Identification Of Bacillus Subtilis BSPE2501 And Inhibitory Effect Against The Pathogen Of Turfgrass Anthracnose Colletortrichum Graminicola

Turfgrass anthracnose, whose pathogen is Colletortrichum graminicola (Ces.) Wilson, is one of most destructive diseases in the lawn. The most conspicuous symptom of the disease is strip speckle first, expands gradually into perished leaves, and the leaves withered, the turfgrass would be accelerated to aging and death at last. Concerning to the control of the disease, no study has been carried out in domestic so far. It has been, commonly, controlled concurrently as one of the turfgrass diseases occurred in summer, and mostly depends on chemical control. Biological control, as one kind of environment friendly method in plant disease control, is attracting more and more public concern with the increasing environment quality consciousness of the people. But the biological control on C. graminicola has not been reported so far.Bacillus subtilis is one of the important agents in plant disease biological control, distribute widely in the nature. Many strains may have the inhibitory action on plant pathogens or induced systemic resistance in plants, some of them has the plant growth-promoting abilities. BSPE2501 is an endophytic strain of B. subtilis obtained from plant. This study identified the species of BSPE2501. With the purpose of the further uses in disease control, the inhibitory effect of the strain cultured in different fermentation conditions on C. graminicola was measured in the study.The main results are as follows:By observation of the culture characters, identification of the bacteria morphology, determination of the gram staining, spore staining and flagella staining, and analysis of 16SrDNA sequence, the results revealed that BSPE2501 is B. subtilis.The inhibitory effect of B. subtilis BSPE2501 against C. graminicola has been determined, and the effect of the fermentation broth cultured for different time, in different medium, medium content, and rotation speed been measured as well. The results showed that BSPE2501 had obvious inhibitory effect to the growth of the pathogen mycelium and spore germination; The inhibitory effect of the fermentation broth cultured in NB and BPY, whose inhibitory rate of fermentation broth diluted 1 time to the growth of the pathogen mycelium could reach 66.2%(NB) and 65.5%(BPY) respectively, which was significantly higher than that of in LB(53.5%) and PD(45.8%), while the inhibitory rate of fermentation broth cultured in NB or BPY to the spore germination was 44.6% and 43.1% respectively, higher than that of in LB(35.2%) and PD(28.6%); The inhibitory effect of the fermentation broth cultured in NB for 72h, in content of 100ml, and at rotation speed of 150rpm had been approved to be the best, whose inhibitory rate of the fermentation broth diluted 1 time to the growth of the mycelium and spore germination was 85.3% and 46.9%, 75.7% and 43.1%, 67.2% and 43.4%, respectively.