DOCSLIB.ORG

Cytological Studies on Some Chlorococcoid Green Algae U. N

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Cytological Studies on Some Chlorococcoid Green Algae U. N Cytologia 48: 543-550, 1983 Cytological Studies on Some Chlorococcoid Green Algae U. N. Rai and Y. B.K. Chowdary Departmentof Botany,Banaras Hindu University, Varanasi-221005,India ReceivedSeptember 18, 1981 Cytological studies on chlorococcoid green algae are meagre. The reason for sucha limited work has been the relatively small size of chromosome which appears as small dots during nuclear division, making them inaccessible to light microscope (Rai 1980). Cytological studies made on this group of microorganism have shown only the basic chromosome number. Consequently no firm conclusions on the cytotaxonomy of this order have been achieved. We, therefore, investigated the morphology and cytology of nine chlorococcoid members available locally. Materials and methods Description of materials Chlorococcum infusionum (Schrank) Meneghini Cells spherical, 6-36ƒÊm in diameter, with a mucilaginous covering of 1.5-7.5ƒÊ m thickness; chloroplast like a hallow sphere with a notch on one side and with a pyrenoid; reproduction by biciliate swarmers. Trebouxia humicola (Treboux) West et Fritsch Subareal, found as green patches in association with some blue-green algae on the bark of Schleichera triguga; cells spherical, 1.5-3.0ƒÊm in diameter, with a thin cell membrane; chloroplast central with lobed margin and a pyrenoid; repro duction through biciliate zoospores. Botryococcus braunii Kuetzing Colonies 12-80ƒÊm in diameter, irregular in shape, free floating, with a muci laginous envelope of irregular wrinkles or folds, often united into net-like aggregates by means of long delicate mucilaginous projections from the colonial envelope; cells 4-64 per colony, arranged in a zig-zag manner, with a solitary, parietal cup shaped or laminate chloroplast with a pyrenoid, measuring 3.5-6.0ƒÊm broad and 5.5-11.0ƒÊm long; reproduction through mature cells producing 8 autospores per cell. Dactylococcus infusionum Naegeli Cells solitary, attached end to end to form fragile colonies or chains, fusiform or slightly curved with parietal chloroplast with a pyrenoid, 2-5ƒÊm broad, 6-11 um long. Ankistrodesmus spiralis (Turner) Lemmermann Cells 1.5-4.5ƒÊm broad and 22-42ƒÊm long, acicular with pointed ends, occur ring in the form of bundle (32-74ƒÊm broad, 32-80ƒÊm long) consisting of 2-24 cells, usually twisted spirally around one another in the middle portion, while free 544 U. N. Rai and Y. B. K. Chowdary Cytologia 48 at the ends; chloroplast single, parietal in position, without pyrenoids. Ankistrodesmus falcatus (Corda) Ralfs Cells 1.5-3.5ƒÊm wide and 10-36ƒÊm long, mostly single, straight, acicular to narrowly fusiform, with tapering to acute apices; chloroplast parietal, without any pyrenoid. Nephrochlamys subsolitaria (G. S. West) Korshikov Cells 3.5-6ƒÊm broad and 9-13.5ƒÊm long, solitary or 2-4 cells enclosed within a persistant covering, crescent shaped having more or less rounded ends with one end slightly broader than the other; chloroplast nearly filling the cell, without any pyrenoid. Scenedesmus incrassatulus Bohlin Cells 4.5-12ƒÊm broad, 12-32ƒÊm long, fusiform, with stumpy ends with apical nodules; coenobia comprising 2-4 cells per coenobium solitary or in the form of cells arranged in a linear or slightly subalternating series; peripheral cells of coenobium convex on their outer side and with more or less straight inner walls. Chlorosarcina stigmatica Deason (Deason 1958) Occurring as cubical packets containing 4-16 cells enclosed in a characteristic pectic matrix; cells solitary, 4.5-12ƒÊm long and 3-7.5ƒÊm broad, nearly spherical but angular when under natural compression; chloroplast parietal, cup-shaped, without any pyrenoid; reproduction by the production of 4 autospores. All the above