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1.
Spores of 61 species and 6 varieties in 9 genera of the Sinopteridaceae were examined under scanning electron microscope (SEM). Based on surface ornamentation and other features, the spores of the Sinopteridaceae are divided into three types. In type Ⅰ , the exospore is smooth and the surface ornamentation, which is reticulate, cristate, echinate or rugate, is formed by the perispore. All the other genera of this family, except for Onychium and Cryptogramma, have this pattern of spores. In type Ⅱ, the surface ornamentation is formed by both perispore and exospore. This pattern is found only in Cryptogramma. In type Ⅲ, the perispore is thin and the surface ornamentation is formed by the exospore. Onychium is characterized by this type of spores. Those genera with spores of type Ⅰ of the Sinopteridaceae seem to be closely related to each other and should be natural members of this family. The systematic position of Cryptogramma and Onychium, with spores of type Ⅱ and type Ⅲ respectively, however, should be reconsidered. Aleuritopteris might be the mostprimitive member of the Sinopteridaceae from the evidence of spore morph  相似文献   

2.
Kengyilia melanthera (Keng)J. L. Yang, Yen et Baum and K. kokonorica (Keng)J. L. Yang, Yen et Baum are two hexaploid perennial grasses of the tribe Triticeae native in west China. K. melanthera and K. kokonorica were hybridized with Roegneria kamoji Ohwi(2n=42,StStHHYY) and K. hirsuta (Keng)J. L. Yang, Yen et Baum (2n = 42, PPStStYY) respectively. Chromosome pairing behaviour at metaphase I in the parents and hybrids was studied. Meiotic configurations were 18.20 Ⅰ + 11.74 Ⅱ + 0.09 Ⅲ + 0.01V for R. kamoji×K. melanthera, 1.06Ⅰ + 20.47 Ⅱ for K. hirsuta×K. melanthera, 19.36Ⅰ + 11.26 Ⅱ + 0.04Ⅲ for R. kamoji×K. kokonorica, and2.46Ⅰ + 19.44Ⅱ + 0.14 Ⅲ + 0.06 Ⅳ for K. hirsuta×K. kokonorica. Considering chromosome pairing in the hybrids, as well as morphological characters, K. melanthera and K. kokonorica should be grouped in Kengyilia Yen et J. L. Yang instead of being keeped inRoegneria sect. Paragropyron Keng , or in Elymus L. or Elytrigia Desv.  相似文献   

3.
The distribution density of oil cells, the morphology and structure of both oil and mucilage cells, and their localization in the mesophyll of 112 species, 5 varieties and 2 forms in 21 genera of the Lauraceae are comparatively studied with the methods of tissue clearing and paraffin sectioning. The results show that there exist obvious differences of the distribution density of oil cells among the species in the Lauraceae. The presence of oil cells and mucilage cells is found to be a marked anatomical feature of the leaves in most of the plants in the Lauraceae. Their distribution in the mesophyll can be divided into 4 types: type Ⅰ , in which only oil cells are present; type Ⅱ, in which both the oil and mucilage cells are present; type Ⅲ, in which only mucilage cells are present; type Ⅳ, in which neither oil cells nor mucilage cells are present. The distribution density of oil cells, the distribution types of oil cells and mucilage cells and their localization in the mesophyll are of some taxonomic value at the specific level in the Lauraceae. In the whole Lauraceae or in some large genera, the evolutionary trend of the distribution types of oil cells and mucilage cells might be as follows: type Ⅰ → type Ⅱ →type Ⅲ →type Ⅳ. The characteristics of the 4 distribution types of oilcells and mucilage cells support the division of two subfamilies in the Lauraceae.  相似文献   

