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1.
国产蔷薇科绣线菊亚科的花粉形态   总被引:6,自引:3,他引:6  
本文报道了国产蔷薇科绣线菊亚科(Spiraeoideae)8属9种植物花粉形态。该亚科花粉近球形,极面观三裂圆形。花粉通常较小,最小花粉见于Spiraeapurpurea,为1487(1275~1658)μm×1517(1275~1734)μm,其中Physocarpusamurensis的花粉比较大,为2797(1989~3825)μm×3091(2677~3366)μm。三孔沟,内孔为长方形,部分种内孔明显外突。沟较长,两端较窄,在Physocarpusamurensis观察到合沟现象。合沟出现时通常三沟在一极汇合,在另一极常不汇合。花粉外壁具穴状、条纹-穴状、条纹-网状、条纹状等数种纹饰。迄今为止,在Rosaceae观察到的所有花粉外壁纹饰中,除较为特化的刺状纹外,其余纹饰在该亚科均存在。在Rosaceae所有的花粉外壁纹饰中,穴状纹饰可能是较为原始的类型,条纹状-网状和条纹状依次是较为进化的,而刺状是最进化的纹饰。在Spiraea中,外壁纹饰有相对进化的条纹-网状和条纹状,然而未观察到穴状这一最原始类型,这表明该属及其属下种的分化程度可能较高。但因Spiraea所含种数较大,这一推论有待进一步深入论证。此外,花粉形态特征支持Takhtajan(1997)关于Spiraeoideae亚科下族与属的排序。  相似文献   

2.
绣线菊亚科是蔷薇科最原始的亚科,共有22属260余种, 包括常绿和落叶两大类群,前者是 原始类型。我国有8属100种,全都为落叶性。本文着重讨论中国各属的起源、演化和分布等 ,同时也概述全亚科植物在世界各植物区的分布等问题。绣线菊属Spiraea是该亚科落叶类群中最原始的属,它在早期发生趋异进化,衍生出形态各异而亲缘关系密切 的不同属,本文阐明了中国各属的系统位置和属间的亲缘关系。通过对我国各属地理分布的 分析对比,属的分布区可归纳为5个类型。对全球绣线菊亚科植物在世界各植物区中的属、种数统计表明,东亚区有8属105种,其中有96个特有种,是该亚科植物分布最多而又最集中 地区,具有在系统发育上处于各主要演化阶段的落叶类型,因此,东亚区是全球绣线菊亚科植 物的现代分布和分化中心,也是落叶类群发生和发展的关键地区。在北美洲,从马德雷区至落基山区一带分布着11属46种,均为特有种,显然北美洲西部也是该亚科植物的现代分布中心,但可能是第二分布中心。南美洲至今保存2个较古老的常绿属,即Quillaja和K ageneckia,基于此,南美洲可能是绣线菊亚科某些常绿属早期分化和发展的关键地区 。中国绣线菊亚科植物在东亚区占绝对优势,有8属82种,其中有62个特有种,分别占该区属 、种和 特有种数的100%、82%、和65%, 这些类群分布最密集地区是在中国喜马拉雅森林植物亚区 中的横断山脉地区和中国日本森林植物亚区的西部,这一带是中国绣线菊亚科的现代分布和多样性中心,很可能是某些属的发源地。由此看来,绣线菊亚科的落叶属可能起源于劳亚古陆。据化石记载,该亚科植物的起源时间可以追溯到白垩纪早白垩世。  相似文献   

3.
云南水龙骨科水龙骨亚科孢子形态的研究   总被引:4,自引:0,他引:4  
利用光学显微镜和扫描电子显微镜对云南产水龙骨科水龙骨亚科4属8种1变种植物的孢子进行了详细观察,其中篦齿蕨Metapolypodium manmeiense以及扫描电镜下观察的蒙自拟水龙骨Polypodiastrum mengtzeense为首次报道。研究结果表明,该亚科植物孢子形态较为一致,均为单裂缝,两侧对称,极面观为椭圆形,赤道面观为豆形,具周壁或不具周壁,外壁正面观均为较整齐的疣状纹饰。本文还就孢子形态及其与该亚科植物的系统分类和演化关系进行了讨论,为水龙骨科的系统分类及孢粉学研究提供了资料。  相似文献   

