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1.
贺氏双子铁与摩瑞大泽米羽片和叶轴的解剖学研究   总被引:2,自引:0,他引:2  
对贺氏双子铁和摩瑞大泽米的羽片和叶轴进行了比较研究,对两种植物的结构特征与对环境的适应性进行了分析,结果表明:两个种类的结构有很大的差异。贺氏双子铁的羽片仅在下表皮有气孔器分布,在近轴面仅有1~2层较短的栅栏组织,维管束与粘液道在垂周方向相对而生;摩瑞大泽米羽片在上下表皮均有气孔器,近轴面和远轴面均有较长的2~3层的栅栏组织,为等面叶,维管束与粘液道在平周方向相间排列。此外,两个种的维管束结构及叶缘结构等也有很大的差异。在叶轴方面,贺氏双子铁的表皮气孔数比摩瑞大泽米的气孔数明显要少,而且摩瑞大泽米的表皮内侧有一环富含叶绿体的栅栏组织,且在栅栏组织的内方还有发达的富含叶绿体的海绵组织,而贺氏双子铁则没有。此外,摩瑞大泽米在基本组织中含有较多的副转输组织,而贺氏双子铁则无。在粘液道大小、排列方式上两种类也有很大的不同。贺氏双子铁的维管束韧皮部明显比木质部发达,而摩瑞大泽米木质部和韧皮部的发达程度相近。  相似文献   

2.
the comparative studies of morphology and anatomy of 19 species of ChineseWoodsiaceae are reported in the present paper. It includes anatomy of root, rhizome, rachisand joint on stipe; comparative morphology of the fronds and its parts, trichomes and indusiaand an observation of the spores under SEM. The information is applied to discussing phylogeny and systematics briefly. The anatomical studies do provide taxonomic studies with evidence so that they should not be abandoned. For example, the stipe joints of Woodsia havetwo types, the stipe joint below the attachment point of the base pair of pinnae and the stipejoint just at the attachment point of that; the abscission layer of the former does not have pinna trace in it and the basic chromosome number is 39. However, the abscission layer of thelatter does and the basic chromosome number is 41. It is obvious that the anatomical cha-racters can be used for infrageneric subdivision of Woodsia.  相似文献   

3.
大蒜花序轴离体培养器官发生途径的解剖学研究   总被引:1,自引:0,他引:1       下载免费PDF全文
以大蒜品种‘三月黄’(Allium sativum L.cv. Sanyuehuang)花序轴为外植体进行离体培养,对其器官发生过程进行了形态学和解剖学观察。结果显示:大蒜花序轴离体培养不经过愈伤组织,通过器官直接发生途径形成不定芽,其不定芽起源于大蒜花序轴维管组织韧皮部一侧周围的皮层薄壁细胞,属于外起源;皮层薄壁细胞经脱分化后,由最先形成的拟分生组织发育为茎尖分生组织,然后环绕其形成叶原基,茎尖和叶共同构成一个完整的不定芽;大蒜花序轴离体培养发生的不定芽与花苞中自然形成的营养芽发生部位一致。不定芽通过壮苗、生根培养可正常生根形成植株,如果继代培养周期超过21 d,鳞茎形成率可达90.56%。  相似文献   

4.
    
《Palaeoworld》2019,28(4):487-507
Scolecopteris libera n. sp. is established on partial three-dimensionally preserved materials containing both sterile and fertile fronds collected from the volcanic tuff at the top of the Taiyuan Formation at the Wuda Coalfield, Inner Mongolia, China. It is characterized by tripinnate fronds with rachises over 200 mm in diameter; and long lanceolate or falciform pinnules with thick veins. Pinnules are of the pecopterid-type, with those at the base of the ultimate pinnae usually divided into small lobes. Eight to twelve circular synangia are arranged in two rows along the midvein. Synangia are borne on a short pedicel attached to the middle of lateral veins. A synangium is composed of 7–10 fusiform exannulate sporangia with pointed apices. The sporangia are free among each other beyond the base of synangia. In situ microspores of the Cyclogranisporites leopoldii type differ from all other in situ Paleozoic marattialean spores.  相似文献   

5.
观音座莲目的角质层特征   总被引:1,自引:0,他引:1  
运用扫描电镜和光学显微镜对观音座莲目4种(属)植物的叶角质层进行了研究。结果表明,其间存在明显共性:表皮构造均为单面气孔式,上下表皮细胞垂周壁皆呈不同程度的波状起伏,气孔器类型皆为环列型。需要指出的是观音座莲目的全部6属植物均具环列型的气孔器,这表明该特征在目一级水平上具有重要的分类学及系统学意义。同时天星蕨属的角质层特征进一步支持了将天星蕨属上升为天星蕨科的观点。  相似文献   

6.

