【作者】 穆立蔷；

【导师】 杨国亭；

【作者基本信息】 东北林业大学 ， 生态学， 2006， 博士

【摘要】 紫椴不仅是著名的蜜源树种，而且是优质胶合板及细木工板的重要原料，树形优美，为优良庭园绿化树种，其花和根可入药，还是国家Ⅱ级保护植物。对紫椴保护方面的理论研究一直没有得到重视，在国内外尚未见报道。在分子水平、化学成分以及种群地理变异与环境相关性方面的研究尚属空白。本研究选择暖温带落叶阔叶林区域，温带针阔叶混交林区域和寒温带针叶林区域9个地点取样，分析了紫椴各主要器官宏观及微观的形态、化学成分、遗传多样性的地理变异与环境相关性。探讨了紫椴的濒危机制及保护策略。宏观上对紫椴当年生枝条长、芽长、芽宽、叶片长、叶片宽、叶柄长、花序的苞片长、苞片宽、苞片与花梗的愈合长度、花梗长、花序长、有花数目、果长、果宽14项指标，微观上对叶片上下表皮的细胞排列、形状、有无气孔和下表皮的表皮毛、气孔数量、气孔形状、气孔外拱盖、外拱盖内缘、气孔纹饰、角质膜、花粉形状、孔沟深度、表面纹饰、果皮毛的长短、分布特点15项指标进行了观察和测量，发现紫椴各器官形态特征随纬度、海拔的变化存在明显的变化规律，随纬度、海拔的升高呈现显著的相关性(多为负相关)。从纬度看，紫椴在中心分布区生长状况要好于边缘区，从海拔看，700-900m之间应为最适宜紫椴生长的海拔高度。从微观形态上看，叶表皮随着纬度和海拔的升高细胞排列由紧密逐渐疏松，蜡质化程度逐渐加深，而花粉和果皮的变化不明显。通过系统预试，检测出紫椴的花及花蕾中含有较多的酚类、糖和甙类，并检测到了黄酮类化合物、蛋白质、香豆素及强心甙等，在花蕾中还含有少量鞣质。紫椴果实中也含有酚类、糖和甙类，还含有少量黄酮化合物、香豆素和鞣质。对不同纬度和海拔紫椴花和果实中可溶性糖、总酚和黄酮的含量进行了分析，发现3种化学成分含量随纬度、海拔的升高存在一定的变化规律。除花中总酚含量差异不明显外，紫椴花和果实中其它化学成分含量随着纬度的升高，呈现降低趋势；随着海拔的升高，呈现增高趋势。并且得出紫椴花中可溶性糖含量明显高于果中的含量，其它化学成分在花和果实中的含量接近。用14个ISSR引物对不同纬度和海拔紫椴种群的210个DNA样品进行了PCR扩增并分析，得出紫椴种群具有较高的遗传多样性。紫椴不同种群的遗传多样性随海拔升高而降低。但随纬度的升高呈先升高后降低，表现为中心分布区种群的遗传多样性高于边缘区。紫椴种群的遗传距离与纬度地理距离没有相关性，但与海拔有较为显著的相关性。从紫椴种群各器官的形态结构特征聚类分析与遗传距离聚类分析比较可见，紫椴的营养器官枝叶、苞片、花序等的各形态及结构特征变异在纬度和海拔梯度上是不连续的，与遗传距离不相关，主要是由于环境压力造成的：而果实形态变异在纬度和海拔梯度上是连续的，与遗传距离一致，说明果实的形态主要受遗传因素的影响。验证了营养器官具可塑性，易受环境变化的影响而变异；生殖器官具稳定性和保守性高的特点。从化学成分含量聚类分析与遗传距离聚类分析比较可见，化学成分含量变异在纬度和海拔梯度上是不连续的，与遗传距离不相关，说明其受遗传影响不大，主要受环境因素影响。紫椴种群遗传多样性较高，且大部分存在种群内，说明紫椴目前受威胁的主要原因不在于其遗传变异方面，而是主要来自人为采伐、生境破坏和生境退化等原因。应加强对紫椴生境的保护，防止人为因素对紫椴种群的进一步破坏。同时应加强遗传多样性保护，充分重视对大群体内不同类型个体的保存，重点放在自然分布中心地区的群体。通过本项研究为营林优良种源的选择，良种定向选育提供了一定科学依据；为寻找紫椴生物活性成分、药用原材料林的选择及造林生产奠定基础；为紫椴遗传资源的有效保护和合理利用提供理论依据；对实践具有一定的指导意义。更多还原