4.
荞麦及其野生种遗传多样性分析   总被引:2,自引:0,他引:2  
荞麦起源于我国西南地区,该地区分布有大量荞麦地方品种和野生近缘种。本研究利用SSR分子标记,对从我国西南地区收集的81份荞麦及其野生资源进行遗传多样性分析。结果显示,利用19对SSR引物共检测出84个等位基因,每对SSR引物平均扩增出4.421个等位基因,19对SSR引物的平均Shannon's信息指数为0.985,平均PIC为0.478。81份荞麦及其野生资源的相似系数范围为0.500~1.000,分析发现大粒组荞麦种(甜荞及其近缘种、苦荞及小米荞、金荞)与小粒组硬枝万年荞亲缘关系比较近。通过聚类分析在遗传相似系数为0.732时,可将81份荞麦种质分为4个类群,第Ⅰ类由小粒组齿翅野荞、细柄野荞、小野荞麦、疏穗小野荞麦和硬枝万年荞组成;第Ⅱ类由甜荞和甜荞近缘种组成;第Ⅲ类都是由金荞组成;第Ⅳ类是由苦荞和小米荞组成。在遗传系数为0.920时,小粒组荞麦种可以明显区分出疏穗小野荞麦、硬枝万年荞、齿翅野荞及其细柄野荞。研究表明,19对SSR引物多态性较高,能较好反应荞麦及其野生种质的遗传多样性,本研究的结果为荞麦属种之间的亲缘关系分析和荞麦起源进化研究提供科学依据。  相似文献   

5.
荞麦起源于我国西南地区,该地区分布着丰富的荞麦野生种,剖析野生荞麦的核型特征对荞麦进化和育种研究具有重要的意义。本研究以甜荞近缘种、硬枝万年荞、疏穗小野荞、细柄野荞、齿翅野荞为试验材料,采用常规压片法进行核型鉴定。结果表明:甜荞近缘种、硬枝万年荞和疏穗小野荞都为二倍体,核型公式分别为2n=2x=16=12M+4m(2SAT)、2n=2x=16=16M、2n=2x=16=14M+2m(2SAT),而细柄野荞和齿翅野荞为四倍体,核型公式分别为2n=4x=32=32M、2n=4x=32=30M+2m(2SAT)。甜荞近缘种和硬枝万年荞核型属1A型,疏穗小野荞、细柄野荞和齿翅野荞核型属1B型,并且甜荞近缘种、疏穗小野荞和齿翅野荞都有1对随体染色体。研究证明,荞麦野生种染色体的基数为8,有二倍体和四倍体野生荞麦。通过比较分析,硬枝万年荞在进化地位上比较原始,齿翅野荞是比细柄野荞较进化的四倍体荞麦野生种。  相似文献   

6.
Spore morphology of 51 species of Cyclosorus in the Thelypteridaceae from China was investigated using scanning electron microscopy (SEM). The spores are monolete, bilaterosymmetric, ellipsoidal in polar view, and kidney-shaped in equatorial view. On the basis of the variation in their surface ornamentation, the spores fall into three main types. Type I: The surface of spores is echinate or perforate with fimbriate wings. 19 species belong to this type. Type Ⅱ: The surface of spores is cristate. 11 species belong to this type. Type Ⅲ: The surface of spores is echinulate. 10 species belong to this type. The remaining 11 species have spores with mixed surface ornamentation of the above three types, which are considered as intermediate types. The results are valuable for a better understanding of the taxonomy and palynology of the genus Cyclosorus.  相似文献   

7.
The structure, type, morphology and location of secretory structures in leaves of 43 species, 1 subspecies and 1 variety of 9 sections in Hypericum L. were comparatively studied using tissue clearing, paraffin sectioning and thin sectioning. The results have shown that the presence of secretory structures is a common feature of leaves in this genus. According to their anatomical characteristics, the secretory structures can be divided into nodules, secretory cavities (canals) and tiny secretory tubes. In their distribution in leaves the nodules fall into two types: the leaf edge type and the scattered type. According to the location of cavities in the cross sections of leaves, the cavities can be divided into 4 types: the median type which is situated between the palisade tissue and spongy tissue, the palisade tissue type, the spongy tissue type and the across-mesophyll type. Based on the location of cavities and nodules in leaves, the species in Hypericum can be divided into 3 groups: group Ⅰ , in which only cavities are present; group Ⅱ, in which only nodules are present; group Ⅲ, in which both cavities and nodules are present. The type, location, distribution density and morphology of secretory structures are of some taxonomic value at the level of species and of section in Hypericum L. From these observations, the evolutionary trends concerning the morphology and anatomy of secretory structures and the affinity among sections in the genus Hypericum ate dis-cussed.  相似文献   

