生物多样性 ›› 2018, Vol. 26 ›› Issue (5): 468-475.DOI: 10.17520/biods.2018037

• 综述 • 上一篇    下一篇

克隆生长对被子植物传粉过程的影响

田昊, 廖万金*()   

  1. 北京师范大学生命科学学院, 生物多样性与生态工程教育部重点实验室, 北京 100875
  • 收稿日期:2018-02-05 接受日期:2018-03-23 出版日期:2018-05-20 发布日期:2018-09-11
  • 通讯作者: 廖万金
  • 作者简介:

    # 共同第一作者

  • 基金资助:
    国家自然科学基金(31770253)

Consequences of clonal growth on pollinator visitation in flowering plants

Hao Tian, Wanjin Liao*()   

  1. Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing 100875
  • Received:2018-02-05 Accepted:2018-03-23 Online:2018-05-20 Published:2018-09-11
  • Contact: Liao Wanjin
  • About author:

    # Co-first authors

摘要:

克隆植物与其传粉者的相互作用是植物繁殖生态学的重要研究领域之一。植物克隆生长与有性繁殖通常相伴进行, 往往产生较大的花展示与复杂的克隆空间结构, 通过传粉过程对有性繁殖过程产生影响, 共同决定植物的适合度。本文回顾了克隆生长对被子植物传粉过程影响的国内外研究进展, 从植物克隆大小、花资源空间配置、克隆构型与种群遗传结构四个方面讨论了克隆生长对传粉过程的影响及其生态学与进化生物学意义。早期研究预期, 随着克隆增大, 同株异花授粉水平增加, 因而通过增大自交率或花粉阻塞效应降低植物的适合度。但是, 后来的一些模拟与野外实验研究发现, 传粉者在同一克隆内访问的花数量并不会随克隆增大而一直增加, 访花行为也主要发生在分株内; 而且分子标记的自交率组分分析也表明自交主要发生在分株内。另一方面, 人工模型模拟以及传粉者访问行为研究表明, 当花朵数量相同时, 与所有花集中生长在同一分株上相比, 将花朵分散在多个分株上的克隆生长方式不会增加, 反而降低了同株异花授粉的发生水平。如果花序内花雌雄同熟, 花朵同时提供与接收花粉, 克隆生长会使植物接收到更高比例的异交花粉, 在提高后代质量的同时不增加同株异花授粉概率。这是从传粉生物学角度对植物克隆生长习性进化的一个全新的解释。今后, 克隆植物传粉生物学研究需要针对传粉者与克隆生长之间的相互作用建立理论模型, 探究克隆大小、克隆构型、花资源空间配置模式对传粉者访问频率和行为、花粉散布、交配格局的影响。同时, 需要在自然种群中, 尤其是克隆与非克隆的近缘类群、同一物种克隆与非克隆种群开展比较研究, 利用更高效的分子标记来研究克隆生长的生态与进化意义。

关键词: 克隆构型, 克隆生长, 花资源空间配置, 同株异花授粉, 交配系统, 传粉者行为

Abstract:

Clonal plants reproduce asexually via clonal growth and simultaneously reproduce sexually, and the consequences of clonal growth on pollination and mating have been one of the essential questions in ecology and evolution of plant reproduction. An increasing number of studies report the effects of clonal size, architecture, genetic diversity, and floral deployments on pollinator visit and behavior. The most common view is that clonal growth produces large floral displays and therefore increases attraction to pollinators. Consequently, clonal growth may help to maximize male reproductive success by dispersing more pollen. On the other hand, geitonogamy, pollination among flowers within one individual plant, is an inevitable byproduct with an increase in clone size. More frequent geitonogamous pollination has been expected in clonal plants with large floral displays and leads to a reduction in female fitness because of inbreeding depression or pollen clogging. However, some recent theoretical and empirical studies suggest new ideas on this issue. First, the number of flowers visited by individual pollinator within a clone did not increase proportionally with clone size in clumped clonal plants, and pollinator movements within a single bout mainly occurred within ramet. The selfing component analyses based on molecular markers further evidenced that within-ramet geitonogamy was the largest contributing factor to the total geitonogamy in two clonal species. Second, the experimental study of bumblebees foraging on artificial flowers showed that when the same amount of flowers was distributed among multiple ramets, geitonogamy was not higher but in fact, lower compared with one single inflorescence. The model-based simulation suggested clonal growth could promote pollination quality without increasing geitonogamy when flowers simultaneously received and donated pollen. These studies support a novel explanation of the evolution of clonality in plants. Future studies on the pollination ecology of clonal plants may focus on the effects of clonal growth on pollinator behavior and plant mating from multiple angles. Comparative studies between clonal and non-clonal taxa or between clonal and non-clonal populations of the same species are required to evaluate the ecological and evolutionary consequences of clonal growth.

Key words: clonal architecture, clonal growth, floral deployments, geitonogamous pollination, mating system, pollinator behavior