nine taxa were collected from nature, isolated and grown in modi fi ed Chu-10 medium (Safferman and Morris 1964) under controlled laboratory conditions. All the algae were morphologically identified as per description given in Brunthaler (1915), Prescott (1951), Korshikov (1953) and Philipose (1967). Actively dividing materials of these taxa, from cultures,were fixed in 1: 3 acetic acid alcohol mixture for about 25 hours. Cytological study was made on these materials employing Godward's iron-alum acetocarmine squash technique (cf. Godward 1948). Cytological observations All the nine taxa investigated in the present study are uninucleate to start with and become multinucleate at the time of reporduction. The number of nuclei in most of the taxa vary per cell depending upon the age of material under study (4-8 nuclei in Chlorococcum infusionum; 4 in Trebouxia humicola, 2-8 in Botryo coccus braunii, 2-4 in Dactylococcus infusionum; 4 in Nephrochalmys subsolitaria; 2-4 in Scenedesmus incrassatulus; 2-4 in Chlorosarcina stigmatica). The nuclear divisions are synchronous in colonial forms. Since the investigated taxa resembled in the details of the nuclear division,a general account is given here for all the isolates studied. The various karyological features for all the taxa have been summarized in Table 1. Interphase nucleus Interphase nucleus is more or less spherical or ovoid in outline and the dia meter varies in different taxa (Table 1). Juvenile cells or colonies invariably ex hibited the interphase nuclei with smaller diameters than those in mature ones. 1983 Cytological Studies on Some Chlorococcoid Green Algae 545 Interphase nucleus takes intense stain and appears homogenous. As a result of this, chromocentres are not discernible in any case. Nucleolus At interphase the nucleolar outline is not distinct as it did not take intense stain . Nucleolus readily takes intense stain in early prophase and becomes clearly visible. Its diameter was found to vary with the size of cells. Large nucleated forms do have bigger nucleoli. In all the taxa studied it disappeared earlier to late pro phase stage. In none of the materials nucleolar material perisisted beyond prophase. Prophase At prophase, the nucleus increases about 2 times the size of its interphase one and the nucleoplasm becomes more granular. The granulated chromatin threads which appear in early prophase condense further to give rise to discrete late pro Table 1. A comparative account of karyological features phase chromosomes. By this time the nucleolus disintegrates and the nucleolar material and nuclear membrane are not visible. Metaphsae Late prophase chromosomes organize themselves into a clear metaphase plate whose diameter is more or less the same or little lesser than that of its prophase nucleus. Metaphase chromosomes are either dot-like or small dot-like. Centro meric positions are not clear in these chromosomes because of their minute sizes. The chromosome size was found to vary from 0.4 to 1.0ƒÊm (Table 1). Anaphase is normal; spindles are distinct in unsquashed preparations. Cytokinesis takes place only when requisite number of nuclei are formed with in a cell. The chromosome numbers determined in the present study for all the taxa have been listed in Table 1 . (see Figs. 1, la, to 10, 10a). The lowest chromo some number reported is n=6 for Dactylococcus infusionum and Nephrochlamys 546 U. N. Rai and Y. B. K. Chowdary Cytologia 48 Figs. 1 and la to 10 and 10a. Cytology of chlorococcoid green algae. 1 and la, metaphase squash preparation and its drawing respectively of Chlorococcum infusionum showing 10 chromo somes. •~3500. 2 and 2a, metaphase squash preparation and its drawing respectively of Trebouxia humicola showing 10 chromosomes. •~3000. 3 and 3a, metaphase squash preparation and its drawing of Botryococcus braunii showing 8 chromosomes. •~4500. 