Spore wall ontogeny in Pseudoplectania nigrella and Plectania nannfeldtii (Ascomycotina, Pezizales)

1995 ◽  
Vol 73 (11) ◽  
pp. 1761-1767 ◽  
Author(s):  
Li-Tzu Li ◽  
James W. Kimbrough
Keyword(s):  
Key Words ◽  
Light Microscope ◽  
Secondary Wall ◽  
Spore Wall ◽  
Wall Layer ◽  
Ultrastructural Studies ◽  
Blue Stain ◽  
Spore Wall Ornamentation

Pseudoplectania and Plectania currently belong to the Sarcosomataceae, tribe Sarcosomateae, a group with members lacking cyanophilic spore markings (absorbing a blue stain). The two genera are morphologically similar in having blackish discoid-shaped apothecia but differ in having globose and ellipsoid spores, respectively. Ultrastructural studies show that ascospores of Pseudoplectania nigrella (Pers. ex Fr.) Fuckel lack a secondary wall layer. On the contrary, Plectania nannfeldtii Korf has secondary spore wall ornamentation that is cyanophilic under a light microscope. The data suggest retention of Pseudoplectania nigrella in the Sarcosomateae; however, the position of certain species of Plectania needs to be reevaluated. Key words: Pezizales, Plectania, Pseudoplectania, Sarcosomataceae, spore ontogeny, ultrastructure.

Spore ontogeny of Galiella rufa (Pezizales)

1996 ◽  
Vol 74 (10) ◽  
pp. 1651-1656 ◽  
Author(s):  
Li-Tzu Li ◽  
James W. Kimbrough
Keyword(s):  
Secondary Wall ◽  
Spore Wall ◽  
The Other ◽  
Ultrastructural Studies

Galiella is one of the genera of the dark-colored apothecial Sarcosomataceae, tribe Galielleae, with cyanophilous spore markings. Ultrastructural studies show that spore wall development of Galiella rufa is similar to the subgenus Discina of Gyromitra in Helvellaceae and to the other Sarcosomataceae, especially Plectania nannfeldtii, which both have fine secondary wall spore ornaments. The multinucleate ascospores found in G. rufa may show relationship to the Morchellaceae and the Helvellaceae. Keywords: ascospore ontogeny, Galiella, Sarcosomataceae, ultrastructure.

Spore ontogeny in species of Phillipsia and Wynnea (Pezizales)

1996 ◽  
Vol 74 (1) ◽  
pp. 10-18 ◽  
Author(s):  
Li-Tzu Li ◽  
James W. Kimbrough
Keyword(s):  
Secondary Wall ◽  
Spore Wall ◽  
Primary Wall ◽  
Ultrastructural Studies ◽  
Wall Components

Some species of the genera Phillipsia and Wynnea have similar longitudinally ridged cyanophobic ascospore markings. Ultrastructural studies show that the cyanophobic spore markings are part of the primary wall. In contrast, the cyanophilous spore ornaments are formed by the secondary wall. The observation of spore wall development indicates that the sources of the spore wall components are the sporoplasm and the epiplasm. Based on the pinkish hymenial color of fresh young apothecia and the cyanophobic spore ridges found only in some members of the Sarcoscyphaceae, Wynnea belongs to the Sarcoscyphaceae. Keywords: Pezizales, Phillipsia, Sarcoscyphaceae, spore wall ontogeny, ultrastructure, Wynnea.

Ultrastructural studies on germinating ascospores of Daldinia concentrica

1976 ◽  
Vol 54 (8) ◽  
pp. 698-705 ◽  
Author(s):  
A. Beckett
Keyword(s):  
Electron Microscope ◽  
Germ Tube ◽  
Tube Wall ◽  
Spore Wall ◽  
Wall Layer ◽  
Ultrastructural Studies ◽  
Early Stages ◽  
Ascospore Germination ◽  
Daldinia Concentrica

Ascospore germination in Daldinia concentrica has been studied using light and electron microscope techniques. Preliminary observations indicated that lipid globules were utilized during early stages of germination. Apical wall vesicles were localized during germ tube initiation and were involved in the differentiation of a filamentous germ tube. Wall synthesis occurred during germination and resulted in a new wall layer, which was different in ultratexture to the spore wall and which formed the germ tube wall. Possible implications of the concept of spore wall and vegetative wall types during germination are discussed.

