生物多样性 ›› 2015, Vol. 23 ›› Issue (5): 658-664.DOI: 10.17520/biods.2015102

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盗蜜对角蒿传粉者行为和生殖成功的影响

杜家潇1,2, 孟璐1, 孙海芹2,*(), 包颖1,*()   

  1. 1 曲阜师范大学生命科学学院, 山东曲阜 273165
    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
  • 收稿日期:2015-04-27 接受日期:2015-06-23 出版日期:2015-09-20 发布日期:2015-10-12
  • 通讯作者: 孙海芹,包颖
  • 基金资助:
    国家自然科学基金(31370403)

Effects of nectar robbing on pollinator behavior and pollination success in facultative selfing Incarvillea sinensis var. sinensis

Jiaxiao Du1,2, Lu Meng1, Haiqin Sun2,*(), Ying Bao1,*()   

  1. 1 College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165
    2 State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093
  • Received:2015-04-27 Accepted:2015-06-23 Online:2015-09-20 Published:2015-10-12
  • Contact: Sun Haiqin,Bao Ying

摘要:

一些研究显示盗蜜对自交植物的结实和结籽没有显著影响。然而, 对于既有传粉者为其传粉实现异交又能通过自交实现生殖保障的兼性自交植物来说, 盗蜜对其生殖的影响还知之甚少。由于兼性自交植物可以自交, 盗蜜对其总体结实可能不会有显著影响, 但可能会通过影响传粉者行为而影响传粉者介导的结实。为了验证这一假说, 本研究以兼性自交的一年生角蒿(Invarvillea sinensis var. sinensis)为研究材料, 通过野外调查和控制实验, 探讨了盗蜜对传粉者介导的结实(传粉者行为)和总体结实率的影响。结果表明: 角蒿的盗蜜者和主要传粉者相同, 均为密林熊蜂(Bombus patagiatus)。熊蜂盗蜜频率平均为20.24% (范围为0-51.43%)。盗蜜对角蒿总体结实率、每果结籽数和每果种子重量没有显著影响。然而, 被盗蜜花的柱头闭合比率显著高于未被盗蜜花, 说明盗蜜影响传粉者的访花行为和传粉者介导的结实率。另外, 被盗蜜花的高度显著高于未被盗蜜花, 说明盗蜜者倾向于从较大较高的花上盗蜜。这些结果为全面认识盗蜜对植物生殖的影响提供了新的信息。

关键词: 角蒿属, 兼性自交, 花高度, 盗蜜, 传粉者介导的结实, 生殖

Abstract:

Some plants benefit from self-fertilization for reproductive assurance, and thus might experience little effect of nectar robbing on fruit production. In facultative selfing plants which involve both outcrossing by pollinators and selfing when pollinators are scare or not available, nectar robbing is expected to have no influence on fruit set, but may affect pollinator-mediated fruit set. In order to test this prediction, we manipulated robbing (open to be robbed or excluding nectar robbers by caging flowers) in an annual facultative selfing plant Invarvillea sinensis var. sinensis and quantified fruit set, seed number and weight per fruit. Pollinator-mediated fruit set was evaluated on the basis of the closure of stigmatic lobes, which generally occurs after pollinator visiting. The height of flowers was measured to test whether nectar robbers have a visiting preference for specific floral traits. Bumble bees, workers of Bombus patagiatus, were the primary pollinators of I. sinensis and some of them were also nectar robbers. Robbers stole nectar from both open flowers and flower buds. Averaged frequency of nectar robbing was 20.24%, ranging from 0 to 51.43%. Experiments excluding nectar robbers showed that nectar robbing did not have significant effects on proportion of fruit set, seed number per fruit and seed mass per fruit. However, the proportion of stigmatic lobes closed was significantly higher in robbed flowers than in unrobbed flowers, suggesting that robbing influences pollinator-mediated fruit set. Height of robbed flowers was significantly higher than that of unrobbed flowers, suggesting that nectar robbers prefer robbing from larger and higher flowers. These results provide insight into the effects of nectar robbing on the reproduction of plants.

Key words: Invarvillea, facultative selfing, flower height, nectar robbing, pollinator-mediated fruit set, reproduction