4and 4a, metaphase squash preparation of Dactylococcus infusionum and its drawing showing 6 chromosomes. •~4500. 5 and 5a, metaphase squash preparation and its drawing respectively of Ankistrodesmus spiralis showing 10 chromosomes. •~4000. 6 and 6a, metaphase squash preparation of Ankistrodesmus falcatus 1983 Cytological Studies on Some Chlorococcoid Green Algae 547 subsolitaria, whereas the highest number recorded is n=10 for Chlorococcum in fusionum,Tribouxia humicola and Ankistrodesmus spiralis. Discussion The cytological work on chlorococcoid green algae is lagging far behind. The workers who contributed to this field are Timberlake (1902), Yamanouchi (1913), Smith (1916, 1918), Bristol (1917), Mainix (1927), Reichardt (1927), Techermack (1942), Proskauer (1952), Palik (1949), Sulek (1969), Sedova (1970) and Chan (1974). The forms so far studied cytologically by Indian workers are Hydrodictyon (Sarma 1962, Chowdary 1967, Sinha and Noor 1967, Sahay and Sinha 1971), Kirchneriella and Characium (Chowdary 1967), Characiosiphon (Petal and Francis 1967), Dimorphococcus (Rai and Chowdary 1980), Chlorocytrium (Rai and Chow dary 1981). Mathew (1976) studied comparative nulcear cytology of nineteen species belonging to eleven genera of Chlorococcales. All the taxa investigated in this study resemble in their cytological features. In having a spherical, homogenously stained interphase nuclei without any con spicuous chromocentres, the members investigated presently agree with the detailed characters described by Mathew (1976). The heterochromatic bodies reported by Sarma (1962) and Mathew (1976) in Hydrodictyon and in Gloeotaenium were not observed in any taxa presently investigated. The diameter of the interphase nuclei ranged between 1.5-3.5ƒÊm in most of the taxa. However, in Trebouxia humicola, Dactylococcus infusionum and Chlorosarcina stigmatica, the size was a little more than 4ƒÊm. All taxa are characterized by having single nucleolus
Load more

Recommended publications
  • Airborne Microalgae: Insights, Opportunities, and Challenges
    crossmark MINIREVIEW Airborne Microalgae: Insights, Opportunities, and Challenges Sylvie V. M. Tesson,a,b Carsten Ambelas Skjøth,c Tina Šantl-Temkiv,d,e Jakob Löndahld Department of Marine Sciences, University of Gothenburg, Gothenburg, Swedena; Department of Biology, Lund University, Lund, Swedenb; National Pollen and Aerobiology Research Unit, Institute of Science and the Environment, University of Worcester, Worcester, United Kingdomc; Department of Design Sciences, Lund University, Lund, Swedend; Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Aarhus, Denmarke Airborne dispersal of microalgae has largely been a blind spot in environmental biological studies because of their low concen- tration in the atmosphere and the technical limitations in investigating microalgae from air samples. Recent studies show that airborne microalgae can survive air transportation and interact with the environment, possibly influencing their deposition rates. This minireview presents a summary of these studies and traces the possible route, step by step, from established ecosys- tems to new habitats through air transportation over a variety of geographic scales. Emission, transportation, deposition, and adaptation to atmospheric stress are discussed, as well as the consequences of their dispersal on health and the environment and Downloaded from state-of-the-art techniques to detect and model airborne microalga dispersal. More-detailed studies on the microalga atmo- spheric cycle, including, for instance, ice nucleation activity and transport simulations, are crucial for improving our under- standing of microalga ecology, identifying microalga interactions with the environment, and preventing unwanted contamina- tion events or invasions. he presence of microorganisms in the atmosphere has been phyta and Ochrophyta in the atmosphere (taxonomic classifica- Tdebated over centuries.
