Effects of a microbial mixture on the growth and rhizosphere functional microbial community of processing tomatoes

Abstract:

[Background] Processing tomatoes are one of the major crops for the “red” planting industry in Xinjiang. Due to the excessive application of chemical fertilizers in processing tomato production, bio-fertilizer has attracted increasing attention. [Objective] To explore the effect of a microbial mixture on the growth of processing tomatoes, stimulate the changes of functional microbial populations in the rhizosphere soil, and provide a theoretical and practical basis for the development and utilization of microbial agents in the future. [Methods] We applied the microbial mixture to the rhizosphere and then determined the agronomic traits of processing tomatoes during the growth period, so as to explore the effects of the microbial mixture on the growth of processing tomatoes. The 16S rRNA gene amplicon analysis was employed to explore the effects of the microbial mixture on the microbial community composition and structure in the rhizosphere soil. [Results] After the treatment with the microbial mixture, the fruit weight, fruit number per plant, and fruit sugar content increased, which improved the quality of fruits. Furthermore, the treatment altered the microbial population and community composition and structure. Specifically, the relative abundance of Actinobacteria, Acidobacteria, and Bacteroidetes increased. The correlation analysis indicated that the microbial mixture affected the growth of processing tomatoes. [Conclusion] The application of the water-dispersible microbial mixture composed of Bacillus tequilensis C-9 and Sphingomonas A1 in the rhizosphere of processing tomatoes affected the functional microbial community structure (increasing the relative abundance of some functional microorganisms) in the rhizosphere of processing tomatoes. It promoted the interaction between rhizosphere microorganisms and plants, thus improving the quality of processing tomato fruits.