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1.
中国大蒜芥族植物花粉形态的研究   总被引:1,自引:0,他引:1  
对中国大蒜芥族10属14种植物花粉形态分别进行了光镜和扫描电镜下的观察研究。结果表明该族花粉形态可划分为4种类型:(1)具3沟,超长球形,网状纹饰,外壁2层;(2)具3沟,超长球形,细网状纹饰,外壁1层;(3)具3沟(偶4沟),长球形,网状纹饰,外壁2层;(4)具6沟,长球形,网状纹饰,外壁2层。因此,中国大蒜芥族的花粉形态多样性程度较高,说明了它不是一个自然类群,是一个多系类群,这与前人研究结果相一致。另外,本文首次报道十字花科锥果芥属植物具6沟花粉,具6沟花粉在十字花科中极为特殊,所以作者将锥果芥属提升为族级,另立新族,即锥果芥族(Tribe Berteroelleae F.Z.Li,G.Y.Tang & Z.Y.Sun,trib.nov.)。  相似文献   

2.
牛奶菜族7属11种植物的花粉器形态   总被引:1,自引:0,他引:1  
在光学显微镜和扫描电子显微镜下观察了萝藦科(Asclepiadaceae R.Br.)牛奶菜族(MarsdenieaeBenth.)7属11种植物花粉器的形态特征。该族植物花粉块直立或平展,通常呈椭圆形、长圆形、肾形或球形;花粉块膜表面平滑、波浪状、脊状或粒状;娃儿藤属(TylophoraR.Br.)的花粉块膜具独特的表面纹饰,与其它属植物差异较大;匙羹藤属和娃儿藤属的花粉块柄不发达,眼树莲属(Dischidia)和纤冠藤属(Gongronema)的花粉块柄发达。  相似文献   

3.
12种十字花科植物花粉形态研究   总被引:1,自引:0,他引:1  
采用扫描电子显微镜对十字花科8属12种植物的花粉形态特征进行了观察分析.其中8种为首次报道.观察结果表明:4族8属12种十字花科植物花粉形态的一般特征为:花粉粒长球形至超长球形;极面观三裂圆形,少数四裂圆形;外壁纹饰为网状或细网状纹饰;三沟,偶四沟.12种植物的花粉可划分为5种类型:(1)花粉粒长球形,网状纹饰,三沟;(2)花粉粒超长球形,网状纹饰,三沟;(3)花粉粒长球形,细网状纹饰,三沟;(4)花粉粒超长球形,细网状纹饰,三沟;(5)花粉粒长球形,三或四沟,网状纹饰.十字花科花粉形态特征在不同族间、不同属间以及同属不同种间均没有明显规律,在十字花科分类过程中,不宜单独以花粉形态特征作为依据.  相似文献   

4.
中国紫草科紫草亚科琉璃草族花粉形态的研究   总被引:6,自引:2,他引:4  
对中国紫草科Boraginaceae 紫草亚科Boraginoideae琉璃草族Trib.Cynoglosseae 7属16种的花粉形态进行了光学显微镜和扫描电镜观察,并对其中5种的花粉外壁超微结构进行了透射电镜观察。该族花粉为茧形,少数为近长球形、长球形或卵球形;体积很小,大小为7~15.7μm×3.5~13.9μm,P/E=1.6~2.02;三孔沟和三假沟相间排列;除斑种草属Bothriospermum Bge.外,均有赤道环带;外壁常光滑,两极具或不具穿孔,少数具小瘤状纹饰;外壁较薄,包括外壁外层和外壁内层,外壁外层又由完全覆盖层、柱状层和基层组成。以上表明该族花粉有很多共同特征,但属之间还是有区别。文中作了花粉分属检索表。在该族中,斑种草属的花粉没有赤道环带,表明它是比较原始的类群。它和齿缘草族的花粉更相似,因此把它放在齿缘草族Trib.Eritrichieae比放在琉璃草族似乎更合适。长蕊琉璃草属SolenanthusLedeb.由于花粉卵球形、亚等极,可认为是琉璃草族中最进化的属。  相似文献   