Ultrastructural observations on Helvellaceae (Pezizales, Ascomycetes). IV. Ascospore ontogeny in selected species of Gyromitra subgenus Discina

1990 ◽  
Vol 68 (2) ◽  
pp. 317-328 ◽  
Author(s):  
James W. Kimbrough ◽  
Chi-Guang Wu ◽  
Jack L. Gibson
Keyword(s):  
Key Words ◽  
Secondary Wall ◽  
Spore Wall ◽  
Wall Material ◽  
Wall Structure ◽  
Primary Wall ◽  
Spore Ornamentation ◽  
Wall Formation ◽  
Secondary Wall Formation ◽  
Definition Of

The ultrastructure of ascospore ontogeny and spore wall microchemistry are described in three sessile, discoid species of Gyromitra previously placed in Discina. Silver proteinate and barium permanganate were used as poststains to enhance the definition of various wall layers and spore organelles. Early stages of ascosporogenesis and primary wall formation are similar to those described in other species of Pezizales. Secondary wall formation, which results in characteristic spore ornamentation, is similar in Gyromitra brunnea, Gyromitra leucoxantha, and Gyromitra perlata. Mature spores of these species differ in the size and shape of translucent lacunae within the secondary wall, and in the morphology of apiculi. The lacunae originate through blebbing of primary wall material through the epispore into the secondary wall, resulting in the isolation of electron-translucent primary wall clumps within the electron-dense secondary wall. These and other ultrastructural observations of apothecial tissues support the maintenance of the Helvellaceae (sensu lato) to include taxa of the tribes Helvelleae, Discineae, and Rhizineae. Phylogenetic linkages of these taxa to other families of Pezizales are suggested. Key words: ascosporogenesis, ascospore wall structure and microchemistry, discomycete systematics and phylogeny.

Ultrastructural studies of primary spores of Conidiobolus, Erynia, and related Entomophthorales

1989 ◽  
Vol 67 (9) ◽  
pp. 2576-2589 ◽  
Author(s):  
J. P. Latgé ◽  
D. F. Perry ◽  
M. C. Prévost ◽  
R. A. Samson
Keyword(s):  
Outer Layer ◽  
Germ Tube ◽  
Spore Wall ◽  
Wall Layer ◽  
Spore Formation ◽  
Dense Layer ◽  
Nuclear Ultrastructure ◽  
Ultrastructural Studies ◽  
Thin Electron ◽  
Definition Of

Wall development during primary spore formation, discharge, and germination of Entomophthorales is emphasized in ultrastructural studies of Conidiobolus, Entomophaga, Neozygites, and Erynia. In the fungi examined, spore and sporophore walls consist of a thick, electron-translucent inner layer and a thin, electron-dense outer layer. During spore formation, cytoplasm of the supporting sporophore cell migrates into the spore initial. As the former cell empties, a septum develops. Discharge is caused by inversion of the papillum, which lacks the electron-dense layer. Only in Erynia did the two spore wall layers separate upon impact. Intracytoplasmic organization of the primary spore is typical of the Zygomycotina; the morphology of organelles was characteristic of species, whereas nuclear ultrastructure was consistent within genera. Conidiobolus nuclei have a prominent nucleolus that lacks heterochromatin, in contrast with the other genera where large patches of heterochromatin were observed. Upon germination, no rupture of the spore outer layer was observed other than at points of germ tube emergence. The germ tube wall was continuous with the inner spore wall layer. The results are discussed in reference to Entomophthorales taxonomy and definition of the terms conidium and monosporous sporangiolum.

A taxonomic reappraisal of the genus Ceriosporopsis based on ultrastructure

1994 ◽  
Vol 72 (10) ◽  
pp. 1550-1559 ◽  
Author(s):  
M. Yusoff ◽  
E. B. G. Jones ◽  
S. T. Moss
Keyword(s):  
Key Words ◽  
New Genus ◽  
Marine Fungi ◽  
Spore Wall ◽  
Ultrastructural Studies ◽  
The Difference

This paper reports results of ultrastructural studies of ascospores and their appendages in Ceriosporopsis caduca, Ceriosporopsis circumvestita, and Ceriosporopsis capillacea. Ceriosporopsis caduca and C. capillacea have polar appendages that arise as outgrowths of the spore wall. The exosporium, which initially extends over the polar appendages, later forms a collar at their base. In C. circumvestita, the sheath is mesosporial in origin and is chambered; an exosporium is absent, and there is no collar at the base of the appendage. Because of the difference in ascospore appendage structure, C. circumvestita is transferred to a new genus Lautisporopsis. The taxonomy of the remaining species of Ceriosporopsis is reviewed, and comparisons are made with Bovicornua intricata. Key words: Ascomycotina, marine fungi, taxonomy, ultrastructure, Lautisporopsis.

