Trichoderma harzianum

About: Trichoderma harzianum is a research topic. Over the lifetime, 4731 publications have been published within this topic receiving 96796 citations.

Contrasting beneficial and pathogenic microbial communities across consecutive cropping fields of greenhouse strawberry.

Abstract: Soil weakness across consecutive cropping fields can be partially explained by the changes in microbial community diversity and structure. Succession patterns and co-occurrence mechanisms of bacteria and fungi, especially beneficial or pathogenic memberships in continuous cropping strawberry fields and their response to edaphic factors remained unclear. In this study, Illumina sequencing of bacterial 16S ribosomal RNA and fungal internal transcribed spacer genes was applied in three time-course (1, 5, and 10 years) fields across spring and winter. Results showed that the richness and diversity of bacterial and fungal communities increased significantly (p < 0.05) in 1-year field and decreased afterwards across two seasons. Network analysis revealed beneficial bacterial and fungal genus (Bacillus and Trichoderma) dominated under 1-year field whereas Fusarium accumulated under 10-year field at either season. Moreover, Trichoderma harzianum and Bacillus subtilis that have been reported to effectively control Fusarium wilt in strawberries accumulated significantly under 1-year field. Canonical correspondence analysis showed that beneficial bacterial Rhodospirillales and Rhizobiales and fungal Glomerales accumulated in 1-year field and their distributions were significantly affected by soil pH, microbial biomass C (MBC), and moisture. On the contrary, fungal pathogenic species Fusarium oxysporum strongly increased under 10-year field at the winter sample and the abundance was positively (p < 0.01) correlated with soil moisture. Our study suggested that the potential of microcosm under 1-year field stimulates the whole microbial diversity and favors different beneficial taxa across two seasons. Soil pH, moisture, and MBC were the most important edaphic factors leading to contrasting beneficial and pathogenic memberships across consecutive strawberry cropping fields.

Colonization of the rhizosphere, rhizoplane and endorhiza of garlic (Allium sativum L.) by strains of Trichoderma harzianum and their capacity to control allium white-rot under field conditions

Abstract: Five strains (C4, C13, C17, C30, C44) of Trichoderma harzianum that efficiently antagonise Sclerotium cepivorum in vitro, were used in central Mexico to inoculate field grown garlic (Allium sativum L.). Endorhiza, rhizosphere and soil colonization were evaluated at different times and at various root and soil depths. Experiments were conducted in both the 2000 and 2001 crop cycles to evaluate the capacity of five strains as biological control agents (BCA) against S. cepivorum. Significant differences were observed among the strains in terms of their ecological behavior. Strain C4 showed the best endorhizal and rhizosphere colonization. Strain C44, besides being a good rhizosphere colonizer, dispersed widely in the soil. In terms of all three variables, strain C30 had poor colonization ability, whereas the strains C4, C17 and C44 were best able to control white rot in the field. Of these, strain C4 showed the best performance over 2 years when it was applied as a pre-colonized substrate at planting time. High early endorhizal colonization was positively correlated with the BCA capacity of the strains. These data suggest that the ecological behavior of Trichoderma strains should be included as a criterion for strain selection for biological control purposes.