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1.
短柄五加大,小孢子发生和雌,雄配子体发育的研究   总被引:6,自引:2,他引:4  
王仲礼  田国伟 《植物研究》1998,18(2):177-183
短柄五加花药5枚,每个花药四个花粉囊。小孢子母细胞减数分裂时,胞质分裂为同时型,产生正四面体形的四分体。花药壁由表皮、药室内壁、中层和绒毡层四层细胞组成,其发育类型为双子叶型。腺质绒毡层,其细胞为二核。三细胞型花粉。子房5室,每室两个胚珠,上胚珠败育,下胚珠可育。下胚珠倒生,具单珠被,厚珠心。大孢子母细胞减数分裂形成线性排列的四个大孢子,雌配子体发育属蓼型。开花当天,花粉散开,雌配子体尚未成熟,处  相似文献   

2.
四川自贡发现合川马门溪龙新材料   总被引:1,自引:0,他引:1  
叶勇  欧阳辉  傅乾明 《古脊椎动物学报》2001,39(4):266-271,T001
记述了产自四川自贡上侏罗统的一具较完整的蜥脚类恐龙骨架 ,将其归入合川马门溪龙 (Mamenchisaurushochuanensis)中。新材料的发现弥补了合川种正型标本的不足 ,对合川种的特征作了重要补充 ,同时也使我们对马门溪龙的末端尾椎形态有了新的认识。  相似文献   

3.
The craniogenesis of Cavia porcellus has been investigated in 7 embryos of different ages. From the developmental stage of 36 mm CRL, a reconstruction of the chondrocranium is described. As there is still a gap in the tectum posterius, the foramen magnum is not closed posteriorly. The course of the notochord is retrobasilar at the beginning, more rostrally it runs intrabasilar. After ossification, the place where the notochord enters the basioccipital is marked by a cavity. This cavity is not identical with the posterior basicranial fenestra. The laminae alares build up strong paracondylar processes. The auditory capsule is connected with the occipital region only by the exoccipitocapsular commissure, but there is no supraoccipitocapsular commissure. The fossa subarcuata is pierced by a subarcuate foramen. The very short lamina parietalis is not in contact with the orbital wing as there is no orbitoparietal commissure. The processus recessus divides the perilymphatic foramen into fenestra rotunda and aquaeductus cochleae. The suprafacial commissure arises from the upper margin of the canalicular part of the auditory capsule, but it does not reach the superior surface of the cochlear part at this stage. The tegmen tympani is well developed. The foramen singulare is not yet separated from the inferior acoustic foramen. At the stage of 36 mm CRL there is no septum spirale cartilagineum. Mm. tensor tympani et stapedius are developed in the typical way. The auditory capsule is connected with the basal plate by the anterior basicochlear and the alicochlear commissures. The floor of the orbitotemporal region is incomplete, the temporal wings are small. The alicochlear commissure, the alar process, the anterior basicochlear commissure, and the basal plate surround the carotid foramen, but there is no blood vessel passing through it. The temporal wing is at the beginning of ossification and shows a fissura ovalis for the mandibular nerve. Although the hypophysial canal is still present, there are no structures passing through it. There is no foramen rotundum. The orbital wing is still cartilagineous. The basal plate and the pre- and postoptic roots border the optical foramen. The straight muscles of the eyeball are attached to the ala hypochiasmatica which projects from the postoptic root. The interorbital septum is absent. The ophthalmic artery, which instead of the obliterated internal carotid artery, contributes to the circulus arteriosus cerebri is well developed. There is no orbitonasal commissure . The epiphanial foramina are present.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   

4.
羚牛(Budorcas taxicolor)部分脏器特点的观察   总被引:2,自引:2,他引:0  
本文对2只羚牛的雌性生殖器官及肝、肾、脾等脏器进行了形态描述,并与黄牛及羊的相应器官进行了比较,为探讨羚牛的分类地位提供了解剖学资料。  相似文献   

5.
大黄鱼精子的超微结构   总被引:43,自引:1,他引:43  
尤永隆  林丹军 《动物学报》1997,43(2):119-126
大黄鱼的精子由头产和尾部两部分组成。头部结构较为独特,其腹侧有一较大的细胞核,背部有中心粒复合体。头部的后端是袖套。细胞核的腹面稍向外突出背面则稍向内凹。细胞核中的染以质浓缩成致密的团块状。团块状的染色质之间分布着松散的纤维状染色质。植入窝位于细胞核的背部表面,由细胞核背面向内凹陷而成,呈一沟状,其走向与精子的长轴平行。  相似文献   

