An ancient push-pull pollination mechanism in cycads

Shayla Salzman; Damon Crook; James D Crall; Robin Hopkins; Naomi E Pierce

doi:10.1126/sciadv.aay6169

An ancient push-pull pollination mechanism in cycads

Sci Adv. 2020 Jun 12;6(24):eaay6169. doi: 10.1126/sciadv.aay6169. eCollection 2020 Jun.

Authors

Shayla Salzman^{1

2

3}, Damon Crook⁴, James D Crall¹, Robin Hopkins^{1

2}, Naomi E Pierce^{1

3}

Affiliations

¹ Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA.
² The Arnold Arboretum, Harvard University, Boston, MA 02131, USA.
³ Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA.
⁴ USDA-APHIS-PPQ CPHST, Otis Laboratory, Building 1398, Otis ANGB, MA 02542, USA.

Abstract

Most cycads engage in brood-site pollination mutualisms, yet the mechanism by which the Cycadales entice pollination services from diverse insect mutualists remains unknown. Here, we characterize a push-pull pollination mechanism between a New World cycad and its weevil pollinators that mirrors the mechanism between a distantly related Old World cycad and its thrips pollinators. The behavioral convergence between weevils and thrips, combined with molecular phylogenetic dating and a meta-analysis of thermogenesis and coordinated patterns of volatile attraction and repulsion suggest that a push-pull pollination mutualism strategy is ancestral in this ancient, dioecious plant group. Hence, it may represent one of the earliest insect/plant pollination mechanisms, arising long before the evolution of visual floral signaling commonly used by flowering plants.

Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.