MORPHOGENESIS OF THE SPORANGIUM OF COMATRICHA

Goodwin , Donna C. (State U. Iowa, Iowa City.) Morphogenesis of the sporangium of Comatricha. Amer. Jour. Bot. 48(2): 148–154. IIlus. 1961.—Three species of the myxomycete genus, Comatricha, were studied: Comatricha nigra, C. fimbriata, and C. elegans. The sporangia developed on living bark of Ulmus americana in moist chamber. The hypothallus is formed under the homogeneous protoplasmic mass of the sporangial initial. The fibrous threads of the hypothallus bend upward, lengthening at the apices to become the fibers of the stalk and columella. The undifferentiated protoplasm is carried upward as the stalk elongates. When the columella has attained its mature height, threads bend out from the columella and grow toward the periphery of the sporangium. These threads form the capillitium. Simultaneous with the appearance of the capillitial initials, the peridium, a delicate membrane, forms. After the capillitium is mature, the protoplast cleaves into many cells, the future spores. The peridium evanesces early in the stage of spore maturation. Cellulose is present in the stalk, capillitium, and spore walls but is not found in the peridium or hypothallus. The capillitium of these species follows a developmental pattern designated as the “Comatricha-type” by Ross (1957) from a study of Comatricha typhoides. The taxonomic implications of the sporangial developmental pattern are discussed.     

A SEM–study of Listerella paradoxa (Myxomycetes)

Apart from the presence of a capillitium, the fructifications of Listerella paradoxa Jahn resemble those of some species of Licea Schrad. Similarities exist in general appearance, mode of dehiscence, structure of peridium, and sculpturing of spores. The capillitium of Listerella is attached near the margins of the peridial lobes, and the moniliform threads are extensions from pillars from which the threads sometimes break. Aberrant capillitial outgrowths may be reminiscent of the processes bordering the peridial lobes in Licea. Although mostly found on podetia of the lichen genus Cladonia, Listerella may also occur on other substrates. A large–spored specimen developed on an oak leaf in California falls within the intraspecific variation of L. paradoxa. LwtereWa–resembling species of Licea may also occur on Cladonia. An x–ray analysis did not reveal any Ca or other elements with an atomic weight equal to or above that of Na in peridium, capillitium and spores of L. paradoxa , nor in peridium, peridial protuberances and spores of Licea pusilla Schrad.     

Composition, speciation and distribution of iron minerals in Imperata cylindrica.

A comparative study of the roots, rhizomes and leaves of an iron hyperaccumulator plant, Imperata cylindrica, isolated from the banks of an extreme acidic environment, using complementary techniques: Mösbauer spectroscopy (MS), X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled to energy-dispersive X-ray microanalysis (EDAX) and transmission electron microscopy (TEM), has shown that two main biominerals, jarosite and ferrihydrate-ferritin, accumulate in the different tissues. Jarosite accumulates mainly in roots and rhizomes, while ferritin has been detected in all the structures. A model of iron management in I. cylindrica is presented.     

Scanning electron microscopy of sporulating cultures of the myxomycete Physarum polycephalum

Scanning electron microscopy of sporulating cultures of Physarum polycephalum shows in detail the fine structure of the stalk, peridium, capillitia and spores. The peridium has a wrinkled structure and funnel-like cavities (5-10 μ in diameter) which are the capillitia openings. The capillitia are a network of tubes with differing diameters. The capillitia are covered with fine granules, and contain various amounts of bead-like granules of up to 2 μ in diameter. The spherical spores (10 μ in diameter) are covered with fine granules similar to those covering the capillitia.     

A new species of Lamproderma (Myxomycetes) found in Java

A new species, Lamproderma retkulospomm , is described from Java. It is characterized by small sporangia, peridium with smooth, elevated patches, capillitium with numerous swellings, and completely banded-reticulate spores.     

中国团毛菌目粘菌Ⅰ.盖碗菌属

本文研究了中国盖碗菌属10种粘菌,其中1个为国内新记录种：四方盖碗菌Perichaenaquadrata;2个为新种：片丝盖碗菌perichaenafrustrifiarissp.nov;灰盖碗菌Perichaenagriseasp.nov,增补了一些种的超微结构特征;增添了新分布区;讨论了种与种之间的关系。新种有拉丁文描述及扫描电镜照片,模式标本保存于吉林农业大学真菌标本室（HJAU）,长春。     

Nanometer-scale visualization and structural analysis of the inorganic/organic hybrid structure of Gallionella ferruginea twisted stalks