6.
The development of the anther wall follows Basic-type. The cytokinesis at the time of pollen mother cell meiosis conforms to successive type. The arrangement of the microspores in the tetrad is referred to isobilateral. The primary wall between the generative cell and the vegetative cell is callose. The callose wall is easily detected under the fluorescence microscope. The mature pollen grain is 2-celled type. The ovule is bitegminous, tenui-nucellar and anatropous. The development of the female gametophyte follows Fritillaria-type. The mature embryo sac. consists of the six cells including the seven nuclei. The fertilization is referred to the premitotic syngamy type. The fusion of the female and male nucleoli is not observed at the end of the fertilization. The division of the primary endosperm nucleus is earlier than that of the zygote. The development of the endosperm is referred to nuclear type. The division of the zygote is transverse of longitudinal, the development of the embryo conforms to Onagradtype. When the seed is mature, the embryo is at the proembryo stage without differentiation and the endosperm cells are not absorbed.  相似文献   

7.
白鱀豚甲状腺及甲状旁腺的初步研究   总被引:1,自引:0,他引:1  
本文是8头白鱀豚(Lipotes vexillifer)的甲状腺及甲状旁腺的初步研究结果。白鱀豚甲状腺的解剖学和组织学结构与其它海豚相似。其甲状腺滤泡呈圆形或椭圆形,滤泡胶质嗜酸性,滤泡平均直径为106.4微米,滤泡上皮平均高为9.4微米,滤泡旁细胞平均直径为11.0微米。甲状旁腺分布在甲状腺的腹侧面或前、后方,其上皮细胞被结缔组织分隔成团索状。文中并讨论了白鱀豚甲状腺的一些组织形态变化。    相似文献   

8.
黑鸢消化系统形态学的初步研究   总被引:8,自引:4,他引:4  
周菊萍  郭延蜀  米志平  胡锦矗 《四川动物》2004,23(4):346-348,F003
对黑鸢消化系统的形态学作了初步的观察与研究,结果表明:黑鸢舌尖钝圆,舌根分叉,叉粘膜上具有尖端指向后方的栉状突;食管宽而扁,无明显可见的嗉囊;肌胃无明显的类角质膜;肠道长是体长2.3倍,小肠较发达,K1275mm,古肠道总长的93.6%,具有不发达的双侧盲肠:胰腺短而厚、并与蛇雌、毛脚鸢的消化系统进行了比较。  相似文献   

9.
采用常规石蜡切片对安南龟的肝脏和肾脏进行了组织学观察。研究结果发现,肝脏分为3叶,肝实质内结缔组织少。肝脏由无数肝小叶构成,肝小叶分界不清。肝细胞为多角形的腺上皮细胞,细胞核圆球形,位于中央。胆小管沿着肝细胞索向肝小叶四周放射并连成细长的微细管道。肾脏由肾小体、颈段、近曲小管、中间段、远曲小管和收集管6部分构成,肾小体由肾小球和肾小囊组成,在肾小体附近可见致密斑样结构,未见髓袢结构。肾小球由盘曲的毛细血管构成。肾小囊是肾小管的起始端,由内、外两层壁层构成,内层与肾小球的毛细血管紧贴,外层为单层扁平上皮细胞。  相似文献   

10.
利用石蜡切片法对中华花龟的心脏、肝脏、脾脏、肺和肾脏等组织器官进行了组织学观察.结果显示心肌的特点是暗带较窄,心肌纤维束状排列.肝脏分3叶,肝实质内结缔组织少,肝小叶分界不清楚.脾脏分被膜和实质两部分,实质由白髓和红髓构成,白髓包括椭球周围淋巴鞘(PELS)和动脉周围淋巴鞘(PALS),红髓由脾索和脾窦组成,未发现淋巴小结和生发中心.肺一对,为长形扁平囊,肺泡囊状,肺泡内可见管壁的结节状膨大.肾脏由肾小体、颈段、近曲小管、中间段、远曲小管和收集管6部分构成,肾小体由肾小球和肾小囊组成,在肾小体附近可见致密斑样结构.  相似文献   

11.
鞑靼滨藜(Atriplex tatarica L.)药壁4层细胞,中层1层;绒毡层腺质型。孢原细胞1列或2弄;同花药异花粉囊小孢子母细胞减数分裂为同步,同花粉囊减数分裂大部分同步,部分非同步;四分孢子多为四面体形,少数是左右对称形,胞质分裂同时型;成熟花粉粒为风状饰纹,3-细胞型;单子叶型药壁。弯生胚珠,厚珠心型;双珠被,四分子孢子直线。反足细胞受精前退化,属蓼型胚囊。胚的发育为藜型,胚乳细胞在球  相似文献   

