Symbiotic microorganisms application in vineyards: impacts on grapevine performance and microbiome

Abstract

Microorganism-based inoculants have been suggested as a viable solution to mitigate the adverse effects of climate change on viticulture. However, the actual effectiveness of these inoculants when applied under field conditions remains a challenge, and their effects on the existing soil microbiota are still uncertain. This study investigates the impact of arbuscular mycorrhizal fungi inoculation on grapevine performance and microbiome. The study was conducted in a vineyard of Callet cultivar in Binissalem, Mallorca, Spain. Two different treatments were applied: control and inoculation with commercial mycorrhizae complex of Rhizoglomus irregulare applied to plants through irrigation. Nine plants per treatment were used to measure physiological parameters, yield, and must quality parameters. Additionally, soil microbial communities were analyzed by sequencing soil DNA from the 16S region (bacteria) and ITS region (fungi) using BeCrop® technology. The results showed that the inoculation did not lead to increased photosynthetic rates or improved water use efficiency. There were no significant differences in terms of yield or the sugar content and acidity of the must. However, berries from the inoculated plants exhibited higher total phenolic content and anthocyanin accumulation. The fungal diversity in the inoculated treatment was greater at the beginning of summer, but this difference was not observed at harvest. Moreover, there was no significant difference in bacterial diversity between the inoculated and non-inoculated soil throughout the season. This study emphasizes the importance of evaluating mycorrhiza-based fertilizers under real field conditions. Although the results confirm that inoculation improves phenolic maturity parameters such as anthocyanin content, the potential of these inoculants to mitigate the impacts of climate change and enhance plant performance in the field requires careful evaluation of specific cultivation conditions.

Acknowledgements: This work was supported by PID2021-125575OR-C22 project funded by MCIN/ AEI /10.13039/501100011033/ and FEDER Una manera de hacer Europa.