INTERCONNECTIONS BETWEEN CYTOPLASMIC MICROTUBULES AND BASAL BODIES OF TETRASPORALEAN PSEUDOCILIA

Ultrastructural investigations of the development and structure of pseudocilia in Tetraspora lubrica and Schizochlamys sp. have disclosed interconnections between cytoptasmic microtubules and pseudo-cilial basal bodies heretofore unreported. Connections between elements of the basal bodies and the proximal connecting fibers are also described. The possible significance of the interconnections in correlating structure and function of these organelles is discussed.     

The taxonomic position of Chaetopeltis

The flagella-like but immobile pseudocilia of the green alga Chaetopeltis are described. Examination of the pseudocilia reveals a similarity to those previously described for other members of the Tetrasporales. The taxonomic position of Chaetopeltis, in relation to other members of the Tetrasporales, is shown to be in the family Chaetopeltidaceae.     

Paraveinal mesophyll: Review and survey of the subtribeErythrininae (Phaseoleae,Papilionoideae, Leguminosae)

Paraveinal mesophyll (PVM) is a distinctive anatomical feature of the leaf mesophyll of some plant taxa that may represent a specialized physiological compartment. A comprehensive review of the 42 published references that mention PVM or similar cell layers and a survey of 121 of the 272 species of all nine genera of thePhaseoleae subtribeErythrininae demonstrate that PVM is nearly exclusively found inLeguminosae. InLeguminosae, PVM is either rare or absent in subfamilyCaesalpinioideae, uncommon inMimosoideae, and extensively distributed amongPapilionoideae. In subtribeErythrininae, PVM is ubiquitous inErythrina, and occurs in four other genera. ThreeErythrininae genera (Apios, Mucuna, andCochlianthus) lack PVM. Unique chloroplast-poor, enlarged conical cells (pellucid palisade idioblasts) occur in 80 species ofErythrina but not in any other genus ofErythrininae.     

ÜberGloeodendron undChrysochaete

Zusammenfassung Gloeodendron catenatum (Thompson)Bourrelly stimmt mitGl. ramosum Korschikoff in allen wesentlichen Merkmalen überein und ist daher als eigene Art zu streichen. Gl. ramosum (inklusivecatenatum), das bisher nur aus der Sowjetunion und Nordamerika bekannt war, tritt auch in einem Becken des Botanischen Gartens in Wien auf und zeigt außer den schon angegebenen einige weitere charakteristische Merkmale; auch die Variationsbreite in der Form der Lager spricht für die Auflassung vonGl. catenatum. Chrysochaete britannica, die bei optimalen Lebensbedingungen — an einem Fundort in Wien in den Herbstmonaten — Schleimborsten mit Gallertgeißeln besitzt, kommt dort im Frühjahr mit sonst typisch ausgebildeten Lagern ohne Schleimborsten vor.

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Summary Gloeodendron catenatum (Thompson)Bourrelly in all siginificant features is congruent withGl. ramosum Korschikoff and cannot be accepted as separate species. Gl. ramosum (Gl. catenatum included), which until now has been reported only from UdSSR and North America, also occurs in Vienna and shows some hitherto unknown characteristics. Variation in form of colonies also indicates abandonment ofGl. catenatum. Chrysochaete britannica, which under optimal conditions in Vienna during fall forms colonies with pseudocilia, during spring shows coenobia with all typical attributes, but without pseudocilia.

     

Inhibition of fungi,actinomycetes and bacteria by Stachybotrys atra

The effect ofStachybotrys atra on fungi, actinomycetes and bacteria was studied in agar culture. Of the 27 genera and 52 species of fungi, 6 species of actinomycetes and 5 genera and 10 species of bacteria tested,S. atra was found to inhibit 95.7 % fungi, all the actinomycetes and 83.3 % of bacteria.Aspergillus ustus, 2 unidentified species ofFusarium, Rhizobium trifolii andPseudomonas spp. were however not inhibited. In experiments in soil,S. atra inhibited the growth ofTrichoderma viride. S atra was ineffective whereT. viride andS. atra were inoculated simultaneously or whereT. viride was added 7 days earlier. Besides,S. atra was not found to controlMacrophomina phaseoli infection on cotton. Soil culture ofS. atra showed phytotoxic effect on cotton seedlings.S. atra produced a dark brown to black thermostable toxic metabolite in the medium. The culture filtrate retarded the growth ofM. phaseoli in agar culture. Despite the importance ofS. atra as a fungistatic agent with wide antimicrobial spectrum, the use ofS. atra as a protectant against plant pathogens seems to be limited because of its phytotoxicity on cotton.     