12.
巨龙竹生殖器官形态结构及雌、雄配子体的发育   总被引:2,自引:0,他引:2  
通过石蜡切片的方法对巨龙竹生殖器官结构、大小孢子的发生和雌、雄配子体的发育过程进行了观察研究。 巨龙竹为一心皮组成的单室单子房,子房内具有一个胚珠,倒生、双珠被、厚珠心。大孢子母细胞减数分裂形成线形排列的4个大孢子,合点端大孢子具功能。胚囊的发育为蓼型,具多个反足细胞。巨龙竹的花药壁由4层结构组成,包括表皮、药室内壁、中层、绒毡层;花药壁发育为单子叶型,绒毡层为腺质型。小孢子母细胞减数分裂中的胞质分裂为连续型,四分孢子为四面体型;成熟花粉粒为2细胞型,具1个萌发孔。小穗发育雌雄异熟,雌蕊的发育早于雄蕊的发育。  相似文献   

13.
路娟  陈非 《生物技术》1994,4(5):34-37
药敏药片经临床对金黄色葡萄球菌、大肠埃希氏菌、铜绿假单胞菌等235株考核.表明药片工艺研究先进,药片与培养基结合牢固,无断裂、崩解,不渗出颗粒,抑菌圈呈同心园扩散.边缘清楚。药物含量均匀,释放度好。药片抑菌差仅1~3mm;而纸片抑菌差为2~12mm。药片变黑系数CV为2.71~4.21;而纸片CV为3.82~14.36。表明纸片片间差大,药片精密度明显好于纸片。  相似文献   

14.
吉林省满族体质特征调查   总被引:8,自引:2,他引:6  
  相似文献   

15.
大花蕙兰营养器官及原球茎的解剖学研究   总被引:1,自引:0,他引:1  
对大花蕙兰试管苗营养器官及原球茎的解剖学研究结果表明:根由复表皮、皮层和维管柱组成,根毛丰富,皮层发达,内皮层明显,初生木质部月多元型,中央具髓,根茎由表皮,基本组织和维管束构成,维管束散生,属周木型;叶为等面叶,在上下表皮处分布有成束的厚壁组织,叶肉无栅栏组织和海绵组织之分,细胞排列紧密,维管束鞘由机械组织构成。原球茎原生分生组织的原套仅一层细胞,在顶端分生组织后面的薄壁细胞中,存在胚性细胞,由胚性细胞经球状胚可发育成幼原球茎。  相似文献   

16.
两型豆花粉和叶表皮的扫描电镜观察   总被引:5,自引:1,他引:4  
两型豆花粉和叶表皮在扫描电镜下的形态特征:花粉近球形至矩球形,三孔沟,外壁表面较粗糙,侧壁具疣状突起至块状突起,极面具粗网状纹饰,但两型豆祖山居群属于萌发沟不明显型,两型豆燕塞湖居群属于萌发沟明显型。叶表皮细胞不规则,排列紧密,叶脉表皮细胞长圆柱形,长轴与叶脉平行,角质膜薄,表皮毛均为单细胞非腺毛,气孔器仅分布在下表皮,属于平列型,偶见不规则型。表皮毛和气孔器在叶片上分布不均匀,两型豆祖山居群叶表皮毛和气孔器的平均密度大于两型豆燕塞湖居群叶表皮毛和气孔器的平均密度,自然生长的两型豆叶表皮毛和气孔器的平均密度大于遮光条件下的两型豆。  相似文献   

