论文题目晚中新世云南先锋植物群及古气候的定量重建.doc

1 论文题目：晚中新世云南先锋植物群及古气候的定量重建作 者：星耀武 博士导 师：周浙昆 研究员 刘裕生 博士摘要： 通过对采自先锋盆地植物化石的研究，恢复了该植物群的基本面貌，并且利用3种方法定量恢复了先锋植物群的古气候，探讨了新近纪以来云南植被类型和古环境的变化。主要研究结论如下： 1）通过初步鉴定该植物群含植物34种，分属9科，21属，另有29个未鉴定的形态种。34种植物中，包括2种裸子植物，其余全为双子叶植物。其中以壳斗科、樟科含种数量最多，占较大优势。因此，先锋植物群是一个以壳斗科、樟科植物为主的亚热带植物群。 2）利用CT扫描技术对植物群中的松科三维球果化石进行了详细地研究发表了松属，铁杉属各一个新种，分别为Pinus prekesiya和Tsuga miodumosa。松属新种Pinus prekesiya的发现支持了分子生物学认为P. kesiya和P. yunnanensis有可能在早上新世分化的观点，而不是以往所认为的两个种是在始新世分化。并提出一个假说，随着青藏高原在新近纪的持续隆起及季风气候的逐渐加强，滇中高原及以北地区逐渐变得干旱，温度也更低，P. prekesiya开始向两支分化，一支逐渐适应更加干旱的环境，演化成为P. yunnanensis；另一支仍生活中较湿润的山地地区，分化成为P. kesiya。 铁杉属新种Tsuga miodumosa的最近亲缘种是Tsuga dumosa。该新种是云南铁杉属大化石的最早记录。T. miodumosa的发现支持了分子生物学认为T. dumosa可能在中新世时分化出来，并且认为T. dumosa的祖先类群在亚洲的观点。通过铁杉属化石记录的研究认为，铁杉属是由于青藏高原抬升后导致了气候的变凉和生境的多样化才逐渐演化而来。 3）三种方法得到的年均温（CA：17.2-18.0C；CLAMP3B-Revised：15.71.33C；LMA：17.21.6C）都稍高于植物群现代年均温，说明晚中新世时，先锋盆地年均温稍高于现代。利用CA和CLAMP重建的先锋植物群的年均降水分别是1206-1537.4mm和1297.0184.7mm，两者均明显高于现代的年降水（1003.2mm）。说明在晚中新世时，当地气候要比现在更湿润。与所模拟的中新世平均降水比现代高的结论相吻合，且这种趋势在欧洲中部和中国多个中新世古气候恢复的研究中被证实。两种方法计算的湿润月和干旱月的降水都有明显差别，说明当时已经有了明显的季节变化，但是由于晚中新世时干季降水远大于现在，所以当时的季节变化没有现在明显。利用共存法的原理恢复了先锋植物群的古海拔，结果为1330-1500m，比现今海拔2200m低，说明自晚中新世以来先锋植物群至少抬升了700m。 4）通过云南新近纪植物群化石记录和古气候资料的对比，探讨了云南新近纪以来的古环境变化。认为中新世时，云南植物群多是以壳斗科、樟科等为优势的常绿阔叶林的植被类型，气候普遍温暖且湿润，中新世到上新世气温和降水变化不大，可能与一些植物群恢复古气候区间较大有关。而晚上新世以后，气温有了一定的下降，降水有了很大减少，植物群中适应高寒环境的成分增多，尤其是高山栎化石的大量出现，说明了这个时期出现了较剧烈的环境变化，环境变得寒冷而干燥，但温度下降幅度小于高纬度植物群的古气候变化。这也说明晚上新世以后的全球变冷对低纬度植物群的影响较小。5）利用旱季降水占全年降水的百分比和雨季旱季降水差值占全年降水的百分比两个指标探讨了自中新世以来季风强度的变化。两个指标的计算结果都表明晚中新世时虽然有干湿季节的变化，但是没有现在明显，说明自新近纪以来，云南地区季风强度有了很大的增强，而且也证明这两个参数可以很好地反映季风强度的变化，可以为讨论季风的演化提供较好的参考。、Abstract： The Xianfeng flora and its palaeoclimte were studied using three quantitative methods. The vegetation and climatic change in Yunnan were also discussed in this paper. The results are summarized as follows:1） 34 species belonging to 9 families, 21 genera were identified in Xianfeng flora. The dominant families are Fagaceae and Lauraceae. Most genera are tropic and subtropic distribution. Consequently, Xianfeng flora is a typical subtropic flora dominanted by Fagaceae and Lauraceae.2）Two new coniferous species were identified, Pinus prekesiya and Tsuga miodumosa. P. prekesiya sp. nov., which belongs to subsection Pinus of subgenus Pinus shows a combination of characters of P. kesiya and P. yunnanensis, but has a closer affinity with P. kesiya which distributes in the humid region of Yunnan and therefore suggests a more humid climate in central Yunnan during the late Miocene than today. The general cooling trend during the late Neogene and topographic change due to the dramatic Tibetan uplift might have cause a vicariance origin of P. kesiya and P. yunnanensis from the ancestral P. prekesiya. Tsuga miodumosa shows a closest affinity with T. dumosa and might represent the ancestral stock of T. dumosa. The discovery of the Tsuga cone confirmed the presence of Tsuga in the Miocene of southwestern China and represents the