Identification of antagonistic bacteria against anthracnose of Sarcandra glabra

Abstract:

[Backgroud] The anthrax of Sarcandra glabra was serious, so far there is no research report on the biological control of endophytic bacteria against this pathogen. [Objective] To screen out bacteria that have an antagonistic effect on Colletotrichum dematium, and to study its antibacterial mechanism. [Methods] Endophytic bacteria were isolated and purified from different tissues of healthy plants collected from different regions of Guangxi by the plate dilution method. [Results] The results of the plate confrontation test showed that RJ-4 and JJ-5 from stems had strong antagonistic effects on anthracnose of Sarcandra glabra. Among them, the strain with the strongest antagonistic effect was RJ-4, with an inhibition rate of 84.10%. The results of the antibacterial spectrum showed that RJ-4 and JJ-5 had obvious antagonistic effects on the 14 pathogenic fungi tested. The strongest antagonistic effect was RJ-4, with an average inhibition rate of 95.3%. It shows that the strain can secrete protease and cellulase and chitinase, destroy the mycelium of the pathogen, and inhibit the growth of the pathogen; The fermentation broth containing the antagonistic bacteria obviously inhibits the mycelium of the pathogen, and the mycelium is distorted, broken, and entangled, color deepens and so on. Based on morphological characteristics and 16S rRNA gene identification, strain RJ-4 was Bacillus amyloliquefaciens. [Conclusion] Strain RJ-4 has bacteriostatic and disease-resistant functions and can produce a variety of antibacterial active substances, which can provide resources for new antibacterial substances.