根据叶表皮特征试论国产三齿稃亚族的属间关系

根据植物叶片表皮结构,尤其下表皮特征,对国产三齿稃亚族6个属(包括1个引进属)进行了属间关系的分析。结果表明：国产三齿稃亚族中固沙草属最原始,草沙蚕属最高级,双稃草属、千金子属、三齿稃属和隐子草属演化居于其间;隐子草属可能直接起源于固沙草属,并在自身基础上派生了较为高级的三齿稃属;双稃草属与千金子属渊源关系直接,前者可能通过后者问接起生于固沙草属;草沙蚕属具有别于它属的性状级次,可能是起源于固沙草属、独树1支的顶级类群。这一结果不仅修正了前人演化理论的差误,而且为今后探讨该亚族的地理起源、散布路线提供了资料。     

三角草属和冠毛草属的系统关系与地理分布的初步研究

根据外部形态上小穗的结构特征分析了针茅族中三角草属和冠毛草属的系统发育关系,并结合地理分布和生境条件对两属植物的起源中心进行了探讨。结果表明:三角草属和冠毛草属是针茅族中亲缘关系最近的类群;冠毛草属高级于三角草属;三角草属中的三角草是两属植物中最原始的种型,它可能既派生了属内的假冠毛草,同时又派生了属外绝灭了的黑穗茅祖种,而黑穗茅祖种又在自身属内间接衍生出了冠毛草和单蕊冠毛草;冠毛草属和三角草属皆起源于我国的西藏地区,其中三角草属可能源于西藏西部,冠毛草属可能源于西藏东部。     

鹅观草属部分种的叶表皮微形态特征及其分类学意义

在过去叶表皮实验的基础上,本从鹅观草属不同组、系中新增解剖了１６个有代表性的种。根据这些种叶片反映的表皮微形态特征,进一步证实了鹅观草属共族分属以及属下类群划分的正确性,揭示了属中各主要类群的演化水平和系统发育关系。研究结果最后表明：鹅观草属的半颖组最原始,在系统发育中它可能既派生了较进化的小颖组和大颖组,又派生了最进化的长颖组;在大颖组中,齿草系较原始,纤毛草系较进化,宽叶草系最进化,纤毛草系     

鹅观草属部分种的叶表皮微形态特征及其分类学意义

在过去叶表皮实验的基础上 ,本文从鹅观草属不同组、系中新增解剖了 1 6个有代表性的种。根据这些种叶片反映的表皮微形态特征 ,进一步证实了鹅观草属共族分属以及属下类群划分的正确性 ,揭示了属中各主要类群的演化水平和系统发育关系。研究结果最后表明 :鹅观草属的半颖组最原始 ,在系统发育中它可能既派生了较进化的小颖组和大颖组 ,又派生了最进化的长颖组 ;在大颖组中 ,齿草系较原始 ,纤毛草系较进化 ,宽叶草系最进化 ,纤毛草系和宽叶草系可能相继起生于齿草系。并且 ,鹅观草属的这种进化关系同过去细胞学和形态学提供的证据是基本一致的。     

基于形态和叶表皮微形态特征试论国产赖草属属下类群间的系统关系

通过对先前学者报道的国产赖草属24个物种、72个代表居群形态和叶表皮微形态性状特征的观测和研究,结果发现:(1)原国产赖草属物种在旗叶长宽、叶片被毛状况、花序直曲和长宽、穗轴每节小穗数、每小穗小花数、外稃和内稃长度等15个外部形态学性状上均存在不同程度的差异,可将参试物种区分为3个不同的组;大赖草、粗穗赖草、硕花赖草和柴达木赖草多穗组植物的穗状花序粗壮呈圆锥状、直立、密集,穗轴同节着生3-多枚小穗,每小穗常含3~10小花,颖线状披针形等,致使其处于该属最原始的地位;皮山赖草、若羌赖草和格尔木赖草单穗组物种的穗状花序细弱呈线状、直立、疏松,穗轴每节仅着生1枚小穗,每小穗往往含2~5小花,颖线状披针形或锥形,这些较高级的外部形态特征使得该组植物隶属于赖草属中较高级的类群;而少穗组植物的外部形态性状通常介于前两组植物的中间过渡状态,因而它的系统地位自然也应处于多穗组和单穗组植物之间。同时,依据外部形态性状的递变趋势分析显示,3组植物具有直接的派生渊源。(2)国产赖草属植物的叶表皮皆由长细胞、短细胞、气孔器细胞和刺毛所组成,表现为典型的狐茅型;它们除在长细胞类型和壁的厚薄、气孔器保卫细胞的体积和类型等性状上具有明显重叠而显示相似外,其它多数性状如长细胞的长度和壁的波曲程度、短细胞的分布式样、副卫细胞的形状及刺毛的类型等性状上具有明显差异,其可将赖草属植物鉴分为与形态学界定结果完全相同的3个组。同时,根据3组植物及组内物种叶表皮性状的演化趋势,对各组和组内物种的演化关系和系统位置分析表明,多穗组植物最原始,少穗组植物较进化,单穗组植物最高级;多穗组可能直接派生了较进化的少穗组,并在少穗组的基础上进而产生了最高级的单穗组。赖草属属下类群的这一系统关系与利用外部形态特征所获得的系统与进化关系基本一致。     

