Relationship between the biocontrol fungus Trichoderma harzianum ThzID1-M3 and the plant pathogen
Fusarium solani f.sp. pisi (Fsp) was determined in this study. Dual culture assay indicated the competitive
interaction between ThzID1-M3 and Fsp. Alginate pellets of ThzID1-M3 and Fsp conidia were added to
non-sterile soil with pea seeds. The interaction between Trichoderma and Fsp adversely affected their
establishment in soil. The addition of ThzID1-M3 significantly reduced the Fsp population, as well as the
colonization of roots by Fsp. In contrast, the added Fsp significantly reduced the proliferation of ThzID1-
M3 and Trichoderma spp. The results suggest that the competition may be the main mechanism of the
antagonistic activity of Trichoderma against Fsp.