嵩草属植物研究进展

嵩草属(KobresiaWilld.)植物是多年生草本植物,主要分布于中国青藏高原,多数是高寒草甸的建群种,具有草质柔软、营养丰富等特点,为各类家畜所喜食,是青藏高原主要的优良牧草和生态草种,其良好生长对维持青藏高原的生态平衡有重要作用.介绍了近年来对嵩草属植物的系统位置、地理分布、生长土壤、繁殖对策以及生理生态等的研究概况,对研究前景作了展望.     

内蒙古嵩草属一新种

从内蒙古大青山采得嵩草属新值物,定为新种——大青山嵩草。本薪种与细叶嵩草K.filifolia(Turcz.)C.B.Clarke及贺兰山嵩草K.helanshanicae W.Z.Di etM.J.Zong相近。与前者不同在于:根状茎明显,秆较高而粗壮,叶较宽;花序含11—22枚小穗,小穗通常含花2—9朵;小坚累矩圆形或倒卵状矩圆形。与后者不同在于:小坚果矩圆形或倒卵状矩圆形,具喙;柱头2—3。     

嵩草属植物对高山气候环境的适应性结构特征

通过对青海湖周地区九种嵩草属植物表皮刮片和显微结构的研究，发现并论述了嵩蜡属植物对高山恶劣气候环境相适应的形态结构特征及其适应关系。     

不同海拔高度上的嵩草属三个种营养器官显微结构的比较

对在不同海拔分布梯度上的嵩草属三个种－矮嵩草、高山嵩草和北方嵩草的显微结构观察比较后发现,随着海 升高,叶片厚度,表皮细胞外切向壁的加厚程度。     

两种沼泽化嵩草草甸建群种的遗传结构

应用随机扩增多态DNA方法研究了青藏高原甘肃嵩草和西藏嵩草的遗传结构.结果表明:在居群水平上,两种嵩草都存在比较丰富的遗传多样性.多态位点百分率为63.27%,71.13%;Nei's基因多样度h为0.2266,0.252 1;Shannon's信息指数Ⅰ为0.3369,0.3772.AMOVA数据表明:甘肃嵩草和西藏嵩草的遗传变异主要分布在居群内,居群内遗传变异分别占总变异的85.71%和80.00%,居群间变异占总变异的14.29%和20%.遗传分化系数也显示了相似的结果(分别为0.143 8和0.1884).这一结果符合风媒异交的繁育系统.在两种嵩草中,其遗传分化和基因流均存在一定差异,西藏嵩草居群间的遗传分化高于甘肃嵩草的,而基因流小于甘肃嵩草的,此差异应与两种嵩草的花序特征和生长的地理环境有关.针对两种嵩草的遗传结构及其差异,对今后的保护利用提出了建议.     

山西五台山嵩草(Kobresia)草甸的初步研究

嵩草草甸在山西仅分布在五台山2400米以上的山地,由北方嵩草(Kobresia bellardii)和小嵩草(K. pygmaea)占优势。本文就草甸植被的组成,外貌和结构以及类型和分布作了初步分析。并将其与我国其他地区的嵩草草甸作了简单比较。最后,讨论了五台山嵩草草甸的垂直地带问题。     

三江源自然保护区湿地种子植物区系分析

经过野外调查和相关文献的分析,统计出三江源自然保护区湿地种子植物共计33科94属219种,毛茛科(Ranunculaceae)、十字花科(Cruciferae)、龙胆科(Gentianaceae)等7个科是三江源湿地植物常见的大科。苔草属(Carex)、马先蒿属(Pedicularis)、毛茛属(Ranunculus)、龙胆属(Gentiana)的植物在三江源湿地中最为常见。蔵嵩草(Kobresia tibetica)、高山嵩草(K.pygmae)、华扁穗(Blysmus sinocompressus)、杉叶藻(Hippuris vulgari)、海韭菜(Triglochin maritimum)等植物作为建群种或优势种在维持湿地植物群落稳定性起着重要的作用。在科的分布类型上,世界分布的科占绝对优势,超过总数的3/4;属的分布上,温带性质十分明显,北温带分布及其变型为最主要分布类型,其次为世界分布;种的分布以北温带分布和世界分布为主,温带性质明显,也有较多其他分布类型的种,水生植物,尤其淡水植物多为世界分布。该地区共有13个特有种,其中,7个为青海特有种,2个为青藏共有特有种。     

rDNA ITS序列分析在中药材白花蛇舌草鉴定中的应用

通过测定茜草科Rubiaceae 4种耳草属Hedyotis植物的rDNA ITS序列并比对,为鉴定中药材白花蛇舌草提供分子依据.     

