Tropische Pilze

Tropical fungi Mycological fieldwork in the tropics is a fascinating activity, because fungi are heterotrophic living beings and acquire nutrients in manyfold ways, often in association with algae, plants, or animals. Numerous fungi live in mutualistic symbiosis with plants or algae (lichens), as parasites of plants, or live on dead plant material. Other fungi kill insects or other animals and use their bodies as substrate to develop fruiting bodies, while a few fungal species live in mutualistic symbiosis with insects. These and further groups of fungi are presented based on examples from Panama. Sometimes, supposed fungal structures turn out to be cases of mimesis – plants or animals copy fungal patterns in order to take cover.     

Die Stellung der Uredineen und Ustilagii der Pilze

Ohne Zusammenfassung     

Die Lokalisation der Peroxidase-Isoenzymgruppe GI in der Zellwand von Tabak-Geweben

Summary By vacuum infiltration of intercellular spaces of tobacco tissues it is possible to extract substances from cell walls which move freely in the walls. The peroxidases (E.C. 1.11.1.7) contained in these extracts are predominantly isoenzymes of G_I (fast migrating anodic group) as was shown by discelektrophoresis of the extracts. As has been demonstrated previously G_I is not present in the protoplast; therefore G_I is the typical cell wall fraction of tobacco peroxidases. Different tissues of tobacco always differ in the isoenzyme pattern of G_I. This pattern also changes during tissue development. We can therefore say that there exists an enzymatic differentiation of plant cell walls during development. As G_I is not bound to the walls, it always appears in high amounts in crude extracts of plant material. Therefore G_I is always called the soluble cytoplasmic fraction, but our investigations clearly demonstrate that G_I is localized in cell walls only. Beside G_I there are much smaller amounts of G_III (slow migrating cathodic group) and if present in the tissue G_II (slow migrating anodic group) detectable in the infiltration fluids of intracellular spaces. G_III and G_II are localized mainly in the protoplast. But they are also bound to the walls, ionically in the case of G_III and covalently in the case of G_II.

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Abkürzungen MDH Malatdehydrogenase (E.C. 1.1.1.37) - G_I, G_II, G_III Enzymgruppen der Peroxydase - FG Frischgewicht     

Die Ultrastruktur der Zellwand und des Chloroplasten von Chlorella

Zusammenfassung Verschiedene Chlorella-Stämme wurden mit der Gefrierätzungsmethode untersucht.Die Zellwand von Chlorella vulgaris ist aus drei Schichten aufgebaut. Die äußerste Lage besteht aus verfestigter Matrixsubstanz. Sie wird bei alten Zellen aufgelöst. In der breiteren, mittleren Zone liegen Zellulosefibrillen und 80 Å-Teilchen in einer amorphen Grundmasse. Eine dünne, fibrillenfreie Matrixschicht bildet die innere Zellwandlage. Das Plasmalemma ist mit verschieden tief eingelagerten 80 Å-Partikeln in statistischer Verteilung besetzt.Zellwandentwicklung: Die Matrixsubstanz entsteht in den Golgi-Vesikeln. Diese werden mit ihrer Umgrenzungsmembran in den Raum zwischen Plasmalemma und Zellwand befördert. Während sich die Plasmamembran einschnürt, platzen die Bläschen und geben ihren Inhalt frei. Von der dabei entstehenden Matrix verfestigt sich die äußerste Lage unter der alten Zellwand und zwischen den Tochterzellen. Darunter sammeln sich ausgeschiedene, 80 Å große Plasmalemmapartikel an. Die Zellulosefibrillen erscheinen zuerst in dieser partikelreichen Zone, kurz darauf in der ganzen mittleren Zellwandschicht. Es wird angenommen, daß die ausgestoßenen Plasmalemmapartikel Enzymkomplexe darstellen, die die Fähigkeit besitzen, in der Matrix Zellulosefibrillen zu synthetisieren.Von den andern Zellbestandteilen wurde besonders der Chloroplast näher untersucht. Die Thylakoidmembran besteht aus einer zentralen Trägerschicht, die beidseitig mit Proteinpartikeln bedeckt ist. Die in der Membran-Außenseite eingelassenen Partikel haben in der Aufsicht einen Durchmesser von 120 Å. Sie scheinen aus vier oder mehr Untereinheiten in quadratischer Anordnung zu bestehen und besitzen eine zentrale Vertiefung. Ihre Dichte ist starken Änderungen unterworfen. Nach den vorliegenden Befunden sind die 120 Å-Teilchen nicht adsorbierte Partikel aus dem Chloroplastenstroma, sondern membraneigene Bestandteile. Auf der Innenseite der Thylakoide liegen 60 Å-Teilchen in dichter Packung. Die innere Plastidenmembran besitzt den gleichen Aufbau wie die Thylakoidmembranen, doch ist die Zahl der Å 120-Partikel sehr gering. Neue Thylakoide entstehen durch Einstülpungen der innern Chloroplastenmembran oder durch Gabelung oder Zurückfaltung schon vorhandener Lamellen. Dabei erfolgt die Synthese der drei Membrankomponenten (Trägerschicht, 120 Å- und 60 Å-Partikel) synchron.In Dunkelzellen der Chlorella-Mutante 5/520 weist die Chloroplasten-Doppelmembran keine Veränderungen auf, während Zahl und Größe der Thylakoide stark abnehmen. Die verbleibenden Lamellen sind blasenförmig erweitert. Bei der Wiederbelichtung der Zellen entstehen neue Thylakoide wie in normalen Chloroplasten.Begast man Dunkelzellen während der Belichtung mit reinem Stickstoff, so bilden die 60 Å-Partikel auf der Außenseite der innern Plastidenmembran wie im Innern der Thylakoide ein polygonales Netzwerk. Im Grundplasma können zahlreiche Verzweigungen des endoplasmatischen Reticulums und eine starke Zunahme der Fetttröpfchen beobachtet werden.

