Comparison between conidial development in Sporendocladia bactrospora and Phialocephala virens

1993 ◽  
Vol 71 (7) ◽  
pp. 985-991 ◽  
Author(s):  
Marnel Mouton ◽  
Michael J. Wingfield
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fluorescence Microscopy ◽  
Key Words ◽  
Conidiogenous Cell ◽  
Secretory Vesicles ◽  
Bright Field ◽  
Transmission Electron ◽  
Building Activity ◽  
Conidial Development

Conidium development was studied and compared in Sporendocladia bactrospora (thought to resemble Chalara spp.) and in Phialocephala virens. Techniques used in the study include bright field and fluorescence microscopy, as well as scanning and transmission electron microscopy. Sporendocladia bactrospora had cylindrical conidia produced in true chains from phialidic conidiogenous cells with long cylindrical collarettes. An area of wall building activity at the base of the conidiogenous cell was characterized by secretory vesicles indicating ring wall building development. In Phialocephala virens, conidia were formed by apical wall building and distinct periclinal thickening was evident. From this study it was possible to confirm the fact that Phialocephala s.l. can clearly be divided into two distinct groups on the basis of conidium development. Key words: apical wall building, conidiogenesis, Phialocephala, ring wall building, Sporendocladia.

The fine structure of conidial development in the genus Torula. I. T. herbarum (Pers.) Link ex S. F. Gray and T. herbarum f. quaternella Sacc.

1975 ◽  
Vol 21 (11) ◽  
pp. 1661-1675 ◽  
Author(s):  
D. H. Ellis ◽  
D. A. Griffiths
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Walls ◽  
Conidiogenous Cell ◽  
Outer Electron ◽  
Transmission Electron ◽  
Conidial Development ◽  
Dense Zone ◽  
Hyaline Zone ◽  
Lateral Walls

Conidiogenesis in Torula herbarum and T. herbarum f. quaternella was observed by scanning and transmission electron microscopy. Conidia of the former were shown to be made up of three equally sized cells capped by a distinctive, and easily recognizable, conidiogenous cell. Conidiogenous cells also arose terminally on erect hyphae and on prostrate hyphae. The single-layered conidial cell walls were differentiated into an inner hyaline zone and an outer electron-dense zone formed by the deposition of melanin. Conidiogenous cells lacked melanin at the apex and, before conidiation, the lateral walls were strengthened by a further deposition of melanin. The apex bulged outwards and was modified into a new multicelled conidium bearing another apical conidiogenous cell. Continued development of new conidia resulted in an acropetal chain which became disarticulated after cytolysis within the conidiogenous cell. The relative distinctions between holoblastic and enteroblastic development are discussed and it is concluded that the conidia should be referred to as blastoconidia.

Conidium development in the Hyalorhinocladiella anamorphs of Ceratocystiopsis minuta-bicolor and Ophiostoma minus

1996 ◽  
Vol 74 (6) ◽  
pp. 891-897 ◽  
Author(s):  
E. Benade ◽  
M. J. Wingfield ◽  
P. S. Van Wyk
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fluorescence Microscopy ◽  
Type Species ◽  
Conidiogenous Cell ◽  
Transmission Electron

The genus Hyalorhinocladiella was characterized by its simple conidiophores with conidiogenous cells that proliferate sympodially. However, recent studies revealed that the Hyalorhinocladiella anamorph of Ophiostoma ips has annellidic conidium development. The aim of this study was to determine whether other species in the genus share this characteristic. Conidium development was examined in the type species, Hyalorhinocladiella minuta-bicolor, and in the Hyalorhinocladiella anamorph of Ophiostoma minus. Light and fluorescence microscopy indicated that conidia developed by sympodial proliferation. In contrast, scanning and transmission electron microscopy revealed distinct annellations on the conidiogenous cells. Conidium development in Hyalorhinocladiella is therefore annellidic, and the appearance of sympodial development results from displacement of the long axis of the conidiogenous cell through percurrent proliferation. The circumscription of the genus Hyalorhinocladiella is therefore revised to include annellidic conidium development. Keywords: Hyalorhinocladiella, Ophiostoma, sympodial, annellidic, conidium development.