Amongst nerineacean gastropods which have been preserved in fine grained carbonate sediments, remnants of a calcite rod system contained within the helically coiled body chamber can frequently be found. The position of these rods, their petrography and the presence of side branches suggest that they represent the original duct system within the digestive gland/gonad complex of the gastropod. The characteristic internal spiral folds secreted by the nerineids were emplaced between the major lobes of the digestive gland/gonad complex, possibly at the expense of the nutrient storage capacity. The absence of folds at the aperture and apex, together with the origin of the superfamily in the Lias, indicates that folding was not developed as a protective adaptation against durophagous molluscivores. Instead, the deposition of calcium carbonate internally enabled these gastropods to exploit the food resources of carbonate substrates, initially infaunally and subsequently epifaunally. Most of this ecological diversification was attained during the Bathonian and from this time, the Nerineacea became prominent members of shallow water Mesozoic carbonate communities.  相似文献   

7.
         下载免费PDF全文
Scolecopteris Zenker, a kind of anatomically-preserved fertile foliage of Late Paleozoic Marattiales, has been well studied in Euramerican Flora. It is composed of 28 species which can be divided into four forms (groups) mainly based on modified or umodified pinnules, the variation of the outer facing sporangial walls, and with or without a prominent central parenchyma area. In contrast, Scolecopteris Zenker in Cathaysian Flora has been poorly studied so far, and only one species S. sinensis Zhao, was reported in 1991 which was considered as a member of Minor Group. The paper reports a second species of Scolecopteris, i.e.S, shanxiensis sp. nov., which differs from the above four groups in that its outer facing wall of the sporangia is thick at the base and top (2 ~ 3 layers of cells), and a little thinner ( 1~2 layers of cells) at the midlevel of the synangia. So a new group, Shanxiensis group, is set for the new species. The other characteristics of Shanxiensis group is comparable with Minor group. The new species comes from the coal balls in Coal Seam No. 7 in the upper part of Taiyuan Formation (early Early Permian) from Taiyuan, Shanxi, China. The identification of Scolecopteris shanxiensis sp. nov. :The fertile pinnule probably peeopterids, 5.5 ~ 6.0 mm in length and 2.0 ~ 2.2 mm in width. The lateral extensions of the lamina of the pinnule bend abaxially and above the synangia. The synangia arrange along the sides of the midrib of the pinnnle and there are about 10 synangia in each row. The synangium is elliptical in longitudinal section and radial in cross section, 0.7 ~ 0.8 mm in height and 0.6 ~ 0.7 mm in diameter. Each synangium has 5-7 (mostly 6) fusiform sporangia fused at the base and attached to the top of the synangial pedicel. The outer facing wall of the sporangia consists of 2~3 layers of cells at the base and becomes thinner at the midlevel (1~2 layers of cells), and at the top of the synangia the wall become thicker again. The cells of the outer facing wall of the sporangia are elongate in the longitudinal sections. The lateral and inner facing walls of the sporangia are one cell thick. The synangial pedicel is small. Spores in situ are small, generally 11~14 µm in diameter, spherical or rounded-triangular, trilete and smooth-walled.  相似文献   

8.
The descent of the larynx is a key phenomenon not only in postnatal development, but also in the evolution of human speech. The positional change of the larynx is affected by the descent of the hyoid bone in relation to the mandible and cranial base, and that of the laryngeal framework in relation to the hyoid bone. The phylogeny of the spatial configuration of the hyo-laryngeal complex is one of the most important sources of information for elucidating the evolution of laryngeal descent. In the present study, the anatomy of the complex was examined in various species of anthropoids to compare the configuration, the shape of the basihyal and thyroid cartilage, and the length of the lateral thyrohyoid ligaments. Non-human hominoids share most features with humans, while cercopithecoids and ceboids have anatomical features that sharply contrast to humans, except for the form of the thyroid cartilage in ceboids. The laryngeal framework in hominoids is well separated from and assured of mobility independent of the hyoid. In cercopithecoids and ceboids, it is, by contrast, locked into and tied tightly with the hyoid so that the hyo-laryngeal complex acts as a functional unit. This spatial configuration is considered to be significantly related to the mechanism that prevents aspiration, including epiglottic movement and vestibular closure. Non-human hominoids are inferred to share the mechanism with human adults, not with cercopithecoids and ceboids, although their larynx is located as high as the latter. Consequently, it is hypothesized that the descent of the larynx evolved in two steps. The first step would have been descent of the thyroid in relation to the hyoid for the evolution of the mechanism preventing aspiration, which occurred in the common ancestor of hominoids. The second step, descent of the hyoid within the neck, occurred during hominid evolution for human speech. Electronic Publication  相似文献   

