Pollinator selection against toxic nectar as a key facilitator of a plant invasion
Egan, Paul A., Stevenson, Philip C. ORCID: https://orcid.org/0000-0002-0736-3619 and Stout, Jane C. (2022) Pollinator selection against toxic nectar as a key facilitator of a plant invasion. Philosophical Transactions of the Royal Society B: Biological Sciences, 377 (1853). ISSN 0962-8436 (Print), 1471-2970 (Online) (doi:10.1098/rstb.2021.0168)
Preview |
PDF (AAM)
35838_STEVENSON_Pollinator_selection_against_toxic_nectar_as_a_key_facilitator.pdf - Accepted Version Available under License Creative Commons Attribution. Download (521kB) | Preview |
Abstract
Plant compounds associated with herbivore defence occur widely in floral nectar and can impact pollinator health. We showed previously that Rhododendron ponticum nectar contains grayanotoxin I (GTX I) at concentrations that are lethal or sublethal to honeybees and a solitary bee in the plant's non-native range in Ireland. Here we further examined this conflict and tested the hypotheses that nectar GTX I is subject to negative pollinator-mediated selection in the non-native range, but that phenotypic linkage between GTX I levels in nectar and leaves acts as a constraint on independent evolution. We found that nectar GTX I experienced negative directional selection in the non-native range, in contrast to the native Iberian range, and that the magnitude and frequency of pollinator limitation indicated that selection was pollinator-mediated. Surprisingly, nectar GTX I levels were decoupled from those of leaves in the non-native range, which may have assisted post-invasion evolution of nectar without compromising the anti-herbivore function of GTX I (here demonstrated in bioassays with an ecologically relevant herbivore). Our study emphasizes the centrality of pollinator health as a concept linked to the invasion process, and how post-invasion evolution can be targeted toward minimizing lethal or sub-lethal effects on pollinators.
Actions (login required)
View Item |
Downloads
Downloads per month over past year