8.
The arbitrarily primed polymerase chain reaction(AP-PCR) technique was applied to the analysis of the phylogenetic relationships among species of Chinese Sagittaria except S. natans which is not included in this study. One hundred and twenty-seven polymorphism DNA fragments were generated by ten arbitrarily primers and used to calculate the genetic distance. A phylogenetic dendrogram was constructed based on genetic distance by UP-GMA method. The results show that Chinese Sagittaria can be divided into three groups, which are composed of seven species and three varieties or forms except S. natans. Thethree groups are: group I ,with only one species S. guayanensis; group Ⅱ ,composed of S. tengtsungensis, S. wuyiensis, S. lichuanensis and Segittaria sp.; group Ⅲ, S. potamogetifolia, S. pygmaea, S. trifolia var. trifolia, S. trifolia var. sinensis, S. trifolia f. longiloba. Results of the present study are congruent with those based on morphologi-cal and karyotypical ones.  相似文献   

9.
The intergeneric hybrids between Roegneria kamoji Ohwi and Dasypyrum villosum (L.)Candargy were successfully obtained by means of embryo culture in vitro. Studies on morphology, fertility and chromosome pairing behavior in meiosis of the parents and their hybrid Fl were carried out in the present work. The results showed that: (1) there were ob vious morphological differences between R. kamoji and D. villosum, and spikes of Fl plants were morphologically intermediate between the two parental species; (2) the seed set of the cross was 11.63%; the hybrid plant was infertile, which indicated that strong repro ductive isolation existed between the parents and R. kamoji and D. villosum were inde pendent biological species; (3) The somatic chromosome number in root-tips of Fl hybrids was 28. Chromosome pairing at MI of PMCs in Fl hybrids was quite low. The meiotic con figuration was 26.72 Ⅰ + 0.62 Ⅱ + 0.02 Ⅲ, which indicated that very low homoeology was detected between the St, H, Y genomes of R. kamoji and the V genome of D. villo- sum, and the relationship between the parental species was remote.  相似文献   

10.
Gross morphology, fruit anatomy, tepal venation, pollen morphology, chromosome number and ITS sequence of Pteroxygonum Damm. & Diels as well as other related genera (Polygonum, Fallopia, Reynoutria, Fagopyrum, and Antenoron) have been investigated to evaluate the generic status of Pteroxygonum. Pt. giraldii Damm. & Diels has three sharp horns at the base of fruit, which is distinctive among all the genera investigated. Upon observation of fruits under a light microscope (LM), the exocarp of Pt. giraldii is usually thickened and delimited by the rectangular cells with some sporadic undulating lumen, while that of Fagopyrum is thin-walled and isodiametric to rectangular in the cell shape. Analysis of tepal venation was performed under a stereomicroscope, and two types of tepal venation were found in Fagopyrum and Pteroxygonum. The type I is trifid, observed in Pt. giraldii, F. esculentum Moench, F. dibotrys (D. Don) Hara and F. tataricum (L.) Gaertn. The type II, found in F. caudatum (Sam.) A. J. Li, F. urophyllum (Bur. & Franch.) H. Gross and F. gracilipes (Hemsl.) Damm. ex Diels, has the main vein extending from tepal base with some secondary veins. Evidence from tepal venation supports the previous classification in which Fagopyrum can be divided into a large-achene group and a small-achene group. Pollen morphology was investigated under a scanning electron microscope (SEM). The exine ornamentation of Pt. giraldii was finely reticulate with lumina diameter wider than muri width. The exine ornamentation in all the examined Fagopyrum species is, however, prominently sunken punctuate. The phylogenetic analysis of nuclear ribosomal DNA (nrDNA) ITS sequences in Pteroxygonum and related genera indicated that all the species form a well-supported monophyletic group with two clades. One includes Polygonum sect. Avicularia Meisn., genus Fallopia and genus Reynoutria, and the other consists of other sections of Polygonum, genus Fagopyrum and Pteroxygonum. The latter clade can be divided into two subclades. Fagopyrum species compose the first one, while Pteroxygonum giraldii, species of Polygonum (except sect. Avicularia) and Antenoron form the second one. In consideration of the above evidence, we conclude that Pteroxygonum is an independent genus in tribe Persicarieae, and should not be merged into the genus Fagopyrum.  相似文献   