earliest Tsuga megafossil record in China. The new species provides fossil evidence to support molecular phylogeny study that T. dumosa might be differentiated in the Miocene. It also support the hypothesis that diversification of the genus occurred mainly during Miocene and Pliocene time as global climate cooled and new habitats formed in response to major orogenic events.3）The MATs results from three methods (CA: 17.2-18.0C；CLAMP3B: 15.71.33C；LMA: 17.21.6C) are higher than present. This indicates that the climate at late Miocene is warmer than today. The MAPs from CA and CLAMP are 1206-1537.4mm and 1297.0184.7mm respectively, which are higher than today (1003.2mm) obviously. This indicates that the climate is more humid in late Miocene. The differences between precipitation in humid season and dry season suggest the existence of seasonality，but not so strong as today. The palaeoelevation was reconstructed using CA method; the result indicates a lower elevation (1330-1500m) of Xianfeng in late Miocene compared to today.4) The palaeoenvirmental change was discussed based on the comparisons of fossil records and paleoclimate constructions. The results show that, at late Miocene, most floras represented ever-green forests dominanted by Fagaceae and Lauraceae etc. The climate of Yunnan in Miocene was warmer and more humid than today. At Pliocene age, the vegetation type in West Yunnan is still typical ever-green forest, while in the Sanying flora, the species adapt to cold environment like Quercus sect. Heterobalnus increased greatly.5) Two monsoon sensitivity indices were used to illustrate the change of sensitivity of monsoon climate. The results suggest lower seasonality and monsoon sensitivity, especially the winter monsoon sensitivity during late Miocene.2 论文题目：壳斗科栎属果实的生物学研究作 者：夏珂 博士导 师：周浙昆 研究员 Hugh W. Pritchard 教授摘要： 广义的栎属（Quercus, Fagaceae）包括青冈亚属（subgenus Cyclobalanopsis）和栎亚属（subg. Quercus），广泛分布于北半球的热带、亚热带和温带森林，其中的许多种类还是北半球森林的主要建群种和优势种。栎属是生产顽坳性种子的植物最重要的组成部分之一。它的种子/果实的生物学研究是顽坳性种子生物学研究的重要内容，对于理解顽坳性种子的生理学机制和生态意义都有着重大的意义。栎属的青冈亚属主要分布在亚洲热带和亚热带，该亚属种类丰富，许多种类是亚洲常绿阔叶林的优势种。但是迄今为止，青冈亚属的果实/种子生物学研究几乎还是空白。为了全面地了解栎属果实的生理特性，填补青冈亚属果实/种子生理学研究的空白；为了进一步理解栎属果实的生理特性及其与生态环境的关系，并有效地保护栎属植物，本论文研究了11种采自中国的青冈亚属和11种采自中国和欧洲的栎亚属植物果实的脱水耐性和它们的萌发特性，并定量研究了其中9种栎属植物果皮的形态解剖学特征，测定了其中18种栎属植物果实的含油量，并对滇青冈（Q. schottkyana）果实的年产量和锥象甲（Curculio sp.）的种群动态做了相关性分析，研究发现：1. 青冈亚属与栎亚属果实都属顽拗性，但果实对于脱水的反应在种间和种内表现出了明显的差异。2栎属植物的果脐占果皮表面积的437，是大多数种类吸收水分的主要部分。水分由维管束直接迅速地进入果脐，并沿果皮不分化层中的维管束到达果皮各部分，形成一个水分传输的纵向系统。栎属果皮的形态解剖学特征能够影响果皮各部分的水流通量和水流量，并造成了栎属果实种间脱水速率的差异。3. 青冈亚属果实大多适宜在较高的温度 （25 C）下萌发。低温可以降低青冈亚属果实的萌发速率，最终可能影响果实的萌发率，但不影响栎亚属果实的萌发率和萌发速率。青冈亚属和栎亚属果实萌发特性的差异表现出了它们对生态环境的适应。4. 青冈亚属果实的含油量（0.703.77%）显著低于栎亚属果实的含油量（1.48%18.01%）。该结果与已报道的另39种栎属果实的含油量的数据相结合，表明栎属果实的含油量在亚属间和亚属内有与栎属分类学相关的差异性。5. 滇青冈果实的年产量有着明显的年际差异，一平方米的滇青冈纯林一年可以生产果实245854粒，但其中14%48%的果实会受到虫害。56月的降雨量可以影响滇青冈果实的年产量而9月和11月“干季信号”（低降雨量）能够引导滇青冈果实散播高峰期的开始和散播期的结束。滇青冈果实的产量与锥象甲种群有着密度制约关系。这种关系使得滇青冈和锥象甲的种群大小在相应的范围内以相同的趋势变动，呈现出周期性的循环。