ULTRASTRUCTURE OF ACTIVE AND RESTING COLONIES OF BOTRYOCOCCUS BRAUNII (CHLOROPHYCEAE)1

The ultrastructure of resting state colonies of Botryococcus braunii Kützing from two localities is compared to active state colonies maintained in the laboratory. Qualitative hydrocarbon analyses confirmed the physiological status of each sample according to the precedent in the literature; resting state colonies contained botryococcenes, while active state colonies contained a predominance of straight-chain olefins. The ultrastructure of resting and active state colonies is fundamentally similar. The chloroplast of resting state cells contains fewer thylakoids and larger relative numbers of plastoglobuli than the chloroplast of active state cells maintained under favorable growth conditions. Previously undescribed phenomena include the cytochemical demonstration of polyphosphate bodies microbody-like organelles and ER-ribosomal-mitochondrial complexes. Attempts to elicit the transition of active to resting state colonies utilizing different light intensities and/or nitrogen deficient media were unsuccessful. Instead, these experiments induced the formation of yellow or whitish-brown senescent colonies which always contained a predominance of olefins. Senescent cells contain reduced, peripherally displaced organelles. Most of the cytoplasm is occupied by vacuoles and lipid (probably hydrocarbon) inclusions. Morphologically identifiable polyphosphate bodies are usually small or absent. Observations pertinent to the mechanism of hydrocarbon secretion were in basic agreement with previously published information. The outer cell wall, or trilamellar structure (TLS), was recently as the primary site of hydrocarbon accumulation and production. The role of the TLS in hydrocarbon biosynthesis, however, should be cautiously regarded without additional evidence.     

Description of Rhynchopus euleeides n. sp. (Diplonemea), a free-living marine euglenozoan

We describe Rhynchopus euleeides n. sp., using light and electron microscopy. This free-living flagellate, which was isolated earlier from a marine habitat, can be grown axenically in a rich medium based on modified seawater. In the trophic stage, cells are predominantly elliptical and laterally flattened, but frequently change their shape (metaboly). Gliding is the predominant manner of locomotion. The two flagella, which are typically concealed in their pocket, are short stubs of unequal length, have conventional axonemes, but apparently lack a paraxonemal rod. Swarmer cells, which form only occasionally, are smaller in size and carry two conspicuous flagella of more than 2 times the body length. Cells are decorated with a prominent apical papillum. Both the flagellar pocket and the adjacent feeding apparatus seem to merge together into a single sub-apical opening. The mitochondrion, which is most likely single, is located peripherally. It is reticulated in shape and contains only a few lamellar cristae. Mitochondrial DNA is abundant and evenly distributed throughout the organelle. Morphological synapomorphies confirm the affiliation of the species with the genus Rhynchopus (Diplonemea, Euglenozoa). We discuss the characters that distinguish Rhynchopus from Diplonema corroborating the validity of the two genera.     

GEITLERINEMA SPECIES (OSCILLATORIALES,CYANOBACTERIA) REVEALED BY CELLULAR MORPHOLOGY,ULTRASTRUCTURE, AND DNA SEQUENCING1

Geitlerinema amphibium (C. Agardh ex Gomont) Anagn. and G. unigranulatum (Rama N. Singh) Komárek et M. T. P. Azevedo are morphologically close species with characteristics frequently overlapping. Ten strains of Geitlerinema (six of G. amphibium and four of G. unigranulatum) were analyzed by DNA sequencing and transmission electronic and optical microscopy. Among the investigated strains, the two species were not separated with respect to cellular dimensions, and cellular width was the most varying characteristic. The number and localization of granules, as well as other ultrastructural characteristics, did not provide a means to discriminate between the two species. The two species were not separated either by geography or environment. These results were further corroborated by the analysis of the cpcB‐cpcA intergenic spacer (PC‐IGS) sequences. Given the fact that morphology is very uniform, plus the coexistence of these populations in the same habitat, it would be nearly impossible to distinguish between them in nature. On the other hand, two of the analyzed strains were distinct from all others based on the PC‐IGS sequences, in spite of their morphological similarity. PC‐IGS sequences indicate that these two strains could be a different species of Geitlerinema. Using morphology, cell ultrastructure, and PC‐IGS sequences, it is not possible to distinguish G. amphibium and G. unigranulatum. Therefore, they should be treated as one species, G. unigranulatum as a synonym of G. amphibium.     

Sporulation of Marteilioides branchialis N. Sp. (Paramyxea) in the Sydney Rock Oyster, Saccostrea commercialis: An Electron Microscope Study

ABSTRACT The ultrastructure of sporulation of a new parasite, Marteilioides branchialis (Paramyxea), in the Sydney Rock oyster, Saccostrea commercialis , is described. The development is typical of other Paramyxea whereby a stem cell internally cleaves a secondary cell contained within a vacuole. It differs from other species in the phylum in that each secondary cell produces a single spore composed of two concentric cells, one within a vacuole of the other. This type of sporulation represents the simplest of all known Paramyxea. Infection results in focal gill lesions and was observed concurrently with an epizootic of another paramyxean, Marteilia sydneyi .     