【Abstract】 Tilia amurensis not only a tamous nectar trees，but also the main raw materlals ofplywoods and blockboards．It is a fine garden tree species with glorious shape，and the flowersand root are used for Chinese traditional medicine．In addition，T amurensis a secondarynatiorlal protection plants．But it attracts little attention to the theoretical study on plantpreservaIion．The researches on me corrclation between geographic variations of T amurensispopulations and its environmental influences at the levels of chemical cornpositions，moleculesare still blank so far．We analyzed geographic variations of the morphology,chemical tomponents，geneticdiversities and its tortelation with environmcnts of various Orans of T amurensis atmacroscopical and microcosmic levels and discussed the elldangered mechanism andconservation strategy by sampling from 9 sample plots in Deciduous broadlcaved forest inwarm temperate zone，Needle and broadleaved mingled forest in temperate zone and Needle-leaf forest in cold temperate zone．Annual branch length，bud length,bud width，leaf length，leaf width，petiole length，bractlength，bract width，concrescence length of petiole and bract，pedicel length，inflorescencelength，flower number，fruit length，fruit width etc．14 kinds of macroscopic indexes，and cellarrange of epidcrmal，shape，stoma，indumentum，number of stoma,stoma,from,outer stomaledge，stoma apparatuses，omamentation,and cuticle of leaves，pollen morphology andcolporate，pericarp indumentum length and characteristics of distribution etc．15 kinds ofmicroscopic indexes were observed and measured．The results showed that anatomical structural characteristics distinctly correlated with thevariatjos of latitude and elevation(mostly negative correlation).Growth status of T amurensistrces was better distributied in central regiotis than in the edges with the changes of latitude。Ftom the point of vicw of elcvltion,700一900m was the optimal altitude for the growth of Tamurensis.The higher the latitude and elcvation were，the looscr the cell arrangement of leafcuticle was，the thicker the thickness of wax coat was；the less irremarkable the changes ofpollen and peel were．There were more hydroxybenzenes，polysaccharides，glucosides，flavone compounds inflowers and buds，and proteins，coumarins,cardiac glycosides，were also detected，in addition，tannins Were found in buds；and hydroxybenzenes，polysaccharides，glucosides，flavones,coumarins and tannins were detected in fruit by systermatic pre-experiments.The determinationof contents of soluble sugars，totaI phenolics and flavones in flowers and fruits of T amutrensiswere displayed that three groups of chemical compositions changed with latitude and altitude． Except total phenolics in flowers，the other contents in flowers and fruits decreased withincreasing of latitude and altitude．The content of soluble sugars in flowers was obvious higherthan in fruits，Other chemical composition contents were similar in flowers and fruits．210 DNA samples from natural populations at different latitudes and altitudes wereselected for PCR amplification with 14 of ISSR primers．The results showed mat T amurensishad fairly high genetic diversities．The genetic diversities of T amurensis decreased with thealtitude increasing，and a single-peak curve was observed with me increase of latitude，andgenetic diversities was higher in central region than in the edges．The correlation betweengenetic distance and geograhic distance Was indistinctive and that between genetic distanceand altitude Was distinctive,but genetic diversity declined with the decrease of altitude．By comparing the cluStering analysis on shape and structure characters and geneticdistance of organs of T amurensis，wc could find that variations of shape and structurecharacters in branthes，leayes，bracts，inflorescence etc．vcgetative Organs were discontinuousat latitudes and altitudes and had no correlations with genetic distance，they mainly derivedfrom environmentaL strsses．However,variations of shape in fruits were continuous atlatitudes and altitudes，and correSponded to genetic distance，which demonstrated that fruitshape was significantly affiected by genetic factors．We testified that the vegetative organs wereplastic and easy to be influenced by environmental changes and reproductive organs weresteady and conservative by our results．The genetic diversity of T. amurensis was high and mainly within the populations, so themainly reason for preservation of T. amurensis was because of cutting, habitat destruction anddegradation but not genetic variations. The protection strategy should be taken to enhance thehabitat protection, avoided from destroying further by mankind, and at the mean time pay moreattention to the preservation of various types of individuals, especially in the core areas.The results would provide the references on choosing good tree species for the forestationand directly breeding cultivars, screen bio-active compositions, establishment forest formedicinal raw materials, and forestation. The results also would provide theoretical foundationfor effective protection and proper utilization of genetic resources of T. amurensis and bebeneficial to practice.更多还原