Roiloa Sergio R, Retuerto Rubén, Campoy Josefina G, Novoa Ana, Barreiro Rodolfo
BioCost Group, Department of Animal Biology, Plant Biology and Ecology, Faculty of Science, University of A Coruña Spain.
Unit of Ecology, Faculty of Biology, University of Santiago de Compostela Santiago de Compostela, Spain.
Front Plant Sci. 2016 Mar 30;7:349. doi: 10.3389/fpls.2016.00349. eCollection 2016.
Why some species become invasive while others do not is a central research request in biological invasions. Clonality has been suggested as an attribute that could contribute to plant invasiveness. Division of labor is an important advantage of clonal growth, and it seems reasonable to anticipate that clonal plants may intensify this clonal attribute in an invaded range because of positive selection on beneficial traits. To test this hypothesis, we collected clones of Carpobrotus edulis from native and invasive populations, grew pairs of connected and severed ramets in a common garden and under negative spatial covariance of nutrients and light to induce division of labor, and measured biomass allocation ratios, final biomass, and photochemical efficiency. Our results showed that both clones from the native and invaded range develop a division of labor at morphological and physiological level. However, the benefit from the division of labor was significantly higher in apical ramets from the invaded range than in ramets from the native area. This is a novel and outstanding result because it provides the first evidence that the benefit of a key clonal trait such as division of labor may have been subjected to evolutionary adaptation in the invaded range. The division of labor can therefore be considered an important trait in the invasiveness of C. edulis. An appropriate assessment of the influence of clonal traits in plant invasions seems key for understanding the underlying mechanisms behind biological invasions of new environments.
为何有些物种会成为入侵物种而有些则不会，这是生物入侵领域的核心研究课题。克隆性被认为是一种可能促成植物入侵性的特性。分工是克隆生长的一个重要优势，而且可以合理推测，由于对有益性状的正向选择，克隆植物在入侵范围内可能会强化这种克隆特性。为了验证这一假设，我们从原生种群和入侵种群中采集了食用滨藜的克隆体，在一个共同园圃中，以及在养分和光照的负空间协方差条件下，种植相连和分离的分株以诱导分工，并测量生物量分配比例、最终生物量和光化学效率。我们的结果表明，来自原生范围和入侵范围的克隆体在形态和生理水平上都形成了分工。然而，入侵范围的顶端分株从分工中获得的益处显著高于原生区域的分株。这是一个新颖且突出的结果，因为它首次提供了证据，表明诸如分工这样的关键克隆性状的益处可能在入侵范围内经历了进化适应。因此，分工可被视为食用滨藜入侵性的一个重要性状。对克隆性状在植物入侵中的影响进行恰当评估，似乎是理解新环境生物入侵背后潜在机制的关键。