    [Show full text]
  • The Green Puzzle Stichococcus (Trebouxiophyceae, Chlorophyta): New Generic and Species Concept Among This Widely Distributed Genus
    Phytotaxa 441 (2): 113–142 ISSN 1179-3155 (print edition) https://www.mapress.com/j/pt/ PHYTOTAXA Copyright © 2020 Magnolia Press Article ISSN 1179-3163 (online edition) https://doi.org/10.11646/phytotaxa.441.2.2 The green puzzle Stichococcus (Trebouxiophyceae, Chlorophyta): New generic and species concept among this widely distributed genus THOMAS PRÖSCHOLD1,3* & TATYANA DARIENKO2,4 1 University of Innsbruck, Research Department for Limnology, A-5310 Mondsee, Austria 2 University of Göttingen, Albrecht-von-Haller-Institute of Plant Sciences, Experimental Phycology and Sammlung für Algenkulturen, D-37073 Göttingen, Germany 3 [email protected]; http://orcid.org/0000-0002-7858-0434 4 [email protected]; http://orcid.org/0000-0002-1957-0076 *Correspondence author Abstract Phylogenetic analyses have revealed that the traditional order Prasiolales, which contains filamentous and pseudoparenchy- matous genera Prasiola and Rosenvingiella with complex life cycle, also contains taxa of more simple morphology such as coccoids like Pseudochlorella and Edaphochlorella or rod-like organisms like Stichococcus and Pseudostichococcus (called Prasiola clade of the Trebouxiophyceae). Recent studies have shown a high biodiversity among these organisms and questioned the traditional generic and species concept. We studied 34 strains assigned as Stichococcus, Pseudostichococcus, Diplosphaera and Desmocococcus. Phylogenetic analyses using a multigene approach revealed that these strains belong to eight independent lineages within the Prasiola clade of the Trebouxiophyceae. For testing if these lineages represent genera, we studied the secondary structures of SSU and ITS rDNA sequences to find genetic synapomorphies. The secondary struc- ture of the V9 region of SSU is diagnostic to support the proposal for separation of eight genera.
    [Show full text]
  • Observations on Aerophytic Cyanobacteria and Algae from Ten Caves in the Ojców National Park
    ACTA AGROBOTANICA Vol. 66 (1), 2013: 39–52 DOI: 10.5586/aa.2013.005 OBSERVATIONS ON AEROPHYTIC CYANOBACTERIA AND ALGAE FROM TEN CAVES IN THE OJCÓW NATIONAL PARK Joanna Czerwik-Marcinkowska Department of Botany, Institute of Biology, Jan Kochanowski University Świętokrzyska 15, 25-420 Kielce, Poland e-mail: [email protected] Received: 19.04.2012 Abstract Hašler, 2007). At the entrance of limestone caves This study, carried out in 2010–11, focuses on species and on the surfaces around electrical lights, cyanobac- composition and distribution of cyanobacterial and algal com- teria compete for light with other algae, bryophytes munities colonizing ten caves (Biała, Ciemna, Koziarnia, Kra- and ferns, but in the deepest recesses of the caves they kowska, Łokietka, Okopy Wielka Dolna, Sąspowska, Sypialnia, are usually the only phototrophs (Round, 1981). Zbójecka and Złodziejska Caves) in the Ojców National Park Most caves represent stable environments characte- (South Poland). A total of 85 taxa were identified, 35 of them rized by uniform temperatures throughout the year, belonging to cyanobacteria, 30 chlorophytes, and 20 belonging high humidity and low natural light (Hernández- to other groups of algae. Aerophytic cyanobacteria dominated -Mariné and Canals, 1994; Ducarme et al. in these calcareous habitats. Nine species, Gloeocapsa alpina, 2004; Poulič ková and Hašler, 2007; Lam- Nostoc commune, Chlorella vulgaris, Dilabifilum arthopyre- niae, Klebsormidium flaccidum, Muriella decolor, Neocystis prinou et al. 2009). According to Lamprinou et subglobosa, and Orthoseira roseana, were the most abundant al. (2012), a typical cave is described as having three taxa in all the caves. The investigated microhabitats offer re- major habitat zones based on light penetration and in- latively stable microclimatic conditions and are likely to be tensity: the entrance-, transition-, and dim light zone.