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Summary Different Chlorella strains were investigated with the freeze-etching method. The cell wall of Chlorella vulgaris is composed of three layers. The outermost layer consists of thickened matrix material, which becomes dissolved in older cells. In the broader, middle zone cellulose fibrils, and particles with a diameter of 80 Å, can be seen in an amorphous ground substance. Finally, a thin layer of matrix material forms the inner side of the wall. The particles that cover the plasmalemma are randomly distributed and have a diameter of 80 Å.Cell wall development: The matrix material is formed in the Golgi vesicles which pass through the cell membrane into the space between the plasmalemma and the cell wall. During the constriction of the cell membrane the vesicles burst and their contents are liberated. The outermost layer of the matrix thus formed becomes thickened under the old cell wall and between the daughter cells. Beneath this layer, the secreted 80 Å-plasmalemma particles accumulate. Cellulose fibrils can first be detected in this zone and shortly later, in the whole middle cell wall layer. It is assumed that the secreted plasmalemma particles are enzyme complexes, which posess the capability to synthesize cellulose fibrils in the matrix.The thylakoid membranes consist of a central layer covered on both sides with protein particles. On the outer side the embedded particles have a diameter of 120 Å and a thickness of 60 Å. They appear to be built up of four or more subunits in a quadratic arrangement with a central pore. The number of these particles, per unit area, differs greatly from one thylakoid to the other. From the data presented the 120 Å-particles belong to the thylakoid membrane and are not adsorbed particles of the chloroplast stroma. The inner side of the thylakoid membrane is densely covered with particles having a diameter of 60 Å. The inner layer of the chloroplast membrane has the game structure as the thylakoid membranes. New lamellae arise from the inner layer of the chloroplast membrane by invagination, or by bifurcation or folding back of already existing thylakoids. The synthesis of the three membrane components (central layer, 120 Å- and 60 Å-particles) occurs synchronously.In dark-grown cells of the Chlorella mutant 5/520, the plastid membrane shows the normal structure. The few remaining thylakoids, however, exhibit an irregular blown up structure. On re-illumination of the cells new thylakoids are formed as in normal chloroplasts. If dark cells are illuminated in a N₂ atmosphere the 60 Å-particles on the outside of the inner chloroplast membrane, and in the thylakoids, form a polygonal network. The endoplasmic reticulum shows extensive development and lipid droplets appear in the groundplasm.