Ultrastruktur und systematische Bedeutung des Pollens beiBocageopsis,Ephedranthus, Malmea undUnonopsis (Annonaceae)

The four genera investigated show solitary sulcate pollen grains. The structure and sculpture of the sporoderm is very similar inBocageopsis andUnonopsis, and supports the close relationship of both genera; their flower morphology also is very similar. In contrast, the sporoderm ofEphedranthus, and especially that ofMalmea, is different in some characters and suggests more remote relationships; this is also confirmed by differences in flower morphology. Within this group of genera a distinct exine progression can be recognized from non-columellate (Malmea) to granular (Unonopsis guatterioides), further to somewhat irregularly (Bocageopsis, someUnonopsis species), and finally to very regularly columellate (Ephedranthus). The sculpture of the tectum varies from a reticulum with large lumina (Malmea) to one with small performations (Ephedranthus). Within theAnnonaceae the genusMalmea is among the most primitive in respect to pollen structure. The sulcus of the four genera is very large and runs over 1/3 of the pollen grain. It is characterized by a reduction of the exine and a bulgy thickening of the intine.

     

Kalkbohrende Mikrothalli beiHelminthocladia undScinaia (Nemaliales,Rhodophyta)

Shell-boring microthalli in Helminthocladia and Scinaia (Nemaliales, Rhodophyta). Spores shed from pink mussel shells were shown to develop into branched monosiphonous thalli, their filaments penetrating into shell fragments. Isolates from four single germlings were cultivated. Two of these produced gametophytes ofHelminthocladia andScinaia; the others have so far only reproduced by tetraspores or monospores. Evidently the microthalli of some genera of the Nemaliales — which are, with the exception ofNemalion multifidum, known only from cultures — are shell-inhabiting and have therefore not been found in nature. The adult algae occur mainly on shells and CaCO₃ substrates. Until the beginning of the century,Helminthocladia andScinaia frequently occurred at Helgoland, but they have not been found there for more than 50 years. Their microthalli, however, are still present as shell-boring algae. This study is intended to stimulate similar ones in other genera of the Nemaliales so as to obtain a broader basis for discussion of systematic and phylogenetic relationships.     

Taxonomic separation ofKengyilia (Poaceae: Triticeae) in relation to nearest relatedRoegneria,Elymus, andAgropyron,based on some morphological characters

Based on 100 species representative of the four genera, we scored 290 herbarium specimens for a number of morphological characters. The data were subjected to canonical discriminant analysis using characters different from those in the identification key to these genera byBaum, Yen, andYang (1991). These characters collectively support the four groupsAgropyron, Kengyilia, Roegneria, andElymus as previously defined. The four groups are also supported by the linear discriminant function with an overall rate of 83% correct classification. Length of lemma awn was found to be an additional diagnostic character asAgropyron andKengyilia have lemma awns shorter than 5 mm, whereasRoegneria andElymus have longer lemma awns with very few exceptions. Length of glume awns is also a useful supplementary generic diagnostic.Agropyron andElymus have glume awns, whereas the majority of species ofKengyilia and more than half of the species ofRoegneria lack them. If a glume awn is present it is usually not longer than 1 mm.     

PROPAGATION OF HANTZSCHIA SP. GRUNOW DAUGHTER CELLS BY NITZSCHIA ALBA LEWIN AND LEWIN1

Electron microscopic investigations of thin sections of Nitzschiaalba revealed that dividing cells yield both Nitzschia and Hantzschia daughter cells, suggesting that these genera are not taxonoinically distinct.     