scholarly journals Annular Bright Field Scanning Transmission Electron Microscopy Imaging Dynamics

2010 ◽  
Vol 16 (S2) ◽  
pp. 80-81 ◽  
Author(s):  
SD Findlay ◽  
N Shibata ◽  
H Sawada ◽  
E Okunishi ◽  
Y Kondo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Bright Field ◽  
Microscopy Imaging ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

Ultrastructural and cytological observations of apothecial tissues of Geopyxis carbonaria (Pezizales, Ascomycetes)

1990 ◽  
Vol 68 (2) ◽  
pp. 243-257 ◽  
Author(s):  
James W. Kimbrough ◽  
Jack L. Gibson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Key Words ◽  
Mother Cell ◽  
Secondary Wall ◽  
Cell Stage ◽  
Wall Structures ◽  
Transmission Electron ◽  
Secondary Wall Formation ◽  
Characteristic Features

Cytological observations are made on apothecial tissues of Geopyxis carbonaria, using transmission electron microscopy. Characteristic features of both the medullary and ectal excipula are examined. Changes in ascus apex and wall structures are examined during ascus ontogeny, especially in relation to operculum position and structure. Ultrastructure of septum configuration is observed and compared in the excipulum, ascogenous hyphae, paraphyses, and at the base of young asci. Ascosporogenesis is observed from the ascus mother cell stage and initial spore delimitation until secondary wall formation. The cytological and ultrastructural observations on this species are discussed in relation to their possible taxonomic or phylogenetic value. Key words: ascosporogenesis, Discomycetes, ascospore ultrastructure, septal ultrastructure, cytochemistry.

Sporophytes, megaspores, and massulae of Azolla stanleyi from the Paleocene Joffre Bridge locality, Alberta

1994 ◽  
Vol 72 (3) ◽  
pp. 301-308 ◽  
Author(s):  
Georgia L. Hoffman ◽  
Ruth A. Stockey
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Key Words ◽  
Red Deer ◽  
The Other ◽  
Evolutionary Trends ◽  
Reproductive Structures ◽  
Transmission Electron ◽  
New Material

Several hundred vegetative and fertile specimens of Azolla Lam. have been recovered from the Paleocene Paskapoo Formation at the Joffre Bridge locality (Middle Tiffanian (Ti3) age) near Red Deer, Alberta. The spore complexes closely resemble those of the Paleocene A. stanleyi Jain & Hall, and the vegetative material is referred to that species. The specimens are unusually complete in that the remains of the fragile sporophyte are preserved, commonly with reproductive structures in place. Plants reaching up to 2.25 cm in length consist of alternately branched rhizomes bearing alternate, imbricate, sessile leaves. Leaves are ovate with entire margins, papillate surfaces, and a single midvein. Reproductive structures have been examined using light, scanning, and transmission electron microscopy. This new material is compared with the other Paleocene species for which sporophytes are known and discussed in terms of evolutionary trends for the genus. The specimens suggest that most of the vegetative characteristics of modern Azolla species were established by the middle Paleocene. Key words: Azolla, Salviniaceae, megaspore, massula, ultrastructure, Paleocene.

Coupling transmission electron microscopy with synchrotron radiation X-ray fluorescence microscopy to image vascular copper

2012 ◽  
Vol 19 (6) ◽  
pp. 1043-1049 ◽  
Author(s):  
Zhenyu Qin ◽  
Barry Lai ◽  
Julio Landero ◽  
Joseph A. Caruso
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Synchrotron Radiation ◽  
Fluorescence Microscopy ◽  
X Ray ◽  
Transmission Electron
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