The so-called Fe/Mn-oxidizing bacteria have long been recognized for their potential to form extracellular iron hydroxide or manganese oxide structures in aquatic environments. Bacterial species belonging to the genus Gallionella, one type of such bacteria, oxidize iron and produce uniquely twisted extracellular stalks consisting of iron oxide-encrusted inorganic/organic fibers. This paper describes the ultrastructure of Gallionella cells and stalks and the visualized structural and spatial localization of constitutive elements within the stalks. Electron microscopy with energy-dispersive X-ray microanalysis showed the export site of the stalk fibers from the cell and the uniform distribution of iron, silicon, and phosphorous in the stalks. Electron energy-loss spectroscopy revealed that the stalk fibers had a central carbon core of bacterial exopolymers and that aquatic iron interacted with oxygen at the surface of the carbon core, resulting in deposition of iron oxides at the surface. This new knowledge of the structural and spatial associations of iron with oxygen and carbon provides deeper insights into the unique inorganic/organic hybrid structure of the stalks.     

LABORATORY CULTIVATION OF CLASTODERMA DEBARYANUM

Mc Manus , Sister Mary Annunciata , R.S.M. (Mount Mercy Coll., Cedar Rapids, Iowa.) Laboratory cultivation of Clastoderma debaryanum. Amer. Jour. Bot. 48(10): 884–888. Illus. 1961.—Clastoderma debaryanum has been cultivated on laboratory media for the first time and its life cycle studied. Spores germinate to produce a single protoplast which may remain a myxamoeba or may become a swarm cell. The swarm cells fuse in pairs to form a zygote, which grows into a microscopic, spherical plasmodium. The plasmodium never develops a network of veins and shows only irregular streaming. At maturity each plasmodium gives rise to 1 sporangium. There is always a sphere of gelatinous material about 4/5 the distance up the stalk, which appears late in the development of the sporangium, and which dries to become a wrinkled enlargement. The peridium dehisces early, leaving only a few plates attached to some of the peripheral tips of the capillitial twigs, and a peridial collar. The solid capillitium branches from the tip of a very short columella.     

Localization of Nickel in Tissues of Streptanthus polygaloides Gray (Cruciferae) and Endemic Nickel Hyperaccumulators from California

The genus Streptanthus Nutt. is one of the most important indicators of ultramafic floras in western North America. This genus contains taxa that are endemic or tolerant of ultramafic soils. Streptanthus polygaloides is an annual nickel hyperaccumulator strictly confined to ultramafic soils throughout the Californian Sierra Nevada foothills. Nickel concentration in S. polygaloides populations was evaluated by elemental microanalysis using inductively coupled plasma mass spectrometry (ICP-MS). Representative samples of S. polygaloides roots, stems, leaves, flowers, and fruits were studied by scanning electron microscopy (SEM) coupled to an energy-dispersive X-ray probe (SEM-EDX). Results show Ni accumulation values between 0.09 and 1.18 %, and a distribution pattern similar to that observed in other Ni hyperaccumulator taxa, with the leaf epidermis accumulating the largest concentrations.     

Silica in the Mesophyll Cell Walls of Italian Rye Grass (Lolium multiflorum Lam. cv. RvP)

Isolated cell envelopes from the leaf mesophyll of Italian ryegrass were examined in a transmission electron microscope equippedwith an energy-dispersive X-ray spectrometer. Silicon was detectedin these walls at an estimated concentration of 1–2 percent. Samples were also subjected to a range of techniques,for the removal of organic matter, which confirmed the presenceof silica throughout the cell walls. Lolium multiflorum Lam, Italian rye grass, cell walls, silica, electron microscopy, X-ray microanalysis     

Observations on the Preparation of Epoxy Embedded Tissue Samples for Energy-Dispersive X-Ray Analysis

Elemental X-ray microanalysis of biological tissues by energy-dispersive detectors attached to conventional transmission or scanning electron microscopes is a technique with many potential applications. Proper specimen preparation and consideration of problems inherent with the method are necessary to achieve satisfactory results. This report concerns some of the problems encountered in analyzing tissue samples embedded for electron microscopy in epoxy resins.     

Fruiting body formation of the nivicolous myxomycete Badhamia alpina in moist chamber culture

The plasmodium of Badhamia alpina thrived at lower temperatures (4 °C), and formed fruiting bodies at 8 °C. The yellow sclerotium and plasmodium were found inside a hollow, dead herbaceous stem under melting snow in Apr, and was cultured in moist chambers at 4 °C. The plasmodium did not form fruiting bodies for 6 wk at 4 °C. Sporulation was observed after the incubation temperatures rose to 8 °C. Sporulation occurred in the morning and cell cleavage at 11 a.m. The order of spore wall formation was observed by TEM for 12 h. The outer spore wall ornamentation was formed first followed by internal wall layers. Round electron transparent object was observed in the capillitium and peridium during the latter part of sporulation.     

