濒危植物海南龙血树居群遗传特征和环境适应性研究

海南龙血树在中国仅分布于海南，是目前国产龙血竭的两种主要基源植物之一，也是我国名贵的观赏植物。由于遭受掠夺性采挖、原生境破坏和种群更新失败，海南龙血树已被列为中国3级稀有濒危保护植物,但关于该物种的濒危机制、保护遗传学等方面的很多基础性研究工作尚未开展。本项目主要的研究内容包括：1、应用SSR标记技术研究海南龙血树的居群遗传特征，包括遗传变异及其在居群间的分布式样、居群内的空间分布式样和时间分布式样、以及居群子代遗传侵蚀情况等；2、通过对居群交配系统的研究，深入探讨造成居群遗传特征的内因；3、结合对居群生态因子差异、形态学和植物营养学的研究结果，深入探讨居群的环境适应性以及形成居群遗传特征的关键生态因子。项目的研究结果将能从居群遗传学角度系统阐述海南龙血树的濒危机制，进而提出合理的保护策略。

Dracaena cambodiana, endemic to Hainan Island in China, is one of two producers of 'longxuejie' and one of the most popular and precious ornamental trees in China. Recently, due to the commercial collection, destruction of its original habitats and failure of population regeneration, D.cambodiana is listed as one of the state-protected three-grade rare and endangered plants as a rare and vulnerable tree in China. But many basic studies on its endangered mechanism and conservation genetics did not carried out. The main research contents in this project are as follows: 1.Population hereditary features of D. cambodiana will be estimated by SSR markers, which mainly include the extent of population genetic diversity and genetic structure among populations, the spatial and time distribution pattern of genetic variation within populations, and genetic erosion for progenies. 2.With the help of study results of population mating systems, the intrinsic reasons for population hereditary features will be discussed; 3.Combined with the phenotypic variations and ecological factors among populations and study results on plant Nutrition, the environmental adaptability of D. cambodiana population will be discussed at the molecular level, the environmental factors leading to hereditary features of D.cambodiana populations will be analysed. All the results will contribute to the illumination of endangered mechanism of D. cambodiana populations, and the reasonable conservation strategies for D. cambodiana will be suggested.