5.
中国蒿属植物比较形态和解剖学研究 Ⅱ花粉形态   总被引:7,自引:0,他引:7  
本文通过光学显微镜和扫描电镜,观察国产菊科蒿属2亚属7组58种代表物的花粉形态,结合有关资料以及菊科12族,30属代表植物花粉作比较,分析研究,取得以下结果:1.蒿属的花粉特征具有高度的一致性。主要体现在:花粉呈球形或近球形,极面观的三形圆形,赤道面观为圆形或椭圆形。  相似文献   

6.
须芒草族植物花粉形态的观察   总被引:2,自引:1,他引:1  
在光学显微镜下和扫描电镜下对禾本科须芒草族(Andropogoneae)中分隶于8个亚族34个属的36种植物的花粉进行形态面容和比较研究。结果显示,本族植物花粉形态较为一致,花粉近形或扁球形,单萌发孔,孔,周围加厚,具盖,外壁表面散布有颗粒。这表明其是一个自然类群。总体来讲,芬烨大的演化分异,只是表面纹饰的和芬烨大小有一;定的差异。纹饰可分为三种类型粗糙型,不明显疠状突起才明显疠状突起型。花粉开矿  相似文献   

7.
在扫描电子显微镜下,对豆科土儿属(Ap ios)和旋花豆属(Coch lianthus)7个种植物的花粉进行了观察.结果表明,2个属的花粉均为三孔沟,形状为三角球形或球形.土儿属的花粉可划分为2种类型:肉色土儿(A.carnea)的花粉外壁为典型的网状纹饰,其它种的花粉外壁较光滑,具颗粒状或短条纹状纹饰,研究结果不支持土儿属下亚属的划分;肉色土儿花粉外壁的网状纹饰式样可能反映了其在土儿属中处在较进化的位置.土儿属东亚分布种的花粉类型较为多样,原始和进化2种类型并存,表明东亚可能是土儿属的起源地和演化中心.旋花豆属的花粉特征和肉色土儿相似,说明两者之间的亲缘关系可能较近.  相似文献   

8.
应用光镜和扫描电镜对山东菊科莴苣亚族11属18种、1变种植物的花粉形态进行了观察研究。结果表明:莴苣亚族植物的花粉呈球形,具3~4沟孔,花粉表面具有网状纹饰,粗网眼15~21个,网脊上具1行刺,属于蒲公英(Taraxacum)型,与已报道的莴苣亚族其它属种的花粉形态相一致。通过莴苣亚族属间花粉形态的比较,认为花粉形态在属间分类上意义不大。  相似文献   

9.
蜘蛛抱蛋亚族的花粉形态   总被引:6,自引:0,他引:6  
本文研究并报道了百合科蜘蛛抱蛋亚族的花粉形态,主要结论如下:1.开口箭属含两种花粉类型即:(1)单槽、椭圆形;(2)无萌发孔、球形。具单槽、椭圆形花粉的种类含单型性核型,花形较小,柱头小而花柱短,雄蕊高于柱头;无萌发孔、球形花粉的种类则为单型性核型,花形较大,柱头常高度膨大,雄蕊常着生在花被筒基部。2.万年青属花粉为椭圆形,具单槽;蜘蛛抱蛋属花粉则为球形,无萌发孔;开口箭属花粉一部分与万年青属相似,另一部分则与蜘蛛抱蛋属雷同。3.蜘蛛抱蛋亚族中最原始的花粉类型为单槽椭圆形,具孔状或网状外壁纹饰。球形,无萌发孔,外壁具皱波状、瘤状或芽孢状纹饰的花粉为派生类型。4.蜘蛛抱蛋亚族种下花粉形状、萌发孔类型和外壁纹饰基本稳定,可作为分种特征。  相似文献   

