Department of Biology, Graduate School of Sciences, Kyushu University, 812-8581 Fukuoka, Japan;
Am J Bot. 2003 Mar;90(3):370-6. doi: 10.3732/ajb.90.3.370.
We evaluated the role of floral scents in the reproductive success of Alocasia odora C. Koch (Araceae). Alocasia odora is pollinated by its specific pollinators, Colocasiomyia alocasiae (Okada) and C. xenalocasiae (Okada) (Diptera: Drosophilidae). These flies use the spadix of A. odora as breeding sites. The appendix, which is at an upper part of the spadix and is the most attractive region, attracted these pollinators by emitting volatiles, although the male zone of the inflorescence was also attractive. The number of flies attracted was positively correlated with appendix size. During the pistillate phase of the protogynous spadix, attracted flies aggregated in the lower part (female zone) to mate, lay eggs, and perhaps obtain nutrients. The flies moved to the upper part (male zone) of the spadix by the tightening of the constriction separating the upper and lower parts, and then the staminate phase started. This movement of the flies on the spadix promotes outcrossing of A. odora. Removal of the appendix or the whole upper part of the spadix resulted in much reduced fruit set, suggesting that the absence of the scent-producing region leads to insufficient pollination because of reduced pollinator attraction.
我们评估了花的气味在 Alocasia odora C. Koch（天南星科）生殖成功中的作用。Alocasia odora 由其特定的传粉者 Colocasiomyia alocasiae (Okada) 和 C. xenalocasiae (Okada)（双翅目：果蝇科）授粉。这些苍蝇将 Alocasia odora 的佛焰苞用作繁殖地。佛焰苞的附属物位于上部，是最具吸引力的区域，尽管花序的雄性区域也具有吸引力，但它通过散发挥发性物质吸引这些传粉者。吸引的苍蝇数量与附属物的大小呈正相关。在雌雄同体的佛焰苞的雌蕊期，吸引的苍蝇聚集在下部（雌性区）交配、产卵，也许还能获得营养。随着上下部分之间的收缩加紧，苍蝇移动到佛焰苞的上部（雄性区），然后开始雄花期。苍蝇在佛焰苞上的这种运动促进了 Alocasia odora 的异交。去除附属物或整个佛焰苞的上部会导致果实数量大大减少，这表明没有产生气味的区域会导致由于传粉者吸引力降低而导致授粉不足。