    [Show full text]
  • Examination of the Terrestrial Algae of the Great Smoky Mountains National Park, USA
    Fottea 10(2): 201–215, 2010 201 Examination of the terrestrial algae of the Great Smoky Mountains National Park, USA Liliya S. KHAYBULLINA 1, Lira A. GAYSINA 1*, Jeffrey R. JOHANSEN 2 & Markéta KRAUTOVÁ 3 1Department of Botany, Bioecology and Landscape Design, Bashkir State Pedagogical University named after M.Akmullah, Ufa, Oktyabrskoy revolucii st., 3a, 450000, Bashkortostan, Russia; * corresponding author e–mail: [email protected] 2Department of Biology, John Carroll University, University Heights, Ohio 44118, USA; e–mail: [email protected] 3Faculty of Science, University of South Bohemia, České Budějovice, Branišovská 31, CZ–370 05, Czech Republic Abstract: Forest soils of the Great Smoky Mountains National Park were examined for soil algae as part of the All Taxa Biodiversity Inventory underway in that park. Soils of both mature and secondary growth forests were sampled, along with samples from rocks and tree bark. A total of 42 taxa were observed, representing Cyanobacteria (3 species), Chlorophyceae (12 species), Trebouxiophyceae (18 species), Ulvophyceae (3 species), Klebsormidiophyceae (1 species), Zygnematophyceae (2 species), Tribophyta (3 species), Eustigmatophyta (1 species), Euglenophyta (1 species), and Dinophyta (1 species). Twenty new taxa records for the park were established. Key words: aerial algae, Chlorophyceae, Cyanobacteria, forest soils, phycobiont, terrestrial algae, Trebouxiophyceae. Introduction more intensive study, the number of the algae was eventually catalogued at 1000 taxa (JOHANSEN et The Great Smoky Mountains National Park al. 2007). These algae were found in rivers, creeks, (GSMNP), an International Biosphere Preserve springs, and seep walls. Soil algae were studied in the Appalachian Mountains, straddles the in a very limited fashion by DEASON & HERN D ON Tennessee–North Carolina border within the (1989), who reported three taxa from soils in the USA.
    [Show full text]
  • Comparative Nitrogen Nutrition of Certain Fresh-Water Algae" (1971)
    Eastern Illinois University The Keep Masters Theses Student Theses & Publications 1971 Comparative Nitrogen Nutrition of Certain Fresh- Water Algae William H. Culp Eastern Illinois University This research is a product of the graduate program in Botany at Eastern Illinois University. Find out more about the program. Recommended Citation Culp, William H., "Comparative Nitrogen Nutrition of Certain Fresh-Water Algae" (1971). Masters Theses. 3941. https://thekeep.eiu.edu/theses/3941 This is brought to you for free and open access by the Student Theses & Publications at The Keep. It has been accepted for inclusion in Masters Theses by an authorized administrator of The Keep. For more information, please contact [email protected]. PAPER GER TIFICATE #2 TO: Graduate Degree Candidates who have written formal theses. SUBJECT: Permission to reproduce theses. The University Library is receiving a number of requests from other institutions asking permission to reproduce dissertations for inclusion in their library holdings. Although no copyright laws are involved, we feel that professional courtesy demands that permission be obtained from the author before we allow theses to be copied. Please sign one of the following statements. Booth Library of Eastern Illinois University has my permission to lend my thesis to a reputable college or university for the purpose of copying it for inclusion in that institution's library or research holdings. Date Author I respectfully request Booth Library of Eastern Illinois University not allow my thesis be reproduced because <(£ ... , � C.-u .. _ (,{) . , ,,, ,, •I, l.. ,./ C-1 /LB1861·C57XC968>C2/ BOOTH LIBRARY �RN ILLINOIS UNIVERSig 9Ji.ARLESTON,ILL. 6192q{Y COMPARATIVE NITROGEN NUTRITION ..