黄河源区藏嵩草沼泽化草甸群落结构特征的研究

为了对黄河源区藏蒿草沼泽草甸资源进行科学管理与保护,采用样方法,对黄河源区不同退化程度藏嵩草沼泽化草甸群落结构特征进行了研究。结果表明:1黄河源区藏嵩草沼泽化草甸植物组成有11科32属49种。不同退化程度群落植物组成及其重要值都有很大变化,随着退化程度的加剧,藏嵩草平均高度由26.2 cm降低为7.3 cm,盖度由76%降低为31%;2随着退化程度的加剧,地上生物量明显下降,排序为未退化草地轻度退化中度退化重度退化极度退化,藏嵩草沼泽化草甸是一个旱化演替的过程,莎禾草类为主——莎禾草类+杂类草——杂类草为主;3群落物种多样性指数与丰富度、均匀度指数呈正相关,与生态优势度呈负相关;物种丰富度在中度退化阶段最高,多样性与均匀度指数在重度退化阶段最高,均匀度很大程度上影响到了群落的多样性。草甸可持续利用的最有效措施是围栏封育与划区轮牧。     

返青期休牧初期对三江源区藏嵩草草甸植被特征的影响

为了解三江源区藏嵩草草甸返青期休牧的效果,以藏嵩草草甸冬春草场为研究对象,返青期休牧结束后,采用样方调查法对藏嵩草草甸地上植被特征进行调查.结果表明:休牧后草地植被的高度、盖度和生物量均出现不同程度的增加,其中植物的总生物量和总盖度呈显著性增加,分别增加了116.9％(P<0.05)和22％(P<0.05).休牧后藏嵩...     

山西省雏蝗属部分种类的遗传关系分析

采用RAPD和SSRP-PCR技术分析雏蝗属(Chorth ippus F ieber)白纹雏蝗(C.a lbonem us Cheng et T u)、夏氏雏蝗(C.hsia i Cheng et T u)、小翅雏蝗(C.f a llax(Zub.))和北方雏蝗(C.hamm arstroem i(M ir.))的遗传关系,9条引物对98头个体产生131条清晰、稳定的谱带.Shannon信息指数表明,小翅雏蝗遗传多样性水平较高(0.2542),白纹雏蝗遗传多样性水平较低(0.1911).N e i's遗传距离显示,种群间遗传距离小于种间遗传距离.用N J法对N e i's遗传距离作聚类分析,构建分子系统树,结果显示:白纹雏蝗与夏氏雏蝗聚为一支,小翅雏蝗与北方雏蝗聚为一支,两支再相聚.聚类图所显示的种间亲缘关系的远近程度与形态分类学结果相一致,说明RAPD和SSRP-PCR技术在雏蝗属种间分子系统学研究中具有很好的适用性.     

Investigations into the perplexing interrelationship of the Genus Takifugu Abe, 1949 (Tetraodontiformes, Tetraodontidae)

The phylogenetic relationships within the genus Takifugu Abe, 1949 (Tetraodontiformes, Tetraodonti- dae) remain unresolved. Because of the use of Takifugu as model organisms, the resolution of these relationships is crucial for the interpretation of evolutionary trends in biology. Pufferfishes of this ge- nus are comprised of a comparatively small number of species and are mainly distributed along the coastal region of the western part of the Sea of Japan and the coastline of China. Mitochondrial gene sequences were employed to test the phylogenetic hypotheses within the genus. Seventeen species of the genus were examined. Molecular phylogenetic trees were constructed using the maximum parsi- mony, neighbor-joining, maximum likelihood and Bayesian methods. Our hypothesis of internal relationships within the genus differs from previous hypotheses. Our results indicate that (1) the genus Takifugu is a monophyletic assemblage; (2) the genus is divided into 6 subgroups based on the mo- lecular data; and (3) there is low genetic diversity among the species within this genus. In addition, speciation within Takifugu appears to be driven by hybridization and isolation by distribution. Our re- sults also suggested that the taxonomy in the genus should be clarified based on both molecular and morphological data.     

