亚马逊蚂蚁通过嗅觉便能够判断种子的种类。据美国《科学》杂志在线报道，蚂蚁(Camponotus femoratus)会采集黑胡椒树的种子，并将它们搬回位于树上的蚁巢（如图）。黑胡椒树的生长能够防止蚁巢解体，而蚂蚁同时也为植物的生长提供了养料。当研究人员在其他种子的表面涂抹上黑胡椒的提取物后，这些蚂蚁便会接踵而至。这是种子的气味能够吸引蚂蚁的第一个例证。研究人员在最近的美国《国家科学院院刊》（PNAS）网络版上报告了这一研究成果。（科学时报 群芳/编译）
（《国家科学院院刊》（PNAS），10.1073/pnas.0708643105，Elsa Youngsteadt, Coby Schal）
Published online before print January 22, 2008
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0708643105
SPECIAL FEATURE / ECOLOGY
Seed odor mediates an obligate ant–plant mutualism in Amazonian rainforests
Elsa Youngsteadt*, Satoshi Nojima*, Christopher Häberlein, Stefan Schulz, and Coby Schal*,
*Department of Entomology and W.M. Keck Center for Behavioral Biology, North Carolina State University, Box 7613, Raleigh, NC 27695; and Institut für Organische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
Edited by Thomas Eisner, Cornell University, Ithaca, NY, and approved November 30, 2007 (received for review September 11, 2007)
Abstract
Seed dispersal mutualisms are essential for the survival of diverse plant species and communities worldwide. Among invertebrates, only ants have a major role in seed dispersal, and thousands of plant species produce seeds specialized for ant dispersal in "diffuse" multispecies interactions. An outstanding but poorly understood ant–seed mutualism occurs in the Amazonian rainforest, where arboreal ants collect seeds of several epiphyte species and cultivate them in nutrient-rich nests, forming abundant and conspicuous hanging gardens known as ant-gardens (AGs). AG ants and plants are dominant members of lowland Amazonian ecosystems, and their interaction is both specific and obligate, but the means by which ants locate, recognize, and accept their mutualist seeds while rejecting other seeds is unknown. Here we address the chemical and behavioral basis of the AG interaction. We show that workers of the AG ant Camponotus femoratus are attracted to odorants emanating from seeds of the AG plant Peperomia macrostachya, and that chemical cues also elicit seed-carrying behavior. We identify five compounds from P. macrostachya seeds that, as a blend, attract C. femoratus workers. This report of attractive odorants from ant-dispersed seeds illustrates the intimacy and complexity of the AG mutualism and begins to illuminate the chemical basis of this important and enigmatic interaction.
seed dispersal | ant-garden | myrmecochory | Camponotus femoratus | Peperomia macrostachya