9.
报道了山西太原西山煤田早二叠世早期太原组上部7号煤层煤核中一种具解剖构造的观音座莲目生殖器官化石。经对比研究,将其归入辉木科虫囊蕨属,它与虫囊蕨属已有的4个组(共29个种)都不一样,因此代表了一个新的类型:Shanxiensis组,标本被命名为山西虫囊蕨(新种),其主要特征是:生殖小羽片可能为栉羊齿型,聚合囊着生于小羽片背面的侧脉上,沿中脉两侧排列,各有一行,每行大约有10枚,侧脉不分叉,叶片边缘  相似文献   

10.
高成芝  冯恒光  赖其瑞   《广西植物》1988,(4):329-334
<正> 芸香科黄皮属(Clausena)植物全球约25种,分布于东半球热带、亚热带地区;我国记载有9种,产长江以南各省区,以两广、云南种类较多;广西现知6种,民间大多作药用,黄皮和小叶黄皮在我国南部广泛栽培,果实供生食或加工,黄皮的优良品种为岭南佳果之一。目前正在挖掘其潜在的药用价值及进行化学成分和挥发油的研究。中国人民解放军181医院药理室,用大鼠进行动物实验,证明黄皮叶有降血脂作用。在研究黄皮属的分类时,某些种的形态特征很接近,叶的形状、大小变化大,在无花果的情况下更难区分,笔者试图从叶的解剖构造探讨种间的差异,为植物分类和生药鉴定提供依据,供临床用药及有关方面参考。  相似文献   

11.
    
Mesophyll conductance to CO2 (gm) may respond to light either through regulated dynamic mechanisms or due to anatomical and structural factors. At low light, some layers of cells in the leaf cross‐section approach photocompensation and contribute minimally to bulk leaf photosynthesis and little to whole leaf gm (gm,leaf). Thus, the bulk gm,leaf will appear to respond to light despite being based upon cells having an anatomically fixed mesophyll conductance. Such behaviour was observed in species with contrasting leaf structure using the variable J or stable isotope method of measuring gm,leaf. A species with bifacial structure, Arbutus × ‘Marina’, and an isobilateral species, Triticum durum L., had contrasting responses of gm,leaf upon varying adaxial or abaxial illumination. Anatomical observations, when coupled with the proposed model of gm,leaf to photosynthetic photon flux density (PPFD) response, successfully represented the observed gas exchange data. The theoretical and observed evidence that gm,leaf apparently responds to light has large implications for how gm,leaf values are interpreted, particularly limitation analyses, and indicates the importance of measuring gm under full light saturation. Responses of gm,leaf to the environment should be treated as an emergent property of a distributed 3D structure, and not solely a leaf area‐based phenomenon.  相似文献   

12.
    
A new species of the late Paleozoic fern Scolecopteris (Marattiales) is described and its relationship within the genus is discussed. Scolecopteris sinensis sp. nov., from Shanxi (coal balls of Taiyuan formation, upper Carboniferous), is similar to S. saharaensis, however some differences in characters are evidenced, such as pedicel and sporal ornamentation, The anatomy of the sporangium wails, pinule morphology, and general spore type support its association with the Minor group of Scolecopteris. The phylogenetic and ecological magnitude of Scolecopteris sinensis is also discussed.  相似文献   

13.
    
A microscopic analysis of the morphology and ultrastructure of the digestive, salivary, and reproductive systems of adult Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) B type was conducted using light, scanning, and transmission electron microscopy. The internal anatomy of B. tabaci was found to be similar to that reported for Trialeurodes vaporariorum. In a microscopic analysis of the salivary glands, we have shown that each primary salivary gland is composed of at least 13 cells varying in morphology and staining differentially, while the accessory salivary glands are composed of four morphologically similar cells. We analyzed the course of the alimentary canal in B. tabaci, demonstrated the internal morphology of the organs, and clarified the location of the filter chamber relative to other organs in the whitefly. Our observations confirm that the pair of structures extending from the connecting chamber are caeca that may aid in fluid movement through the midgut and are not Malpighian tubules, as previously suggested. We confirm an earlier finding that the whitefly lacks Malpighian tubules, having instead specialized Malpighian-like cells within the filter chamber at the juncture with the internal ileum. Finally, we provide the first scanning electron microscopic analysis showing the reproductive organs of B. tabaci. Our investigation provides clarified terminology for several components of the digestive and excretory system. We also provide drawings and micrographs that will aid future researchers in localizing the internal organs of B. tabaci. We expect our analysis to provide a valuable tool for studying B. tabaci / plant virus interactions and physiological and biological aspects of this insect.  相似文献   