Abstract： The genus Quercus consists of subgenera Quercus and Cyclobalanopsis and has approximately 531 species, making this the largest and most widely distributed genus within the Fagaceae family, occurring throughout temperate and subtropical montane areas of the Northern Hemisphere. The occurrence of recalcitrant (desiccation-sensitive) seeded plants is common in the genus Quercus, making it one of the key genera for understanding the physiology and the ecology of recalcitrant seeds. Due to habitat loss and poor regeneration, some populations of the genus Quercus are now declining. Moreover, the limited availability of good-quality seed may lead to its natural regeneration problems. To understand the cause of the population decline and to conserve iteffectively, knowledge on the seed/fruit biology of Quercus is necessary. Despite this, the seed/fruit biology of the Asian Quercus species is largely overlooked and the seed/fruit biology of Quercus subgenus Cyclobalanopsis,which is predominately distributed across tropical and subtropical Asia, is less well documented. To provide new data on the fruit biology of subgenus Cyclobalanopsis and to understand the fruit physiology and ecology of the genus Quercus comprehensively for a conservation aim, the germination and desiccation response of 11 species of subgenus Cyclobalanopsis (from S and SW China) and 11 species of subgenus Quercus (from both SW China and Europe) were investigated. The anatomic characteristics of the fruit coats was analysed on 9 of these species and the oil contents were quantified from 18 of these species. In addition, a study was carried out over 4 years on the fruit production of Q. schottkyana (subgenus Cyclobalanopsis) to fill the gap in knowledge. The data demonstrate that:1. All 22 species of subgenus Cyclobalanopsis and subgenus Quercus had desiccation-sensitive (recalcitrant) fruits. For these 22 species which had fruit dry masses spanning 0.57 to 6.41 g and seed coat ratios spanning 0.15 to 0.48, there were wide differences in drying rates (0.26-4.10 %d-1). These differences were independent of fruit mass and seed coat ratio, but were related to the morphology of the fruit coat.2. The scar, composing 4% to 37% (surface area) of the whole fruit coat, was found to be the main water passage for most species. Water transferred directly and quickly through the scar. From the scar through to the pericarp and ending at the apex, there was a longitudinal passage of water flow. The anatomic characteristics of the fruit coats controlled the water flux, which furthermore introduced the wide differences in drying rates between the Quercus species.3. In comparison to species of Quercus subgenus Quercus, fruits in subgenus Cyclobalanopsis germinated faster and most had maximum germination at the highest temperature of 25C. At lower temperatures (15C, 20C), germination of subgenus Cyclobalanopsis was slower and the germination