Biocontrol potential of indigenous AMF strains: A systematic review and meta-analysis

• Indigenous AMF biocontrol effects were higher than commercial ones. • Investigating biocontrol potential of Gigasporales spp. is promising. • Field studies are needed to better understand and implement effects of indigenous AMF. Arbuscular Mycorrhizal Fungi (AMF) contribution to plant nutrition and health has been widely investigated. Regarding nutrition, indigenous inocula have been reported to be at least as efficient as commercial ones. However, regarding biocontrol, this has not been proven yet. A meta-analysis was conducted to address this issue and to investigate the role of AMF functional diversity. Two online databases were searched for trials in which plants were inoculated with local, commercial or laboratory collection AMF and with either phytopathogenic fungi, oomycetes or root-knot nematodes. Grouped meta-analyses were conducted on the collected data to evaluate the biocontrol effect of AMF inoculation. Seventy-four studies were included in the analysis. Indigenous AMF inocula resulted in a higher biocontrol effect than collection and commercial inocula on phytopathogenic fungi and oomycetes. The efficiency of indigenous AMF inocula was also higher on nematodes. Although AMF species from the Gigasporaceae family displayed the best biocontrol effect against phytopathogenic fungi and oomycetes, no AMF family stand out against root-knot nematodes. Indigenous AMF inocula seem to have a high potential for crop protection against plant pathogens. However, field studies are needed to better identify indigenous strains and understand their mechanisms of action. It is also crucial to further investigate how indigenous AMF species can be promoted. The production and on-farm implementation of more diverse inocula will help fully benefit from AMF biocontrol potential.