Fungi and bacteria associated with rhizosphere soils (within a 1 mm vicinity of the roots) were isolated using the traditional serial dilution technique [20 (link),51 (link)]. Afterward, 1 g of each rhizosphere soil sample was added to 99 mL of ddH2O, and a 10-fold serial dilution was made from the suspension (10−3 to 10−6). Dilutions of 10−4 and 10−5 were used to isolate fungi, and 10−5 and 10−6 were used to isolate bacteria. One hundred microliters of each diluted suspension was spread evenly onto potato dextrose agar (PDA, Hopebio, Qingdao), malt extract agar (MEA, Huankai Microbiol, Guangzhou) and Czapek-Dox media (CDM, Huankai Microbiol, Guangzhou) (to isolate the fungi) or onto tryptic soy agar (TSA, Hopebio, Qingdao) (to isolate the bacteria). We added 0.02 g L−1 tetracycline hydrochloride and 0.05 g L−1 streptomycin sulfate to the PDA to eliminate bacterial contamination. The PDA plates were incubated at 28 °C in darkness for 3 days, and the TSA plates were incubated for 1–2 days until colonies appeared. The colonies were removed and transferred to fresh PDA or TSA plates for purification.
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