4.
The spores of 8 species and 1 variety belonging to 4 genera of Polypodiaceae subfam. Polypodioideae in Yunnan, China were examined under LM and SEM. Of the species it is the first time to study the spores of Metapolyp odium manmeiense and Polypodiastrum mengtzeense under SEM. The results show that the spores of this subfam. Polypodioideae are morphologic uniform; they are monolete, bilaterally symmetric, ellipsoidal in polar view, bean- shaped in equatorial view, and with or without perispore. The surface ornamentation is regularly verrucate. In addition, the relationship of the spore morphology and taxonomy in Polypodiaceae subfam. Polypodioideae was discussed in this paper, providing more informative data for the systematics and palynology of Polypodiaceae.  相似文献   

5.
AS Breure 《ZooKeys》2012,(216):1-3
The status of the genus Bostryx is discussed and, based on morphological and molecular data, restricted to a group of species related to Bostryx solutus, for which the new subfamily name Bostrycinae is introduced.  相似文献   

6.
水龙骨亚科植物叶表皮微形态及其系统学意义   总被引:1,自引:0,他引:1  
利用光学显微镜对水龙骨亚科(Subfam.Polypodioideae Nayar)4属11种1变种植物,即篦齿蕨、日本水龙骨、光茎水龙骨、栗柄水龙骨、假毛柄水龙骨、假友水龙骨、中华水龙骨、友水龙骨、柔毛水龙骨、喜马拉雅水龙骨、蒙自拟水龙骨和穴果棱脉蕨植物的叶表皮微形态进行了观察比较。结果表明:该亚科植物的叶表皮细胞都为不规则型,垂周壁为波状或深波状。它们的气孔器类型有7种,为极细胞型、共环极细胞型、腋下细胞型、聚腋下细胞型、不等细胞型、不规则四细胞型和不规则细胞型。对篦齿蕨属与多足蕨属、栗柄水龙骨与篦齿蕨、光茎水龙骨与日本水龙骨的亲缘关系进行了讨论。  相似文献   

7.
中国蔷薇科一新属--多蕊石灰树属   总被引:2,自引:0,他引:2  
技术了中国蔷薇科一新属,多蕊石灰树属和属下的唯一分类单位多蕊石灰树。在新分类群描述了基础上,据形态学资料对其进行了初步的系统学讨论。  相似文献   

8.
浙江蔷薇科新分类群   总被引:1,自引:0,他引:1  
描述了浙江蔷薇科1新亚种和1新变种,并分别附有线条图。它们是:腺瓣蔷薇(新亚种)和遂昌红腺悬钩子(新变种)。腺瓣蔷薇与模式亚种单花合柱蔷薇区别在托叶、叶柄和萼片仅密被短柔毛而无腺毛,小叶片较大,两面近无毛或疏被短柔毛,伞房花序具1~3花,花瓣宽倒卵形。遂昌红腺悬钩子与模式变种红腺悬钩子区别在于花梗、小枝和老枝密被腺毛而无柔毛,小叶片两面具腺毛,萼片较长,长13~15mm,先端长尾尖。  相似文献   

