Isolation and identification of endophytic biocontrol bacteria from understory Panax ginseng and study on colonization ability

Abstract:

[Background] Understory Panax ginseng grows in the natural environment for many years, and the endogenous bacteria present in its body have stronger adaptability and colonization, which can better play the role of interacting with plants to improve plant resistance and inhibit the growth of pathogenic bacteria. [Objective] To select the dominant strains with strong colonization ability, fast reproductive ability, and antagonistic effects on pathogenic bacteria, understory P. ginseng became the optimal choice. [Methods] The conventional tissue isolation method was used to isolate endophytic bacteria from the root tissues of healthy understory P. ginseng, and the endophytic bacteria with antagonistic effects on ginseng pathogens were screened out by the confrontation test and identified by traditional identification methods. [Results] Among the 6 endophytic bacteria obtained, the strain LXS-N2 had obvious bacteriostatic effects against Rhizoctonia solani and Pythium debaryanum, and it had the characteristics of good colonization and fast reproduction. The strain LXS-N2 inhibited pathogenic fungal growth by destroying the cell wall and membrane of pathogenic fungi and changing hyphae morphology. [Conclusion] The endophytic LXS-N2 was identified as Bacillus velezensis by morphological observation, physiological biochemical reaction, and 16S rRNA gene sequence analysis, which has good application development potential.