核果茶属的气孔器类型及其系统学意义

为了检验有关核果茶属气孔器类型不同的研究结果 ,使用从模式标本上获取的实验材料重新观察了耿煊 (H .Keng)在 1 962年报道过的具有毛茛型气孔器的核果茶属 3个种的叶片下表皮 ,得到了与耿煊不同的研究结果 ,即核果茶属的气孔器属大头茶型 ,与邻近的石笔木属、拟核果茶属乃至山茶亚科的气孔器类型一致。结果提示 ,气孔器类型可以作为划分山茶亚科和厚皮香亚科的依据     

竹亚科系统学和生物地理学研究进展及存在的问题

对近年来在竹亚科作为一个单系类群的界定、其系统位置的确定、内部系统演化趋势以及地理分布和起源方面研究所取得的进展进行了评述。竹亚科作为一个单系类群仅包括了木本的竹族（Bambuseae)和一个草本的莪利竹族（Olyreae),其中莪利竹族分布在新几内亚的伊里安竹（Buergersiochloa)处于Olyreae最基部。禾本科12个亚科中除了3个亚科为基部类群以外,其余9个亚科分成PACCAD（包括黍亚科,狭义的芦竹亚科,广义的虎尾草亚科,假淡竹叶亚科,三芒草亚科和扁芒草亚科）和BOP单系分支（包括竹亚科,稻亚科和早熟禾亚科）。在BOP支中,竹亚科与早熟禾亚科相近缘,共同组成稻亚科的姐妹群。竹亚科分成草本和木本两个单系类群,木本竹子又分成热带和温带支系,热带支系进一步分成新世界热带和旧世界热带两个单系类群。从现有的化石证据和基部类群的地理分布推断,竹亚科很可能起源于晚白垩纪的冈瓦纳古陆。最后,本文就竹亚科研究尚存在的问题做了初步探讨。     

20种山茶科植物的叶表皮微形态研究

为解决一些山茶科(Theaceae)的分类学问题,该研究在光学显微镜下对山茶科2亚科6属共20种植物的13种叶表皮微形态特征进行了观察,并利用聚类分析和主成分分析对这些特征进行分析,为山茶科的科学分类提供参考资料。结果表明:(1)山茶科20种植物的13种叶表皮微形态特征能够区分种间差异和分类等级,显示了比较全面的分类价值。(2)基于微形态特征的聚类分析和主成分分析结果显示,20个种分为2个大类群以及10个分支,很好地区分了山茶亚科(Theoideae)与厚皮香亚科(Ternstroemoideae),并将大部分分类地位相近的物种归类到一起,较好地反映了物种之间的亲缘关系。(3)该研究结果支持将小黄花茶组(Sect.Luteoflora)作为独立的一个组;支持将重庆山茶(Camellia chungkingensis Chang)从瘤果茶组(Sect.Tuberculata Chang Tax.)中分离;支持将山茶亚科与厚皮香亚科划分为两个较大类群,认为将厚皮香亚科并入五列木科(Pentaphylacaceae)的观点还有待更多实验证据的支持。     

虎尾草亚科系统发育关系的初步研究

运用广义形态学性状对虎尾草亚科（Chloridoideae）进行系统发育分析。内类群包括虎尾草亚科52属的69种植物,代表虎尾草亚科的主要类群;芦竹亚科（Arundinoideae）扁芒草族（Danthonieae）的Centropodia和Danthonia被选作外类群。分支分析表明,虎尾草亚科是一个单系类群。其严格一致树包括A、B、C、D、E5个分支。两个大族画眉草族（Eragrostideae）和虎尾草族（Chlorideae）代表虎尾草亚科内部类群分化的两个方向,分开处理较合理。细穗草族（Leptureae）放到虎尾草族中较合理。冠芒草族（Pappophoreae）是虎尾草亚科的基部类群,与画眉草族近缘。我们的研究支持虎尾草亚科从旧世界向新世界扩散的地理分布假说,并提供了虎尾草亚科属上类群的系统发育关系的框架。     

