Strain HD25G2 as a Novel Biocontrol Agent of , the Causal Agent of Root and Crown Rot of Soft Wheat.

is the causal agent of root rot and crown rot in soft wheat. The aim of this study was to investigate the control mechanism of HD25G2 as a biocontrol agent against . This involved the isolation and molecular identification of and strains from soft wheat. The assay included the inhibition test of mycelial growth on potato dextrose agar and soft wheat media at two water activity values (0.98 and 0.95), its production of mycotoxins, and the fungal cell wall-degrading enzymes implicated in the antagonistic effect of . The results showed that and its extract free of cells reduced the growth of by over 55%. Interestingly, the HD25G2 showed high chitinase, protease, and cellulose production on solid media. In addition, chitinolytic and proteolytic activities were estimated at the values of 1.72 ± 0.02UI and 0.49 ± 0.01UI, respectively. However, the mycotoxin evaluation assay revealed that HD15C10 produced zearalenone (ZEA) and the biocontrol agent enhanced its production, but the early inoculation of , before growth onset, inhibited 100% its growth and, therefore, prevented the presence of ZEA. Hence, this strain can be proposed as a biocontrol agent against , and it can be further investigated for biocontrol of root and crown rot in vivo.