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1.
The development of the shoot apex is studied in regard to relationships between morphogenesis and histogenesis. Differentiation of procambium starts only some distance from the shoot apex at the basis of leaf initials and continues from the node into leaf and axis. Lateral strands appear parallel with the first ternation in the leaf. The development of procambium strands is correlated with the differentiation in the axis and there seems to be a mutual stimulation between leaf initial and procambium.
Teil einer Dissertation an der Fakultät für Biologie der Universität Heidelberg. 1. Beitrag einer Serie über Die Sproßentwicklung vonClematis vitalba (Ranunculaceae).  相似文献   

2.
The shoot organization and inflorescence structure ofEpithema is analyzed. On the main axis micro- and macrocotyledon (the latter falling off early) are followed by a ± long epicotyl, then a large, solitary leaf (B3) and above this a dimerous leaf whorl (B4, B5). The last internode of the main axis is the basic internode of the main florescence (Troll). Peculiarly enough, the latter includes only one partial florescence which is embraced by its subtending bract (B6) and represents a capitulum-like, congenital, pair-flowered cincinnus. Paracladia arise from the axils of B3 to B5 (sometimes also from the macrocotyledon); they are either reduced to their co-florescence (with the same structure as the main florescence), or carry further shoots resp. co-florescences from the axils of a dimerous leaf whorl.—Epithema can be interpreted as anisophyllous.—From flower morphology and ontogenesis a number of new differential characters are revealed. Together with shoot and inflorescence characters their systematic and possible functional significance is discussed.
Frau Univ.-Prof. Dr. E.Tschermak-Woess zum 60. Geburtstag gewidmet.  相似文献   

3.
The two characters used byBurtt (1974) to segregate the genusSchizoboea fromDidymocarpus, viz. terminal inflorescence and fruit splitting into 4 valves, have been studied in detail: (a) The terminal inflorescence represents a bracteate florescence (sensuTroll), that is an open thyrse, peculiar because of its only two extremely condensed internodes (basic internode + 1 following internode). Correspondingly, there are only two pairs of bracts from which the lower one only is capable to develop axillary partial florescences, i.e. pair-flowered cymes. Thus, the number of cymes is restricted to 2. Because of the condensed internodes, the inconspicuous bracts, and the densely aggregated flowers the two cymes simulate a unitary, terminal structure. By sympodial (± asymmetrically dichasial) linkage of shoot units, composed of an extended internode, a foliage leaf pair (from the axils of which the consecutive units arise) and the florescence,Schizoboea forms (polytelic) anthocladial shoot systems like some genera of the tribeKlugieae (incl.Loxonieae). (b) The fruit dehisces first loculicidally, then each valve splits into three portions (lateral rib and 2 semivalves). Moreover, the 4 placentae become isolated, thus the old fruit comprises 10 elements forming a loose fascicle.—The segregation ofSchizoboea fromDidymocarpus is supported. Whether the affinity is closer toSaintpaulia (as suspected byBurtt) ot toDidymocarpus, remains undecided: In regard to its shoot and inflorescence organization a morphological derivation is possible from both genera.
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4.
An electron microscopical investigation of the cell walls in young antheridia ofPolypodium crassifolium andPlatycerium alcicorne confirms the classical developmental model as postulated byStrasburger and byKny. The structure of the basal cell walls, both of the funnel cell and of the operculum, and especially the evidence of plasmodesmata in those walls, disprove the widely accepted interpretation presented 1951 byDavie.
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5.
Within the genusLoxonia Jack, currently regarded as monotypic, three species are recognized:L. hirsuta Jack (Sumatra, Mentawai-Islands, Java, Borneo, Anambas-Islands, Malay Peninsula),L. discolor Jack (Sumatra) andL. burttiana A. Weber, spec. nova (Borneo). [Key with English translation p. 203.] There is evidence thatL. discolor is the most primitive species within the genus, the two others being derived from it.
Teil V der Beiträge zur Morphologie und Systematik derKlugieae undLoxonieae (Gesneriaceae).  相似文献   

6.
InEchinops the flowers are surrounded by several scales and initiated in an acropetal and spiral succession on a cone-like inflorescence axis (Figs. 1–6). The floral organs originate in the following sequence: petals—stamens—carpels—pappus. The petals arise from a meristematic rim and therefore are already interconnected when they arise as primordia. This sympetalous zone remains rather inconspicuous for a long period, but eventually, the elongated corolla tube is formed through intercalary growth in a ring zone. Thereby, the stamens are moved upwards and form ledges on the corolla tube (Fig. 34). In the inferior ovary the usual zones of the typical angiospermous gynoecium can be distinguished, namely a synascidiate, symplicate and hemisymplicate zone. The ovule is borne on carpellary tissue.
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7.
The thickened shoot bases ofNeoalsomitra podagrica carry spines of an undescribed nature: they represent morphologically phyllodes. A closed ring of sclerenchyma originating from the fusion of vascular bundle sheaths is responsible for the rigidity of these organs. Contrary to their cylindric structure these phyllodes are to be considered as bifacial. Between the region of phyllodial spines and foliage leaves there is a transition zone with petiole spines characterized by secondary loss of rudimentary leaf blades.
Herrn Prof. Dr.W. Leinfellner zum 65. Geburtstag gewidmet.  相似文献   