9.
The Rosaceae is one of the five largest families of Xizang flora, consisting of 30 genera with 242 species, the total number of species is slightly less than those of Compositae, Graminae, Leguminosae and Ericaceae in Xizang, amounting to 62.5% of the total number of genera and 28% of the total number of species of the rosaceous flora in China. The four subfamilies of Rosaceae including primitive, intermediate and advanced groups have been found in Xizang. These groups consist of 11 types of floristic elements, i.e. 4 genera belong to cosmopolitan, 9 genera belong to North Temperate, 3, E. Asian-N. American, 3 Sino-Himalayan, 3 Sino-Japanesa, 2 Old World Temperate, 1 Temperate Asian, 2 Mediterranean-W. and O. Asian, 1 C. Asian, I Tropical Asian and 1 endemic to China. It is obvious that Rosaceae in Xizang comprises holarctic, Ancient Mediterranean and paleotropical elements, among which the temperate components are the most dominant. The characteristics of the floristic composition of Rosaceae in Xizang may be summarized as follows: (1) Xizang abounds in both genera and species of the family which are diverse in forms, including the primitive, intermediate and advanced groups, (2) The geographical elements are rather complex, mostly belonging to the temperate, among which the Sino- Himalayan components and the elements endemic to China are dominant, (3) The proportion of plants endemic to China and distributed in Xizang is much higher than those endemic to Xizang itself, but there exist newly arisen species and infraspecific forms or varieties which show that the speciation is apparently still active in Xizang. The rosaceous flora of Xizang is a combination of old and new floristic elements, based on the old floristic components, affected by the upheaval of the Himalayas, the differentiation and speciation have been taking place in the long history. The geographical distribution of Rosaceae in Xizang may be divided into 5 regions, i.e. the northeastern, southeastern, southern, northwestern and northern. The rosaceous plants are most abundant in the southeastern area, next in southern area, fewer in the northeastern and very rare in the northwestern and northern regions. The general tendency of the distribution of Rosaceae in Xizang is that the number of species gradually decreases from the southeast to the northwest and the habit gradually changes from trees, shrubs and herbaceous plants in the southeast to cushion-like scrubs and dwarf perennial herbs in the northwest. These facts clearly show that the uplift of the Himalayas has deeply affected the phytogeographical distribution of Xizang Rosaceae. The rosaceous flora of Xizang has close relationships with those of the adjoring regions, i.e. Yunnan and Sichuan. Besides, it is connected with floras of Nepal, Sikkim, Bhutan nothern Buram and nothern India, but silghtly influenced by the Ancient Mediterranean flora.  相似文献   

10.
贵州悬钩子属(蔷薇科)一新种--务川悬钩子   总被引:3,自引:0,他引:3  
报道了贵州省务川县发现的悬钩子属Rubus(蔷薇科Rosaceae)一新种——务川悬钩子R.wuchuanensis S.Z.He。该种在体态上与锯叶悬钩子R.wuzhianus L.T.Lu&Boufford相近,区别在于其叶片卵状披针形,边缘疏生小锯齿;叶柄较短,长0.7-1cm;花序为顶生稀疏总状花序,具花8-10朵:花梗长3.55cm;花瓣先端具骤突尖头。  相似文献   

11.
Rubus is a taxonomically difficult group and cytological data are expected hopefully to gain insight into the relationships of the genus. In this study the chromosome numbers and karyotypes of 18 taxa from sect. Idaeobatus and 10 taxa from sect. Malachobatus were investigated. Among them, the chromosome numbers of 10 taxa and karyotypes of 26 taxa were reported for the first time and mixoploidy was observed new in the genus. The chromosomes are small in size with a length of less than 3 µm and metacentric (about 90%) or submetacentric. All taxa have karyotypes of “1A” except R. cockburnianus, R. innominatus and R. ellipticus var. obcordatus, which have karyotypes of “2A”. No aneuploids were found in all the 28 taxa studied. Plants of sect. Idaeobatus have diploids with 2n=2x=14, except R. idaeopsis (2n=3x=21) and R. parvifolius (A mixoploid of 2n=2x=14 and 2n=4x=28). However, plants of sect. Malachobatus have tetraploids with 2n=4x=28, except for R. buergeri with 2n=8x=56. In addition, conspicuous karyotype differences existed within the 18 taxa belonging to 11 of 7 subsections in sect. Idaeobatus, and the differences between some species within subsections are greater than that between subsections, while uniform karyotypes within subsections and variable karyotypes between subsections were observed in six of 13 subsections in sect. Malachobatus represented by 10 taxa. Systematic values of the cytological data were discussed for some cases when applicable to the two sections.  相似文献   