     

Die Stellung der Uredineen und Ustilagineen im System der Pilze

Ohne Zusammenfassung     

Die Bedeutung der Tintinnen als Glied der Nahrungskette

Zusammenfassung 1. Viele Tintinnenarten sind kosmopolitisch verbreitet. Gebiete des Weltmeeres mit ähnlichen Lebensbedingungen beherbergen gleiche Tintinnen. Sie leben in der lichtdurchfluteten Zone des Meeres, wo das Angebot an Nahrung am größten ist. Tägliche vertikale Wanderungen wurden nachgewiesen.2. Die jahreszeitliche Verbreitung richtet sich nach der geographischen Breite. Bei der ozeanischen Wetterschiffstation India liegt das Maximum mit 4 000 000 Exemplaren unter 1 m² im Mai bis Juli; das entspricht einer Biomasse von etwa 300 mm³.3. Der begrenzende Faktor für die Entwicklung und Verbreitung von Tintinnen ist vor allem die Wassertemperatur. Der Einfluß von Salzgehalt und Sauerstoffsättigung ist offensichtlich weniger bedeutsam.4. Die Nahrung der Tintinnen besteht aus Detritus, Bakterien, nackten Flagellaten, Coccolithophoriden, Peridineen, Diatomeen und Silicoflagellaten. Die Tintinnen selbst werden von Euphausiaceen, Copepoden, Tunicaten und Fischlarven gefressen.5. Tintinnen bilden eines der ersten Glieder in der Nahrungskette. Man sollte in Zukunft dieser interessanten Giliatengruppe bei produktionsbiologischen Untersuchungen mehr Beachtung schenken.

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The significance of the tintinnids as a link in the food web

Tintinnids are shell building Protozoa regarded as heterotrich ciliates. Most of them are marine; less than 2% of the 800 known species occur in fresh water. Tintinnids live almost exclusively free-swimming pelagic and occur at all latitudes, in all seas, predominantly in the upper illuminated water layers. Their geographical distribution is primarily controlled by temperature and so is their development; salinity and oxygen seem of little importance. Tintinnids are one of the first links in the food chain. They feed on detritus, bacteria, naked flagellates, coccolithophores, peridineans and diatoms. The tintinnids themselves are eaten by copepods, euphausiids, tunicates and fish larvae.

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Diese Untersuchungen wurden zum Teil gefördert durch den Kontrakt N 62 558-3612 zwischen Office of Naval Research, Department of the United States Navy und der Scottish Marine Biological Association.     

Die Feinde der Raubmilben als Reduzierender Faktor der Spinnmilben

Summary The relations betweenMetatetranychus ulmi living on apple trees and its different predators are complex. The most important natural enemy of this spider mite is the predacious miteTyphlodromus pyri (= T. tiliae). It destroys more spider mites than the beneficial insects do. In the district of Stuttgart-Hohenheim about 38 species of insects and spiders feed onTyphlodromus mites. For instanceT. pyri is reduced considerably byOrius minutus. This bug is a natural enemy of aphids and spider mites, however it prefers the predatory mites. It attacks the spider mites and aphids only ifTyphlodromus mites are not available.Chrysopa vulgaris andAnthocoris nemorum are similar in their feeding habits. These two destroyTyphlodromus pyri also but they are less important thanO. minutus. The other beneficial insects in our orchards have little effect on spider mites or predacious mites. If we have enough pests on our apple trees to make spraying necessary, we should look forTyphlodromus mites and be careful no to destroy them. We should always examine the composition of the biocoenosis applying chemical agents because the populations of insects and predacious mites may vary from one area to the other.      

Die Plasmodien der Myxomyceten als Objekt der chemischen Protoplasmauntersuchung

Ohne Zusammenfassung     

Die Seleriten der Oktokoralle Briareum als Biokristalle

Ohne Zusammenfassung Mit Tafel III und 15 Textabbildungen.     

