Pseudomonas sp. T1-3-2 with antimicrobial activities improves the disease resistance and promotes the growth of Cunninghamia lanceolata

Abstract:

[Background] Biocontrol is a nature-based solution that meets the requirements of ecological civilization and sustainable development. Clarifying the biocontrol effects and antibacterial characteristics of the bacterial strain are the basis of biocontrol of technology research. [Objective] To develop biocontrol agent for the control of anthracnose in Cunninghamia lanceolata, we studied the antimicrobial activity and growth-promoting effect of strain T1-3-2 isolated from C. lanceolata. [Methods] Strain T1-3-2 was identified based on morphological, physiological and biochemical characteristics, and the 16S rRNA gene sequence-based phylogenetic analysis. The antimicrobial effects of the bacterial strain, volatile gas and secondary metabolites of the strain were determined by plate confrontation method, plate culture method, and colony growth inhibition test. The plant growth-promoting effect of the strain was determined by pot experiment indoors. [Results] Strain T1-3-2 belongs to Pseudomonas, forming a monophyletic group with Pseudomonas eucalypticola. It had stronger antagonistic effects on 10 target strains, with the inhibition rates over 80% on 6 strains of Colletotrichum, Pestalotiopsis, Nigrospora, and Botryosphaeria. The pot experiments showed the fermentation broth of T1-3-2 in Kings Medium B controlled the occurrence of anthracnose in C. lanceolata, with the control effect of 74.20%. Moreover, it improved the growth and increased the biomass accumulation of C. lanceolata seedlings. [Conclusion] Strain T1-3-2 is belonging to the Pseudomonas genus and it is beneficial to the biocontrol and growth-promoting on C. lanceolata. Thus, it is a great potential biocontrol strain.