10.
槭树科花粉形态及其系统学意义   总被引:10,自引:1,他引:9  
报道了槭树科(Aceraceae)槭属21组33种和金钱槭属2种植物的花粉形态。本科花粉近球形至长球形,极面观为三裂圆形。从花粉萌发孔类型看,金钱槭属Dipteronia具三孔沟,槭属(Acer)除4组具三孔沟外,其余均为三沟。从花粉外壁纹饰看,金钱槭属2个种和槭属的大多数种为条纹状,罕为细条纹-拟网状和皱波状。通过花粉形态分析,并结合其它方向的证据,我们认为:(1)Sect.Palmata,Sect.Spicata和Sect.Microcarpa可能是槭属中与金钱槭属关系最密切的类群;(2)A.distalum和A.nipponicum代表了近缘的两个单种组;(3)A.pseudoplatanus不同于Sect.Acer的其它4个种而与A.saccharum可能存在更为密切的关系;(4)Sect.Carpinifolia(细条纹-拟网状外壁纹饰)和Sect.Negundo(皱波状外壁纹饰)则可能代表了槭属中最特化的类群;(5)按槭树科花粉三孔沟到三沟的演化规律,Dipteronia较Acer原始。  相似文献   

11.
All taxa endemic to the Qinghai-Tibet Plateau are hypothesized to have originated in situ or from immediately adjacent areas because of the relatively recent formation of the plateau since the Pliocene, followed by the large-scaled biota extinction and recession caused by the Quaternary ice sheet. However, identification of specific progenitors remains difficult for some endemics, especially some endemic genera. Nannoglottis, with about eight species endemic to this region, is one such genus. Past taxonomic treatments have suggested its relationships with four different tribes of Asteraceae. We intend to identify the closest relatives of Nannoglottis by evaluating the level of monophyly, tribal delimitation, and systematic position of the genus by using molecular data from ndhF gene, trnL-F, and ITS region sequences. We find that all sampled species of Nannoglottis are a well-defined monophyly. This supports all recent taxonomic treatments of Nannoglottis, in which all sampled species were placed in one broadly re-circumscribed genus. Nannoglottis is most closely related to the Astereae, but stands as an isolated genus as the first diverging lineage of the tribe, without close relatives. A tentative relationship was suggested for Nannoglottis and the next lineage of the tribe was based on the ITS topology, the "basal group," which consists of seven genera from the Southern Hemisphere. Such a relationship is supported by some commonly shared plesiomorphic morphological characters. Despite the very early divergence of Nannoglottis in the Astereae, the tribe must be regarded to have its origin in Southern Hemisphere rather than in Asia, because based on all morphological, molecular, biogeographical, and fossil data, the Asteraceae and its major lineages (tribes) are supposed to have originated in the former area. Long-distance dispersal using Southeast Asia as a steppingstone from Southern Hemisphere to the Qinghai-Tibet Plateau is the most likely explanation for this unusual biogeographic link of Nannoglottis. The 23-32-million-year divergence time between Nannoglottis and the other Astereae estimated by DNA sequences predated the formation of the plateau. This estimation is further favored by the fossil record of the Asteraceae and the possible time of origin of the Astereae. Nannoglottis seems to have reached the Qinghai-Tibet area in the Oligocene-Eocene and then re-diversified with the uplift of the plateau. The molecular infragenetic phylogeny of the genus identifies two distinct clades, which reject the earlier infrageneric classification based on the arrangement of the involucral bracts and the length of the ligules, but agree well with the habits and ecological preferences of its current species. The "alpine shrub" vs. "coniferous forest" divergence within Nannoglottis was estimated at about 3.4 million years ago when the plateau began its first large-scale uplifting and the coniferous vegetation began to appear. Most of the current species at the "coniferous forest" clade of the genus are estimated to have originated from 1.02 to 1.94 million years ago, when the second and third uprisings of the plateau occurred, the climate oscillated and the habitats were strongly changed. The assumed evolution, speciation diversity, and radiation of Nannoglottis based on molecular phylogeny and divergence times agree well with the known geological and paleobotanical histories of the Qinghai-Tibet Plateau.  相似文献   

