Abstract
The use of arbuscular mycorrhizal (AM) fungal inoculants as a means to promote plant growth is gaining momentum worldwide. Although there is an increasing number of commercial products available for various applications, the quality of these remains uncertain. We determined the AM fungal species composition in eleven inoculants from four producers by using DNA metabarcoding and compared them to the AM fungal species declared on the product labels. Our DNA metabarcoding of the inoculants revealed a concerning discrepancy between the declared and detected AM fungal species compositions of the products. While nine products contained at least one declared species, two did not contain any matching species and all inoculants but one contained additional species not declared on the product label. These findings highlight the need for better guidelines and industry standards to ensure consumer protection in the AM fungal inoculum market. Additionally, we call for caution when using commercial AM fungal inoculants in scientific experiments without confirmatory information about their species composition.
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Data availability
Raw sequences from every inoculant were submitted to NCBI Sequence Read Archive (SRA) under bioproject (PRJNA931824).
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Acknowledgements
The authors are thankful to the Editor Prof. David Janos, and anonymous reviewers for their useful suggestions on both language and academic aspects.
Funding
This study was supported by grants from the Estonian Research Council (PUT1170, PSG784, PRG1789, PRG1065, PRG1836) and the European Regional Development Fund (Centre of Excellence EcolChange).
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Conceptualization: Tanel Vahter, Epp Maria Lillipuu, Inga Hiiesalu, and Maarja Öpik; Methodology: Tanel Vahter, Inga Hiiesalu, Maarja Öpik, Martti Vasar, and Jane Oja; Formal analysis and investigation: Tanel Vahter, Epp Maria Lillipuu, Inga Hiiesalu, Martti Vasar, and Maarja Öpik; Writing—original draft preparation: Tanel Vahter, Epp Maria Lillipuu, and Inga Hiiesalu; Writing—review and editing: all authors; Resources: Inga Hiiesalu and Maarja Öpik.
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Vahter, T., Lillipuu, E.M., Oja, J. et al. Do commercial arbuscular mycorrhizal inoculants contain the species that they claim?. Mycorrhiza 33, 211–220 (2023). https://doi.org/10.1007/s00572-023-01105-9
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DOI: https://doi.org/10.1007/s00572-023-01105-9