    [Show full text]
  • Biodiesel from Algae
    National Renewable Energy Laboratory NREL/TP-580-24190 A Look Back at the U.S. Department of Energy’s Aquatic Species Program: Biodiesel from Algae Close-Out Report A Look Back at the U.S. Department of Energy’s Aquatic Species Program—Biodiesel from Algae July 1998 By John Sheehan Terri Dunahay John Benemann Paul Roessler Prepared for: U.S. Department of Energy’s Office of Fuels Development Prepared by: the National Renewable Energy Laboratory 1617 Cole Boulevard Golden, Colorado 80401-3393 A national laboratory of the U.S. Department of Energy Operated by Midwest Research Institute Under Contract No. DE-AC36-83CH10093 NREL/TP-580-24190 Executive Summary From 1978 to 1996, the U.S. Department of Energy’s Office of Fuels Development funded a program to develop renewable transportation fuels from algae. The main focus of the program, know as the Aquatic Species Program (or ASP) was the production of biodiesel from high lipid-content algae grown in ponds, utilizing waste CO2 from coal fired power plants. Over the almost two decades of this program, tremendous advances were made in the science of manipulating the metabolism of algae and the engineering of microalgae algae production systems. Technical highlights of the program are summarized below: Applied Biology A unique collection of oil-producing microalgae. The ASP studied a fairly specific aspect of algae—their ability to produce natural oils. Researchers not only concerned themselves with finding algae that produced a lot of oil, but also with algae that grow under severe conditions—extremes of temperature, pH and salinity. At the outset of the program, no collections existed that either emphasized or characterized algae in terms of these constraints.
    [Show full text]
  • Green Algae and the Origin of Land Plants1
    American Journal of Botany 91(10): 1535±1556. 2004. GREEN ALGAE AND THE ORIGIN OF LAND PLANTS1 LOUISE A. LEWIS2,4 AND RICHARD M. MCCOURT3,4 2Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut 06269 USA; and 3Department of Botany, Academy of Natural Sciences, 1900 Benjamin Franklin Parkway, Philadelphia, Pennsylvania 19103 USA Over the past two decades, molecular phylogenetic data have allowed evaluations of hypotheses on the evolution of green algae based on vegetative morphological and ultrastructural characters. Higher taxa are now generally recognized on the basis of ultrastruc- tural characters. Molecular analyses have mostly employed primarily nuclear small subunit rDNA (18S) and plastid rbcL data, as well as data on intron gain, complete genome sequencing, and mitochondrial sequences. Molecular-based revisions of classi®cation at nearly all levels have occurred, from dismemberment of long-established genera and families into multiple classes, to the circumscription of two major lineages within the green algae. One lineage, the chlorophyte algae or Chlorophyta sensu stricto, comprises most of what are commonly called green algae and includes most members of the grade of putatively ancestral scaly ¯agellates in Prasinophyceae plus members of Ulvophyceae, Trebouxiophyceae, and Chlorophyceae. The other lineage (charophyte algae and embryophyte land plants), comprises at least ®ve monophyletic groups of green algae, plus embryophytes. A recent multigene analysis corroborates a close relationship between Mesostigma (formerly in the Prasinophyceae) and the charophyte algae, although sequence data of the Mesostigma mitochondrial genome analysis places the genus as sister to charophyte and chlorophyte algae. These studies also support Charales as sister to land plants.
    [Show full text]
  • Multiple Origins of Endosymbionts in Chlorellaceae with No Reductive
    www.nature.com/scientificreports OPEN Multiple origins of endosymbionts in Chlorellaceae with no reductive efects on the plastid or Received: 14 March 2017 Accepted: 8 August 2017 mitochondrial genomes Published: xx xx xxxx Weishu Fan1,2, Wenhu Guo3, James L. Van Etten4 & Jefrey P. Mower1,2 Ancient endosymbiotic relationships have led to extreme genomic reduction in many bacterial and eukaryotic algal endosymbionts. Endosymbionts in more recent and/or facultative relationships can also experience genomic reduction to a lesser extent, but little is known about the efects of the endosymbiotic transition on the organellar genomes of eukaryotes. To understand how the endosymbiotic lifestyle has afected the organellar genomes of photosynthetic green algae, we generated the complete plastid genome (plastome) and mitochondrial genome (mitogenome) sequences from three green algal endosymbionts (Chlorella heliozoae, Chlorella variabilis and Micractinium conductrix). The mitogenomes and plastomes of the three newly sequenced endosymbionts have a standard set of genes compared with free-living trebouxiophytes, providing no evidence for functional genomic reduction. Instead, their organellar genomes are generally larger and more intron rich. Intron content is highly variable among the members of Chlorella, suggesting very high rates of gain and/or loss of introns during evolution. Phylogenetic analysis of plastid and mitochondrial genes demonstrated that the three endosymbionts do not form a monophyletic group, indicating that the endosymbiotic lifestyle has evolved multiple times in Chlorellaceae. In addition, M. conductrix is deeply nested within the Chlorella clade, suggesting that taxonomic revision is needed for one or both genera. It is well established that the transition to an obligate endosymbiotic lifestyle ofen results in massive genomic reduction, particularly in ancient and obligate endosymbiont-host relationships.