percentage of most species was decreased, but germination of species in subgenus Quercus was not affected at these low temperatures. The thermal requirements for the germination of these two subgenera suggested an adaptability of these fruits to their habitats.4. Fruit oil content of subgenus Cyclobalanopsis (0.70% to 3.77%) was significantly lower than that of subgenus Quercus (1.48 to 18.01%) and across the 18 species studied, moisture content of the storage tissue (cotyledons) was negatively related to fruit oil content. These data were combined with that from the literature, resulting in a total of 57 species, and mapped against the current phylogeny for Quercus to reveal the highest fruit oil contents associated with sect. Lobatae. 5. The fruit production of Q. schottkyana varied markedly between years. Each square meter of Q. schottkyana pure forest produced 245-854 fruits but 14%-48% of them were infected by weevils (Curculio sp.). The annual production of Q. schottkyana was most likely affected by the average monthly rainfall during May and June, but the time of fruit dispersal was related to the rainfall of September and November. The infestation rates of weevils were density-dependent on the fruit production of Q. schottkyana that furthermore regulated the populations of these two species.3 论文题目：毛茛科铁线莲属的分子系统学与繁育生物学研究作 者：江南 博士导 师：管开云 研究员摘要： 铁线莲属(Clematis L.)隶属于毛茛科(Ranunculaceae)，共355种左右，为世界广布类群，主要分布于温带和亚热带。该属的属下分类等级划分一直倍受争议。本文通过分子手段，比较了分子系统与传统分类系统的异同，并探讨了属下分类等级等问题。此外还对该属植物的繁育生物学及萌发特性进行了研究。主要研究结果如下：1.云南铁线莲属物种多样和地理分布横断山区可能是铁线莲属的起源、分化和特有中心，而滇西、滇西南以及滇东南地区也与该属的分化有一定联系。云南铁线莲属植物特有现象较为突出：含中国特有的56种(含变种)，占云南总种数的67.2；云南特有16种(含变种)，占云南分布的中国特有种的35.0。云南铁线莲属植物与国内邻近的四川关系最为密切，西藏的关系最弱；与国外邻近的缅甸具有一定的联系。 2.分子系统学研究基于ITS、psbA-trnQ、atpB-rbcL和rpoB-trnC四个基因片段对铁线莲属及其近缘属79种138个样品进行了分子系统学研究。结果表明，铁线莲属是一个并系类群(paraphyly)，其包含了锡兰莲属和互叶铁线莲属。在属下分类等级上，联合分析结果没有支持王文采和李良千系统以及任何一个传统分类系统，所研究的12个组多为多系(polyphyly)或并系类群，组间关系错综复杂。我们认为，这是由于该属与银莲花亚族分化时间较早，但属内各种间是在近期发生的快速分化的结果；同时，种间杂交可能也是主要因素之一。结合植株及幼苗性状，我们发现，单一以花部性状作为该属属下分类依据是不太合理的，应以幼苗叶序作为主要的鉴别特征，结合花瓣有无、心皮数量、花开放于新枝或老枝作为亚属或组等级划分标准。 3.命名学问题处理对金毛铁线莲及罂粟银莲花进行了后选模式指定；订正了王文采和李良千系统中属下等级作者引证中的错误；同时，对非毛茛科的一些种类，尖叶酒饼簕、长茎金耳环、封开酒饼簕和霸王金橘进行了合格发表。 4.繁育生物学研究本研究选取了三种不同花冠类型的铁线莲，进行传粉和繁育生物学研究。通过花部特征的测量、传粉者行为的观察、评估其近交衰退系数和花粉限制系数等研究，结果表明，蕊-雌蕊的比例可以像花粉-胚珠比一样在评价铁线莲繁育系统非常有价值；花冠形态分化与传粉昆虫种类和行为密切相关，平展型花冠是适应蝇类传粉，钟状和管状花冠是适应熊蜂传粉；花冠形状与传粉系统和繁育系统之间的关系非常密切。近交衰退系数与繁育系统之间密切相关。花萼、雄蕊和蜜腺(金毛铁线莲除外)在传粉吸引中扮演了不同的角色。 5.金毛铁线莲的花部性状通过对金毛铁线莲花部性状的测量，包括萼片长、萼片宽、雄蕊数量、雌蕊数量、花药长、单个萼片大小、总萼片大小等，并采用不同年份单独分析和三年联合分析性状之间的相关性，来检验各性状年际间的稳定性，验证性配置理论。花部性状(除萼片长)在三年连续的研究中保持着较高的稳定性。部分花部性状之间的相关性在各年份单独分析和联合分析时一致，说明它们可能在演化过程关系密切；而相关性不一致或相反的花部性状，一方面可能是取样随机性误差所造成的，也有可能是它们之间存在一定的相互关系，但不密切相关。雄蕊数量与花药长不存在负相关关系（第一年呈显著正相关，后两年没有明显相关性）；雄蕊数量和雌蕊数量之间呈显著正相关关系；雌蕊数量、总花药大小和总萼片大小三者之间呈显著的正相关关系。综合以上结果，我们发现金毛铁线莲的性资源配置不属于“补偿”理论模型，而是由基因和资源量决定。 6.种子萌发特性研究本研究通过设置不同的预处理（砂纸打磨和不同时长的冲洗处理）、不同浓度的GA3浸种、不同光照和温度条件以及不同的土壤播种基质，对六种铁线莲进行了种子萌发特性的研究。冲洗处理可提高种子萌发率和缩短平均萌发时间。不同浓度的GA3对不同种的铁线莲影响不一，但总体来说，低浓度的GA3有一定的促萌作用。