|LI, LIHUA - China Agricultural University
|MA, JINCAI - Jilin University
|Ibekwe, Abasiofiok - Mark
|WANG, QI - China Agricultural University
|YANG, CHING-HONG - University Of Wisconsin
Submitted to: Plant and Soil
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/8/2018
Publication Date: 6/18/2018
Citation: Li, L., Ma, J., Ibekwe, A.M., Wang, Q., Yang, C. 2018. Influence of Bacillus subtilis B068150 on cucumber rhizosphere microbial composition as a plant protective agent. Plant and Soil. 429(1):519-531. https://doi.org/10.1007/s11104-018-3709-3.
Interpretive Summary: Biological control may be a potential alternative approach to controlling soilborne plant diseases, since chemical methods may have some adverse effects on the environment and food safety. However, an introduced biocontrol agent will interact not only with the pathogen to be controlled but also with all the biotic components of the soil. In this study, we assess the ecological fitness of B. subtilis strain B068150 by deep sequencing method to explore the influence of soil types on the rhizosphere competence and biocontrol activity of strain B068150 and its effects on the indigenous soil bacteria and fungi. During our study, no significant differences were found between native microbial communities with strain B068150 except in bacterial community in clay. There were also no significant differences in microbial diversity between the control and cucumber rhizosphere inoculated with B subtilis B068150. The results of this research will be used by growers, researchers, FDA, and different state agencies that are involved in crop production.
Technical Abstract: Aim Our aim was to investigate factors that influenced bacterial and fungal community composition in the cucumber rhizosphere with the addition of Bacillus subtilis B068150 in soils. Methods Using pyrosequencing, we tracked changes in total bacterial and fungal community composition and structures in cucumber rhizosphere planted in clay, loam and sandy soils and inoculated with B. subtilis B068150. Results B. subtilis B068150 colonized the rhizosphere of cucumber without altering the indigenous microbial community composition. B068150 strain did not significantly affect microbial diversity in cucumber rhizosphere, but both soils texture and chemistry did, based on principal coordinates analysis (PCoA), hierarchical clustering in UniFrac, and canonical correspondence analysis (CCA). Shannon diversity values (H') suggest that rhizosphere diversity varied among the three soils with the significant highest diversity observed in loamy soil. Fungi were dominated by Ascomycota, Chytridiomycota, Basidiomycotina, with Ascomycota accounting for 29.1%. Fusarium was found only in cucumber rhizosphere grown in loamy soil; however, this did not affect the health of cucumber in three loamy soils during the three months study. Conclusion Bacillus subtilis B068150 could be an environmental compatible plant protective agent in soils depending on the soil type.