12.
杏属(蔷薇科)一新种   总被引:2,自引:0,他引:2  
发表了蔷薇科杏属的一个新种,即仙居杏(Armeniaca Xianjuxing J.Y.Zhang et Z.X.Wu),其与普通杏(Armeniaca vulgaris Lam.)的区别在于叶片两面具有短柔毛,花梗或果梗长1~1.2 cm,花瓣边缘钝锯齿或小裂片状,萼片边缘有小钝锯齿。  相似文献   

13.
Based on Burtts classification and relevant references, the geographical distribution of the subfamily Cyrtandroideae Endl. emend. Burtt is outlined, distribution maps of 79 genera are provided, and some evolutionary trends of the taxa are inferred. The main points may be summarized as follows:1. The centre of distribution The Cyrtandroideae consists of four tribes, 79 genera and about 1770 species, widely distributed in tropical and subtropical regions of the Old World, ranging from Guinea eastwards to Nukuhiva Islands and from Western Bulgaria southwards to Southern Natal, with only one species disjunctly occurring in tropical America. According to Takhtajans (1978) regionalization of the world flora, and referring to Goods (1974) and Wus (1979) scheme, the distribution patterns of Cyrtandroideae may be generalized as: (1) Pantropics, with 3 genera; (2) Palaeotropics, with 47 genera; and (3) North Temperate, with 27 genera. Tropical Asia (Indo Malaysia) is the centre of variation and diversity of the Cyrtandroideae, where the most primitive taxa, with the chromosome number of n=8 or n=9, and all of the four tribes exist, and where more genera(50) and species (1200 odd) are found than elsewhere. Among the four tribes of the Cyrtandroideae, only two tribes are distributed west of India. Three European genera with six species, confined to the Mediterranean, belong to one tribe, Didymocarpeae. Of 10 African and Madagascar genera, 9(7 endemic) belong to Trib. Didymocarpeae, 1 to Trib. Klugieae, and a11 of 168 African and Mada gascar species are not outside both of these regions. 2. Disjunct distribution and dispersal In Trib. Klugieae, two species of Epithema are found disjunctly in west Africa, and one species of Rhynchoglossum, R. azureum, is disjunct in tropical America, from southern Mexico to northern Peru. Their closely allied species and neighbouring genera are in tropical Asia. Rhynchoglossun azureum has a close relationship with R. notonianum, which is located in India and Sri Lanka, so it is hypothesized that Rhyncho glossum existed in north Africa, where there were tropical rain forests similar to those in Malaysia during the Tertiary. The author noticed that seeds of R. obliquum from tropical areas of southern Yunnan can still germinate after seven months at normal temperature. Most seeds of this genus are not only long lived but very tiny (0.3~0.4 mm long), and can be dispersed by wind or birds (epizoochore through the agency of mucus). One or two species of Rhipsalis in Cactaceae was carried by birds from south America to Madagascar, the Mascarene Islands and Sri Lanka at an early period. This example indicates the possibility of this means of distribution. More than 200 species from the volcanic islands of the Polynesian region, including the Hawaiian Islands,all belonging to Cyrtandra, were obviously spread by birds from tropical Asia during an earllier period. The distribution of two species of Boea and one species of Cyrtandra in northeast Queensland shows that some early taxa of the genera entered Yorke Peninsua from New Guinea when the sea level was lower during the Quaternary glaciations The modern vicarious distribution patterns of the two subfamilies indicate that the main taxa of the family were produced during the course of the continental drift and the climatic and environmental changes. According to the principle of common origin, the ancestor of Gesneriaceae appeared most probably not later than the late Cretaceous, and might be traced back to the Mid Cretaceous. 3. Some problems about evolutionary tendencies In general, the actinomorphic corolla precedes the bilabiate one, and the flower with stamens all fertile precedes those with 1 or 3 staminodes (Ivanina, 1965; Wang, 1989、 1992). In some diandrous genera of Cyrtandroideae, 4 or 5 fertile stamens may occur exceptionally, and are associated with a more or less regular corolla. The exceptional appearances may possibly be atavistic, not representing the main evolutionary tendencies. In the genus Aeschynanthus, pollen grains of Sect. Haplotrichum and Sect. Diplotrichum, whose corollas usually have indistinct bilabiate limbs, are comparatively small, but large in sections Microtrichium, Xanthanthos and Aeschynanthus, whose corollas have distinct bilabiate limbs. 4. The relationships of the four tribes he tribes Cyrtandreae, Trichosporeae and Didymocarpeae are closely related (Kvist and Pedersen, 1986). Some terrestrial plants of Trib. Trichosporeae (e.g.Anna and Lysionotus Sect. Didymocarpoides), in which the seeds have subulate appendages at their ends, may represent the intermediate links between tribes Didymocarpeae and Trichosporea.Boeica and Hexatheca form natural links between the tribes Cyrtandreae and Didymocarpeae. The tribes Didymocarpeae and Klugieae probably originated from a common ancestor at an early stage in the evolution of the family.  相似文献   