    [Show full text]
  • Systematic Position of Some Genera of Green Algae Characterized By"" the Formation of Mucilaginous Or Pseudo Filamentous Colonies
    Preslia, Praha, .54: 1-18, 1982 Systematic position of some genera of green algae characterized by"" the formation of mucilaginous or pseudo filamentous colonies Systematicke postavenie niektorych rodov zelenych rias vyznacnych tvorbou slizovitych a pseudovlaknicych kol6nif Frantisek Hindak HINDAK F. (1982): Systematic position of some genera of green algae characterized by the formation of mucilaginous or pseurlofilarnentous coloni es. - Preslia, Pra.ha., 54:1 - 18. Some genera of colonial green algae have been studied which though characterized by mutually detached cells in the mucilage a.sin the ord~r Chlorococcales, woukl never­ theless reproduce by cell division into two parts as simple ulotrichacean algae. Since the mode of a.sexual reproduction by autospores and by cell division into two parts is considered as a feature differentiating the orders Chlorococctiles and Ulotrichales, the genera Hormotila BoRZI, Dispora PRINTZ, Ohaetopedia SKUJA = Cruciglow :::loEDER, Disporops'is KoRSIKOV = Planochloris KOMAREK, Phacomyxa SKUJA and Parallela FLINT were taken as representatives of the order Ulotrichales. The generic limits of Hormotila BoRZI, Hormidiopsis REEH.ING, Parnlella FLINT, Radiofilum ScHMIDLE and Geminella TURPIN are discussed. One new genus (Posson~a HrnDAK) with a new species (P. sestonica HINDAK) is described and four new combinations [Heleoooccus ramosissimus (KoRSIKOV) HINDAK, Geminella .flavescens (G. S. WEST) HINDAK, G. sca­ lariforme (G. S. WEST) HIND.AK, G. ellipsoidea (PRESCOTT) HINDAK] are proposed. Institute of Experimental B'iology and Ecology, Slovak Academy of Sciences, Dubravska cesta 14, 814 34 Bratislava, Gzechoskwaki,a. ()J ft J 4 In this paper some genera of green algae have been studied ~racterizcd by mucilaginous colonies in which the cells are detached fro;/, ~~~h other as in some representatives of chlorococcal algae.
    [Show full text]
  • A Reassessment of Geminella (Chlorophyta) Based Upon Photosynthetic Pigments, Dna Sequence Analysis and Electron Microscopy
    A REASSESSMENT OF GEMINELLA (CHLOROPHYTA) BASED UPON PHOTOSYNTHETIC PIGMENTS, DNA SEQUENCE ANALYSIS AND ELECTRON MICROSCOPY Maris R. Durako A Thesis Submitted to the University of North Carolina Wilmington in Partial Fulfillment Of the Requirements for the Degree of Master of Science Department of Biology and Marine Biology University of North Carolina Wilmington 2007 Approved by Advisory Committee _____________________________Dr. Gregory T. Chandler ______________________________Dr. D. Wilson Freshwater _____________________________Dr. J. Craig Bailey Chair Accepted by _____________________________Dr. Robert D. Roer Dean, Graduate School This thesis has been prepared in the style and format consistent with the journal European Journal of Phycology ii TABLE OF CONTENTS ABSTRACT....................................................................................................................... iv ACKNOWLEDGEMENTS.................................................................................................v DEDICATION................................................................................................................... vi LIST OF TABLES............................................................................................................ vii LIST OF FIGURES ......................................................................................................... viii INTRODUCTION ...............................................................................................................1 MATERIALS AND METHODS.........................................................................................3
    [Show full text]
  • (Chlorophyceae) and Scotinosphaera (Scotinosphaerales, Ord