17.
This paper reports the studies of megasporogenesis and microsporogenesis, development of female and male gametophytes, fertilization, and development of embryo and endosperm, The anther wall consists of four layers, i.e. epidermis, endothecium, middle layer and tapetum. Part of the tapetum cells originates from the primary parietal cells, and the other part comes from the basic tissue of the anther partition. Tapeta? cells are uninucleate or binucleate, and belong to the secretory type. Microsporocyte originates directly from the primary sporogenous cell, Cytokinesis is of the simultaneous type. Arrangement of microspores in tetrad is isobilateral. Mature pollen grain is of the 2-celled type. The ovary is tricarpellum, trilocular with many ovules. The ovule is mono-integinous, tenui-nucellar and anatropous. The embryo sac originates from the single-archesporial cell. The one chalazal megaspore in linear tetrad is the functional megaspore. The development of embryo sac is of the Polygonum type. Before fertilization, two polar nuclei fuse in to a secondary nucleus and the antipodal cells degenerate. Fertilization is porogamy, fusion of one sperm with secondary nucleus is faster than that of one sperm with egg nucleus. The development of endosperm is of the cellular type. The first three divisions of endosperm ceils are regular. Two endosperm cells near the ends of chalaza and the micropyle develop into haustorium without division. The haustoria gradually degenerate at the late stage of globular embryo. The mature seeds contain abundant endosperm. The development of embryo is of the Solanad type. The suspensor consists of 12–20 cells. The optimum development of the suspensor is at the early stage of the globular embryo. It begins to degenerate after late globular stage. The embryo develops from proembryo, heartshaped embryo, dicotyledenous- to mature embryo.  相似文献   

18.
The ultrastructure of the microfilaria of Brugia, Nematoda: Filarioidea   总被引:2,自引:0,他引:2  
The microfilaria of Brugia pahangi is a differentiated nematode larva. The basic nematode body plan is present showing cuticle, hypodermis, dorsal, ventral, and lateral cords, muscle cells, longitudinal nerves, papillary nerves, amphids and phasmids. Secretory granules are present in ganglionic cells and in axons in the nerve ring. There is no differentiated pseudocoelom. There is only a single row of muscle cells between each pair of cords. The excretory cell complex is similar in structure to the hypodermal gland cells of other nematodes. The alimentary canal of the microfilaria is very much modified. The pharyngeal cells are attached to the pharyngeal thread which is circular in cross section and there is no pharyngeal musculature. The intestine is represented by the solid mass of the inner body within paired intestinal cells. The intestine is separated from the rectum. The three rectal cells form a syncytium of villi in the anal vesicle. The structure in Brugia is related to the ultrastructure of other microfilariae and it is concluded that the evolution of the modifications of the basic larval structure is due to the small size of these nematodes as a consequence of their adaptation to a parasitic mode of life in the capillaries of the vertebrate host with transmission through an intermediate arthropod vector.  相似文献   

19.
李平  郑学经 《植物研究》1986,6(1):43-53
本文描述延龄草(Trillium tschonoskii Maxim.)的大孢子发生,雌配子体的形成和雄配子体的形态。胚珠为倒生型,双珠被,厚珠心型。胎座为侧膜胎座向中轴胎座的过渡类型,胶囊发育为葱型的变异型。孢原细胞直接发生于幼胚珠的珠心表皮细胞之下,孢原细胞平周分裂,形成初生周缘细胞及初生造孢细胞。初生周缘细胞分裂先于初生造孢细胞,分裂结果与珠心表皮细胞共同形成了珠心组织。初生造孢细胞进一步发育,形成大孢子母细胞。大孢子母细胞经减数第一次分裂后,即出现壁,形成二分体。一般是珠孔端二分体细胞小于合点端二分体细胞,但偶尔也见到前者大于后者的情况。在二分体形成后珠孔端二分体细胞立即退化、或经减数第二次分裂后再退化(该次分裂多为斜向的)。合点端二分体细胞发育,经二核胚囊,四核胚囊,六核胚囊阶段至成熟胚囊。一般在珠孔端的周围淀粉粒丰富,并先于合点端的核进行分裂。珠孔端由二个助细胞,一个卵细胞构成卵器,助细胞具钩突,并具丝状器,两个极核。合点端常见多核仁的大核,成熟胚囊未见八核。成熟花粉粒为二细胞的,花药壁具变形绒毡层,花粉中充满淀粉粒。沼生目型胚乳。  相似文献   

20.
白花败酱染色体的核型分析   总被引:3,自引:0,他引:3  
用去壁低渗染色体制片方法,对白花败酱(Patrinia villosa Juss)茎尖细胞染色体制片,研究其染色体组型.结果表明:白花败酱为二倍体、体细胞染色体数目为22;染色体组型公式为2n=2x=22=10m 4sm 4st 4t,第2、3、4、5、8号染色体为中间着丝点染色体,第6、11号染色体为近中着丝点染色体,第1、10号染色体为近端着丝点染色体,第7、9号染色体为端部着丝点染色体;染色体基数x=11,该染色体组内最长与最短染色体长度比值为3.037,臂比大于2:1的染色体共4条,占总数的36.4%,则白花败酱的核型类型为2B型.  相似文献   

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