Mycoparasitism of teliospores of Ustilago bullata by an oomycete

1990 ◽  
Vol 68 (11) ◽  
pp. 2415-2421 ◽  
Author(s):  
Robert W. Roberson ◽  
E. S. Luttrell ◽  
Melvin S. Fuller
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Key Words ◽  
Enzymatic Degradation ◽  
Spore Wall ◽  
Wall Layer ◽  
Smut Fungus ◽  
Pythium Vexans ◽  
Transmission Electron ◽  
Host Parasite

The mycoparasitism of teliospores of the smut fungus Ustilago bullata was discovered by transmission electron microscopy (TEM). Large, multinucleate chlamydospores germinated, producing hyphae that directly penetrated the walls of mature teliospores after forming an appressorium-like structure. Invagination of the exosporium at the point of penetration suggested mechanical penetration of this outer spore wall layer. The inner endosporium layer was fibrillar in appearance, with irregular electron-transparent regions suggesting enzymatic degradation. The cytoplasm and endosporium of parasitized teliospores were completely disintegrated, leaving only the spiny exosporium layer distributed throughout the sorus. Hyphae of the mycoparasite emerged from the teliospore shell, and their tips penetrated surrounding teliospores. TEM characteristics of the parasite confirmed oomycetous affinities. Pythium vexans was isolated from smutted tissue collected at the same time as tissue used for TEM observations. Pythium vexans was able to parasitize U. bullata teliospores in culture. Key words: hyperparasitism, ultrastructure, smut, Pythium, host–parasite relationships, infection.

Ultrastructural study of ascoma and ascospore development in Ophiostoma distortum and Ophiostoma minus

1991 ◽  
Vol 69 (11) ◽  
pp. 2529-2538 ◽  
Author(s):  
P. W. J. van Wyk ◽  
M. J. Wingfield
Keyword(s):  
Key Words ◽  
Ultrastructural Study ◽  
Secondary Wall ◽  
Outer Wall ◽  
Ultrastructural Level ◽  
Uniform Thickness ◽  
Central Cluster ◽  
Ultrastructural Studies ◽  
Ascospore Development ◽  
Development And Evolution

The development of the ascoma, ascus, and elongated ascospores in Ophiostoma distortum and Ophiostoma minus was studied at the ultrastructural level and compared with that of other related Ascomycetes. The organization of the centra in O. distortum and O. minus differed considerably. In O. distortum, asci were irregularly arranged in clusters that occurred in the lower half along the periphery of the ascoma. In O. minus, asci developed from a central cluster at the base of the ascoma. The asci extended upwards and outwards from the base. Ascospore development in both fungi commenced with the formation of double, delimiting membranes in the ascus. Between these membranes ascospore walls developed, consisting of the primary and secondary wall. In comparison with other species having similar ascospores, differences were found between the number of wall layers of the ascospores and formation of the outer wall layers. The secondary wall and perisporic sac of O. minus were smooth and of uniform thickness, whereas the inner layer of the secondary wall in O. distortum was thickened and distorted in certain areas. It is suggested that additional ultrastructural studies should be undertaken to provide a better understanding of the development and evolution of ascospore sheaths in Ceratocystis sensu lato. Key words: Ceratocystis, elongated ascospores, centrum.

The rusts (Uredinales) of arctic Canada

1989 ◽  
Vol 67 (11) ◽  
pp. 3315-3365 ◽  
Author(s):  
J. A. Parmelee
Keyword(s):  
Species Delimitation ◽  
Light Microscope ◽  
Canadian Arctic ◽  
Spore Wall ◽  
Arctic Canada ◽  
Spore Wall Ornamentation

Fifty-three taxa in 11 genera are described and illustrated from the Canadian Arctic. Included are a key to the genera and keys to the species within each genus. Prior records in many journals mostly lacked illustrations. Herein light microscope photographs are complemented by SEM photographs to show spore wall ornamentation, an essential character in species delimitation.

Ultrastructural observations on a marine lignicolous ascomycete: Bovicornua intricata gen. et sp.nov.

1993 ◽  
Vol 71 (2) ◽  
pp. 346-352 ◽  
Author(s):  
M. Yusoff ◽  
J. Koch ◽  
E. B. Gareth Jones ◽  
S. T. Moss
Keyword(s):  
Key Words ◽  
Outer Region ◽  
Spore Wall ◽  
Wall Layer ◽  
Fibrillar Material ◽  
South Wales ◽  
Inner Region

Bovicornua intricata sp.nov. is described from driftwood found at Marloes, South Wales, U.K. and Stenbjerg, Jutland, Denmark and compared with species of Ceriosporopsis Linder. Bovicornua intricata is separated from Ceriosporopsis species by the greater complexity of the structure of the appendaged ascospores. In ascospores of B. intricata, the exosporic wall layer enrobes both the spore wall and the polar appendages which arise as outgrowths of the spore. The exosporium is bipartite, the inner region has regular, parallel electron-dense lamellations that radiate from the episporium. The outer region of the exosporium consists of electron-dense fibrillar material at which the lamellae terminate. Key words: ascospore, marine ascomycete, spore appendage, taxonomy, ultrastructure.

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