    J. Phycol. 49, 115–129 (2013) © 2012 Phycological Society of America DOI: 10.1111/jpy.12021 MORPHOLOGY AND PHYLOGENETIC POSITION OF THE FRESHWATER GREEN MICROALGAE CHLOROCHYTRIUM (CHLOROPHYCEAE) AND SCOTINOSPHAERA (SCOTINOSPHAERALES, ORD. NOV., ULVOPHYCEAE)1 2 Pavel Skaloud, Tomas Kalina, Katarına Nemjova Charles University in Prague, Faculty of Science, Department of Botany, Benatska 2, 128 01, Prague 2, Czech Republic Olivier De Clerck, and Frederik Leliaert Phycology Research Group, Biology Department, Ghent University, Krijgslaan 281 S8, 9000, Ghent, Belgium The green algal family Chlorochytriaceae comprises plementary DNA; DAPI, 4′,6-diamidino-2-phenylin- relatively large coccoid algae with secondarily dole; EMBL, European Molecular Biology thickened cell walls. Despite its morphological Laboratory; ML, maximum likelihood; PP, posterior distinctness, the family remained molecularly probability; rbcL, ribulose-bisphosphate carboxylase uncharacterized. In this study, we investigated the morphology and phylogenetic position of 16 strains determined as members of two Chlorochytriaceae genera, Chlorochytrium and Scotinosphaera.The phylogenetic reconstructions were based on the Diversity of eukaryotic microorganisms is gener- analyses of two data sets, including a broad, ally poorly known and likely underestimated, espe- concatenated alignment of small subunit rDNA and cially when compared to animals and land plants. In rbcL sequences, and a 10-gene alignment of 32 selected the past two decades, the use of molecular tools has taxa. All analyses revealed the distant relation of the revolutionized microbial diversity research, includ- two genera, segregated in two different classes: ing the discovery of numerous deeply branching Chlorophyceae and Ulvophyceae. Chlorochytrium phylogenetic lineages (Edgcomb et al. 2002, Kaw- strains were inferred in two distinct clades of the achi et al.
    [Show full text]
  • Pseudoneochloris Marina (Chlorophyta), a New Coccoid Ulvophycean Alga, and Its Phylogenetic Position Inferred from Morphological and Molecular Data1
    J. Phycol. 36, 596–604 (2000) PSEUDONEOCHLORIS MARINA (CHLOROPHYTA), A NEW COCCOID ULVOPHYCEAN ALGA, AND ITS PHYLOGENETIC POSITION INFERRED FROM MORPHOLOGICAL AND MOLECULAR DATA1 Shin Watanabe,2 Atsumi Himizu Department of Biology, Faculty of Education, Toyama University, Toyama, 930 Japan Louise A. Lewis3 Department of Biology, University of New Mexico, Albuquerque, New Mexico 87131 Gary L. Floyd Department of Plant Biology, Ohio State University, Columbus, Ohio 43210 and Paul A. Fuerst Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210 Ultrastructural and molecular sequence data were Abbreviations: b1, first basal body; b2, second basal used to assess the phylogenetic position of the coc- body; DO, directly opposed; dr, d-rootlet; M, mito- coid green alga deposited in the culture collection of chondrial profile; N, nucleus; P, pyrenoid matrix; St, the University of Texas at Austin under the name of stigma; sr, s-rootlet; V, vacuole Neochloris sp. (1445). This alga has uninucleate vegeta- tive cells and a parietal chloroplast with pyrenoids; it reproduces by forming naked biflagellate zoospores. Unicellular green algae are one of the more difficult Electron microscopy revealed that zoospores have algal groups to resolve taxonomically because of the basal bodies displaced in the counterclockwise abso- relatively small number of morphological traits present lute orientation and overlapped at their proximal in their vegetative cells. However, intensive efforts to ends. Four microtubular rootlets numbering 2 and characterize flagellar apparatus architecture of coc- 2/1 are alternatively arranged in a cruciate pattern. coid green algae have aided in understanding their A system I fiber extends beneath each d rootlet and phylogenetic affinities (Watanabe and Floyd 1996).
    [Show full text]