Die Plastidenzahl als Merkmal bei der Kartoffel

Summary The average number of plastids in ten pairs of guard cells is a very useful aid for screening haploids among tetraploid plants fromS. tuberosum x S. phureja.In individual seedlings the stomatal plastid number decreases from the cotyledons to the first leaves. From the lower to the upper part of stems there exists a decreasing gradient for plastid number and an increasing gradient for the number of stomata per leaf area unit, whereas the stomatal length does not show a consistent trend.In the stomata, plastid number and stomatal length are positively correlated.Mean numbers of plastids in guard cells increase by a factor below 2 (1.8–1.9) after each doubling of the chromosome number.The stomatal plastid numbers of 48-chromosome breeding lines and of their haploid progenies show a clear positive correlation. The mean plastid numbers in various haploid families from different mother plants display significant differences.The origin of the cytoplasm (plasmone + plastome) fromS. demissum, S. stoloniferum, S. tuberosum, andigena forms ofS. tuberosum orS. spegazzinii in which the genome of the haploid is incorporated definitely influences the number of plastids in the guard cells.The stomatal numbers of plastids in 72 trisomic haploids show no significant deviation from the normal distribution of plastid numbers in haploids.Plastid number and stomatal length show a positive correlation in a population of 48 haploid lines and also in the same lines after doubling and quadrupling the chromosome number, the coefficient of regression decreasing with increasing ploidy level. In the above mentioned material there exists a strong positive correlation between the haploid and the corresponding homodiploid plants concerning stomatal length and the number of plastids.A comparison of the correlation stomatal length/plastid number at the 24-, 48- and 96-chromosome levels in three different genotypes reveals that some individuals are more sensitive to a rise in ploidy level than others and that the stomatal plastid number is a more reliable indicator of ploidy level than the stomatal length.We found some scattered polysomatic doubled stomata in leaf epidermissystems, stolons and tuber primordia of potatoes from various ploidy levels. The stomata at the border of the lamina are regularly endomitotically doubled, regardless of the original ploidy level.The hypothesis of a specific basic number of plastids for a given species, multiples of which should give origin to tissue-specific numbers, is criticized.High plastid numbers were negatively correlated with vitality. potatoes the possible correlation between plastid number in haploids and the direction of their original phyllotacticAs both the plastid number and the direction of the phyllotactic leaf spiral show some correlation with vitality in potatoes the possible correlation between plastid number in haploids and the direction of their original phyllotactic spiral was tried. The two groups with low and normal stomatal plastid numbers displayed almost equal distribution between left- and right-directed spirals; in the category with high plastid number, however, this relation was significantly displaced in favor of right spirals. It is tentatively proposed that both vitality and the direction of the phyllotactic spiral are governed by a common hormonal principle (pissibly auxins) which also influences the number of plastids.     

Die Stria terminalis als Einrichtung der Liquorresorption

Zusammenfassung Es wird die Auffassung unterbaut, daß die Stria terminalis eine Resorptions- bzw. Reinigungsfunktion des Liquors innehabe. Als Argumente hiefür werden angeführt: Das dort befindliche Furchenfeld, das embryonale Verhalten der Gegend, besondere Vaskularisationsverhältnisse, die Anordnung der Corpora amylacea, ferner gewisse pathologische Befunde.     

Swm1p, a subunit of the APC/cyclosome, is required to maintain cell wall integrity during growth at high temperature in Saccharomyces cerevisiae

Swm1p, a subunit of the APC cyclosome, was originally identified for its role in the later stages of the sporulation process and is required for spore wall assembly. In addition, this protein is required to maintain cell wall integrity in vegetative cells during growth at high temperature. Electron microscopy analyses of mutant cells grown at the restrictive temperature in the absence of osmotic support show that the cell wall is clearly abnormal, with large number of discontinuities that may be responsible for the observed lysis. The mutant cells show a 7-fold reduction in glucan synthase activity during growth at 38 degrees C and a 3.5-fold increase in the chitin content of the cell wall. The chitin is deposited in a delocalized manner all over the cell wall, where it accumulates in patches in abnormal regions. The excess chitin is mainly synthesized by the action of chitin synthase III (Chs3p), since it disappears in the swm1 chs3 double-mutant.     

Die Microflora Vaginalis als Beispiel der Syndynamik bei Bakteriengesellschaften

Ohne ZusammenfassungKurzfassung eines Vortrags am Symposium der Syndynamik in Rinteln, 21. März 1967.