the colonization ability. The results showed that strain could be colonize in cucumber plant with the colony numbers in root > leaf > stem based on drenching root experiments. The
n-butanol extract from fermentation suspension could split the spores of
T.
incarnata to make the cytoplasm exudate and inhibit 91.72% of spores’ germination. When it was sprayed on cucumber it also prevented 66.26% of cucumber powdery mildew and induced significant disease resistance. It is concluded that YN201490 has an obvious inhibitory effect on many pathogenic fungi and colonization ability in cucumber, which has the potential as a biological agent.