12.
This paper describes for the first time the karyomorphology of 4 populations of 2 species of Nannoglottis Maxim. s. l. The two species both show the resting nuclei of the complex chromocenter type and the mitotic prophase chromosomes of the interstitial type. The karyotype formula of N. gynura is 2n = 18 = 14m + 2sm + 2st(SAT) in two populations while that of N. carpesioides is 2n = 18 = 14m + 2sm(2SAT) + 2st in two populations. The two species under study represent two sections of Nannoglottis s. l. N. gynura, the only species of sect. Stenolepis, is considered as the most primitive member of the genus. Accordingly, the basic chromosome number of the genus might be x=9. Karyomorphological data indicate that Nannoglottis should be placed in the tribe Astereaerather than in the Inuleae and the Senecioneae.  相似文献   

13.
毛冠菊属系统位置的核形态证据   总被引:3,自引:2,他引:1  
首次记载了毛冠菊属2种4居群的核形态资料。两种植物的染色体间期和前期染色体为复杂型 和中间型。狭舌毛冠菊两居群的染色体数目与核型公式为2n=18=14m+2sm+2st(2SAT);毛冠菊两居 群的染色体数目与核型公式为2n=18=14m+2sm(2SAT)+2st。它们分别代表了整个毛冠菊属的两组 植物,并包含了形态学上最原始的种类,因此,该属的染色体基数可能为x=9。核形态证据表明毛冠菊属放在紫菀族比放在旋覆花族和千里光族中更为合理。  相似文献   

14.
The Guyana Highland-centred genera, or Stenopadus group, are a complex of species that belong to the tribes Mutisieae and Stifftieae of Asteraceae. The pollen morphologies of 29 species, from 12 of 13 genera of this complex, are described and illustrated using light and scanning electron microscopy. The exine sculpture and structure are highly significant. Four exine types, previously characterized, were distinguished: Gongylolepis , Wunderlichia , Mutisia , and Stenopadus . The characterization of the Stenopadus exine type is enlarged here. These exine types led to the recognition of four well-defined pollen types, whereas the spine length and exine thickness characterized six subtypes. Pollen types circumscribe genera or groups of genera, and some subtypes distinguish species. The pollen morphology within the complex is discussed in relation to the rest of Mutisioideae and other palynologically allied tribes of Cichorioideae. There is little correlation between pollen types and tribes; only the Stenopadus exine type is exclusive to the Stifftieae tribe. The remaining types are shared by the two tribes of the complex. Pollen morphology supports the hypothesis that this group of genera is close to the Gochnatia complex and the Cardueae tribe.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 327–340.  相似文献   

15.
在扫描电镜下观察了毛冠菊属Nannoglottis 8种植物舌片的微形态特征,以探讨其颇有争议的系统位置。所有种类舌片近轴面的细胞为板状,长圆形;径向、切向壁直;外壁特征性突起,外壁中央为纵向皱纹,相邻细胞之间的纹饰无系统连接。这些特征表明毛冠菊属和紫菀族Astereae关系密切,但它在紫菀族内的系统位置可能比较特殊。这些结果和依据ITS序列推测的紫菀族系统发育的结果相吻合。文中还讨论了一些微形态性状的演化趋势以及微形态性状在毛冠菊属部分种类分类中的应用。  相似文献   

16.
Pollen morphology of 15 species of Siphonoglossa and of two closely related groups was investigated. Two tribal-specific pollen types are found within Siphonoglossa sensu lato suggesting that the genus is artificial, composed of taxa belonging in several genera among two tribes (subtribes sensu Bremekamp) of Acanthaceae. Five taxa currently included in an informal subgeneric category of Siphonoglossa have tricolporate, prolate pollen (termed Type I) that is characteristic of Odontonemeae (= Odontoneminae, Justicieae). Pollen of the remaining taxa, belonging in two formal sections of the genus, are mostly 2-porate, bilateral (Type II) with a sexine sculpturing characteristic of Justicieae (= Justiciinae). Pollen of section Siphonoglossa is rather uniform, 2-porate, bilateral with lolongate pores, and seem to delimit a natural group. Taxa of section Pentaloba have a more heterogeneous pollen morphology, mostly 2-porate, bilateral with lalongate pores. Controversial aspects of the interpretation of pollen morphology in Justiciinae are presented and their relevance to this study are examined. Hypothetical trends in the evolution of pollen of Justiciinae are discussed and the application of pollen morphology to taxonomy of the genus is presented, including a recommendation for narrowing the generic concept of Siphonoglossa to the taxa of the type section.  相似文献   