14.
Tubificid and enchytraeid oligochaetes are common members of the interstitial fauna of sandy beaches. Their abundance dynamics, life cycles and distribution patterns were investigated at two beaches on the western Baltic Sea and at a North Sea beach (Isle of Sylt). Populations of 115,000 ind./m2 were found at protected Baltic beaches. Reproduction of the tubificids, Phallodrilus monospermathecus and Spiridion insigne takes place within a well defined breeding period once a year. The market horizontal and vertical distribution patterns of various tubificid and enchytraeid species are elucidated by preference reactions to several physiographic parameters, such as oxygen and water content of the sediment, and salinity.  相似文献   

15.
Sequences of the chloroplast ndhF gene and the nuclear ribosomal ITS regions are employed to reconstruct the phylogeny of Prunus (Rosaceae), and evaluate the classification schemes of this genus. The two data sets are congruent in that the genera Prunus s.l. and Maddenia form a monophyletic group, with Maddenia nested within Prunus. However, the ndhF data set is incongruent with the ITS data supporting two major groups within Prunus one consisting of subgenera Laurocerasus (including Pygeum) and Padus as well as the genus Maddenia and another of subgenera Amygdalus, Cerasus, and Prunus. The ITS data, on the other hand, support a clade composed of subgenera Amygdalus and Prunus and Prunus sect. Microcerasus in addition to a paraphyletic grade of subgenera Laurocerasus and Padus (and the genus Maddenia) taxa. In general, the subgeneric classifications of Prunus s.l. are not supported. The ITS and ndhF phylogenies differ mainly in interspecific relationships and the relative position of the Padus/Laurocerasus group. Both ITS and ndhF data sets suggest that the formerly recognized genus Pygeum is polyphyletic and that the distinction of the subgenera Padus and Laurocerasus is not supported. The biogeographic interactions of the temperate and tropical members in the Padus/Laurocera- sus/Maddenia alliance including Pygeum are shown to be highly dynamic and complex.  相似文献   

