Ultrastructure Of Conidium And Disjunctor Development In The Plant Pathogenic Fungus Monilinia Vaccinii-Corymbosi

1999 ◽  
Vol 5 (S2) ◽  
pp. 1278-1279
Author(s):  
C. W. Mims ◽  
E. A. Richardson
Keyword(s):  
Electron Microscopy ◽  
United States ◽  
Scanning Electron Microscopy ◽  
Pathogenic Fungus ◽  
The United States ◽  
Exact Nature ◽  
Taxonomic Character ◽  
Plant Pathogenic Fungus ◽  
Disease Initiation ◽  
Scanning Electron

Monilinia vaccinii-corymbosi is the cause of mummy berry disease of commercial blueberries (Vaccinium spp.) grown in the United States and Canada (1). Ovaries of blueberry flowers are infected by the conidia (asexual spores) of this pathogen. However, despite their importance in disease initiation, little is known of the ultrastructural features of these conidia. The only ultrastructural data on these spores has come from the work of Batra (2) who used scanning electron microscopy to describe the morphology of the so-called “disjunctors” which connect adjacent conidia of M. vaccinii-corymbosi. The presence or absence of disjunctors is an important taxonomic character in the genus Monilinia (1) but little is known of their development and exact nature. The objective of this study was, therefore, to elucidate details of conidium and disjunctor development in M. vaccinii-corymbosi.

Punctastriata altera sp. nov. (Bacillariophyta, Fragilariophyceae), a diatom from the United States of America

Phytotaxa ◽  
2021 ◽  
Vol 516 (3) ◽  
Author(s):  
EDUARDO A. MORALES
Keyword(s):  
Electron Microscopy ◽  
United States ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
United States Of America ◽  
The United States ◽  
Scanning Electron

The genus Punctastriata D.M.Williams & Round (1988: 278) contains 10 species that are difficult to identify under light microscopy (LM) (Wetzel & Ector 2021, Morales et al. 2021). The difficulty lies in the differentiation of the overall valve outline and striation pattern of these species from members of Staurosirella D.M.Williams & Round (1988: 274). Under scanning electron microscopy (SEM), the striae of species of Punctastriata are typically multiseriate, the consequence of a profuse formation of viminules. In Staurosirella, the striae are composed of long and slender vimines delimiting apically oriented lineolae (Morales et al. 2021), while the production of viminules is incomplete and rare (Morales 2005).

Wall Sculpturing in Vessel Elements of Juglans Species of the United States

IAWA Journal ◽  
2008 ◽  
Vol 29 (2) ◽  
pp. 153-160
Author(s):  
Young Geun Eom ◽  
Ohkyung Kwon ◽  
Robert B. Hanna ◽  
Robert W. Meyer
Keyword(s):  
Electron Microscopy ◽  
United States ◽  
Scanning Electron Microscopy ◽  
Vessel Wall ◽  
The United States ◽  
Diagnostic Value ◽  
Black Walnut ◽  
Large Vessel ◽  
Vessel Elements ◽  
Scanning Electron

Wall sculpturing in the vessel elements of some Juglans species of the United States, four black walnuts (J. major, J. nigra, J. microcarpa (= J. rupestris), and J. californica) and one butternut (J. cinerea), was investigated through light and scanning electron microscopy. This feature showed various forms such as helical and reticulate thickenings, and thickening-like structures formed by coalescent pit apertures and large vessel to ray pits. Light to prominent wall sculpturing occurred regularly in black walnuts but fine and indistinctive wall sculpturing was observed rarely in butternut. Thus, vessel wall sculpturing was of some diagnostic value for separating black walnut from butternut.

Scanning electron microscopy of asbestos-containing material where the asbestos fibers are considered locked in a binder

1993 ◽  
Vol 51 ◽  
pp. 472-473
Author(s):  
J. R. Millette ◽  
R. S. Brown
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Protection Agency ◽  
Building Materials ◽  
The United States ◽  
Protection Agency ◽  
Asbestos Fibers ◽  
Different Types ◽  
Binder Material ◽  
Scanning Electron

The United States Environmental Protection Agency (EPA) has labeled as “friable” those building materials that are likely to readily release fibers. Friable materials when dry, can easily be crumbled, pulverized, or reduced to powder using hand pressure. Other asbestos containing building materials (ACBM) where the asbestos fibers are in a matrix of cement or bituminous or resinous binders are considered non-friable. However, when subjected to sanding, grinding, cutting or other forms of abrasion, these non-friable materials are to be treated as friable asbestos material. There has been a hypothesis that all raw asbestos fibers are encapsulated in solvents and binders and are not released as individual fibers if the material is cut or abraded. Examination of a number of different types of non-friable materials under the SEM show that after cutting or abrasion, tuffs or bundles of fibers are evident on the surfaces of the materials. When these tuffs or bundles are examined, they are shown to contain asbestos fibers which are free from binder material. These free fibers may be released into the air upon further cutting or abrasion.

