*4.1. Microorganisms*

*B. velezensis* BZR 86 and *B. velezensis* BZR 277 were isolated from the field soil of the Krasnodar region (45◦1 N, 38◦59 E). Winter wheat plants were selected under aseptic conditions, placed in sterile bags, and stored in a refrigerator at +4 ◦C. The strains were isolated from the root zone of winter wheat plants by the method of successive washing of the roots from adjacent soil particles [58]. The roots with soil were placed in a flask with 100 mL of sterile water and shaken for 40 min at 180 rpm. The roots were removed from the flask with sterile tweezers and transferred to the next flask containing 100 mL of sterile tap water. The procedure was repeated, successively washing the roots in three flasks (40 min each). The bacteria were inoculated by streaking from the second and third flasks. The *B. velezensis* BZR 277 strain was inoculated on potato-glucose agar and the *B. velezensis* BZR 86 strain on a medium with chitinase. Petri dishes with *B. velezensis* BZR 86 strain were incubated at +28 ◦C for three days. Petri dishes with *B. velezensis* BZR 277 strain were incubated at +4 ◦C for 21 days. Isolated colonies were streaked onto potato-glucose agar. This procedure was repeated until a pure culture of the strain was obtained in the Petri dish.

Strains deposited in the Bioresource collection "State collection of beneficial insects, mites and microorganisms" of the Federal State Budgetary Scientific Institution "Federal Research Center of Biological Plant Protection" (FSBSI "FRCBPP") (registry number 585858).
