Document Type

Article

Article Version

Publisher's PDF

Publication Date

10-2010

Abstract

Abstract: Premise of the study: Seed dispersal performance is an essential component of plant fitness. Despite their significance in shaping performance, the mechanical processes that drive dispersal are poorly understood. We have quantified seed dispersal mechanics in Cardamine parviflora (Brassicaceae), a ballistic disperser that launches seeds with specialized catapult-like structures. To determine which aspects of catapult function dictate interspecific dispersal differences, we compared this disperser with other ballistic dispersers. Comparison with brassicas that lack ballistic dispersal may also provide insight into the evolution of this mechanism.

Methods: Catapult performance was quantified using high-speed video analysis of dehiscence, ballistic modeling of seed trajectories, and measuring the mechanical energy storage capacity of the spring-like siliqua valve tissue that launched the seeds.

Key results: The siliquae valves coiled rapidly outward, launching the seeds in 4.7 ± 1.3 ms (mean ± SD, N = 11). Coiling was likely driven by the bilayered valve structure. The catapult was 21.3 ± 10.3% efficient (mean ± SD, N = 11) at transferring stored elastic energy to the seeds as kinetic energy. The majority of seeds (71.4%) were not launched effectively.

Conclusions: The efficiency of the C. parviflora catapult was high in comparison to that of a ballistic diplochore, a dispersal mode associated with poor ballistic performance, although the unreliability of the launch mechanism limited dispersal distance. Effective launching requires temporary seed-valve adhesion. The adhesion mechanism may be the source of the unreliability. Valve curvature is likely driven by the bilayered valve structure, a feature absent in nonballistic brassicas.

Comments

Copyright 2010 Botanical Society of America

Archived (after 12 month embargo) with permission of copyright holder.

Also available on publisher website: http://www.amjbot.org/content/97/10/1595.short

Publication Title

American Journal of Botany

Published Citation

Hayashi, Marika, Gerry, Shannon P. and Ellerby, David J. 2010. The seed dispersal catapault of Cardamine parviflora is efficient but unreliable. American Journal of Botany. 97(10): 1-7.

DOI

10.3732/ajb.1000173

Peer Reviewed

Download

Share

COinS