中国蛇床属植物研究

经研究整理,我国蛇床属(Cnidium Cuss.)植物有4种,2变种:蛇床(C.monnieri(L.)Cuss.),碱蛇床(C.salinum Turcz.),兴安蛇床(C.dahuricum(Jacq.)Turcz.ex Fisch.et Mey.),滨蛇床(C.japonicum Miq.),台湾蛇床(C.monnieri var.formosana(Yabe)Kitag.)和根茎碱蛇床(C.salinum var.rhizomaticum Ma),对原属蛇床属的两个种做了名称新组合:辛家山亮蛇床(Selinum sinchianum(Fu)Yuan et Li),无油管亮蛇床(Selinum nullivittatum(Fu)Yuan et Li)。对上述种类进行了分类研究、果实显微及扫描电镜观察和花粉粒扫描电镜观察。     

The ultrastructure of the ascus apical apparatus of some Dermateaceae (Helotiales)

The ascus apical apparatus ultrastructure of 12 species of the Dermateaceae (Helotiales, Ascomycota) was studied. Its development and details are described on the basis of transmission electron microscopy micrographs for all studied species. A majority of them, 8 species belonging to the genera Belonopsis, Mollisia, and Pyrenopeziza, show considerable similarity in the structure of their ascus apical apparatus. Two species, Mollisia melaleuca and Mollisia ramealis, show some deviations from this type, suggesting that the genus Mollisia is not fully homogeneous. Two other species, Podophacidium xanthomelum and Pezicula cinnamomea represent two ascus apical apparatus structure types of their own, which are remarkably different from the Mollisia type. The possible taxonomic implications arising from ascus apical apparatus diversity in the Dermateaceae are discussed.     

Description and Phylogenetic Relationships of Spumochlamys perforata n. sp. and Spumochlamys bryora n. sp. (Amoebozoa, Arcellinida)

ABSTRACT. Spumochlamys perforata n. sp. and Spumochlamys bryora n. sp. were isolated and described from dry epiphytic moss. The morphology and ultrastructure of both species clearly demonstrate that they belong to the genus Spumochlamys (family Microchlamyiidae). They differ from its only described member, Spumochlamys iliensis (as well as from species of Microchlamys ), in the relief of the dorsal surface of the test, revealed by scanning electron microscopy, which can represent a good characteristic for species identification. They also differ in the structure of the dorsal part of the test wall (especially S. perforata ). Small subunit ribosomal DNA-based molecular phylogenetic analyses show that Spumochlamys is a deeply branching lineage of the Arcellinida, without any close affinities. Actin gene sequence analysis places this genus within the Tubulinea, close to two other arcellinid lineages but without forming a monophyletic group with them. These data together strongly suggest that the lack of resolution in the arcellinid molecular phylogenies is due to serious undersampling of taxa, a limited number of sequence data, and high divergence rates in most of the species.     

Heterodera longicolla,n. sp. (Nematoda: Heteroderidae) from Buffalo-grass (Buchlo? dactyloides) in Kansas

Heterodera longicolla n. sp., a member of the H. goettingiana group, is described and illustrated from roots of buffalo-grass, Buchloë dactyloides (Nutt.) Engelm., in Manhattan, Kansas. This new abullate species, having second-stage larvae with only three lines in the lateral field, is most closely related to H. cyperi Golden, Rau & Cobb, 1962, but differs particularly in having a shorter stylet in larvae, males and females; in possessing only three annules on the head of larvae and males; in having a shorter tail in larvae; and by the presence on cysts of a small anus without a circum-anal pattern.     

Pterotylenchus cecidogenus n. gen., n. sp., a New Stem-gall Nematode Parasitizing Desmodium ovalifolium in Colombia

Pterotylenchus cecidogenus n. gen., n. sp. from stem-galls of Desmodium ovalifolium Wall. in Colombia is described and illustrated. The new genus belongs to Anguinidae and is related to Orrina Brzeski, 1980 but is unique in having large vulval flaps. P. cecidogenus has females with body 0.59-0.8 mm long, stylet 9-11 μm long, no median oesophageal bulb, a crustaformeria of 32-36 cells, a short post-vulval uterine sac, and a conical pointed tail.     

中国科学院微生物研究所菌物标本馆馆藏菌寄生属Hypomyces标本的分类研究

对中国科学院微生物研究所菌物标本馆保存的菌寄生属标本进行了分类学方面的清理和订正,鉴定出9个种,其中大孢菌寄生H. marcrosporus、丝层菌寄生H. subiculosus和侧毛斑菌寄生H. tegillum为中国新记录种。     

The Esophageal Glands of Pratylenchus Filipjev and Apratylenchoides belli n. gen. n. sp. (Nematoda: Tylenchoidea)

The esophageal glands in the genus Pratylenchus occur in a large, single ventral lobe except for four populations in which a few specimens had the glands located dorsally. Apratylenchoides belli n. gen. n. sp. in the subfamily Radopholinae is proposed for a species having two esophageal glands in a large dorsal lobe and one gland in a smaller, shorter ventral lobe.