11.
通过对翼蓼Pteroxygonum giraldii Damm. &; Diels及相关属(蓼属Polygonum、何首乌属Fallopia、虎杖属Reynoutria、荞麦属Fagopyrum和金线草属Antenoron)的形态观察、果实解剖学观察、花被片脉序观察、花粉形态、核型分析, 以及ITS序列的分析确定了翼蓼和荞麦F. esculentum Moench较远的亲缘关系。其中我们发现翼蓼果实基部有三个角状物明显不同于其他属果实的形态特征。翼蓼外果皮明显加厚, 并有零星散布的波状内腔, 而荞麦的外果皮很薄, 细胞不等径, 中果皮极厚。以上证据证明了翼蓼与荞麦属亲缘关系较远。在观察荞麦属和翼蓼的花被片脉络时发现了两种不同的脉序类型, 符合将荞麦属分为两个组的划分。翼蓼花被片脉序为三出状, 支持将翼蓼归为Persicarieae族。对翼蓼及荞麦属植物的花粉进行比较后, 发现荞麦属植物的花粉网孔有明显的内凹穿孔而翼蓼却没有, 结果表明二者亲缘关系较远。通过对nrDNA ITS区域序列分析得出翼蓼及相关属为一个单系类群, 含有两个稳定的分支: 第一个分支由蓼属(萹蓄组sect. Avicularia)、何首乌属、虎杖属的植物组成, 第二个分支由蓼属(刺蓼组sect. Echinocaulon、蓼组sect. Polygonum、分叉蓼组sect. Aconogonon、拳参组sect. Bistorta、翼蓼和荞麦属植物组成。同时第二个分支又分成了两个亚分支, 蓼属(刺蓼组、蓼组、分叉蓼组、拳参组)和翼蓼属Pteroxygonum植物属于第一个亚支而荞麦属植物属于第二个亚支。结果支持翼蓼不属于荞麦属的范畴。实验结果显示翼蓼是个单型属, 属于Persicarieae族。  相似文献   

12.
In order to investigate morphological variations of Elymus sibiricus L., E. nutans Griseb., and E. burchan-buddae (Nevski) Tzvelev [=Roegneria nutans (Keng) Keng], and to explore their systematic relationships, six morphological characters were measured and compared between the Elymus species. Interspecific hybridizations between E. nutans and E. sibiricus, and E. burchan-buddae were carried out with the aid of embryo rescue. Chromosome pairing behaviour was also analysed at metaphase- I of meiosis in pollen mother cells of F1 hybrids. Morphologic characters, such as length of spikes and length of glumes varied considerably between different individuals of each species, whereas length and width of paleas were quite stable and different between species. The interspecific hybrids were completely sterile and their meioses were irregular. Meiotic configuration of E. nutans × E. burchan-buddae was 7.70I +13.40Ⅱ+0.06Ⅲ+0.08 IV, whereas that of E. sibircus×E. nutans was 11.98I+9.61Ⅱ+0.64Ⅲ+0.39Ⅳ+0.01V. It is concluded from the morphological and cytological study that (1) it is possible to identify the three Elymus species using the palea character, in addition to other traditionally applied characters; (2) Elymus nutans and E. burchan-buddae have a comparatively high genomie relationship, while E. nutans and E. sibircus have a relatively low genomic affinity to one another; and (3) a certain chromosome pairing regulator was presented in the hybrid between E. burchan-buddae andE. nutans.  相似文献   