8.
H. -U. Koop 《Protoplasma》1979,101(4):363-371
Summary Stalks ofAcetabularia mediterranea cells after cyst formation contain residual nuclei,e.g., secondary nuclei not used for cyst formation. Residual nuclei may lead to the formation in the stalk of direct germlings (Hämmerling 1955), cysts, and—without preceeding cyst formation—of biflagellate swarmers, identical in appearance with gametes.  相似文献   

9.
The remarkable diversity of fruits inValerianella andFedia is revealed by a comparative morphological and anatomical analysis. Characters are evaluated in regard to a new systematic grouping. The knowledge on dispersal biology is summarized and supplemented. Finally, salient features of fruit differentiation are discussed.
3. Teil der Publikationsserie Beiträge zur Systematik und Evolution vonValerianella undFedia (Valerianaceae) (vgl.Ernet 1977a, b).  相似文献   

10.
Cells ofMicrasterias denticulata Bréb. were kept in nutrient solution of high osmolality (salt stress) for four weeks. In a special cell multiplication test it was established that cell division is gradually inhibited at increasing salt concentrations and totally arrested at the highest concentration (26 mosm/kg). Recovery studies proved that even cells from the highest concentration range start dividing immediately after being placed in aqua bidest. thus indicating the full reversibility of the inhibiting effect. — Cells of the highest concentration range show marked ultrastructural changes. Besides an enormous accumulation of starch and oil bodies and a condensed appearance of the ground plasma, a reduction of mitochondria, ER and the Golgi-system is found. The most striking effect occurs on the vacuolar system which appears extremely reduced and condensed. The cell wall is thickened by the formation of an additional cell wall layer with a spongy electron microscopical appearance. Through the cell wall many droplets of a probably fat-like substance are excreted. — In summary, salt stress induces growth-inhibited akinete cells in the sense ofFritsch; these can be reactivated by decreasing the salt concentration. The salt-induced akinete state seems to be an ecological adaption to unfavourable conditions rather than a degeneration of the cells.Dedicated to Prof. DrLothar Geitler on the occasion of his 90th birthday.23. 12. 1988  相似文献   

11.
A stratagem for the synthesis ofneoglycoproteins suitable for the selective serodiagnosis of leprosy is described in which synthetic 3,6-di-O-methyl--d-glucopyranose, the epitope of phenolic glycolipid I fromMycobacterium leprae, was used. Condensation of 8-methoxycarbonyloctanol with the acetobromo derivative of 3,6-di-O-methylglucose gave 8-methoxycarbonyloctyl 2,4-di-O-acetyl-3,6-di-O-methyl--d-glucopyranoside in 65% yield, and with absolute stereospecificity for the anomer. The deacylated product was converted to the crystalline hydrazide and coupled to bovine gamma globulin, bovine serum albumin and poly-d-lysinevia intermediate acyl azide formation to produce the 8-carbonyloctyl 3,6-di-O-methyl--d-glucopyranosyl polypeptides. Theneoglycoproteins were highly sensitive in ELISA and emulated the specificity of the native glycolipid in analysis of sera from patients throughout the spectrum of leprosy and from different geographical regions. The 8-carbonyloctyl 3,6-di-O-methyl--d-glucopyranoside-bovine serum albumin was also synthesized and shown to have about one-half the activity of the -linkedneoglycoprotein. A different synthetic approach produced the 8-carbonyloctyl 4-O-(3,6-di-O-methyl--d-glucopyranosyl)--l-rhamnopyranoside-bovine serum albumin which was also highly sensitive and specific for the serodiagnosis of leprosy. The presence of the second sugar unit, similar to that in the native glycolipid but for the absence ofO-methyl groups, seemed to provide a probe with greater felicity for the serological detection of tuberculoid leprosy.Thus, the results indicate that highly sensitive and specific antigen probes for the serodiagnosis of leprosy can be constructed based only on the terminal one or two sugars of phenolic glycolipid I, and the synthetic approach leads to the formation of haptens with absolute stereospecificity.Nomenclature BGG bovine gamma globulin - PGL-I phenolic glycolipid I - PDL poly-d-lysine - PBS phophate-buffered saline - 3,6-Me2-Glc-Link-BSA 8-carbonyloctyl 3,6-di-O-methyl-glucopyranoside-bovine senalbumin - 3,6-Me2-Glc-Rha-Link-BSA 8-carbonyloctyl 4-O-(3,6-di-O-methyl--d-glucopyranosyl)--l-rhan pyranoside-BSA  相似文献   