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。     

菊科千里光簇未冬亚族的花粉超薄结构及其系统学意义

研究了国产菊科千里光族款冬亚族及其相关类群１１属１５种植物的花粉超薄结构。研究类群的花粉超薄结构可分为２类：“千里光型”和“向日葵型”。多榔菊属、大吴风草属和毛冠菊属为“向日葵型”,其余种类均为“千里光型”。根据花粉超薄结构类型,结合其它有关方面的研究,认为大吴风草属与橐吾属并不近缘,而毛冠菊属可能接近于紫菀族。     

三蕊草属Sinochasea Keng系统位置的研究

叶片表皮、叶片横切面、花粉和淀粉粒的微观特征,对青藏高原的特有类群三蕊草属Sinochasea Keng的系统位置进行了探讨。结果表明,三蕊草S.trigyna Keng在上述微观性状上与毛蕊草Duthiea brachypodia(P.Candargy) Keng et Keng f.差距最小,与冠毛草Stephanachne pappophorea(Hack.)Keng差距次之,与宝兴野青茅Deyeuxia moupinensis(Franch.) Pilger和拂子茅Calamagrostis epigeios(L.) Roth差距最大;三蕊草属的系统位置应处于毛蕊草所隶的燕麦族Aveneae中;在系统演化上,燕麦族是最原始的类群,它可能直接或间接地派生了针茅族Stipeae和剪股颖族Agrostideae。     

菊科千里光族款冬亚族的花粉超薄结构及其系统学意义

研究了国产菊科千里光族款冬亚族及其相关类群 1 1属 1 5种植物的花粉超薄结构。研究类群的花粉超薄结构可分为 2类 :“千里光型”和“向日葵型”。多榔菊属、大吴风草属和毛冠菊属为“向日葵型”,其余种类均为“千里光型”。根据花粉超薄结构类型 ,结合其它有关方面的研究 ,认为大吴风草属与橐吾属并不近缘 ,而毛冠菊属可能接近于紫菀族。     

桔梗科的地理分布:关于分布中心问题

对桔梗科44个属的分布作了分析,发现属的3个频度分布中心：东亚区(13个属),开普区(10个),地中海区(14个)。东亚区有12个属集中分布于中国西南部(云南东部和北部、四川西南部和贵州西南部);在地中海区属的分布相对均匀,但巴尔干半岛比较集中,有9个属。因此中国西南部是桔梗科属的最集中分布的中心。对桔梗科作了尝试性的划分,将该科分为6个类群,7个亚类群。东亚是类群和亚类群最集中分布的地区,因此可以称为类型的多样性中心。本文选择Polemoniaceae为外类群,把Cyphiaceae和Lobeliaceae作为参考类群,并考虑一般承认的进化原则,据此分析了26个性状的演化趋势,进而计算出每一个属的性状原始指数,并据此确定各属的原始性和进化性。最原始的属和大部分比较原始的属分布在东亚,因而可以认为东亚,特别是中国西南部,是桔梗科的原始类型中心。这个地区也就是康滇古陆的所在地,地史上一直稳定,为桔梗科原始类群的分化提供了历史地理背景,这里就是原始类群分化、发展的地区,推测桔梗科起源于白垩纪,但具体的起源地难于判断。     