Morphological and ultrastructural features in selected species of Licea (Myxomycetes)

Ultrastructural studies of selected species of Licea were made in order to elucidate relationships among species. Based on structural studies, species may be grouped as representing different stages of morphological complexity. The majority of species possess protoplasmodia and form sporangia. The two plasmodiocarpous species L. retiformis and L. variabilis possess more highly differentiated plasmodia and are an anomaly among Licea species. Processes along the margin of peridial lobes in several species of the genus are probably homologous with the capillitium in Listerella . The latter genus is morphologically and structurally very similar to species of the Licea pusilla group, but its plasmodium is still unknown. The sole species of Listerella agrees with Licea operculata in the structure of spore ornamentation, the processes consisting of densely packed granules of high electron density. This structure is quite different from that of L. pusilla and L. minima , where the processes have an internal structure of alternating layers different in electron transparency. Presence of spore-like bodies, different in size and ornamentation from normal spores, have been demonstrated in the border region between stalk and sporangium in L. operculata . This is a feature previously supposed to be restricted to Arcyria and related genera. Using X-ray analysis, calcium has been found in the peridium of several species of Licea . Since environmental factors may influence the presence or absence of calcium, caution should be taken in interpreting differences taxonomically. The similarity in elemental composition between the spores and sporangial lid in L. operculata is interesting, considering the fact that the sporangial lid of Trichia crateriformb has been demonstrated to be composed of spore-like structures.     

Iron Bacteria in Drinking-Water Distribution Systems: Elemental Analysis of Gallionella Stalks, Using X-Ray Energy-Dispersive Microanalysis

“Iron” bacteria belonging to the genus Gallionella were observed by scanning electron microscopy in water samples and attached to pipe surfaces in a Southern California drinking-water distribution system. The cells were recognized by their characteristic elongated helical stalks composed of numerous intertwined microfibrils. Many of the stalks were partially coated with insoluble ferric salt deposits. Stalks recovered directly from water samples were analyzed for their elemental composition by using X-ray energy-dispersive microanalysis. Silicon, aluminum, calcium, and iron were the predominant elements present in the stalks. Smaller quantities of the elements phosphorous, sulfur, chlorine, copper, and zinc were also detected. Manganese, though present in measurable quantities in the water supply, was not detected in the stalks, suggesting that this organism is unable to utilize this element as an electron donor. This represents the first such analysis of Gallionella stalks recovered from environmental samples without prior subculturing in artificial laboratory media.     

The chemoreceptor surface of the taste disc in the frog,Rana esculenta. An ultrastructural study with lanthanum nitrate

Summary The distribution of lanthanum on the taste disc of the frog,Rana esculenta, afteren bloc staining of the tongue with lanthanum nitrate was studied at the ultrastructural level by means of scanning electron microscopy (in the secondary electron mode or in the back scattered electron mode), energy-dispersive X-ray microanalysis, transmission electron microscopy and electron spectroscopic imaging. It was consistently found that lanthanum distribution on the surface of the taste disc is not homogeneous and that the surface of putative receptor cells is in contact with strongly lanthanum-positive material. Calcium co-localizes with lanthanum at that level. These results suggest that different microenvironments exist at the surface of the taste disc and that this could be relevant to the receptor function.     

Spore ultrastructural features and significance of their diverse ornamental elements in the evolutionary history of the order Trichiales (Myxomycetes,Amoebozoa)

Spores are the dispersal and reproductive units in Myxomycetes, and their ornamentation, usually at the light microscopy resolution limit, is taxonomically meaningful. Here, we analyze with scanning and transmission electron microscopy the spore ultrastructural features in Trichiales, one of the most morphologically diverse orders. In Trichiales, the spore wall consists of two layers, an outer one, including the ornamentation, and an inner layer subdivided into two sections. The diversity of ornamental elements includes verrucae, bacula, pila, muri, and cristae, the two latter creating reticulate patterns. Each of these elements defines a broadly recognized ornamentation type except cristae, from which we differentiate for the first time the cristate reticulate and patched subtypes. Besides, our results point out a previous incorrect classification of the spores of the species Trichia decipiens and T. scabra. Advances in Trichiales phylogeny showed that the capillitium ornamental elements, such as the spirals, do not reflect phylogenetic relationships among the species. The same seems to apply to some of spore ornamentation types, e.g., baculate. Consequently, we may consider the need to combine multiple characters, like the spore and capillitium ornamentation, so that Trichiales systematics better reflect the still cryptic phylogenetic affinities.     