16.
The Cyathocotylidae is a globally distributed family of digeneans parasitic as adults in fish, reptiles, birds and mammals in both freshwater and marine environments. Molecular phylogenetic analysis of interrelationships among cyathocotylids is lacking with only a few species included in previous studies. We used sequences of the nuclear 28S rRNA gene to examine phylogenetic affinities of 11 newly sequenced taxa of cyathocotylids and the closely related family Brauninidae collected from fish, reptiles, birds and dolphins from Australia, Southeast Asia, Europe, North America and South America. This is the first study to provide sequence data from adult cyathocotylids parasitic in fish and reptiles. Our analyses demonstrated that the members of the genus Braunina (family Brauninidae) belong to the Cyathocotylidae, placing the Brauninidae into synonymy with the Cyathocotylidae. In addition, our DNA sequences supported the presence of a second species in the currently monotypic Braunina. Our phylogeny revealed that Cyathocotyle spp. from crocodilians belong to a separate genus (Suchocyathocotyle, previously proposed as a subgenus) and subfamily (Suchocyathocotylinae subfam. n.). Morphological study of Gogatea serpentum indicum supported its elevation to species as Gogatea mehri. The phylogeny did not support Holostephanoides within the subfamily Cyathocotylinae; instead, Holostephanoides formed a strongly supported clade with members of the subfamily Szidatiinae (Gogatea and Neogogatea). Therefore, we transfer Holostephanoides into the Szidatiinae. DNA sequence data revealed the potential presence of cryptic species reported under the name Mesostephanus microbursa. Our phylogeny indicated at least two major host switching events in the evolutionary history of the subfamily Szidatiinae which likely resulted in the transition of these parasites from birds to fish and snakes. Likewise, the transition to dolphins by Braunina represents another major host switching event among the Cyathocotylidae. In addition, our phylogeny revealed more than a single transition between freshwater and marine environments demonstrated in our dataset by Braunina and some Mesostephanus.  相似文献   

17.
Apomixis in Crataegus is primarily aposporous and requires pollination. The embryo sac is of the Polygonum type. A combination of meiotically unreduced embryo sacs with apparently reduced pollen would violate the usual requirement for a 2 : 1 ratio of maternal to paternal contributions to the endosperm. We therefore investigated the origin of endosperm in seeds of sexual diploids and apomictic polyploids of the sister genera Crataegus and Mespilus. Flow-cytometric DNA measurements from embryo and endosperm in mature seeds were converted to ploidy levels using leaf-tissue information. The diploids had triploid endosperm. In c. 60% of seed from polyploids, one sperm apparently contributes to the endosperm, while 25% or more may involve two sperm. Additional results suggest that trinucleate central cells also occur. Fertilization of meiotically unreduced eggs is indicated. The ratio of maternal to paternal contributions to the endosperm in these apomictic Crataegus is not constrained to 2 : 1. They thus resemble some Sorbus (Pyreae) and very distantly related Ranunculus (Ranunculaceae). It is suggested that Paspalum (Poaceae) may have similarly flexible endosperm ploidy levels.  相似文献   

18.
Abstract

Across 64 sites 8 species were found, with Clarkus propapillatus at 60 sites, C. composticola at 7, Prionchulus muscorum at 3, Mylonchulus ubis at 7, M. sigmaturus at 1, Cobbonchus australis at 9, lotonchus basidontus at 4, and I. stockdilli n. sp. at 3 sites. Sampling effort varied at the sites and significant annual and management effects have previously been reported on mononchid populations. No clear geographic or soil factor is apparent in the distributions, but more species may occur at sites with higher annual rainfall. lotonchus stockdilli n. sp. is a large (female L = 3.05–5.90 mm), bisexual species with dorsal tooth at the posterior of the sclerite, female tail about 400 μm or 14%, and no cuticular pores in the vulval region.  相似文献   

19.
为了探索我国梨属植物资源种类、分布及传播途径,本研究选择与陆地隔离的山东省长岛县为调查地域,对该地域梨属植物资源进行了实地调查和遗传分析。结果表明,长岛县梨属植物资源较为丰富,主要有杜梨、豆梨、沙梨等种类,变异类型较多,并发现一种特异类型;野生资源主要分布在山脊和半山腰,较为集中,且在小范围内能够发现多种资源类型。遗传分析结果显示,长岛梨属植物资源与邻近陆地资源关系较近。通过田间果实调查证实,鸟类吃食梨属植物,推定鸟类在梨属植物资源传播中可能充当一定的角色,这为进一步了解我国梨属植物的资源分布及演化提供了新的研究思路。  相似文献   

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