Synergetic suppression of soybean cyst nematodes by chitosan and Hirsutella minnesotensis via the assembly of the soybean rhizosphere microbial communities

•Chitosan enhanced biocontrol efficacy of H. minnesotensis to parasitize SCNs.•Checking DNA amount of H. minnesotensis by real-time PCR.•Chitosan and H. minnesotensis changed the structure of rhizosphere microbial communities.•Chitosan and H. minnesotensis increased the relative abundance of suppressive bacteria and fungi.