五列木科和肋果茶科花粉外壁超微结构及其与山茶科的系统学关系

借助光学显微镜、扫描电镜和透射电镜对五列木科Ｐｅｎｔａｐｈｙｌａｃａｃｅａｅ和肋果茶科Ｓｌａｄｅｎｉａｃｅａｅ花粉进行了观察,并与山茶科Ｔｈｅａｃｅａｅ若干属的花粉进行了详细的比较,同时参考了猕猴桃科Ａｃｔｉｎｉｄｉａｃｅａｅ的花粉特征。研究表明,肋果茶科的花粉与山茶科的花粉具有较多的相似性,如其形状和大小与山茶科中厚皮香亚科的几乎一致;而花粉的表面纹饰（粗糙至模糊的皱波状纹饰）则与山茶属,Ｆｒｅｚｉｅｒａ属和厚皮香亚科部分属的花粉纹饰相类似。从花粉外壁的结构看,肋果茶的花粉与石笔木属和山茶属的更接近,表现为：花粉外壁层次分化明显,复盖层和柱状层均较厚,外壁内层薄。而五列木科花粉除了形状和萌发孔类型与山茶科的相似外,其纹饰特征和外壁结构均与山茶科的差异较大,如五列木科花粉表面近光滑,外壁覆盖层较簿,柱状层很不发达,外壁内层相对较厚等。孢粉学上认为,肋果茶科与山茶科具有更为密切的关系,五列木科则与山茶科较疏远。支持把肋果茶科作为一个属置于山茶科内或作为山茶科的一个亚科     

真正柑桔果树群植物的分支学研究

本文用相容性分析方法(Compatability snalysis)分析了真正柑桔果树群(芸香科Rutaceae-柑桔亚科Aurantioideae-柑桔族(Citreae)-柑桔亚族(Citrinae)植物内各属间的分支学关系。给出了建立在7个相容性性状组成的最大族所决定的分支图。性状极性的确定使用了外群法。结果表明,柑桔属(Citrus L.)和多蕊桔属(Clymenia Swing)构成一个单系类群,他们的姐妹群是金柑属(Fortunella Swing.)。被认为起源于中国的3个属,柑桔属(Citrus)、金柑属(Fortunella)和积属(Poncirus Raf.)并未构成一个单系类群。本文还利用分支关系分析和讨论了真正柑桔果树群的种系发生关系。     

基于28S rRNA D2序列的内茧蜂亚科的分子系统发育

首次利用同源28S rRNA D2基因序列对内茧蜂亚科Rogadinae （昆虫纲Insecta：膜翅目Hymenoptera：茧蜂科Braconidae）进行了分子系统学研究。本研究从95%～100%乙醇浸渍保存的标本中提取基因组DNA并扩增了10种内群种类和5种外群种类的28S rDNA D2片段并测序（GenBank序列号AY167645-AY167659）,利用BLAST搜索相关的同源序列, 采用了GenBank中13个种类的28S rRNA D2同源序列,然后据此进行分子分析。利用3个外群（共8个种类）和3种建树方法 (距离邻近法distance based neighbor joining, NJ; 最大俭约法maximum parsimony, MP; 和最大似然法maximum likelihood, ML)分析了内茧蜂亚科内的分子系统发育关系。结果表明,由分子数据产生的不同的分子系统树均显示内茧蜂亚科是一个单系群。内茧蜂亚科内依据形态和生物学特征的分群（族和亚族）及其系统发育关系得到部分支持。NJ、MP和ML分析结果均表明内茧蜂族Rogadini不是一个单系,而是一个并系,其余3族则得到不同程度的支持。内茧蜂族可分成2个分支：“脊茧蜂属Aleiodes+弓脉茧蜂属Arcaleiodes”和“沟内茧蜂属Canalirogas+锥齿茧蜂属Conspinaria+刺茧蜂属Spinaria+内茧蜂属Rogas”,二者不是姐妹群。脊茧蜂属Aleiodes和弓脉茧蜂属Arcaleiodes始终是姐妹群。脊茧蜂属Aleiodes是一个单系,并可分成2个姐妹分支,这与依据形态和生物学特征的亚属分群相一致。弓脉茧蜂属Arcaleiodes Chen et He,1991是一个独立的属。分支“沟内茧蜂属Canalirogas+锥齿茧蜂属Conspinaria+刺茧蜂属Spinaria+内茧蜂属Rogas”的单系性仅得到部分分子数据的支持;因形态特异（腹部成甲壳状）而列为亚族级的刺茧蜂属Spinaria,分子分析没有证实这一点。横纹茧蜂族Clinocentrini是个单系,并在内茧蜂亚科的系统发育中处于基部（原始）的位置。我们研究结果还表明,阔跗茧蜂属Yelicones和潜蛾茧蜂属Stiropius相对应的阔跗茧蜂族Yeliconini和潜蛾茧蜂族Stiropiini为2个独立的分支, 与形态和生物学的结果一致,但它们在内茧蜂亚科的系统发育的位置不明,有待今后进一步研究。     

