Evaluation of wheat genotype responses to Trichoderma afroharzianum strain T22

Sammanfattning

Trichoderma afroharzianum strain T22 is used in agriculture as a biocontrol agent and plant growth promoter. However, its effects can vary depending on the plant species and genotype. In this study, 190 winter wheat genotypes were evaluated for their differential responses to T. afroharzianum T22 inoculation and mock-treated controls. Growth traits (shoot length, root length, and dry weight) and disease incidence (root browning) were assessed under controlled conditions. The results showed that most wheat genotypes had a neutral response to inoculation, with no significant reduction in shoot and root length. Some genotypes had a negative response, whereas only a small number exhibited increased growth. Browning of roots and stems occurred more frequently in Trichoderma-treated plants, while similar but less frequent discoloration appeared in the mock treatment. Genotypes with more than 50% of plants showing browning frequently exhibited reduced growth, suggesting a potential link between browning of the roots and stem base and growth suppression. While this browning is not interpreted as a direct disease symptom, its increased occurrence in treated plants may be related to additional stress experienced by the roots during exposure to Trichoderma. Overall, these findings highlight that the effect of T. afroharzianum T22 on wheat is strongly genotype-dependent, with growth promotion being rare and growth inhibition being more prevalent. This underscores the need for careful genotypespecific evaluations before agricultural application.