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Plant Diversity ›› 2014, Vol. 36 ›› Issue (05): 661-667.DOI: 10.7677/ynzwyj201414008

• 研究论文 • 上一篇    下一篇

青藏高原特有植物露蕊乌头 (毛茛科) 从冰期避难所扩张后繁殖资源分配的变化

  

  1. 1 云南农业大学植物保护学院，云南 昆明650201；2 中国科学院昆明植物研究所，云南 昆明650201
  • 收稿日期:2014-01-16 出版日期:2014-09-25 发布日期:2014-03-25
  • 基金资助:

    国家自然科学基金 (31270434)

Changes in Reproductive Allocation after Expansion from the Glacial Refugium and Implications for the Distribution Range in the QinghaiTibet Plateau Native Herb, Gymnaconitum gymnandrum (Ranunculaceae)

  1. 1 College of Plant Protection, Yunnan Agricultural University, Kunming 650201, China; 2 Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
  • Received:2014-01-16 Online:2014-09-25 Published:2014-03-25
  • Supported by:

    国家自然科学基金 (31270434)

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摘要：

物种分布范围的形成是进化生态学研究的基本问题之一，但植物的资源分配策略是否与物种边界形成有关一直没有相关研究。青藏高原特有植物露蕊乌头在末次最大冰期时有4个避难所，但冰期后只有一个避难所的种群发生了扩张并最终形成了现代分布格局。以露蕊乌头的避难所种群（同仁种群）和扩张后邻近分布区边缘的两个种群（兴海种群和海北种群）为研究对象，通过比较避难所种群和边缘种群的资源分配方式，探讨露蕊乌头的资源分配与该植物分布区及边界形成的关系。结果发现：1）兴海和海北种群的营养结构（包括根、植株高度和茎叶生物量）均显著低于同仁种群，海北种群的繁殖结构（花数量和花生物量）显著低于同仁和兴海种群，但海北和兴海的繁殖分配均显著高于同仁种群；2）3个种群的繁殖资源与个体大小呈现显著的正相关关系，投入到繁殖资源的比例（繁殖分配）与个体大小呈显著的负相关关系。对露蕊乌头的研究结果一方面进一步证明了个体大小依赖的繁殖分配，但不符合“植物开始繁殖必须达到一定的大小（阈值）”这一结论，这可能与露蕊乌头的生活史特征有关；而另一方面，露蕊乌头在扩张过程中逐渐增加了对繁殖资源投资的比例，说明胁迫生境中有性繁殖对该植物具有更为重要的意义，且露蕊乌头在扩张过程中可能逐渐实现繁殖产出最大化，并可能在边缘种群实现最优繁殖分配进而最终形成该物种分布区的边界，但这一结论仍需在更多的植物类群中验证。

关键词: 露蕊乌头, 避难所, 扩张, 繁殖分配, 边界

Abstract:

A fundamental goal of ecology and evolution is to explain patterns of species distribution and abundance. However, the way in which stable distribution ranges are shaped by natural selection is still poorly understood, especially whether patterns of resource allocation have contributed to the range size and the formation of range boundary received little attention. For annual herb, the maximum reproductive allocation is predicted to be 50%, and thus we predicted that reproductive allocation might contribute to the formation of range boundary since plant will enhance allocations to reproduction in stressful environments. In this study, we presented our data on resource allocation between population from the glacial refegium and those from the marginal populations in Gymnaconitum gymnandrum, an alpine biennial native to the QinghaiTibet Plateau, aiming to find the contribution of resource allocation to the formation of range boundary. Our results showed that resource allocations to vegetative organs, including roots, plant height and stemleaf biomass, were significantly higher in the refugium population that in the two marginal populations, and allocations to reproductive organs, including flower number and flower biomass, were significantly lower in one marginal population (Haibei population) than in the other marginal population (Xinghai population) and the refugium population (Tongren population). However, reproductive allocation was significantly higher in the marginal populations than in the refugium population. In addition, in each of the three populations, we found a positive relationship between the plant size and flower biomass but a negative relationship between the plant size and reproductive allocation. Our results indicated a sizedependent reproductive allocation in Ggymnandrum, but we did not find a size threshold for reproduction in each of the three populations of this plant, which might be attributed to the life history of this biennial herb. We also suggested that reproductive allocation was increased during the process of range expansion and may rise to the optimal reproductive allocation in the marginal populations, which suggested the important role of sexual reproduction for plants in more stressful environments and the formation of range boundary. However, these conclusions need to be further proved in other plant species.

Key words: Gymnaconitum gymnandrum, Refugium, Expansion, Reproduction allocation, Range boundary

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