Radicle ofEchinocactus platyacanthus (Cactaceae)

Radicle of matureEchinocactus platyacanthus embryo is approximately 320 m long and represents less then 1/7 of the embryonal axis length. The radicle-hypocotyl boundary can be distinguished according to the striking difference in the size and shape of cells in protoderm and procambium, as well as discontinuity and different number of the cell files in the ground meristem. The root cap is small, consists of 4 layers of cells covering the apex of the radicle. The upper limit of the root cap is approximately 100 m closer towards the radicle tip than the radicle-hypocotyl boundary. Ultrastructure of radicle cells showed numerous lipid bodies as is typical for other oily seeds. Protein bodies of variable structure were also present together with other cell structures. Striking differences in protein body structure were found when protoderm and ground meristem were compared. Several small globoid crystals were present in each protein body of the protoderm, while protein bodies in the radicle ground meristem mostly contained one large globoid crystal. X-ray microanalysis revealed presence of P, K and Mg in all analyzed globoid crystals. Fe, Ca and Zn were detected in some of them.Abbreviations EDX microanalysis energy-dispersive X-ray microanalysis - GC(s) globoid crystals - ICP spectroscopy ion-coupled plasma spectroscopy - LM light microscopy - PB(s) protein bodies - SEM scanning electron microscopy - TEM transmission electron microscopy     

Quantitative X-ray microanalysis of calcium with the Camebax-TEM system in frozen, freeze-substituted and resin-embedded tissue sections. Application to molluscan glio-interstitial granules

The relevance of the continuum method for a quantitative X-ray microanalysis of epon embedded tissue sections in the particular conditions offered by the Camebax-TEM system was tested and an improved model of specimen holder is proposed. The absolute calcium concentration [Ca] of membrane-bound intracellular glio-interstitial granules was determined by X-ray microanalysis in transmission electron microscopy of Mytilus retractor muscle. The Ca peak and background values were measured by the wavelength-dispersive spectrometer of the Camebax; the mass thickness of the section was recorded simultaneously with an added energy-dispersive detector. The tissue was frozen at approximately equal to 77 K in a mixture of liquid propane and butane, freeze-substituted in the presence of oxalic acid and embedded in epoxy resin. The calcium concentration of glio-interstitial granules can be as high as 180 mmol.kg-1 of epoxy-embedded tissue, with an average of 40 mmol.kg-1. The sampling of the data through repeated experiments is discussed and it is proposed that the cell would be the main level of variation. The Ca content of glio-interstitial granules is significantly lower in the tissues of animals submitted to high-potassium artificial sea-water for 10 min. This finding was predicted by the hypothesis that glio-interstitial tissue is a regulator of calcium concentration in extracellular spaces.     

Arctic Gasteromycetes II. Calvatia in Greenland, Svalbard and Iceland

Species of Calvatia (Lycoperdaceae) from arctic and subarctic regions are described. The diagnostic characters in Calvatia are discused with emphasis on strutures of peridium and capillitium and colour of gleba. Ten species are recognized. Three species: C. Candida, C. excipuliformis, C. utriformis are confined to subarctic stations, while seven species have their main distribution in the arctic zones. Three of these are new species: C. connivens, C. horrida, C. septentrionalis , while three other species are redefined after studies of type material: C. arctica, C. bellii and C. turneri. Several specimens studied show characters pointing to a hybrid origin.     

Characterization Of Multi-layered Fish Scales (Atractosteus spatula) Using Nanoindentation,X-ray CT,FTIR, and SEM

The hierarchical architecture of protective biological materials such as mineralized fish scales, gastropod shells, ram’s horn, antlers, and turtle shells provides unique design principles with potentials for guiding the design of protective materials and systems in the future. Understanding the structure-property relationships for these material systems at the microscale and nanoscale where failure initiates is essential. Currently, experimental techniques such as nanoindentation, X-ray CT, and SEM provide researchers with a way to correlate the mechanical behavior with hierarchical microstructures of these material systems^1-6. However, a well-defined standard procedure for specimen preparation of mineralized biomaterials is not currently available. In this study, the methods for probing spatially correlated chemical, structural, and mechanical properties of the multilayered scale of A. spatula using nanoindentation, FTIR, SEM, with energy-dispersive X-ray (EDX) microanalysis, and X-ray CT are presented.