Crop-specific and single-species mycorrhizal inoculation is the best approach to improve crop growth in controlled environments

Abstract

Arbuscular mycorrhizal fungi are root symbionts that play a key role in crop growth. A systematic quantitative analysis of the response of crops to arbuscular mycorrhizal inoculation, however, remains to be done. Additionally, little is known regarding the role of mycorrhizal specificity and the diversity of the inoculum on crop growth. Therefore, we collected data from 115 inoculation studies, including 435 experiments. We then used meta-analysis to examine the effect of crop identity, arbuscular mycorrhizal fungus identity, and mycorrhizal diversity on crop biomass increase, following inoculation. Our results show that total crop biomass was on average 34.9 % higher in inoculated versus non-inoculated plants. We found that specific combinations of arbuscular mycorrhizal fungus genera and host plant families were more beneficial for growth promotion as compared to other combinations. Moreover, a single-species inoculum increased crop growth response on average by 41.2 % compared to a multi-species inoculum. Overall, our findings show that a broad range of crops highly benefit from the inoculation with arbuscular mycorrhizal fungi. They also strongly suggest that selecting specific arbuscular mycorrhizal taxa for specific crops is the most promising approach to enhance crop growth. There is no "onesize-fits-all" arbuscular mycorrhizal fungus. Finally, and at least in stable and controlled environments, inoculation with a single arbuscular mycorrhizal species is more effective, compared to inoculation with a mixture of different arbuscular mycorrhizal taxa. This may be explained by fungi superior in extraradical growth, but less beneficial to the host, that outcompete the more mutualistic fungi. Therefore, it may be beneficial to maintain a high dominance of one beneficial arbuscular mycorrhizal taxon in simplified agricultural systems.

Benefits of Arbuscular Mycorrhizal Fungi Application to Crop Production under Water Scarcity

“…In such cases, isolation of indigenous mycorrhizal strains for inoculum production, then large-scale reintroduction of these native fungi in the field could be a feasible solution for a useful AMF application [142]. It is worth mentioning that selection of specific AM taxa for particular crops is the best approach to improve crop growth, and there is no 'one-size-fits-all' AMF [143]. In controlled environments, application of a single AMF is more effective than using a mixture of different AM taxa [143].…”

“…It is worth mentioning that selection of specific AM taxa for particular crops is the best approach to improve crop growth, and there is no 'one-size-fits-all' AMF [143]. In controlled environments, application of a single AMF is more effective than using a mixture of different AM taxa [143].…”

Arbuscular Mycorrhiza Changes the Impact of Potato Virus Y on Growth and Stress Tolerance of Solanum tuberosum L. in vitro

“…These tripartite biotic interactions (involving antagonistic, protective, exclusive, or synergistic effects) are of particular interest with regard to crop plants, since they strongly influence the crop productivity. It is documented that under the field conditions the majority of crop plants establishes symbiotic association between their roots and arbuscular mycorrhizal fungi (AMF) being an inherent component of each agricultural ecosystem (Smith and Smith, 2011;Van Geel et al, 2016). In this endomycorrhizal relationship both partners benefit from one another.…”

Abiotic rather than biotic filtering shapes the arbuscular mycorrhizal fungal communities of European seminatural grasslands

“…For instance, herbaceous plant species that co-occur in the same grasslands have been shown to harbor distinct AMF communities (Vandenkoornhuyse et al, 2003;Valyi et al, 2015; but see Honnay et al, 2017). A metaanalysis of 435 crop inoculation experiments also showed that specific combinations of AMF taxa and host plants were more beneficial for growth promotion as compared with others, suggesting a functional AMF-host plant specificity (Van Geel et al, 2016).…”