| 桫椤科植物生物学特性及白桫椤保护遗传学研究 |
| 王紫娟
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| 学位类型 | 博士
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| 导师 | 管开云
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| 2010-05
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| 学位授予单位 | 中国科学院研究生院
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| 学位专业 | 植物学
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| 摘要 | 桫椤科植物常被称之为“树蕨”，它们是白垩纪遗留下来的“活化石”，为了找到该科植物数量减少的原因以及为保护这类孑遗植物提供一些参考资料，本研究对中国云南的该科植物的生物学特性进行了分析，并利用AFLP分子标记以及cpDNA trnL-F和atpB-rbcL序列变异，侧重对中国的白桫椤居群进行了遗传多样性检测，同时开展了其谱系地理学研究，并根据研究的结果提出了保护策略，主要结论如下：(1) 云南桫椤科植物分布范围广，其中以滇东南的种类最多。其孢子形态多样，适应能力较强，但由于人类的影响，其种群更新困难。黑桫椤、大叶黑桫椤和滇南桫椤是有性二倍性种。化学成分分析揭示白桫椤具有一定的食用和药用价值。(2) 白桫椤的核基因组DNA具有较高的居群总遗传多样性，而叶绿体DNA的遗传多样性较低。(3) 白桫椤在云南和海南有两个不同的种质基因库，这两个区域间居群之间遗传分化明显，而区域内居群间的差异较小。(4) 云南的白桫椤居群是由过去连续分布的大居群在冰期时片断化而成的。海南居群可能起源于东南亚、是新形成的。(5) 在制定保护方案时，云南和海南这两个区域的白桫椤都必须考虑涉及到。在实施就地保护时，应首先保护其生境，解除人类的干扰；其次在选取地点时，应优先考虑个体数量多的居群。 |
| 资助项目 | Cyatheaceae species, usually called tree ferns, are considered as relicts of a time when dinosaurs were common. In recent several decades, the number of Cyatheaceae plants decreases dramatically. In order to find the reasons and provide directions for protecting these endangered plants, the biological characteristics of Cyatheaceae were surveyed. Using AFLP and cpDNA sequence variations, the genetic diversity and phylogeography of Sphaeropteris brunoniana were also analyzed. Based on these findings, implications for conservation strategies were discussed for this relict tree fern. Main results of the dissertation were summarized as follows, (1) Cyatheaceae plants have extensive distribution in Yunnan, China, and most of them distribute in southeast of Yunnan. In southeast, they usually inhabit margins of evergreen broad-leaved forests or secondary coniferous forests; however, the population update is very different and the age structure is unscientific. The spore of Cyatheaceae is trilete, radially symmetrical, and perinous. The spores of Alsophila species feature a ridged perine and a granular, verrucate or smooth exine. The spores of S. brunoniana are characterized by an incipient granular outermost layer and a verrucate exine. The metaphase chromosome numbers of gametophytes in the three examined species, viz. A. podophylla, A. gigantea and A. austro-yunnanensis, are 69, indicating that they are diploid and do not display variety in chromosome number. The chemical constituents of S. brunoniana are main simple and familiar compounds, such as saccharides, fatty acids and alcohols, and stigmasterols. (2) An unexpectedly high level of nDNA genetic diversity and low cpDNA diversity were detected in S. brunoniana. (3) This study showed that the genetic differentiation among populations within regions was low and between regions was significant. (4) There were several refugia of S. brunoniana in Yunnan during glacial periods. The Hainan populations were likely new colonizations and originated from Southeast Asia. (5) To retain existing genetic diversity, whether in situ or ex situ conservation or collection of germplasm is used, the populations of the two regions should be considered equally. Furthermore, ex situ conservation of this species should be preferably conducted on large populations.
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| 语种 | 中文
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| 文献类型 | 学位论文
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| 条目标识符 | http://ir.kib.ac.cn/handle/151853/16138
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| 专题 | 昆明植物所硕博研究生毕业学位论文
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推荐引用方式
GB/T 7714 |
王紫娟. 桫椤科植物生物学特性及白桫椤保护遗传学研究[D]. 中国科学院研究生院,2010.
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