Highbush Blueberries Bloom with Help from Fungal Friends

A blueberry’s ability to attract pollinators might owe something to aid in the soil, according to a study published in the journal PLOS One. O’Neill and colleagues have investigated an intricate web of interactions between plants, fungi, and pollinators that influences the reproductive success of highbush blueberries (Vaccinium corymbosum).

The researchers found that most terrestrial flowering plants, or angiosperms, form relationships with both mycorrhizal fungi – beneficial fungi that boost plant nutrient intake – and animal pollinators. However, the impact of these fungi on pollinator behaviour and plant reproduction remains a mystery for many species. The team sought to clarify this by examining the effects of introducing ericoid mycorrhizal fungi – a specific type of fungi that forms symbiotic relationships with plants – to highbush blueberries.

The findings revealed that plants inoculated with mycorrhizal fungi were more likely to flower and produced more inflorescence buds – clusters of flowers – compared to non-inoculated plants. Interestingly, this effect was especially strong when the fungi were sourced from local soil rather than a commercial inoculant. This suggests that local mycorrhizal fungi might be better adapted to interact with the local plant species.

It’s important to note that while the fungi increased flowering, they didn’t directly affect fruit set (the proportion of flowers that turn into fruit) or fruit sugar content. The study also found that increased flower production didn’t necessarily translate into more pollinator visits. O’Neill and colleagues write:

Our results add to the growing evidence that plant interactions with belowground organisms can affect those aboveground. In addition, our results demonstrate that the outcome of the interactions can depend on identity of the fungal partners, the match between fungi and host, and interactions beyond plant host and mycorrhizal fungi such as those with pollinators and plant diseases. The complexity of these interactions challenges generalization and points to the need for greater study at scales that range from molecular mechanisms to functional traits within hosts and fungi, to effects that can only be elucidated in communities and ecosystems.

O’Neill et al. 2023

This research reveals the intricate relationships between plants, fungi, and pollinators and underlines the need for a better understanding of these interactions to enhance plant reproduction, particularly for crops like highbush blueberries. As a consumer, improved agricultural practices could result in more abundant, sustainable crops, which could impact your grocery shopping in terms of availability and price.

READ THE ARTICLE

O’Neill, E., Brody, A.K. and Ricketts, T. (2023) “Inoculum source dependent effects of ericoid, mycorrhizal fungi on flowering and reproductive success in highbush blueberry (Vaccinium corymbosum),” PLOS One, 18(4), p. e0284631. Available at: https://doi.org/10.1371/journal.pone.0284631.