珍珠岩基质中的种子萌发率最高，可达80%以上，是较理想的铁线莲播种基质。Abstract： The genus Clematis, with about 355 species, is one of the largest genera of Ranunculaceae. The genus is distributed through out the world except Antarctica, primarily in temperate and subtropical zone. Numerous infra-generic classification systems have been proposed, whereas the infra-generic ranks were confusing. In the present study, we used four molecular regions, ITS, psbA-trnH, atpB-rbcL and rpoB-trnC to reconstruct the phylogeny of Clematis. On the basis of comparison with traditional classification system, criteria of the infra-generic ranks are discussed. In addition, investigations of reproductive biology and seed germination were also conducted. The main important results and conclusions are as follows: 1. Species diversity and geographical distribution of the Genus Clematis in Yunnan provinceAccording to the latest system of Wang and Li in 2005, there are 59 species and 24 varieties in 6 sections of 3 subgenera recognized within the genus of Clematis in Yunnan, which is the richest province in terms of species numbers in China. The Hengduan Mountains is regarded as an origination, differentiation and endemic center of the genus. West, Northwest and Northeast of Yunnan have some relationship with its differentiation. There are 56 species (including varieties) endemic to China, accounting for 67.2% of Yunnans total number of species. There are 16 species (including varieties) endemic to Yunnan, accounting for 35.0% of Chinas endemic number of species distributed in Yunnan. Among the adjacent provinces, Sichuan has the largest common number of Clematis to Yunnan, while Tibet has the smallest. The floristic links with Myanmar is also relatively weak.2. Molecular phylogeny of ClematisPhylogenetic relationships within and out of Clematis were analysed using nucleotide sequences of chloroplast DNA psbA-trnQ, atpB-rbcL and rpoB-trnC, and the nuclear ITS regions. The phylogenetic trees suggested that the genus Clematis was paraphyletic. The genera Archiclematis and Naravelia were found to be nested within the genus Clematis, and should be included in it. The molecular results did not agree with Wang and Lis taxonomic system and other classifications of Clematis at the phylogeneric level. And the sections we studied were found to be paraphyletic or polyphyletic. The complicated relationship between sections and species indicated the recent radiation of the genus and the possibility of hybrid origin. Our results suggested that flower characters which have been used for previous infrageneric classification do not correlate with the phylogenic tree. Phyllotaxy of seedlings as the primarily diagnostic characters may reflect the phylogeny within Clematis, the following characters should be considered at the same time: presence/absence of petals, carpel number, and flowering at the new-bornformer-born branches.3. Nomenclature notes of Clematis and other plantsTwo