Do antagonistic fungi interfere with successful biocontrol?
In this section
Mycoparasites (fungi that parasitise other fungi) may be responsible for lower success rates of rust fungi biocontrol agents. Globally, 60% of all rust fungi agents only achieve moderate or variable success as biocontrol agents, and at least 15% fail.
A 2022 study has identified how naturally occurring antagonistic fungi, known as mycoparasites, may potentially affect the establishment and success of fungal pathogen biocontrol agents. Mycoparasites can reduce infection pressure of the pathogen agent in the field. They decrease the availability of agent inoculum during spore production, which impacts the ability to conduct laboratory and glasshouse tests. They compromise agent inoculum safety, as it becomes challenging to produce mycoparasite-free cultures for testing the pathogen agent in the introduced range. They can lower efficacy of the agent if it accumulates native mycoparasites in the introduced range. Lastly, such accumulation of native pathogens can diminish the impact of the pathogen agent.
The authors concluded that mycoparasites may well contribute to the lower success rate of fungal pathogen biocontrol agents. A lack of concrete evidence highlights the need for collecting and publishing observations and information about plant-associated and mycoparasitic taxa. Further investigations into how these antagonists infect their fungal hosts, their range of hosts, and their response to abiotic factors will ultimately enhance our understanding of the interactions between target plants, biocontrol pathogens and potential antagonists that can impede biocontrol efforts.
This project is funded by the Ministry of Business, Innovation and Employment as part of Manaaki Whenua – Landcare Research’s Beating Weeds Programme.