Morphology of the lateral fields of the infective juvenile of the entomopathogenic family Steinernematidae (Nematoda) using high pressure freezing (HPF)

Nematology ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 69-74
Author(s):  
Zdeněk Mráček ◽  
Jiří Nermut’ ◽  
Martina Tesařová ◽  
Vladimír Půža
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Pressure ◽  
Infective Juvenile ◽  
Field Pattern ◽  
Taxonomic Character ◽  
High Pressure Freezing ◽  
Lateral Field ◽  
Transmission Electron ◽  
Scanning Electron

Summary The lateral field pattern of infective juveniles of the nematode family Steinernematidae is an important taxonomic character. Scanning electron microscopy (SEM) shows the number of ridges and lines or incisures clearly, but does not provide other details. In the present study, ten species from six clades of Steinernematidae have been studied for their lateral field morphology using SEM and high pressure freezing (HPF) with transmission electron microscopy (TEM). Both methods indicated the same number of ridges and lines, although HPF/TEM resulted in a more detailed morphology with differences between the species. The tips of the ridges are either finely rounded or pointed and the lines are V-shaped or have a broadened bottom. These characters represent an additional pattern that may be characteristic for some species within the phylogenetic clades. Further studies of the lateral field morphology of other species is needed to ascertain whether each pattern is clade specific and phylogenetically valuable.

Taxonomically Important Features on the Surface of Floatoblasts in Plumatella (Bryozoa)

2000 ◽  
Vol 6 (3) ◽  
pp. 202-210
Author(s):  
Kevin T. Reynolds
Keyword(s):  
Electron Microscopy ◽  
United States ◽  
Scanning Electron Microscopy ◽  
Suture Line ◽  
Species Level ◽  
Surface Features ◽  
The Family ◽  
Group A ◽  
Distinguishing Features ◽  
Scanning Electron

Abstract At the species level, bryozoans (class Phylactolaemata) in the family Plumatellidae are difficult to organize taxonomically. Of principal concern is the absence of consistent distinguishing features due mainly to plasticity of the group, a common problem with soft-bodied invertebrates. Yet, within the last three decades, analysis of distinctive chitinous statoblasts—using scanning electron microscopy—has resolved certain taxonomic questions. I examined statoblasts from 30 similar collections, the majority from the midwestern United States, and identified four distinct subgroups. Also, nine new statoblast surface features were identified: fold, polar grooves, bead, cave, demarcation, parasutural zone, ridge, sutural band, and sutural knob. The surface features of floating statoblasts (floatoblasts) provide useful data for species identification. Most consistently useful in plumatellids is a suture which varies from one species to the next. Mound-like tubercles and net-like ridges are next in the extent of variability. Finally, folds and polar grooves are present but vary even within floatoblasts from the same colony. Analysis of the suture in Plumatella fungosa, over a 5-day germination period, reveals all features at the site remain intact regardless of the initial age of the floatoblast. Only the suture line itself splits lengthwise to permit emergence of the new animal.

Echinostoma revolution (Froelich, 1802) Looss, 1899 and Isthmiophora melis (Schrank, 1788) Lühe, 1909 (Echinostomatinae, Digenea): Scanning electron microscopy of the tegumental surfaces

1984 ◽  
Vol 58 (3) ◽  
pp. 187-195 ◽  
Author(s):  
Lesley R. Smales ◽  
Harvey D. Blankespoor
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Topography ◽  
Body Surface ◽  
Secretory Granules ◽  
The Body ◽  
Taxonomic Character ◽  
Secretory Structures ◽  
Unusual Structure ◽  
Scanning Electron

ABSTRACTA detailed study of the surface topography of the echinostomes Echinostoma revolution and Isthmiophora melis has been carried out using SEM. The tegument of the body surface has a cobblestone-like appearance with interspersed pits. The presence of possible secretory granules is noted. Observations of the anterior end reveal that the collar spines are retractable. An unusual structure is described from the ventral gap of the spiny collar of E. revolutum. The origins of this structure and the possible functions of the spiny collar are discussed. The shape and distribution of body spines is described. Differences in cirrus morphology for the two species are described. The taxonomic position of, I. melis and the significance of cirrus morphology as a useful taxonomic character are discussed. Four types of presumed sensory or secretory structures occur—ciliated, domed, button and bilobed papillae. Their distribution is described and possible functions discussed.

scholarly journals Description of the Demicyclic life Cycle of Puccinia Sherardiana in Sphaeralcea Angustifolia in Mexico.

