Isolation of Growth-Promoting Bacteria and Effect of Compound Bacteria on Yield of Fritillaria przewalskii / 中国实验方剂学杂志

ABSTRACT

Objective:To explore the effects of anti-microbial compound （T1） from<italic> Bacillus </italic>（Phylum Firmicutes） and anti-microbial compound （T2） from <italic>Pseudomonas</italic> and <italic>Rhizobium</italic>， two growth-promoting agents， on the physiological characteristics and growth of <italic>Fritillaria przewalskii</italic>， in order to lay a foundation for the development of functional microbial agents and the promotion of ecological planting. Method:The endophytic bacteria of <italic>F. przewalskii</italic> were isolated and identified using conventional methods. The leaves of three-year-old <italic>F. przewalskii</italic> were sprayed with T1 and T2， followed by yield determination. The enzyme activities and physiological and biochemical indexes in the plant and microorganisms were measured using the corresponding assay kits， and the contents of related hormones by liquid chromatography-mass spectrometry （LC-MS）. Result:The isolated endophytic bacteria were classified into Firmicutes，Proteobacteria， and Actinomycetes. The activities of superoxide dismutase（SOD） and peroxidase（POD） and auxin content after T2 treatment were significantly higher than those after T1 treatment， while the contents of siderophore，salicylic acid， and gibberellin were lower. Compared with the blank （CK） group， T1 and T2 increased the contents of endogenous gibberellin，cytokinin， and auxin in <italic>F. przewalskii</italic> leaves，but did not significantly change jasmonic acid and abscisic acid. T1 promoted the accumulation of endogenous salicylic acid in <italic>F. przewalskii</italic> leaves， but there was no significant change after T2 treatment. Compared with CK，T1 and T2 enhanced the activities of SOD， POD， and catalase （CAT） and decreased the content of malondialdehyde. T2 promoted the accumulation of hydrogen peroxide in <italic>F. przewalskii</italic> leaves， but no significant difference was observed after T1 treatment. Compared with CK，both T1 and T2 increased chlorophyll，average iron content in rhizosphere soil， and 100-plant weight. Conclusion:T1 and T2 treatments help to increase the yield，and their specific mechanisms differ from each other. T1 exhibits better effect than T2.