Karyologie und ökologisch-morphologische Differenzierung vonPeumus boldus (Monimiaceae,Laurales)

The karyotype analysis ofPeumus boldus reveals a remarkable differentiation of chromosomes in size and form. C-banding pattern and interphase nuclei are discribed and compared with other genera. The great variation in leaf-shape and growth-form is continuous and correlated with the very diverse habitats of the species. The recognition of infraspecific taxa is therefore not recommended. The lower leaf surface is very uniform within the monotypic genus and ± similar with that ofSiparuna. The different evolutionary strategies ofPeumus and related genera are discussed and show a different eco-systematic situation than inMollinedia andSiparuna.

     

DIVERSITY AMONG TETRASPORALEAN TAXA: EVIDENCE FROM ULTRASTRUCTURE AND MOLECULES

Recent phylogenetic studies of tetrasporalean exemplars using 18S rDNA revealed the extent of diversity among taxa in this non-monophyletic group (Booton et al. 1998). In particular, two distinct tetrasporalean lineages were identified; one group allied with chlamydomonadalean taxa and the other group comprising taxa now placed in a separate order, the Chaetopeltidales. Using these observations as a framework, a new investigation of diversity among a broader sampling of putative tetrasporalean genera (e.g. Asterococcus , Chloranomala , Chlorophysema , Gloeocystis , Gloeodendron , Palmella , Paulschulzia , Physocytium , Schizochlamys and Tetraspora ) was undertaken. Phylogenetic studies of both 18S and 26S rDNA were compared with ultrastructural investigations of vegetative cells. Molecular phylogenetic analyses corroborate the earlier 18S rDNA results, but also reveal additional diversity. The new data raise doubts regarding the monophyly of two genera, Palmella and Tetraspora. The new data also link two enigmatic green algal genera, Physocytium and Heterochlamydomonas , in a long-branch lineage within the Chlamydomonadales. Another enigmatic genus, Schizochlamys , is allied with Bracteacoccus in the Sphaeropleales. Lastly, Chloranomala is resolved as an ally of Paulschulzia , Tetraspora sp., and the green flagellate, Lobomonas. Comparison of pyrenoid ultrastructure generally supports the molecular phylogenetic analyses, suggesting that this non-molecular character will be a useful marker for broad phylogenetic studies of chlamydomonadalean taxa. (Supported by NSF grant, DEB 9726588)     

Caprellids (Crustacea: Amphipoda) from Papua New Guinea,with the description of a new species

This is the first study of caprellid amphipods from the coast of Papua New Guinea. Several collections from Madang Lagoon (north) and Bootless Bay (south) have been studied. Seven species in seven genera are recorded, of which Pseudoproto papua sp. nov. is described as new to science. The genus Pseudoproto Mayer, 1903 has consisted, so far, of only one species, Pseudoproto fallax Mayer, 1903. Although only a single male has been found of Pseudoproto papua sp. nov., differences in antennae, mouthparts, gnathopod 2 and pereopods 3 and 4 have revealed that it represents a new species of Pseudoproto. Lateral view figures of all species, together with a key to species level for the Caprellidea from Papua New Guinea are also included. Communicated by H.-D. Franke     

RELATIONSHIP OF TEMPERATURE TO ZOOSPORE PRODUCTION IN TETRASPORA GELATINOSA

A strain of Tetraspora gelatinosa was isolated from a field collection and a technique for measuring quantitatively the production of zoospores was devised. The method employed compound colonies grown on agar from zoospore suspensions. The effect of 3 temperatures on zoospore production was tested: no zoospores were produced by the colonies at 3 C; zoospores were produced at 11 and 23 C and the final yield of zoospores at the 2 temperatures was not significantly different. However, at 11 C the maximum density of zoospores produced, measured by cell count, occurred after IS hr, while the maximum density at 23 C occurred after 21 hr.     

Taxonomic relationships ofThiobacillus halophilus,T. aquaesulis,and other species ofThiobacillus,as determined using 16S rDNA sequencing

Total base sequences of the 16S rRNA genes ofThiobacillus halophilus andThiobacillus aquaesulis show that these bacteria fall into the gamma- and beta-subdivisions, respectively of the Proteobacteria. The closest relative ofT. halophilus isThiobacillus hydrothermalis (with 98.7% similarity), and the closest relative ofT. aquaesulis isThiobacillus thioparus (93.2% similarity). Physiological properties and mol% G+C content of their DNA serve to confirm that these four organisms are all distinct species. It is reiterated that the species currently assigned to the genusThiobacillus are clearly so diverse that they need reclassification into several genera. The type species,T. thioparus, is unequivocally placed in the beta-subdivision of the Proteobacteria, thus requiring that the use of the genus nameThiobacillus be restricted to the chemolithoautotrophic species falling into that group.T. aquaesulis andT. thioparus may thus be regarded as true species ofThiobacillus. The relatively large number of obligately chemolithoautotrophicThiobacillus species falling in the gamma-subdivision of the Proteobacteria need further study in order to assess the case for reclassification into one or more new or different genera.     

