生物多样性 ›› 2008, Vol. 16 ›› Issue (5): 477-483.DOI: 10.3724/SP.J.1003.2008.08096

• 研究报告 • 上一篇    下一篇

足茎毛兰的欺骗性传粉研究

上官法智1, 程瑾2,3, 熊源新1, 罗毅波2,*()   

  1. 1 贵州大学生命科学学院, 贵阳 550025
    2 中国科学院植物研究所系统与进化植物学国家重点实验室, 北京 100093
    3 中国科学院研究生院, 北京 100049
  • 收稿日期:2008-04-23 接受日期:2008-05-27 出版日期:2008-09-20 发布日期:2008-09-20
  • 通讯作者: 罗毅波
  • 作者简介:*(luoyb@ibcas.ac.cn)
  • 基金资助:
    国家自然科学基金项目(30770379)

Deceptive pollination of an autumn flowering orchid Eria coronaria (Orchidaceae)

Shangguan Fazhi1, Cheng Jin2,3, Xiong Yuanxin1, Luo Yibo2,*()   

  1. 1 College of Life Science, Guizhou University, Guiyang 550025
    2 State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093
    3 Graduate University of the Chinese Academy of Sciences, Beijing 100049
  • Received:2008-04-23 Accepted:2008-05-27 Online:2008-09-20 Published:2008-09-20
  • Contact: Luo Yibo

摘要:

一些兰科植物常常利用多种多样的欺骗性传粉机制吸引传粉者, 唇瓣上的附属物就是其中之一。黄色被认为对昆虫具有吸引作用。在广西雅长兰科植物自治区级保护区内秋季开花的足茎毛兰(Eria coronaria)唇瓣上具有鲜明的黄色斑块, 这种花部信号很可能与吸引昆虫有关系。为验证这一假设, 我们在广西雅长保护区内对足茎毛兰的传粉过程进行了观察。研究发现, 足茎毛兰的唯一传粉者是中华蜜蜂(Apis cerana cerana)。与足茎毛兰同在秋季开花的植物主要有光叶海桐(Pittosporum glabratum)。光叶海桐的花中有丰富的花蜜和花粉, 吸引大量中华蜜蜂访问。足茎毛兰虽然不为中华蜜蜂提供任何报酬, 但其唇瓣上的黄色斑块的颜色和形态大小与光叶海桐的黄色花相似。根据中华蜜蜂在足茎毛兰和光叶海桐花上的活动情况, 我们认为足茎毛兰唇瓣上鲜明的黄色斑块对中华蜜蜂有吸引作用。中华蜜蜂访花时, 通常降落在唇瓣的黄色斑块上, 调整身体姿势后进入花内, 在退出的过程中将花粉块带出或将所携带的花粉块授到柱头上, 而药帽留在原来的位置。足茎毛兰的花部构造, 特别是药帽的形状与中华蜜蜂的形态以及在花上的行为十分吻合, 因此中华蜜蜂的传粉效率较高。人工授粉实验表明足茎毛兰需要依赖传粉者才能完成传粉过程。足茎毛兰在研究样地的自然结实率为20.72%, 接近于食源欺骗性传粉兰科植物的平均结实率(20.7%)。

关键词: 黄色斑块, 唇瓣, 欺骗性传粉机制, 中华蜜蜂, 药帽, 同期开花植物

Abstract

Appendages on orchid floral labellum that lack floral rewards for pollinators are considered attractive signals to potential pollinators. Eria coronaria, which has an unusual autumn flowering season in some locations, has a bright yellow spot on its labellum. This spot has been hypothesized to function as a visual attractant to potential pollinators because its color may be attractive to insects. We tested this hypothesis using field observations between October and November of 2006 in the Yachang Nature Reserve, Guangxi, southwestern China. Honeybee (Apis cerana cerana) was the only pollinator of this orchid. Generally, honeybees landed directly on the yellow spot on labellum, and then adjusted their position and entered the flower. When honeybees retreated from flowers, the pollinaria were adhered on their thorax, or the pollinaria carried by honeybee were stuck on the stigma. The anther cap, however, did not separate from the column when the pollinaria were carried away from the flower. This orchid did not provide any rewards to honeybees. The flowers of a co-blooming plant,Pittosporum glabratum, with abundant nectars and pollens, attracted numerous honeybee visitations during this period. The flower color and size of P. glabratum were similar to that of the spot on the labellum of E. coronaria. Based on the behaviors of honeybees on the flowers of bothP. glabratum and E. coronaria, we speculated that the bright yellow spot on labellum of this orchid functions as an attractant to honeybees. Hand-pollination experiments showed that E. coronaria was self-compatible, but that reproductive success depended on pollinators. Under natural conditions, the rate of fruit set of E. coronaria was 20.72%, which is very close to the average fruit set of other food deceptive orchids (20.7%).

Key words: yellow spot, labellum, attractive signal, Apis cerana cerana, anther cap, co-blooming plants