论山毛榉科植物的系统发育

本文运用分支分类学方法,对山毛榉科植物进行了系统发育的分析。山毛榉科作为单元发生群包括柯属、锥属、粟属、三棱栎属、水青冈属和栎属。桦木科和南山毛榉属被选择作为外类群。对大量的性状进行评估之后,选择了25对性状作为建立数据矩阵的基本资料。性状极化以外类群比较为主,同时也采用了化石证据和通行的形态演化的基本原则。数据矩阵由7个分类群、2个外类群和25个性状组成。采用最大同步法、演化极端结合法和综合分析法对该数据矩阵进行了分析。在得到的3个树状分支图中按照最简约的原则,选出演化长度最短的谱系分支图作为本文讨论山毛榉科属间的系统演化关系的基础。关于山毛榉科植物的系统发育,作者的观点如下：(A)现存的山毛榉科的6个属形成了4条平行进化的分支路线,它们分别被处理作4个亚科,即：栗亚科,三棱栎亚科,水青冈亚科和栎亚科;(B)平行进化是山毛榉科植物系统发育过程中的主要形式。生殖过程中的一些特征,如：果实第二年成熟,胚珠通常败育等,是影响山毛榉科植物属间基因交流的主要原因。在现存的山毛榉科植物中,柯属是最原始的类群。三棱栎属和锥属的起源也较早,而栗属、水青冈属和栎属是特化的类群。     

湖北省泽泻科、水鳖科、眼子菜科及茨藻科植物花粉形态研究

本文利用光镜及扫描电镜对湖北省泽泻科、水鳖科、眼子菜科及茨藻科11属29种1变种1变型植物(另加采于湛江的软骨草)的花粉形态进行了研究,发现泽泻科植物花粉具多个圆形萌发孔,外壁表面为小刺状纹饰;茨藻科植物花粉具远极单槽,表面为绉波状纹饰;眼子菜科及本文研究的水鳖科植物花粉均无萌发孔,分别具网状和小刺状饰纹饰。1.茨藻科植物花粉最原始,泽泻科花粉较进化,眼子菜科花粉较水鳖科花粉进化;2.泽泻属与泽苔草属花粉较慈姑属花粉原始;3.鞘叶眼子菜亚屈花粉较眼子菜亚属的花粉处于更高演化阶段;4.多孔茨藻花粉在该科中最原始。本文工作尚对易变形水生植物花粉形态研究方法进行了尝试。     

Pollen morphology of the tribe Cynoglosseae of Boraginoideae (Boraginaceae) in China

Pollen morphology of 16 Chinese species representing 7 genera in the tribe Cynoglosseae of Boraginoideae(Boraginaceae) was examined under LM and SEM, and 5 species under TEM. Pollen grains are cocoon-shaped, rarely subprolate, prolate or ovoid, very small, 7～ 15.7μm× 3.5 ~ 13.9 μm in size, P/E = 1.6～2.02; 3-colporate apertures alternate with 3-pseudocolpi, with equatorial endocingulus except those in Bothriospermum; exine surface is usually smooth, with or without perforations in two poles, rarely with tuberculate ornamentation; exine is rather thin and includes ectexine and endexine, while ectexine consists of imperforate tectum, columellae and foot-layer. The tribe Cynoglosseae has many common characters of pollen grains, but there are some differences among genera. A key to the genera is given based on pollen morphology. Bothriospermum, without endocingulus, may be a primitive genus in this tribe, and its pollen morphology is more similar to that of Eritrichieae than to Cynoglosseae, thus it seems more reasonable to put it into Eritrichieae. Solenanthus may be the most advanced genus in the tribe Cynoglosseae for its pollen grains of sub-isopolar and ovoid shape.     