gatherings of Clematis chrysocoma Franchet and Anemoclama glaucifolia (Franchet) W. T. Wang were cited in the protologues, whereas none of them was indicated as type or holotype. After examining the cited specimens, we designate one specimen of them as lectotype in according with ICBN. We list the incorrect author(s) citation of infra-generic names by Wang and Li in their new Clematis classification systems. Additionally, four names, Atalantia acuminata C. C. Huang, Asarum longerhizomatosum C. F. Liang & C. S. Yang, Atalantia fongkaica C. C. Huang and Fortunella wawangica C. C. Huang, are validated.4. Reproductive biology of three Clematis speciesAn integrative study was undertaken, focusing on pollination and reproductive biology of three species representing all three floral types of Clematis. Floral traits were measured, and pollinator assemblages were observed in the field. Bagging, hand-pollination and removal treatments were used to examine breeding system. The values of inbreeding depression and pollen limitation were calculated based on experimental data obtained from breeding system. Their floral traits were distinctly different. Floral traits were highly associated with pollination syndrome and breeding system. Among them, Clematis akebioides and C. rehderiana were facultative autogamy (the former was delayed selfing, and the later competing selfing), and C. chrysocoma was nearly obligate outcrossing. This conclusion was reflected by their stamen-pistil ratios. The levels of inbreeding depression negatively associated with autonomous self-pollination. Selfing evolution of C. akebioides and C. rehderiana, and reproduction of the three Clematis species no pollen limitation were discussed. Present study integrating with previous results will help us to comprehensively recognize and understand pollination system and reproductive characteristics of Clematis.5. Correlation among floral traits of Clematis chrysocoma Floral traits of C. chrysocoma including sepal length and width and anther length were measured, stamen and pistil number were counted, single and total sepal size, and total anther size were calculated in three continued years from 2007 to 2009. These traits of three years were analyzed as united and independent data, respectively, which was used to compare the stability of floral traits among three years, and to test sexual allocation theory. Our results show that floral traits except sepal length are stable in three continued years, correlation among floral traits of three years as whole and independence, respectively, some of which are consistent, and some of which are inconsistent or negative. The consistent traits demonstrate that they highly co-evolve, whereas the inconsistent or negative traits may be results from the stochastically errors or that they may have some correlation but not close. Association of stamen number with anther length is not negative, but with pistil number is