13.
Cytological and biosystematic studies on the genus Pteris have made a great contribution to the theory of speciation and evolution in ferns. Sino-Japanese area is one of the speciation centers of this genus. But only a few Chinese species have been known cytologically. As a preliminary study, ten species of the genus Pteris and two species of the related genera Pteridium and Histiopteris were observed. All the materials were collected from southwest and south China. Their young sori were fixed in ethanol and glacial acetic acid (3:1), in the field. The preparations were made with acetocarmine squash method. The vouchers are deposited in PE. The results of observation are summarized in Table 1. Of Pteris, four species are agamosporous, eight are polyploid, six are actually the members of species complexes. Only two species are purely sexual diploids. Pteris cretica L. var. nervosa (Thunb.) Ching et S. H. Wu has 58 autobivalents at meiosis of spore mother cell, and usually produces 32 diplospores per sporangium. It is obviously an agamosporous diploid. Apart from 32-spored sporangium, some 4-, 8-, 16-, 64-, 13-, 34-, 36-spored, completely abortive or partly abortive sporangia were also found in the fixed material of a single individual. For explaining these unusual types of sporangia at least nine sporogenesis routes can be inferred. It may not be impossible that besides mainly producing functional diplospores, P. cretica var. nervosa also gives a few functional giant spores with a doubled or multiplied somatic chromosome number, which means that polyploids may be simply derived from the spores produced by their diploid parent. The spores in a sporangium are usually tetrahedral, but a few bilateral ones are also found in some sporangia. Sometimes, the bilateral spores are even more than the tetrahedral ones in a sporangium. Pteris vittata L. from the type locality shows 58 bivalents at diakinesis of meiosis. Without doubt, it is a sexual tetraploid, which was also found in south Guangdong and south Yunnan. However, Its natural ancestral diploid has been widely found in the subtropical regions of China, such as Sichuan, Guizhou, Yunnan and Hubei provinces. A sterile triploid with the chromosome number of n=201Ⅰ+26Ⅱ+5Ⅲ and a sterile tetraploid hybrid with the chromosome number of n=9Ⅰ+45Ⅱ+3Ⅲ+21Ⅴ were found in south Yunnan and south Guangdong respec tively. It is evident that P. vittata L. sensu lato is a species complex which includes several cy totypes. Its hexaploid form was reported from south India by Abraham et al. The distribu tion pattern of different cytotypes in P. vittata complex may indicate that the tropics is more favourable to formation and surviving of polyploid than the subtropics. However, it is most possible that Chinese subtropics is the origin place of the ancestral member in the P. vittata complex. In gross morphology, the tetraploid and triploid forms are only bigger and stronger than the diploid form. But the diploid can also grow rather big in cultivation. They can har dly be distinguished from each other. Therefore, they are not given formal names here. The author fully agree with Prof. T. Reichstein when he said in 1983 that it was hoped that a new nomenclature could be adopted for the cytotypes of species complex in future. The special chromosome number of Pteris deltodon Bak .was counted in this work for the first time. It has 55 bivalents at meiosis of SMC. This number is the only exception in the genus Pteris, and shows that aneuploidy may have taken place in this genus. However, the pos sibility can not be ruled out that P. deltodon is an allotetraploid came from two diploid species respectively with the chromosome number 26 and 29. Pteris gallinopes described by Prof. Ching in i983 is an agamosporous tetraploid with 116 autobivalents at meiosis, different from the related triploid species P. dactylina Hook. and P. henryi Christ. P. ensiformis Burm P. muftifida Poir. and P. semipinnata L. are sexual tetraploids with n=58. P. excelsa Gaud. and P. oshimensis Hieron. var. paraemeiensis Ching are agamosporous triploids with n = 87 autobivalents. P. wallichiana Agardh is a sexual diploid with n=29. The high frequency of polyploids and agamospory among these random sampled Chinese species futher confirms the conclusion that both polyploidy and apomixis have played an important role in speciation and evolution of the genus Pteris. Pteridium aquilimum (L.) Kunh var. latiusculum (Desv.) Underw. ex Heller and Histiopteris incisa (Thunb.) J. Sm. have n=52 and n=96 respectively. They are both sexual tetraploids. Their chromosome numbers show again that the genera Pteridium and Histiopteris are distinquished from the genus Pteris by different basic numbers. This project is supported by the National Natural Science Foundation of China.  相似文献   

