荇菜沿海拔梯度的引种驯化及生态适应机制研究

At present, under the situation of global climate change, the plant researches focus on the rule of ecological adaptation to climate in the world. China's vast territory and complex topography offer a unique platform for carrying out the study of plant ecological adaptation to climate. Because Nymphoides peltata, a common floating-leaved aquatic plant in China, widely distributes from the low plains of east China to the Qinghai-Tibet Plateau, N. peltata is a superior plant material for the study of ecological adaptation over large-scale environmental gradients. By the combining use of field investigation, position observation, introduction and acclimatization experiment, we want to collect wild populations of N. peltata along the China's three ladder elevation gradient and introduce these populations to different climate area, then research the fitness (growth, florescence, reproduction, etc.) and physiological metabolism (photosynthesis, enzymology, etc.) of transplant populations. The aim of this study is to investigate the acclimatization capacity and local adaptation for N. peltata along latitudinal gradients. This study helps to reveal the mechanism of ecological adaptation for acclimatization of aquatic flowers over large-scale environmental gradients, and provide theoretical guidance to protect and use aquatic plants under global climate change.

目前在全球气候变化的背景下，探讨植物对气候的适应规律成为植物学研究的热点。中国辽阔的疆域和复杂的地形为开展植物对气候的生态适应研究提供了一个得天独厚的平台。荇菜是我国常见的一种浮叶水生植物，由于其从中国东部平原到青藏高原都有分布，因此对于研究植物沿大尺度海拔梯度下的生态适应规律，荇菜是一个良好材料。本项目采用野外调查、定位观测和引种驯化实验相结合的方法，沿中国三级阶梯海拔梯度采集荇菜种群，然后在各海拔高度之间交互引种，观测异地移栽种群的驯化情况，包括生长、开花、繁殖等适合度变化及光合、酶活等新陈代谢水平，探讨荇菜沿海拔梯度的驯化能力及本地适应规律。本研究有助于揭示水生植物跨越大尺度环境梯度进行引种驯化的生态适应机制，为全球气候变化下的水生植被保护和利用提供科学理论依据。

目前利用移栽实验探讨大尺度环境梯度下的物种分布、适应与进化的研究是国际生态学的热点。本项目采用野外调查、定位观测和引种驯化实验相结合的方法，沿着中国海拔梯度采集水生植物广布种荇菜(Nymphoides peltata)的野生种群，然后在不同海拔高度之间交互引种，观测异地移栽种群的驯化情况，包括生长、开花、繁殖等变化，探讨荇菜沿海拔梯度的驯化能力及本地适应规律。研究结果显示，荇菜沿海拔梯度已经产生了明显的生活史和繁殖策略变化，在本地适合度最高，验证了本地适应现象。另外，本项目还在海南重新发现了已消失一百年的海丰荇菜以及揭示了水生植物丰富度随着海拔的升高而下降的规律。本研究深化了对水生植物大尺度分布格局的理解，进一步丰富了生态适应理论。