12.
Zusammenfassung Die Verwertung von Carnitin und Carnitinderivaten (O-Acylcarnitine, Carnitincarboxyl-derivate) und strukturverwandten Trimethylammoniumverbindungen (Betaine und Stickstoffbasen) durch Acinetobacter calcoaceticus wurde anhand des Wachstums und des quantitativen Nachweises der Metabolite untersucht. Der Stamm wuchs auf l-Carnitin, l-O-Acylcarnitinen und -Butyrobetain als jeweils einziger C-Quelle. Der Verbrauch dieser Verbindungen und das Wachstum korrelierten mit der Spaltung der C-N-Bindung und mit dem gebildeten Trimethylamin. d-Carnitin wurde metabolisiert, wenn als zusätzliche C-Quelle l-Carnitin im Nährmedium vorhanden war, oder wenn die Bakterien mit l-oder dl-Carnitin vorinkubiert worden waren. Mit d-Carnitin als einziger C-Quelle wuchsen die Bakterien jedoch nicht. Die Bakterien oxidierten Cholin zu Glycinbetain in Gegenwart einer zusätzlichen C-Quelle, Glycinbetain selbst wurde nicht assimiliert. In Hinsicht auf den Abbau quaternärer Stickstoffverbindungen besitzt Acinetobacter calcoaceticus im Vergleich zu anderen Carnitin-verwertenden Bakterienarten einen für ihn charakteristischen Stoffwechselweg.
Utilization of trimethylammonium-compounds by Acinetobacter calcoaceticus
The utilization of carnitine and carnitine derivatives (O-acylcarnitines, carnitine carboxylderivatives) and structure-related trimethylammonium-compounds (betaines and nitrogen-bases) by Acinetobacter calcoaceticus was studied by means of the control of growth and the quantitative detection of metabolites. The strain grew only on l-carnitine, l-O-acylcarnitines, and -butyrobetaine as the sole carbon sources. The utilization of these compounds and the growth correlated with the cleavage of the C-N bond and thereby with the formation of trimethylamine. d-Carnitine was metabolized, if an additional carbon source, like l-carnitine, was present in the incubation mixture, or if the bacteria were preincubated with l-or dl-carnitine, but no growth was observed on d-carnitine as the sole carbon source. The bacteria oxidized choline to glycinebetaine in the presence of additional carbon sources, glycinebetaine itself was not assimilated. With regard to the catabolism of quaternary nitrogen compounds Acinetobacter calcoaceticus shows a different pathway in comparison with other bacterial species metabolizing carnitine.
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13.
The leaf base vascularization in most of theRubiaceae corresponds to the unilacunar pattern with one complex trace. Only some species are known to have a trilacunar nodal pattern with three traces. In the unilacunar type one pair of smaller bundles separates from the complex lacunary leaf trace laterally, each soon forking into two arms: One arm becomes a marginal vein of the petiole, the other, besides supplying the stipules, forms a ± distinct vascular bridge within the cortex of the nodal flanks. In theRubieae this flank bridge develops as a very distinct vascular ring commissure out of which the whorled leaf-like appendages are vascularized; only the opposite true leaves receive their complex trace out of the lacunes directly. Axillary branches originate only from these true leaves.
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14.
The sequence of subfamilies,Cinchonoideae, Antirheoideae andRubioideae, attemps to show their natural affinities and phylogeny. The subfamilies are those ofVerdcourt, and the order in which they are presented is that ofBremekamp. A list is presented of the subfamilies, tribes and genera of theRubiaceae to be utilized in the Catálogo Ilustrado de las plantas de Cundinamarca, Colombia.  相似文献   

