杂交蟛蜞菊对不同环境胁迫的生理生态响应及其抗逆性的适应进化

外来生物入侵不仅威胁着当地的生物多样性、生态系统的结构和功能，而且会严重影响社会和人类健康，造成重大的经济损失。生物入侵是一个适应性进化的过程, 自然杂交可以改变外来物种对环境的适应性并提高其入侵能力, 使其可能进化为新的入侵种。本项目以我国华南地区的常见入侵种南美蟛蜞菊与本地亲缘种蟛蜞菊天然杂交形成的新物种杂交蟛蜞菊及其亲本为材料，在项目申请人发现杂交种抗干旱或耐水淹胁迫能力处于亲本之间，但抗重金属镉胁迫能力明显强于亲本的基础上，进一步分析和比较水分或镉等不同胁迫下杂交种及其亲本的光合作用特性、抗氧化特性、激素含量变化、抗逆相关机制的变化，应用转录组手段分析不同胁迫下与生长、光合及抗逆机制等相关基因的表达变化，将不同胁迫下的生理生态变化与相关基因表达量的变化耦合起来，揭示不同逆境下杂交种较亲本显示不同抗性的适应性进化机制，为植物入侵的进化研究奠定理论基础，也能指导重金属超富集植物筛选。

The biological invasion of exotic species not only threats the biodiversity, the structure and functions of native ecosystem, but also influences the society and human health, and sometimes causes serious economic loss. Biological invasion is a process of adaptive evolution in which hybridization and introgression play an important role in promoting invasive species by changing their invasiveness. A natural hybrid between invasion species Sphagneticola trilobata and native species Sphagneticola calendulacea were found and identified in Southern China in 2013. Applicant’s results showed that the ability of resistance to drought or flood in hybrid is between it’s parents, however, it’s cadmium tolerance stronger than it’s parents. In this project, Sphagneticola trilobata, Sphagneticola calendulacea and their hybrid were selected as the research objects. Their physiological responses to different stresses (drought, flood or Cd stress) including photosynthesis, phytohormone content, antioxidative ability and relative resistance mechanism were detected.By using RNA sequencing, the expression genes relative to growth, photosynthesis and resistance mechanism is evaluated under different stresses. The mechanism of adaptive evolution in hybrid with different resistance to different stresses is elucidated by analyzing the coupling relationship between eco-physiological response and gene expression. The results will provide a reference for the study of mechanism of invasive adaptive evolution.