Sporulation rate—not mycelial growth—predicts Clonostachys efficacy, redefining selection criteria for high-performance biocontrol agents. 2. Direct mycoparasitism of perithecia eliminates overwintering inoculum, breaking the Fusarium disease cycle at the source on crop residues. 3. Endophytic colonization primes systemic immunity, conferring broad-spectrum resistance against diverse soilborne and head-infecting pathogens. Fusarium head blight (FHB) and crown rot (FCR) threaten global wheat production, demanding sustainable biocontrol solutions. We isolated 50 indigenous Clonostachys strains ( C. chloroleuca, C. rosea, C. rogersoniana ) from Chinese agroecosystems and identified key biocontrol traits. Critically, sporulation rate—not mycelial growth—correlates with Fusarium suppression efficacy, revolutionizing agent selection criteria. Five elite strains completely prevented perithecia formation on crop residues. Microscopy revealed direct mycoparasitism through perithecial wall adhesion and enzymatic destruction of asci/ascospores. Transcriptomics of parasitized perithecia showed Fusarium stress responses including ABC transporter induction, membrane remodeling, and DNA repair activation, confirming membrane damage and genotoxic stress. Strain Cc878 exhibited dual-mode protection: suppressing residue-borne inoculum while establishing root endophytism via seed treatment. This protected against multiple soilborne diseases (FCR, common root rot, take-all) without yield penalties and primed systemic immunity through MAPK/phenylpropanoid pathways. Genome analysis revealed extensive secretomes, CAZymes, and secondary metabolite clusters underpinning biocontrol mechanisms. This integrated strategy combining inoculum reduction with immunity priming provides a sustainable alternative to chemical fungicides for managing devastating Fusarium diseases in wheat production systems.
Zhang et al. (Sun,) studied this question.