根据叶表皮微形态特征试论新麦草属、芒麦草属和三柄麦属间的系统关系

观察了禾本科新麦草属、芒麦草属和三柄麦属主要代表种的叶片表皮形态学特征,总结了三属植物叶表皮结构的异同,探讨了叶表皮特征的分类学意义。同时,根据三属植物叶表皮性状的演化趋势,分析了各属的演化关系和系统位置。结果表明,新麦草属最原始,芒麦草属较进化,三柄麦属最高级;新麦草属可能直接派生了较进化的芒麦草属,并在芒麦草属的基础上进而产生了最高级的三柄麦属。三柄麦属、芒麦草属和新麦草属的这一系统关系同它们外部形态上三联小穗的演化趋势是相互印证的。     

Pollen Morphology of Microula Benth. and Allied Genera (Boraginaceae)

Pollen grains of 16 species of Microula Benth. and six species of three related genera were examined under LM and SEM, and four of them also under TEM. Pollen grains of Microula and three related genera are dumb-bell-shaped, 3-colporate apertures alternate with three pseudocolpi. Pollen grains are very small,ranging from 12.18 x 7.13 μm to 6.36 x 3.66μm. In general, colpi with os are wider and shorter, rhomboid, but sometimes they are equal to pseudocolpi in length. Colpus margins are regularly or irregularly tooth-like. The surface of colpi is psilate or processed. Ora are circular or lalongated in outline, protruded or not; surface of os membrane is smooth or scabrid. The exine is usually indistinctly layered under LM. The exine surface is psilate, and more or less perforate. TEM examination shows that the pollen wall is differentiated into exine and intine: the exine includes ectexine and endexine, while the ectexine consists of tectum, columellae and foot-layer. However, there are differences in constriction of equatorial area, apertural characters, ornamentation and exinous ultrastructure between these genera. Pollen morphology indicates that the genus Microula Benth. is primitive, directly related to the genus Actinocarya Benth .; the genus Asperugo L. Is more advanced. The genus Eritrichium Schrad. which has two ora or one os and is anisopolar, represents the most advanced group among them. Noteworthily, the diorate phenomenon is found for the first time not onlyin the genus but in the family Boraginaceae.     

Does Actaea asiatica Have the Most Symmetric and Primitive Karyotype in the Ranunculaceae?

Actaea asiatica was previously reported to have the most symmetric and primitive karyotype, consisting of 10 m- and 6 sm-chromosomes, which is quite different from those of the remaining species in the genus Actaea, consisting of 10 m-, 4 sm- and two T-chromo somes. In this paper, the chromosomes of this species were re-examined. The results show that Actaea asiatica has the same karyotype as the other species in the genus. Compared with the species in other genera in the tribe Cimicifugeae, i.e. Beesia, Anemonopsis, Souliea and Cimicifuga, Actaea asiatica, together with the remaining species of the genus, has the most asymmetric and thus probably the most advanced karyotype in this tribe because of the presence of two T- chromosomes in their chromosome complements. The two T- chromosomes may serve as one of the most important cytological markers, by which the species in Actaea are clearly distinguishable cytologically from those in Beesia, Anemonop-sis, Souliea and Cimicifuga.     

The Origin,Evolution and Distribution of Ligularia Cass. (Compositae)

The genus Ligularia Cass. is one of the large genera in Compositae-SenecioneaeTussilagininae. In subtrib. Tussilaginae, Ligularia is closely related to, but more advanced than, the genus Farfugium Lindl. It includes six sections, 11 series and 129 species. All the taxa are distributed in Asia with only two species extending to Europe. There are 119 species in E. Asia, Comprising 96 % of the world total. The highest concentration of species in E. Asia occurs in the Hengduan Mountains. In this area there are four section, six series and 67 species, of which 61 species are local endemics; thus 66% of sections, 54.5% of series and about 52 % of species in the world occur in this small area, indicating that it is a major distribution centre for Ligularia. According to character analysis, sect. Corymbosae ser. Calthifoliae with 5 species was considered as the most primitive group in this genus, which has reniform leaves, palmate veins, a few large capitula (arranging in Corymb-like inflorescence), and semispherical involucre etc. The primitive species, L. dentata and L. hodgsonii, are distributed from E. Sichuan to Japan via Hubei, Hunnan, Anhui, Fujian. This distribution pattern is consistent with that of its allied genus, Farfugium. According to the principle of common origin, the ancestors of the two genera appeared most probably in the same area. It was inferred that the area from E. Sichuan of China to Japan was the original area of the genus Ligularia, However, on the basis of geological history and the modern distribution of this genus, the author considers that central China with E. Sichuan might be the primary original area of Ligularia. Its dispersal route was mainly along the mountains of southern margin of Asia, with relatively few members dispersed northea stwards to NE. Asia. The origi-nal time of the genus Ligularia was at least not later than the middle Cretaceous.