基于叶绿体四个DNA 片段联合分析探讨山茶属长柄山茶组、金花茶组和超长柄茶组的系统位置与亲缘关系

为探讨山茶属茶亚属 (Camellia subgenThea) 中长柄山茶组 (sectLongipedicellata)、金花茶组 (sectChrysantha)和超长柄茶组 (sectLongissima) 的系统位置和亲缘关系,本研究选取了该属4个亚属11组28个种及2个外类群的材料,对这些材料的叶绿体4个DNA片段 (rpl16、psbA trnH、trnL F和rpl32 trnL) 进行了测序,运用邻接法 (neighbor joining)、最大简约法 (maximum parsimony) 和贝叶斯推断 (Bayesian inference) 对获得的序列进行了联合矩阵分析,并构建基因树。基因树的拓扑结构显示：1) 金花茶组包括3个平行的支系,并且长柄山茶组的模式种长柄山茶 (Camellia longipedicellata) 嵌于其中一个支系,因而金花茶组可能是一个并系或多系类群;2) 长柄山茶与越南分布的金花茶组种类在分子系统树上构成一个单系支,暗示了长柄山茶组和金花茶组之间可能具有紧密的亲缘关系;3) 超长柄茶组不是一个单系类群,该组的河口超长柄茶 (C. hekouensis) 位于系统树的基部,与山茶属其余种构成姐妹群。由于缺乏更广泛取样的分析,超长柄茶在山茶属中的系统位置仍然不明确,超长柄茶组与长柄山茶组的亲缘关系问题也没有得到解决。     

基于叶绿体四个DNA片段联合分析探讨山茶属长柄山茶组、金花茶组和超长柄茶组的系统位置与亲缘关系

为探讨山茶属茶亚属(Camellia subgen.Thea)中长柄山茶组(sect.Longipedicellata)、金花茶组(sect.Chrysantha)和超长柄茶组(sect.Longissima)的系统位置和亲缘关系,本研究选取了该属4个亚属11组28个种及2个外类群的材料,对这些材料的叶绿体4个DNA片段(rp/16、psbA-trnH、trnL-F和rp/32-trnL)进行了测序,运用邻接法(neighbor-joining)、最大简约法(maximum-parsimony)和贝叶斯推断(Bayesian inference)对获得的序列进行了联合矩阵分析.并构建基因树.基因树的拓扑结构显示:1)金花茶组包括3个平行的支系,并且长柄山茶组的模式种长柄山茶(Camellia longipedicellata)嵌于其中一个支系,因而金花茶组可能是一个并系或多系类群;2)长柄山茶与越南分布的金花茶组种类在分子系统树上构成一个单系支,暗示了长柄山茶组和金花茶组之间可能具有紧密的亲缘关系;3)超长柄茶组不是一个单系类群,该组的河口超长柄茶(C.hekouensis)位于系统树的基部,与山茶属其余种构成姐妹群.由于缺乏更广泛取样的分析,超长柄茶在山茶属中的系统位置仍然不明确,超长柄茶组与长柄山茶组的亲缘关系问题也没有得到解决.     

