RESUMEN
We applied different concentrations of spore suspension of Streptomyces exfoliatus FT05W and S. cyaneus ZEA17I to inoculate Gerbera jamesonii to screen for the most effective application concentration. We aimed to explore the effects of two Streptomyces strains on growth and physiological properties of G. jamesonii, and to provide scientific evidence for the application of Streptomyces in G. jamesonii production. The results showed that different concentrations of S. exfoliatus FT05W and S. cyaneus ZEA17I spore suspension could effectively promote the growth of G. jamesonii. In general, S. exfoliatus FT05W performed better than S. cyaneus ZEA17I. S. exfoliatus FT05W (1×109 CFU·mL-1) could significantly increase the height and crown width of G. jamesonii respectively by 30.2% and 41.5%. Meanwhile, it increased the length and width of the stem. When treated by S. exfoliatus FT05W (1×109 CFU·mL-1), the content of chlorophyll in G. jamesonii was significantly increased by 65.2%, root activity was significantly increased by 103.3%, and the superoxide dismutase activity was increased by 84.4%. The malondialdehyde content in G. jamesonii was maintained at a low level when treated with the two Streptomyces strains. In summary, S. exfoliatus FT05W and S. cyaneus ZEA17I could effectively promote the growth and physiological properties of G. jamesonii, which could further contribute to its resistance to stress. Therefore, S. exfoliatus FT05W had the potential as a bio-fertilizer for G. jamesonii to solve cultivation obstacles.