Rosbakh Sergey, Pacini Ettore, Nepi Massimo, Poschlod Peter
Chair of Ecology and Conservation Biology, University of Regensburg, Regensburg, Germany.
Department of Life Sciences, University of Siena, Siena, Italy.
Front Plant Sci. 2018 Jul 18;9:1036. doi: 10.3389/fpls.2018.01036. eCollection 2018.
In 1977, Peter Grubb introduced the regeneration niche concept, which assumes that a plant species cannot persist if the environmental conditions are only suitable for adult plant growth and survival, but not for seed production, dispersal, germination, and seedling establishment. During the last decade, this concept has received considerable research attention as it helps to better understand community assembly, population dynamics, and plant responses to environmental changes. Yet, in its present form, it focuses too much on the post-fertilization stages of plant sexual reproduction, neglecting the fact that the environment can operate as a constraint at many points in the chain of processes necessary for successful regeneration. In this review, we draw the attention of the plant ecology research community to the pre-fertilization stages of plant sexual reproduction, an almost ignored but important aspect of the regeneration niche, and their potential consequences for successful seed production. Particularly, we focus on how temperature affects pollen performance and determines plant reproduction success by playing an important role in the temporal and spatial variations in seed quality and quantity. We also review the pollen adaptations to temperature stresses at different levels of plant organization and discuss the plasticity of the performance of pollen under changing temperature conditions. The reviewed literature demonstrates that pre-fertilization stages of seed production, particularly the extreme sensitivity of male gametophyte performance to temperature, are the key determinants of a species' regeneration niche. Thus, we suggest that previous views stating that the regeneration niche begins with the production of seeds should be modified to include the preceding stages. Lastly, we identify several gaps in pollen-related studies revealing a framework of opportunities for future research, particularly how these findings could be used in the field of plant biology and ecology.
1977年，彼得·格鲁布提出了再生生态位概念，该概念假定，如果环境条件仅适合成年植物的生长和存活，而不适合种子生产、传播、萌发和幼苗建立，那么一个植物物种就无法持续存在。在过去十年中，这一概念受到了相当多的研究关注，因为它有助于更好地理解群落组装、种群动态以及植物对环境变化的反应。然而，就其目前的形式而言，它过于关注植物有性生殖的受精后阶段，而忽略了这样一个事实，即在成功再生所需的一系列过程中，环境在许多环节都可能成为一种限制因素。在这篇综述中，我们提请植物生态学研究界关注植物有性生殖的受精前阶段，这是再生生态位中一个几乎被忽视但很重要的方面，以及它们对成功种子生产的潜在影响。特别地，我们关注温度如何影响花粉性能，并通过在种子质量和数量的时空变化中发挥重要作用来决定植物繁殖的成功。我们还综述了植物在不同组织水平上对温度胁迫的花粉适应性，并讨论了在不断变化的温度条件下花粉性能的可塑性。所综述的文献表明，种子生产的受精前阶段，尤其是雄配子体性能对温度的极端敏感性，是一个物种再生生态位的关键决定因素。因此，我们建议，先前认为再生生态位始于种子生产的观点应加以修正，以纳入之前的阶段。最后，我们指出了花粉相关研究中的几个空白，揭示了未来研究的机会框架，特别是这些发现如何能够应用于植物生物学和生态学领域。