14.
Spore morphology of thirteen species of the genus Bryum Hedw. were observed by LM and SEM. The results show that the ornamentation of spore exine could be divided into three types: Type I , blunt at the top of baculate processes, to which four species belong: Bryum argenteum, B. lonchocaulon , B. uliginosum and B. arcticum. Type Ⅱ, sharp or with small processes at the top of baculate processes, represented by seven species: B. pallescens, B. caespiticium, B. pallens, B. pseudotriquetrum, B. paradoxum, B. alpinum and B. thomsoii. Type Ⅲ, expanded into hemispherical-shaped at the top of baculate processes, represented by two species: B.coronatum and B.sauteri. The Bryum species may also be divided into three groups according to the variation of spore diameter. Group I , with spore diameter under 10 μm, including one species, B. uliginosum. Group Ⅱ, with spore diameter 11~20 μm, including seven species: B. argenteum, B. alpinum, B. coronatum, B. pallens, B.paradoxum, B.sauteri, B.thomsonii. Group Ⅲ, spore diameter 21~30 μm, with five species: B. pallescens, B. caespiticium, B. pseudotriquetrum, B. lonchocaulon, B. arcticum. There are resemblances of spore morphology and exine ornamentation among the thirteen species. In the view of palynology, the genus Bryum is a natural taxon which is more advanced than the genus Pohlia Hedw. But spores of thirteen species are different at some characters such as diameter, shape ofproximal leptoma, etc., which indicates the genetic differentiation in the genus Bryum.  相似文献   

15.
六个不同类型荞麦花花粉粒形态的电镜观察比较研究   总被引:2,自引:0,他引:2  
张玉霞  陈庆富 《广西植物》2002,22(3):232-236
对二倍体甜荞长花柱类型 (ES2 s)、二倍体甜荞短花柱类型 (ES2 S)、四倍体甜荞长花柱类型 (ES4s)、四倍体甜荞短花柱类型 (ES4S)、四倍体有翅细野荞 (GR4HI)、四倍体无翅细野荞 (GR4HO)等 6个不同荞麦类型花的花粉形态学进行了电镜观察。结果表明 :这些荞麦类型的花粉粒都是椭圆形 ,都有网状纹饰、3孔沟等特征。二倍体甜荞染色体加倍后形成的四倍体甜荞 ,相对于二倍体甜荞而言 ,花粉粒显著增大和明显变圆。无论二倍体还是四倍体甜荞 ,其长花柱型花的花粉粒都比其对应短花柱型花的花粉粒要小。尽管四倍体甜荞和四倍体细野荞在染色体数目和倍性上一样 ,但是它们在花粉粒的大小上有显著差异。四倍体细野荞有翅类型和无翅类型的花粉粒大小和形态差异不显著  相似文献   

16.
中国飘拂草属植物果皮微形态   总被引:1,自引:0,他引:1  
利用扫描电子显微镜对国产莎草科飘拂草属4组18系42种1变种植物果皮微形态特征进行观察,并作了系统描述。研究表明,飘拂草属植物在纹饰类型,超微结构等方面存在着明显的种间差异,具有分类学意义。根据纹饰及微形态特征的不同,支持将褐鳞飘拂草和知风飘拂草各自作为独立的种。依照果皮纹饰的差异,飘拂草属可分为4种类型(1)瘤(疣)-网状复合纹饰;(2)瘤(疣)状纹饰;(3)网状纹饰;(4)脊-疣状复合纹饰。其中(1)和(3)类型的纹饰根据网脊曲直不同各自又可分为2个亚型。  相似文献   

17.
五味子属种子形态及其分类学意义   总被引:5,自引:1,他引:4  
用光学显微镜及扫描电镜对五味子属(Schisandra)10种96号样品的种子宏观形态和种皮的微观形态特征进行观察,首次对该属的种皮微观形态特征进行系统报道,并编排有分种检索表。研究结果表明:该属的种子宏观形态呈现平滑、细皱纹或瘤状突起,并认为五味子属种子形态可有从平滑到有细皱纹再到有瘤状突起的演化趋势;该属种皮表面微观形态可分为疣状突起型和网纹型。结合其它性状,本文认为网纹型所代表的两种植物应与本属中其它植物建立并列的分类单元。五味子属植物在种子形态特征上存在一定的差异,可为属以下、种以上的分类提供依据,并为探讨该属的系统演化提供有价值的参考资料。  相似文献   