17.
利用光学显微镜和扫描电镜观察了伞形科东俄芹属(TongoloaH.Wolff)7个种的花粉形态,结果表明:除宜昌东俄芹T.dunnii(Boissieu)H.Wolff和城口东俄芹T.silaifolia(Boissieu)H.wolff的花粉为矩形类型外,其它几种的为菱形类型,然而并非都是原始的或典型的菱形,而是处于分化过程中的菱形类型,如纤细东俄芹T.gracilisH.Wolff,大东俄芹T.elataH.Wolff的花粉形态,表现出近菱形、近椭圆形和近矩形的特征,在我们近期的工作中曾涉及滇芎属PhysospermopsisH.Wolff类似的花粉形态及分化情况,从花粉资料启示,东俄芹属可能与滇芎属近缘。  相似文献   

18.
A wide range of transitional forms of granular interstitia from simple to complex and from random to ordered occur in the pollen of the subfamily Papilionoideae. Three main types are described: 1) large, widely spaced irregular granules (Type A); 2) densely packed groups of columellae and granules (Type B); and 3) a mass of more or less disorganized granules (Type C). In the genus Calopogonium (tribe Phaseoleae) all three types have been found in different species. Two of the types have been found in different species of the genus Psoralea (tribe Psoraleeae). Granular structures so far occur in six tribes: Desmodieae, Indigofereae, Loteae, Phaseoleae, Psoraleeae, and Vicieae. All of the tribes are regarded as being evolutionarily advanced in both macro and micro characters and many, but not all, show specialized pollen characters. It is concluded that the granular interstitium is a derived structure in papilionoid legumes.  相似文献   

19.
锦鸡儿属花粉形态及其分类意义   总被引:15,自引:2,他引:13  
在光学显微镜和扫锚电镜下对锦鸡儿属31种2变种植物花粉形态进行了观察。根据外壁表面纹饰,可分:类型I,表面具小穿孔;类型II, 具网状纹饰。 在类型II中据网眼大小和网脊宽度特征又分为两个亚类型。 根据花粉体积大小,可分4个类型。本属植物花粉形态较为一致,表明是一个自然类群。组、 系的花粉形态特征与一般形态变异不一定相对应,即形态上有明显区别的种类,在花粉形态上未必有很大区别,仅一些种类及矮锦鸡儿系 Ser. Pygmaeae的花粉形态相近。 本属花粉形态在种下等级的变异, 特别是青藏高原分布的种类的变异较为明显,例如 C.bicolor,C. jubata,C. erinacea 与各自的近缘种类。花粉形态为分类处理提供了参考。本属植物花粉形态是从表面具小穿孔向具网状纹饰演化,对应于羽状叶类群向掌状叶类群演化。  相似文献   

20.
The genus Krameria is currently recognized as an enigmatic, monotypic family of dicotyledons. Previous studies of morphology, anatomy, and cytology have been unable to establish unequivocably its phyletic affinities. We report here the results of an intensive investigation of the pollen of Krameria using light, scanning electron (SEM), and transmission electron microscopy (TEM). Pollen characteristics of the genus were compared to those of all families referred to the Polygalales and to selected species of the Leguminosae-Caesalpinoideae, both groups with which Krameria has historically been allied. Superficially, the pollen of Krameria resembles that of the legumes more than that of genera in the Polygalales. However, in ultrastructure, it differs from the pollen of all taxa investigated from both groups. Within Krameria, several variations of a basic type of 3-colporate pollen are discernible. Species with similar pollen variants appear, on the basis of other morphological data, to represent natural groups within the genus. Nevertheless, an arrangement of groups of species of Krameria from “least” to “most” specialized, based on a logical sequence of modification of the pollen morphology, does not agree with any sequence of specialization using other morphological or ecological characters. It is concluded that pollen morphology and ultrastructure has systematic value for intrafamilial groupings of the Krameriaceae but that palynological modifications are incongruous with trends of specializations of other characters and, like many other lines of investigation, pollen studies do not provide significant data as to the phylogenetic affinities of the family.  相似文献   

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