Investisations into the perplexing interrelationship of the Genus Takifugu Abe, 1949 （Tetraodontiformes,Tetraodontidae）

The phylogenetic relationships within the genus Takifugu Abe, 1949 （Tetraodontiformes, Tetraodontidae） remain unresolved. Because of the use of Takifugu as model organisms, the resolution of these relationships is crucial for the interpretation of evolutionary trends in biology. Pufferfishes of this genus are comprised of a comparatively small number of species and are mainly distributed along the coastal region of the western part of the Sea of Japan and the coastline of China. Mitochondrial gene sequences were employed to test the phylogenetic hypotheses within the genus. Seventeen species of the genus were examined. Molecular phylogenetic trees were constructed using the maximum parsi- mony, neighbor-joining, maximum likelihood and Bayesian methods. Our hypothesis of internal relationships within the genus differs from previous hypotheses. Our results indicate that （1） the genus Takifugu is a monophyletic assemblage; （2） the genus is divided into 6 subgroups based on the moecular data; and （3） there is low genetic diversity among the species within this genus. In addition, speciation within Takifugu appears to be driven by hybridization and isolation by distribution. Our results also suggested that the taxonomy in the genus should be clarified based on both molecular and morphological data.     

中国斑腿蝗科线粒体基因的分子系统学研究(英文)

使用线粒体基因COⅠ,COⅡ,Cytb分析并建立中国斑腿蝗科部分种属的系统发育关系,其中对7个新种(Apalacris eminifronta,Caryanda pseudodentata,Caryanda bannaensis,Caryanda ruiliensis,Longchuanacris fui,Longchuanacris xiaoheis-hanensis,Podismodes dabieshanensis)的归属从分子角度也做了讨论。本研究将实验所获得的56条序列与NCBI中所收录的斑腿蝗科序列进行联合分析,采用最大似然法、贝叶斯推论等系统分析方法并综合P距离进行分析,最终得出以下几点结论:①龙川蝗属Longchuanaceis Zheng et Fu划归卵翅蝗亚科Caryandinae;②蹦蝗属Sinopodisma Chang、云秃蝗属Yunnanacris Chang均为华秃蝗属Podismodes Ramme的同物异名;③不支持Storozhenko将豫蝗属Yupodisma Zhang et Xia并入安秃蝗属AnapodismaDovnar-Zapolskii,从本研究所建的系统发育树来看,豫蝗属仍应作为秃蝗亚科Podisminae的一个独立属;④前人利用形态特征鉴定的七个新种与分子系统发育分析结果一致,新种独立有效。     

基于16S rRNA序列的鳃金龟亚科5族种类的系统发育关系

测定了鳃金龟亚科部分种类的线粒体16SrRNA部分序列,运用MEGA 4.0、PAUP*4.0b10和MrBayes等软件,对5个族29个代表种的序列变异和系统关系进行了研究.序列变异分析结果显示:绢金龟族Sericini、哦鳃金龟族Hopliini、鳃金龟族Melolonthini的族内遗传距离分别为7.7%,11.3%,10.6%,族间遗传距离在12.6%～19.2%.最大似然树(ML)和贝叶斯树(BI)结果表明,所有种类分别聚集在所属的族下,哦鳃金龟族、绢金龟族分别为单系.齿爪鳃金龟属Holotrichia、云鳃金龟属Polyphylla、胸突鳃金龟属Hoplosternus、Hilyotrogus、双绺鳃金龟属Amphimallon、Hoplochelus、婆鳃金龟属Brahmina和皱鳃金龟属Trematodes聚在鳃金龟族分支下,没有形成明显的根鳃金龟族Rhizotrogini分支.齿爪鳃金龟属的非单系性与前人研究结果一致.皱鳃金龟属Trematodes和婆鳃金龟属Brahmina的代表种为姐妹种.绢金龟族的绢金龟属Serica和玛绢金龟属Maladera多数种类聚在本属分支下.证明16SrRNA序列可探讨鳃金龟亚科高级阶元的系统发育关系.     