18.
Plastid atpB/rbcL intergenic spacer sequences were obtained from 21 selected taxa and one hybrid of Anemoninae (Anemone, Pulsatilla, Hepatica) and compared with Ficaria (Ranunculinae) as an outgroup. From the resulting matrix (1226 bp) a single most parsimonious tree was obtained (Fig. 1 ). The branching of this tree is confirmed by many informative indels and appears largely congruent with past plastid restriction analyses. Several new taxa are added. The monophyly of the Anemoninae and their early split into two major clades is supported: clade I with the chromosome base number x = 8, clade Ⅱ with the reduced x = 7. Clade Ⅰ is made up of the basal Pulsatilla and the Rivularis + Vitifolia groups. The Multifida group links to the crown groups Coronaria, Blanda and Nemorosa. Clade Ⅱ consists of the basal Dichotoma group, followed by Hepatica, and finally by the N. Hemisphere Narcissiflora and the S. Hemisphere Antucensis groups as sisters. The problems of the Anemoninae ancestry, phylogenetic differentiation, and recent attempts for systematic classification are critically discussed. In view of the still incomplete sampling of DNA data, aconservative and informal approach to classification problems is recommended.  相似文献   

19.
Studied in this work was seed morphology of the genus Plantago (2 subgenera, 8 sections, 17 species and 1 variety )in China. The sculpture was observed under scanning election microscope. Four forms of seed morphology are recognized as follows: (1)Multi-angular type: seeds are variously angulate, yellow-brown or black, 6-30 in a fruit; seed-coat sculpture ranges from reticulate to papillate. It occurs in Subgen. Plantago Sect. Polyneuron: P. scheideri, P. denstflorus, P. major, P. hostifolia, P. asiatica, P. erosa and P. centralis. (2) Navicular type: seeds are navicular, yellow, brown to black, 2 in a fruit; seed-coat sculpture is reticulate. It was found in Subgen. Plantago Sect. Novorbis: P. virginica; Sect. Arnoglossum: P. lanceolata; Sect. Leucopsyllium: P. minuta, P. lessingii and P. aristata and Subgen. Psyllium Sect. Psyllium: P. indica. (3)Ovoid type: seeds are long-ovoid, yellow-brown, black and lustrous. Seed-coat sculpture scali-ratiform. P. maxima in Subgen. Plantago Sect. Lamprosantha belongs to this type. (4)Recti-circular type: seeds are recti-circular, yellow-brown, black, 1-2 or 4-5 in a fruit; seed-coat sculpture is reticulate and papillate. It was found in P. maritima var. salsa of Subgen. Plantago Sect. Coronopus and P. depressa, P. camtschatica and P. arachnoidea of Sect. Mesembrynia. The seed morphology and seed-coat sculture exhibit specific characters, by which some of confused species can be clarified and a new species, P. densiflorus J. Z. Liu. is established. The present author’s seed morphology classification is in accordance with Pilger’s systemof the genus, which was established using other features.  相似文献   

20.
山西霍山罂粟科植物花粉形态   总被引:3,自引:0,他引:3  
杨瑞林  魏学智  毕润成 《广西植物》2003,23(3):231-232,I003,I004
利用光学显微镜和扫描电子显微镜对山西霍山罂粟科白屈菜属白屈菜、紫堇属延胡索、角茴香属角茴香、秃疮花属秃疮花 4种的花粉形态进行了观察和比较研究 ,以上 4种花粉差异大。角茴香花粉粒近球形 ,具合沟 ;延胡索花粉粒长球形 ,表面纹饰较光滑 ;白屈菜花粉粒长球形或近球形 ;秃疮花花粉粒近球形。角茴香花粉表面纹饰为刺状纹和细网状纹的复合纹 ,白屈菜花粉表面纹饰为细网状纹和颗粒状纹的复合纹 ,秃疮花花粉表面纹饰为细颗粒状纹。延胡索、白屈菜、秃疮花花粉粒的萌发沟均为三沟 ,但沟的形态均不相同  相似文献   

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