The potential of Trichoderma brevicompactum for controlling root rot on Atractylodes macrocephala

Abstract

Root rot is an important disease of the medicinal plant Atractylodes macrocephala (bai zhu) in China. This study evaluates an antagonistic fungal agent, Trichoderma brevicompactum, as an alternative to chemical pesticides for control of root rot caused by Fusarium oxysporum. The inhibitory effect of T. brevicompactum on F. oxysporum was examined in dual-culture experiments, with mycelial growth of the pathogen found to be reduced by 74.4%. The results of an enzyme-linked immunosorbent assayindicated that T. brevicompactum produced enzymes such as cellulase and chitinase, suggesting that the fungal agent may inhibit F. oxysporum growth by producing cell wall hydrolases. Under greenhouse conditions, the efficacy of T. brevicompactum was evaluated based on its effects on root rot severity, plant height, root dry weight, and root fresh weight. When used as a soil treatment, T. brevicompactum reduced root rot severity by 48% to 58% and increased plant growth and biomass significantly when compared with the control (healthy) group. The plant growth-promoting effect of T. brevicompactum seems related to its production of secondary metabolites that contain an auxin (indoleacetic acid), and to the disease resistance induced in the host by the fungal agent. The results of this study suggest that T. brevicompactum not only controls root rot in A. macrocephala but may also promote growth of the plant.