The role of microtubules in establishing nuclear spatial patterns in multinucleate green algae

Summary In uninucleate cells, cytokinesis follows karyokinesis, thereby reestablishing a specific nucleus-to-cytoplasm ratio. In multinucleate cells, cytokinesis is absent or infrequent; no plasmalemma boundary defines the cytoplasmic territory of an individual nucleus. Several genera of large multinucleate green algae were examined with epifluorescence light microscopy to determine whether the patterns of cytoplasmic organization establish nuclear cytoplasmic domains. Randomly spaced nuclei, singular mitotic events and cytoplasmic streaming characterize the organization of two genera,Derbesia andBryopsis (Caulerpales). The cells ofValonia, Valoniopsis, Boergesenia, Ventricaria (Siphonocladales), andHydrodictyon (Chlorococcales) display regularly spaced nuclei which undergo synchronous divisions in a stationary cytoplasm. In the cytoplasm of genera with regularly spaced nuclei, microtubules radiate from all nuclei in late telophase-early interphase. These internuclear microtubule arrays are not found in algal genera with randomly spaced nuclei. It is hypothesized that these microtubule arrays play a role in establishing the cytoplasmic domain of each nucleus in genera with regularly spaced nuclei. Loss of microtubule arrays during the events of mitosis correlated positively with the increasing randomization of nuclear patterns in algae grown in microtubule inhibitors. Cytoplasmic domains were maintained when cells were grown in the same media in the dark. This suggests that, after a round of division, regular nuclear spacing in certain multinucleate algae is reestablished by internuclear microtubule arrays, which are not, however, required to maintain spacing during interphase.Dedicated to the memory of Professor Oswald Kiermayer     

Relationships ofLomatium among other genera ofApiaceae

Lomatium is the largest North American genus ofApiaceae (=Umbelliferae). Relations amongLomatium and other genera have not been well understood. TheApiaceae-Araliaceae lineage and genera of North AmericanApiaceae were analyzed phenetically and cladistically in turn, and seven phenetic alliances of genera are identified. Data on frequencies of character-state combinations were assembled and usingSporne's notions of maximal and minimal co-variation of states, two character-states were identified that are derived among Umbellifer genera. Using cladistic analysis of the alliance consisting ofLomatium and six other genera we identified three sister groups toLomatium:Polytaenia alone;Polytaenia withPseudocymopterus, and a group of four genera. Not all genera in the group of seven withLomatium are supported by autapomorphies impeding phylogenetic reconstructions. Both phenetics and cladistics have helped to suggest and evaluate relationships; to call attention to groups requiring further study, and in particular to identify derived character-states.     

The occurrence of multinucleate giant cells in yeasts

Summary The spontaneous occurrence of giant cells has been observed in young cultures ofLipomyces lipofer and three different genotypes ofSaccharomyces. Stained preparations of all abnormal cultures revealed that the giant cells characteristically contained more than one nucleus, the number ranging from one to six. In both genera the phenomenon was found to be transient, for rapidlygrowing cultures arising from isolated giant cells reverted, at varying rates, to populations of small uninucleate cells which appeared normal in all respects.     