大头茶族的范围及族内属的界限

广义大头茶族几乎包括了整个山茶亚科的属,分群的界限不够明确,易于造成混乱,经过研究,作者所持的是狭义大头茶族的概念。考察这一族包括Polyspora, Gordonia和Laplacea三个属形态特征上的差异和洲际分布的事实,这三个属虽然有共同的祖先,但由于演化上的歧异,仍应作为独立的属看待。在划分属的界限上,苞被分化与否和花部其他形态的差异具有最重要的意义,花粉表面纹饰的差异也可作为一种依据。Polyspora种群划分也被讨论。     

The phylogenetic position of Apterosperma (Theaceae) based on morphological and karyotype characters

Classifications of Theaceae have usually placed the endangered monotypic genus Apterosperma in tribe Schimeae (x=18), whereas recent molecular phylogenetic evidence supports its transfer to tribe Theeae (x=15). Molecular data have not resolved the phylogenetic position of Apterosperma within Theeae. We investigated the chromosome number and karyotype of Apterosperma in the context of molecular and morphological phylogenetic evidence to provide further insight into the placement of Apterosperma within Theaceae. The chromosome number and karyotype was found to be 2n = 30 = 26m + 4sm, consistent with the transfer of Apterosperma to tribe Theeae. When the chromosome data were incorporated into a data set of 46 other nonmolecular characters, Apterosperma was placed as the first-diverging lineage within the clade comprising tribe Theeae. This supports its placement based on molecular data. The low intrachromosomal asymmetry (type 1A) of Apterosperma, presumably ancestral for the family, is also consistent with this placement. Character optimization strongly supports a base chromosome number of x=15 for tribe Theeae. Because of variable and sometimes conflicting chromosome count reports of species in tribes Schimeae and Stewartieae, the base chromosome number of Theaceae could be either x=15 or 17.     

Reassessing the relationships between Gordoniaand Polyspora (Theaceae) based on the combined analyses of molecular data from the nuclear, plastid and mitochondrial genomes

The combined analyses, based on ITS, trnL-F and matR DNA sequence data respectively from the nuclear, plastid and mitochondrial genomes, reveal that Gordonia is not a monophyletic group, and on the contrary, distributed in two major lineages in Theaceae. The only North American species, G. lasianthus, is located in Gordonieae together with Schima and Franklinia, whereas the Chinese Gordonia species are positioned in Theeae together with Camellia, Pyrenaria s.l. and Apterosperma. This result, to great extent, supports the viewpoints of separating the North American and Asiatic Gordonia species into two different genera, Gordonia s.str. and Polyspora, respectively.The study was partially supported by funds from a project of the Provincial Natural Sciences Foundation Committee of Yunnan, P. R. China (97C039Q), the special support grants from The Chinese Academy of Sciences for biotaxonomy and floristics.     

山茶科濒危植物猪血木的花器官发生

利用扫描电镜首次观察了山茶科极濒危植物猪血木(Euryodendron excelsum)的花器官发生过程。猪血木的花为两性完全花,萼片和花瓣均为2/5螺旋向心发生,单轮排列,且有逆时针和顺时针两种方式。雄蕊的形成是先形成一个环形分生组织,然后在环形分生组织上以2/5螺旋产生5束雄蕊原基,每一束雄蕊原基的第一雄蕊原基都是在对萼的位置产生,其它的雄蕊原基在其两侧产生。3心皮顺序发生,愈合成3室单子房,柱头平截不裂。猪血木与山茶亚科的花器官发生明显不同。     

