入侵植物剑叶金鸡菊克隆生长与有性繁殖适应机制研究

Most plants can reproduce both sexually and vegetatively, and the balance between the two reproductive may vary widely between species, sexual reproduction is abandoned gradually in some clonal species, however, sexual reproduction is essential to population expansion to some invasive clonal species. Ecologist concerned whether did clone growth affect the sexual reproduction? what are adaptive strategy between the two reproductive modes? The process is often accompanied by rapid evolution during biological invasion, research on the characteristics of invasion plant breeding will provide a good perspective to reveal these scientific problems. Coreopsis lanceolate is an invasive plant, which is characterized by phalanx clonal growth architectures and high out-crossing rate, we assumed that there must had some kind of adaptive evolution strategy between two reproductive modes. Use the technologies of fixed-point observation in the field, artificial control and molecular markers, we will reveal the mechanism of how to avoid negative effects of phalanx clonal growth and clone growth on out-crossing rate of Coreopsis lanceolate, then, we will further explore the mechanism of cooperative coevolution between mating system and clone growth architecture. The project will contribute greatly to development and enrich the theory of clonal and sexual reprodutive strategy, and the findings will provide certain theory value for the prevention of Coreopsis lanceolate.

克隆和有性两种繁殖方式间的平衡在不同物种间变化很大，有的克隆植物逐渐放弃了有性繁殖过程，但是有性繁殖对一些入侵克隆植物的种群扩张却是必须的。克隆生长是否影响了有性繁殖过程？克隆生长与有性繁殖之间存在怎样的进化关系？外来种在入侵过程中往往伴随快速进化，对入侵植物繁殖特征的研究为揭示这些科学问题提供了很好的研究视角。入侵植物剑叶金鸡菊以密集型克隆生长为主，交配系统为专性异交，且异交率高，两种繁殖方式之间必定存在某种适应进化策略。本项目通过野外定点观察、人工控制实验，并结合分子标记等方法阐明⑴剑叶金鸡菊密集型克隆大小对异交率的影响；⑵剑叶金鸡菊避免密集型克隆构型对异交影响的机制。研究通过比较不同克隆生长构型格局对有性繁殖特征及异交率的影响，探讨交配系统和克隆生长构型间可能的协同进化机制，丰富和完善克隆植物的无性和有性繁殖对策理论和实践资料，同时也可为剑叶金鸡菊的防治提供一定的理论参考。

本项目采用野外定点观察、人工控制实验、分子标记等方法，对剑叶金鸡菊的有性、克隆繁殖特性及交配系统和克隆生长构型间可能的协同进化机制进行了研究。主要研究结果如下：（1）有性繁殖能力强和多次引入是该克隆植物保持种群高遗传多样性的重要原因。较高的种群克隆多样性降低了剑叶金鸡菊同株异花授粉几率，是其专性异交交配系统有性繁殖成功的重要策略。遗传多样性高同时也提高了有性繁殖适合度，促进了有性繁殖成功。（2）花期吸引大量本地传粉昆虫，充分利用了本地传粉昆虫资源，保障了剑叶金鸡菊专性异交交配系统繁殖成功。（3）在种群的郁闭作用、凋落物分解物和根茎分泌物的自毒作用综合效应下，剑叶金鸡菊种群内种子萌发和实生苗的生长受到抑制，种内竞争减少。而在裸地全光照生境下，剑叶金鸡菊可形成大量实生苗占据新生境。项目完成为揭示入侵植物剑叶金鸡菊的繁殖机制，阐明异交交配系统和克隆生长之间协同进化机制提供了重要理论依据，同时也可为剑叶金鸡菊的防治提供一定的理论参考。