14.
鄂西荆当盆地的九里岗组,化石植物比较丰富。本文着重报道其中两种,即疏脉蕉羊齿(新种)(Compsopteris laxivenosa sp.nov.)和西河蕉羊齿(新组合)[C.xiheensis(Feng),comb.nov.]此外,还订正了副镰羽叶属(Paradrepanozamites),描述了大道场副镰羽叶(新订正)(Paradrepanozamites dadaochangensis Chen,emend.nov.)和小副镰羽叶(新种)(P.minorsp.nov.)等中生代新资料。在本植物组合中,中生代和古生代植物化石属同层位出现,这一现象说明九里岗组的地质时代,可能属晚三叠世的卡尼期—诺利期的早期。  相似文献   

15.
The cytokinin 6-benzylaminopurine (BAP) increases pod set of soybean Glycine max (L.) Merr. This study was performed to determine the effect of site and method of BAP application on pedicel abscission and the accompanying changes in rachis anatomy. Spraying racemes with BAP in solution, or applying in a lanolin suspension to proximal nodes on a rachis where proximal pedicels had been excised, delayed pedicel abscission at distal nodes. Applying BAP in lanolin to distal pedicels following flower excision failed to delay their abscission. BAP caused rachis swelling only when pods were present, but BAP could delay pedicel abscission either in the presence or absence of pods. These results suggest that rachis swelling following BAP treatment does not have a causal relationship to a delay or decrease of pedicel abscission.Alabama Agricultural Experiment Station Journal No. 6-912843P.  相似文献   

16.
    
This paper deals with a few fossil plants of the Jiuligang Formation found ill Jingmen-Dangyang Basin, western Hubei, China. Of which a few are related to paleozoic taxa, such as Compsopteris laxivenosa sp. nov. and C. xiheensis (Feng) comb. nov., Besides those, Paradrepanozamites dadaochangensis Chen, emend, nov. and P. minor sp. nov. are described. The geological age of the Jiuligang Formation is assigned to Carnic to early Noric.  相似文献   

17.
18.
云南元江普通野生稻穗颈维管束和穗部性状的QTL分析   总被引:9,自引:0,他引:9  
以云南元江普通野生稻为供体亲本,籼稻品种特青为轮回亲本构建高代回交群体,用SSR标记构建连锁图谱,在第1、2、3、4、7和10染色体上定位到7个控制穗颈大维管束数的QTL,在第1、2、3、4和8染色体上定位到5个控制穗颈小维管束数的QTL,在第11和12以外的10条染色体上,共定位到15个控制穗一、二次枝梗数和穗颖花数QTL。来自野生稻的等位基因大多表现负效,能显著减少群体的穗颈维管束数、枝梗数和颖花数,说明从野生稻演化成栽培稻的过程中,可能淘汰了一些对产量不利的QTL,保留了有利的QTL。相当一部分控制穗颈维管束数、枝梗数及颖花数的QTL在染色体上成簇分布或紧密连锁,且加性效应的方向一致,从理论上解释了这些性状表型显著相关的遗传基础,同时也说明在人工选择或自然选择下,这些性状可能存在平行进化或协同进化的关系。  相似文献   

19.
Evidence from vegetative anatomy, reproductive morphology, and palynology does not support a relationship of Oceanopapaver with Cistaceae, Cruciferae, Flacourtiaceae, Papaveraceae, and Tiliaceae, but suggests placement of the genus in Capparaceae. The apparent occurrence of myrosin cells, among other features, effectively excludes all of the aforenoted families except Capparaceae and Cruciferae. However, multicellular non-glandular trichomes, bracteate inflorescences, sepals and petals each occasionally other than four per flower, presence of an androgynophore, numerous stamens, tricolporate and binucleate pollen, the unilocular mature ovary, the stipitate fruit, and the exotegmic seed in Oceanopapaver favour Capparaceae over Cruciferae. Floral histology and vasculature provide no clues about the relationships of Oceanopapaver. A few features are anomalous, most notably the presence of secretory canals and secretory cells in the genus versus their absence in Capparaceae and their rarity in Cruciferae, the trichomic floral nectary in the genus versus the massive, non-trichomic nectaries in these two families, and the straight embryo in the genus versus the more or less curved or folded embryo in the two families. The fleshy endosperm in Oceanopapaver has counterparts in a few Capparaceae, contrary to previous claims that endosperm is absent or scanty in this family. The report of stamen fascicle traces for Oceanopapaver is the first for Capparaceae, but these should be sought elsewhere in the family. Within Capparaceae the genus fits best in Capparoideae compared to Cleomoideae or the nine other very restrictive subfamilies variously proposed for Capparaceae. There is no justification for the monotypic segregate Oceanopapaveraceae. The phylogenetic and functional anatomy of vegetative and reproductive structures is discussed.  相似文献   

20.
中国水蛇的神经系统   总被引:1,自引:0,他引:1       下载免费PDF全文
本文报道中国水蛇神经系统的大体解剖,其中,对三叉神经叙述较详。  相似文献   

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