Teliospores of smut fungi teliospore connections, appendages, and germ pores studied by electron microscopy; phylogenetic discussion of characteristics of teliospores

Summary Special features of teliospores in smut fungi are described, including teliospore connections, appendages, and germ pores. Balls of teliospores in species of many different genera cohere by remnants of hyphal walls, sheaths, and sometimes interlocking ornamentation. Teliospores are connected in pairs in species ofMycosyrinx andGeminago by special local structures. Appendages can be formed locally by persistent material from the sheath (Cintractia, Anthracoidea, Sphacelotheca), thickened parts of the spore wall (e.g.,Georgefischeria, Jamesdicksonia, Rhamphospora, Tolyposporella), or persistent walls of sporogenous hyphae (Rhamphospora, genera of the Tilletia relationship). Species ofGeorgefischeria, Jamesdicksonia, andTolyposporella have teliospore walls composed of more than three layers of different electron density. Germ areas corresponding to thinner parts of the spore wall are known, e.g., for species ofAnthracoidea, Cintractia, andUstilago infecting members of the family Poaceae, while distinct germ pores, one per teliospore, are found in some species ofThecaphora, Tolyposporium, andSporisorium. Teliospores ofMycosyrinx cissi have a germination ring. Characteristics of teliospores are used to discuss the phylogeny of smut fungi. A phylogenetic tree in accordance with teliospore characteristics is compared to those obtained from ultrastructural characteristics of host-parasite interaction, of septal pores, and from sequence data. Aspects of teliospore development help to define taxa at a high systematic level (Entorrhizales, Ustilaginales, Tilletiales/Entylomatales, Microbotryaceae), while details of ornamentation ontogeny delimit groups of genera (e.g., genera related toUstilago on members of the Poaceae andSporisorium, Cintractia andAnthracoidea, Tilletia) or single genera (e.g.,Melanopsichium, Dermatosorus, Mycosyrinx, Doassinga, Rhamphospora). Types of ornamentation (warty, reticulate), middle layers, teliospore balls, and germ pores evolved repeatedly by convergence. The smut teliospore itself probably evolved independently at least twice, or perhaps three (or more) times, in the Microbotryales, in the Entorrhizales, and in a common ancestor of the remainder of the Ustilaginomycetes.Part 166 in the series Studies in Heterobasidiomycetes from the Botanical Institute, University of Tübingen.     

Ultrastructure and phototactic action spectra of two genera of cryptophyte flagellate algae,Cryptomonas and Chroomonas

Summary A comparative action spectroscopical study was made on phototaxis in two genera of cryptomonads (cryptophyte flagellate algae), namely,Cryptomonas (rostratiformis) andChroomonas (nordstedtii andcoeruled). The two genera differ in their characteristic phycobilin pigmentation and, among three species, onlyChroomonas coerulea possesses an eyespot. The two species with no eyespot,Cryptomonas rostratiformis andChroomonas nordstedtii, exhibited positive phototaxis, showing very similar action spectra characterized by a broad band in the region from 450 nm to 650 nm, with an action maximum at about 560 nm; these features are essentially the same as those observed previously forCryptomonas strain CR-1. InCryptomonas rostratiformis, a small peak was also found at 280 nm in the UV-B/C region.Chroomonas coerulea, with eyespot, did not exhibit distinct positive phototaxis in a wide spectral region at any given, even very low, light intensity, but exhibited negative phototaxis of spectral sensitivity maximal at 400–450 nm. These results indicate that the positive phototaxis ofCryptomonas (rostratiformis and CR-1) andChroomonas nordstedtii is mediated by the same, yet unidentified photoreceptor(s).Chroomonas nordstedtii, possessing no phycoerythrin absorbing at 545 nm, also exhibits positive phototaxis at ca. 560 nm, and this result disfavors the so far proposed possibility that the positive phototaxis of the cryptophytes may be mediated by phycobilin pigments. On the other hand, the spectral characteristics of negative phototaxis ofChroomonas coerulea can possibly be ascribed to the presence of an eyespot.     

Anatomy ofTrigonognathus kabeyai,with comments on feeding mechanism and phylogenetic relationships (Elasmobranchii,Squalidae)

The skeleton and musculature ofTrigonognathus kabeyai are described in detail. The particular jaw dentition suggests thatTrigonognathus has a clutching-type feeding action. Several characters that might serve this function are discussed from the point of the functional morphology. The phylogenetic relationships ofTrigonognathus are not fully resolved, but it possesses three of the four synapomorphies of the Etmopterinae, i.e., two separate labial cartilages, no supraotic shelf, and prespinal radiais. Furthermore, three equally probable hypotheses ofTrigonognathus relationships, a sister relationship with all etmopterine genera,Etmopterus+Miroscyllium, andAculeola+Centroscyllium, are discussed.