中国特有裸子植物——巴山榧树的保护生物学研究

Torreya fargesii is an endangered species of Torreya (Taxaceae), which is endemic to China and under second class state protection. It is a very important forest resource, with hard wood and dense structure. Its wood could be manufactured into fine cabinetwork and agricultural implements and seeds could be extracted oil. Previous studies have indicated that T. fargesii is distributed from Qinling Mountain, Daba Mountain, Qionglai Mountain, Dalou Mountain to Wu Mountain, Wuling Mountain and Dabie Mountain, where are subtropical mountainous area of 800 to 2 700 meters above sea level. Although T. fargesii has a wide distribution range and plenty of localities, most of its populations have only a few individuals and a narrow area. This species and its habitat need urgent protection. However, previous study on T. fargesi was not adequately, especially in the basic research like resource assessment and the destroyed degree, genetic diversity and population genetic structure. The study on population genetics, molecular phylogeography and conservation biology is extremely scarce. This study focus on morphological and anatomical features, photosynthesis physiological and ecological characteristics, reaction of physiology biochemistry under water stress, population structure and dynamics, and genetic diversity of T. fargesii systematically and comprehensively from the views of morphology and anatomy, physiological ecology, population ecology, reproductive ecology and conservation genetics. The endangered mechanism of T. fargesii would be discussed and some suggestions on species conservation strategies would be provided from different perspectives. In the meantime, a better cutting propagation and tissue culture systems would be to establish by the research on cutting propagation and tissue culture of T. fargesii and to provide scientific basis and technical support for large scale production. The study is of great significance on population restoration of T. fargesii.

巴山榧树是我国特有的裸子植物，具有较高的经济价值和生态价值，被列为国家二级重点保护野生植物。前期研究表明，巴山榧树间断分布于我国亚热带海拔800～2 700m的山区。虽然巴山榧树水平分布范围跨度较大，分布点较多，但绝大多数种群的个体数量稀少，分布区狭窄，种群及其栖息地亟待保护。然而当前对巴山榧树的研究还很欠缺，种群生态学、居群遗传学、繁殖生物学等保护生物学领域的研究工作仍很少涉及。本研究综合运用形态解剖学、生理生态学、种群生态学、保护遗传学、繁殖生物学等理论与方法，较全面、系统地开展巴山榧树的形态解剖特征、光合生理生态特性、水分胁迫生理生化反应、种群结构和动态、遗传多样性等研究，从多角度揭示巴山榧树濒危机制并提出科学保护对策。同时，通过扦插繁殖和组织培养试验研究，建立良好的扦插繁殖和组织培养体系，为规模化生产提供科学依据和技术保障，对于巴山榧树种群恢复具有重要意义。

本项目以巴山榧树为研究对象，通过幼苗营养器官解剖结构及不同海拔生境巴山榧树营养器官形态解剖特征的比较分析，阐释巴山榧树形态解剖特征及其与环境因子的相关性。通过测定不同海拔梯度上巴山榧树叶片光合色素含量、膜脂过氧化和抗氧化酶活性的变化规律，比较不同温度处理后的幼苗光合特性和光合作用指标，分析水分胁迫对幼苗生长和生理特性的影响，揭示巴山榧树对环境因子的生理适应机制。通过不同地理种群的密度、径级结构、高度级结构及数量动态特征的比较分析，阐明了巴山榧树种群特征及发展趋势。通过大巴山和金佛山巴山榧树群落物种多样性、生态位特征和种间关系等的分析，阐明了巴山榧树群落的主要生态特征。通过ISSR、RAPD分子标记及psbA-trnH序列分析，揭示了巴山榧树种群不同尺度范围的遗传多样性和遗传结构。通过种子繁育、扦插繁殖和组培试验，揭示了巴山榧树种子休眠特性和幼苗生长规律，探讨了不同基质、插穗和生根剂对扦插生根的影响，尝试了不同培养基及激素配比对组培的影响，为巴山榧树繁育和规模化生产奠定了基础。通过巴山榧树种子生物活性成分的研究，分析评价了巴山榧树的开发利用潜力。本项目从多角度揭示了巴山榧树的生物生态学特性及对环境的适应性，濒危现状和退化机制，为巴山榧树的深入研究及保护管理策略的制定和实施提供了切实有效的科学依据。.整体而言，本项目进展顺利，按照计划完成了各项研究内容，达到了预期目标。项目执行期间已发表论文15篇，其中SCI论文3篇，较好地完成了预期研究成果指标。