Wind-borne insects mediate directional pollen transfer between desert fig trees 160 kilometers apart

Sophia Ahmed, Stephen G. Compton, Roger K. Butlin, Philip M. Gilmartin

Research output: Contribution to journalArticle

135 Citations (Scopus)

Abstract

The question of how far pollen can move between plants has implications for topics as diverse as habitat fragmentation, conservation management, and the containment of genetically modified crops. The monoecious African fig tree Ficus sycomorus L. relies on the small, short-lived, night-flying, host-specific fig wasp Ceratosolen arabicus Mayr for pollination. We used microsatellite markers to characterize a geographically isolated riparian population of F. sycomorus growing along the Ugab River in the Namib Desert, Namibia, together with paternity analysis of seedlings from known mothers, to map pollen movement within this population. In this way we tracked insect movements between individually recognizable trees by means of their pollen cargo and documented the movement of C. arabicus between known trees separated by more than 160 km, with a mean distance for confirmed successful pollination events of 88.6 km. The predominant observed movement of pollinators was in a westerly direction, toward the sea, reflecting seasonal nighttime wind direction and the wind-borne dispersal of fig wasps. Our results suggest the existence of an extensive panmictic population of trees that are well suited to overcome the effects of geographical isolation.
Original languageEnglish
Pages (from-to)20342-20347
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America (PNAS)
Volume106
Issue number48
DOIs
Publication statusPublished - 1 Dec 2009

Keywords

  • Ficus sycomorus
  • fig wasp
  • gene flow
  • spatial structure
  • pollen dispersal

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