Abstract Detail

Recent Topics Posters

Kephart, Susan [1], Pahlke, Gina [2].

Comparing the effect of inflorescence architecture on pollinator visitation patterns and female fecundity for insect-pollinated angiosperms.

Maximal seed production in angiosperms is reached when pollinator visitation rates and patterns lead to high rates of pollen deposition but low rates of pollen wastage and intra-plant (geitonogamous) mating. Four naturally occurring species, Camassia quamash, C. leichtlinii, Delphinium nuttallianum,and Zigadenus venenosus, are all herbaceous perennials that potentially provide important resources for hymenopteran and dipteran pollinator guilds in lowland to montane meadows. We explored how variations in inflorescence architecture, including the inflorescence height, length of the raceme,the number of open flowers, and inflorescence floral density influence the rate, duration, and pattern of pollinator visits as well as seed and fruits et.. Pollinator visitation patterns and subsequent seed set varied among populations due to differences in flowering times and pollinator composition.Pollinators were most attracted to, and visited most frequently, inflorescences with more flowers or longer racemes. Insect pollinators visiting these inflorescences stayed longer and visited a greater number of flowers, but worked a smaller proportion of available flowers and visited individual flowers less frequently than when visiting shorter, few-flowered racemes. In D.nuttallianum and Z. venenosus maximal seed production is reached by increasing fruit set. In C. quamash, it is reached through increases in the number of seeds produced per fruit. Large inflorescences had both the greatest pollinator visitation rates and female fecundity, suggesting that geitonogamous mating did not limit seed set in these populations.

Broader Impacts:

1 - WILLAMETTE UNIVERSITY, Department Of Biology, SALEM, OR, 97301, USA
2 - Willamette University, Biology, 900 State St, Salem, OR, 97301, USA

Keywords:
pollinator visitation
inflorescence
floral traits
Delphinium
Camassia
Zigadenus.

Presentation Type: Recent Topics Poster
Session: P
Location: Battelle South/Convention Center
Date: Monday, July 9th, 2012
Time: 5:30 PM
Number: PRT003
Abstract ID:1286