15.
Statistical population analyses have been carried out on so-calledOphrys arachnitiformis, partly sympatricO. sphecodes s. l. as well as on other species ofOphrys (O. holosericea, O. exaltata, O. apulica, O. cornuta, O. biscutella, O. bertolonii, O. bertoloniiformis.). Altogether 63 populations with 521 individuals were studied in regard to 54 morphological parameters. — It can be shown thatO. arachnitiformis is an extremely heterogeneous assemblage which includes taxa of most diverse origin, different degrees of stability and nomenclatorial rank. Only common trait is their very diverse relationships withO. specodes s.l.—The basionymO. arachnitiformis Gren. & Phil. refers to a colour variant ofO. sphecodes Mill. subsp.sphecodes only, and is not applicable to other segments of the assemblage.A late flowering, morphologically and biologically well isolated group of populations from southern France without any perceptible hybrid influence is established as a new species:Ophrys splendida Gölz & Reinhard. Populations from north and central Italy with distinct characters but hybrid influences fromO. holosericea/O. exaltata are calledO. tyrrhena Gölz & Reinhard.O. morisii, an endemic to Sardinia, represents an independent species of still obscure evolution. The hybrid interpretation ofO. catalaunica is statistically corroborated, but somewhat modified. For the remaining segments ofO. arachnitiformis investigated (from Castilia, Dalmatia, and the Monte Gargano) no formal taxonomic proposals are made, but some suggestions about their genesis are possible.
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16.
A new genus,Aurantiosporium Piepenbring, Vánky & Oberwinkler (Ustilaginales), is proposed for the smut speciesUstilago subnitens Schröter & Hennings onScleria melaleuca Reichb. The soral morphology, teliospore development, the ultrastructure of the teliospore wall and teliospore germination ofAurantiosporium subnitens, studied on collections from Costa Rica, are described for the first time. The character set ofA. subnitens including intercellular teliospore development, spores in irregular groups and light coloured spore walls with numerous layers in TEM is neither known fromUstilago norCintractia nor any other smut species.Part 113 in the series Studies inHeterobasidiomycetes from the Botanical Institute, University of Tübingen.  相似文献   

17.
Nicolaia elatior is used as an example to demonstrate that the mucronate tepals ofZingiberaceae correspond to hypsophylls (bracts) consisting of a leaf sheath and a rudimentary Oberblatt (= leaf petiole + lamina) represented by the mucro. Evidence for this interpretation is furnished by all available criteria: leaf sequence (exhibiting a complete continuum of forms from foliage leaves over cata- and hypsophylls to the tepals), nervature, and ontogeny.The present conception is compared with the well-founded thesis ofLeinfellner that the perigone ofLiliaceae is derived from the androecium. The different morphological status of the perigone in both families is not regarded as the result of different phylogenetic origin, but as a manifestation of morphogenetic transgressions from one phyllome category to an adjacent one: In theLiliaceae the perigone is under a strong morphogenetic influence of the androecium, and therefore displays staminal characters, in theZingiberaceae it is under the dominating influence of the extrafloral region, and thus appears as a hypsophyllous structure. If this assumption of a morphologically oscillating perigone is correct, it will be fundamentally impossible to demonstrate unequivocally the phylogenetic origin of the monocotyledonous perigone.
Im wissenschaftlichen Werk Prof. Dr.Walter Leinfellners steht an erster Stelle die Morphologie der Blütenorgane. Als sein dankbarer Schüler möchte ich ihm aus Anlaß seines 70. Geburtstages die folgende Studie zu einem Thema zueignen, das ihn wie mich gleichermaßen angesprochen hat und schon Gegenstand der Forschungsarbeit des Jubilars war: die Homologie des Monokotylen-Perigons.  相似文献   

18.
The preparation of benzyl 2,3,6,2,6-penta-O-benzyl--d-lactoside, which is a key intermediate for chemical synthesis of oligosaccharide components of glycosphingolipids, was achieved by an improved method. The 3-O-p-methoxybenzyl and 3-O-methyl derivatives were prepared from benzyl 2,3,6,2,6-penta-O-benzyl--d-lactoside through stannylation. By using benzyl -d-lactoside as starting material, benzyl 3-O-methyl-, 3-O-benzyl- and 3-O-p-methoxybenzyl--d-lactoside were regioselectively synthesized using the same procedure.  相似文献   

19.
Asperula visianii Korica is described as a new stenoendemic species from the small Central Dalmatian island of Svetac (near Vis). It differs in several morphological features (which remain constant in cultivation) and in its ecology from the closely relatedA. staliana Vis., endemic on the nearby island of Bievo.
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20.
The efficacy of benzyladenine (BA) to induce multiple shoots from seed explants of chickpea (Cicer arietinum L.) was assessed. Shoot differentiation was influenced by the type of seed explant, genotype and concentration of BA. Orientation of the explant also strongly influenced the shoot regeneration response. The optimum BA concentration for shoot/shoot bud regeneration was genotype dependent. Two types of BA-induced response were observed: (1) at less than 7.5 gm BA, direct shoot differentiation (2 to 4-cm-long shoots) was observed within 30 days; (2) at higher BA concentrations (75–100 m), shoot/shoot bud differentiation was achieved in 45–90 days. A high BA concentration inhibited subsequent rooting of shoots. Roots, however, could be easily induced on shoots derived from <12.5 m BA. Following transfer to soil, 80% of the regenerants developed into morphologically normal and fertile plants.Abbreviations BA Benzyladenine  相似文献   

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