白杨派,青杨派和黑杨派的DNA多态性及系统进化研究

收集了杨属三个派内２０个种的２８个无性系，筛选７个引物进行ＲＡＰＤ分析。共产生５４条有效谱带，其中４３条（７９．６３％）表现多态性。任意两无性系间的遗传距离（Ｄ）为０．９３０￣０．０３１，相应其相似性为０．５１８￣０．９７０。以Ｄ值为基础研究三个派的系统进化关系，聚类结果表明三个派明显独立，且青杨派与黑杨派关系较近，而与白杨派则相对较远，结合其它研究成果推测白杨派较早从杨属中分离出来，而青杨派和黑     

Phylogenetic position of three Condylostoma species （Protozoa,Ciliophora, Heterotrichea） inferred from the small subunit rRNA gene sequence

The systematically poorly known ciliate genus Condylostoma was erected by Vincent in 1826. About 10 morphotypes have been reported, but any molecular investigations concerning this group so far are lacking. In this work, the small subunit ribosomal RNA （SS rRNA） gene of three marine Condylostoma species was sequenced, by which the phylogenetic trees were constructed by distancematrix, maximum parsimony and Bayesian inference methods. The results show that （1） all the trees have similar topologies with high supports; （2） Condylostoma is mostly related to the genus Condylostentor; and （3） three Condylostoma species as well as Condylostentor auriculatus cluster together and form a sister group with other heterotrichs. This is moderately consistent with the assessment of phylogenetic relationships of Condylostoma-related heterotrichs from the morphological information. The phylogenetic relationship of some other related heterotrichs, Peritromus, Folliculina, Stentor and Blepharisma, has been also discussed.     

5种菊头蝠的随机扩增DNA多态(RAPD)的分析

以5种菊头蝠为材料,用随机扩增DNA多态(RAPD)方法分析它们的亲缘关系。结果显示:5种菊头蝠均表现出各自不同的多态性RAPD标记,6条单个引物分别扩增出2~10条的RAPD条带,其分子量约在700~2 600bp之间。依据这些多态性标记计算其种间遗传相似性,建立亲缘关系树形图。     

中国柏木属(Cupressus L.)植物的petG-trnP序列分析及其系统学意义

对中国柏科（Cupressaceae）柏木属（Cupressus L．）5个种及扁柏属4个种的cpDNA非编码区petG—trnP序列进行了分析,其片段的长度范围在417bp～479bp之间．以侧柏（Platycladus orientalis）作为功能性外类群,运用PAUP＊和MEGA软件分别对其进行聚类分析,应用最大似然法得到一棵最优系统树,其-Ln=2232．47．结果表明：用petG-trnP序列来分析柏木属和扁柏属的系统发育关系是可行的;中国柏木属植物是一个单系类群;Ctmmaecyparis nootkatensis与扁柏属其它植物关系较远．因此,柏木（Cupressus funebris）和Ch．nootkatensis均应并入柏木属．     

Bayesian mixed models and divergence time estimation of Chinese cavefishes (Cyprinidae: Sinocyclocheilus)

The genus Sinocyclocheilus is distributed in Yun-Gui Plateau and its surrounding region only, within more than 10 cave species showing different degrees of degeneration of eyes and pigmentation with wonderful adaptations. To present, published morphological and molecular phylogenetic hypotheses of Sinocyclocheilus from prior works are very different and the relationships within the genus are still far from clear. We obtained the sequences of cytochrome b (cyt b) and NADH dehydrogenase subunit 4 (ND4) of 34 species within Sinocyclocheilus, which represent the most dense taxon sampling to date. We performed Bayesian mixed models analyses with this data set. Under this phylogenetic framework, we estimated the divergence times of recovered clades using different methods under relaxed mo-lecular clock. Our phyloegentic results supported the monophyly of Sinocyclocheilus and showed that this genus could be subdivided into 6 major clades. In addition, an earlier finding demonstrating the polyphyletic of cave species and the most basal position of S. jii was corroborated. Relaxed diver-gence-time estimation suggested that Sinocyclocheilus originated at the late Miocene, about 11 million years ago (Ma), which is older than what have been assumed.