Comparison of mechanisms of reproductive interference in Taraxacum
Comparison of mechanisms of reproductive interference in Taraxacum
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DOI：
10.1093/aob/mcz007
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发表时间：
2019-02
期刊：
影响因子：
4.2
通讯作者：
Akane Takemori;A. Naiki;K. Takakura;M. Kanaoka;Sachiko Nishida
中科院分区：
文献类型：
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作者：
Akane Takemori;A. Naiki;K. Takakura;M. Kanaoka;Sachiko Nishida
摘要背景和目的生殖干扰可能会降低任何一个相关物种的适合度，具有潜在的重要生态和进化后果。然而，除了共享传粉者对生殖成功的影响外，生殖干扰的机制几乎没有研究，尽管其影响的严重程度可能取决于具体的机制。因此，本研究的目的是探讨日本蒲公英（原产地）和蒲公英（外来）之间的生殖干扰的机制。方法通过野外调查，研究了外来种密度与赤眼蜂结实率的关系。japonicum，以及传粉者的行为是否表明对外来物种的偏好。异种花粉沉积的影响进行了测量，在一系列的手授粉实验，包括混合授粉实验中，同种和异种花粉的应用程序是不同的。最后，为了调查杂交频率，比较了自然、混合或异种授粉后产生的幼苗的亲子关系。外来物种密度并没有负面影响本地种子集，也没有传粉者似乎有一个外来花卉的偏好。人工授粉实验表明，异源花粉沉积对本地结实率有不利影响，特别是当在同种花粉之前施用外来花粉时。自然授粉后没有发现有活力的杂种，这表明杂交可能是一个罕见的事件。结论在所研究的机制中，异种花粉沉积可能对本地物种的有害影响最大。这种影响是频率依赖的;因此，正反馈循环可能会导致对种群动态的影响随着时间的推移而增加，结果是外来物种可能最终取代种群中的本地物种。研究机制对种群动态的影响应进一步调查，以提高对植物群落结构的生殖干扰的影响的理解。
Abstract Background and Aims Reproductive interference may reduce fitness of either of the involved species, with potentially important ecological and evolutionary consequences. Except for the effect of shared pollinators on reproductive success, however, mechanisms underlying reproductive interference have been little studied, even though the severity of its impact may depend on the specific mechanism. The aim of this study was therefore to explore the mechanisms of reproductive interference between Taraxacum japonicum (native to Japan) and Taraxacum officinale (alien). Methods In a field survey, the association between alien species density and seed set in T. japonicum, and whether pollinator behaviour indicated a preference for the alien, were examined. Effects of heterospecific pollen deposition were measured in a series of hand pollination experiments, including mixed pollination experiments in which the order of application of conspecific and heterospecific pollen was varied. Finally, to investigate hybridization frequency, the parentage of seedlings produced following natural, mixed or heterospecific pollination was compared. Key Results Alien species density did not negatively affect native seed set, nor did pollinators appear to have a preference for alien flowers. The hand pollination experiments showed that heterospecific pollen deposition adversely affected native seed set, especially when alien pollen was applied before conspecific pollen. No viable hybrids were found following natural pollination, which suggests that hybridization might be a rare event. Conclusion Among the examined mechanisms, heterospecific pollen deposition might have the largest deleterious effect on the native species. This effect is frequency dependent; thus, a positive feedback loop may cause the effect on the population dynamics to increase over time, with the result that the alien might eventually displace the native in a population. Effects of the examined mechanisms on population dynamics should be investigated further to improve understanding of the impact of reproductive interference on the structure of plant communities.