Early Floral Development of Endangered Euryodendron excelsum (Ternstroemioideae: Theaceae)

The floral development of a critically endangered plant Euryodendron excelsum from Ternstroemioideae (Theaceae) has been observed under scanning electron microscope (SEM) for the first time . The flower of E. excelsum is bisexual and teleianthous . Five sepal primordia are initiated 2􊄯5 spirally and arranged in one whorl when mature , and so are petals. Sepals and petals are initiated in the same order either clockwise or counterclockwise in the same flower . The androecial part is a ring primordium in the beginning . The first five stamen primordia are initiated on this ring primordium at antisepalous positions and then other stamen primordia appear on two sides of each of the first five primordia . Finally a total of 25 stamen primordia are initiated from the ring primordium and arranged in one whorl but could be grouped into 5 fascicles. Three sequentially initiated carpels compose an ovary which has an axile- central placenta with three locules and a truncateand indehiscent stigma . The floral development of E. excelsum is distinctly different from plants in Theoideae .     

阔叶杨桐的花器官发生(山茶科)

利用扫描电镜首次观察了山茶科厚皮香亚科植物阔叶杨桐的花器官发生过程。阔叶杨桐的花被片和五束雄蕊都是2/5螺旋向心发生,且有逆时针和顺时针两种螺旋方式;五束雄蕊在环形雄蕊原基上产生,且每一束都是由中间向两端发生;由五心皮形成的中轴胎座内出现一衍生的可育胎座。阔叶杨桐的花器官发生过程与本亚科的猪血木明显不同,该研究为厚皮香亚科乃至山茶科的系统发育与演化提供花器官方面的依据。     

Molecular Phylogeny of Tribe Theeae (Theaceae s.s.) and Its Implications for Generic Delimitation

Tribe Theeae, which includes some economically important and widely grown plants, such as beverage tea and a number of woody ornamentals, is the largest member of the Theaceae family. Using five genomic regions (chloroplast: atpI-H, matK, psbA5''R-ALS-11F, rbcL; nuclear: LEAFY) and 30 species representing four of the five genera in this tribe (Apterosperma, Camellia, Polyspora, and Pyrenaria s.l.), we investigated the phylogeny of Theeae and assessed the delimitation of genera in the tribe. Our results showed that Polyspora was monophyletic and the sister of the three other genera of Theeae investigated, Camellia was paraphyletic and Pyrenaria was polyphyletic. The inconsistent phylogenetic placement of some species of Theeae between the nuclear and chloroplast trees suggested widespread hybridization between Camellia and Pyrenaria, Polyspora and Parapyrenaria. These results indicate that hybridization, rather than morphological homoplasy, has confused the current classification of Theeae. In addition, the phylogenetic placement and possible allies of Laplacea are also discussed.     

FRUITS AND SEEDS OF TRIBE GORDONIEAE (THEACEAE) FROM THE EOCENE OF NORTH AMERICA

A new genus and species Gordoniopsis polysperma and two new species of Gordonia (Gordonieae, Camellioideae, Theaceae) are described based on fossil fruit and seed remains. These specimens are part of a large flora consisting of various plant organs from the middle Eocene Claiborne Formation in western Kentucky and Tennessee. Gordoniopsis is a five-valved loculicidally dehiscent capsule similar to capsules of Gordonia but differing in having unwinged seeds and a greater number of seeds per locule. The two Gordonia species are among the earliest unequivocal records of the genus and two of only four fossil Gordonia species known with in situ seeds. Two extinct genera, Gordoniopsis and Andrewsiocarpon, and the extant genus Gordonia in the tribe Gordonieae are known from the middle Eocene Claiborne flora, suggesting an early radiation within the tribe. Based on a survey of Recent fruits and seeds we concur with Keng's proposal to merge Laplacea with Gordonia.