2021 ◽  
Author(s):  
Magnolia Moreno-Velázquez ◽  
Jesús Ricardo Sánchez-Pale ◽  
Ricardo Tapia-Nuño ◽  
Moisés Camacho-Tapia ◽  
José Manuel Cambrón-Crisantos ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Life Cycle ◽  
Pathogenic Fungus ◽  
Morphological Characteristics ◽  
Identity Verification ◽  
Pathogenicity Tests ◽  
Koch Postulates ◽  
Scanning Electron ◽  
Observation Period

Abstract During 2017-2019, leaves and stems with dark brown lesions containing hypophyllous telia surrounded by chlorotic halos were collected from Sphaeralcea angustifolia plants located in Axapusco, State of Mexico. Based on the morphological characteristics of pycnia, aecia and telia observed by light microscopy and scanning electron microscopy, the fungus Puccinia sherardiana was identified. Uredial stage was not present during the observation period. Identity verification was carried out by phylogenetic analysis with sequences of part of the 28S gene from ribosomal DNA. In addition, pathogenicity tests were done on S. angustifolia leaves by inoculating teliospores. The inoculated plants developed symptoms 15 days after inoculation, the signs beginning with the presence of aecia in the epidermis of the host and later telia were formed, completing the Koch Postulates. Puccinia sherardiana was previously described as a rust with a microcyclic life cycle on species of the genera Alcea, Malvastrum, Sidalcea and Sphaeralcea , belonging to the Malvaceae family, however, this study revealed that this plant pathogenic fungus has a demicyclic life cycle.

Scanning electron microscopy of three types of ectomycorrhizae formed on Eucalyptus nova-anglica in the southeastern United States

1981 ◽  
Vol 59 (5) ◽  
pp. 683-688 ◽  
Author(s):  
R. W. Rose Jr. ◽  
C. Gerald Van Dyke ◽  
C. B. Davey
Keyword(s):  
Electron Microscopy ◽  
United States ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Southeastern United States ◽  
The Other ◽  
Cenococcum Geophilum ◽  
Different Types ◽  
Scanning Electron

Three different types of ectomycorrhizae found in the Southeastern United States on Eucalyptus nova-anglica and identified as being formed by Cenococcum geophilum, Pisolithus tinctorius, and Scleroderma geaster were examined with a scanning electron microscope (SEM). In overall appearance the three types of mycorrhizae could be distinguished easily from each other, particularly C. geophilum, which had a relatively smooth, undulate surface in comparison with the other two types. Detailed descriptions and comparisons of these ectomycorrhizae are given and the value of SEM in characterizing ectomycorrhizae is discussed

Scanning electron microscopy of eggs of Ochlerotatus taeniorhynchus (Diptera: Culicidae, Aedini)

Zootaxa ◽  
2012 ◽  
Vol 3509 (1) ◽  
pp. 77 ◽  
Author(s):  
CARLOS BRISOLA MARCONDES ◽  
GERSON AZULIM MÜLLER ◽  
JACENIR SANTOS-MALLET ◽  
JERONIMO ALENCAR ◽  
JULIANA SOARES SARMENTO ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
United States ◽  
Scanning Electron Microscopy ◽  
North Carolina ◽  
External Morphology ◽  
Aquatic Habitats ◽  
Coastal Habitats ◽  
Egg Morphology ◽  
Scanning Electron

The study of egg morphology is useful for the identification of material from aquatic habitats. For example, based on brief descriptions of external morphology of the eggs, Scotton and Axtell (1979) analysed the distribution of Ochlerotatus sollicitans (Walker) and Oc. taeniorhynchus (Wiedemann) in several coastal habitats in North Carolina, United States.

Studies in Australian Gryllacrididae: the proventriculus as a taxonomic character

1991 ◽  
Vol 5 (2) ◽  
pp. 443 ◽  
Author(s):  
RG Bland ◽  
DCF Rentz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Internal Structure ◽  
Food Type ◽  
Taxonomic Character ◽  
Structural Differences ◽  
Scanning Electron

The internal structure of the proventriculus of 17 species from 12 gryllacridid genera is described using light and scanning electron microscopy and is discussed in relation to its use as a taxonomic character. Structural differences were sufficient at 60 to 200 x to separate genera and species. Correlations between proventricular structure and food type are briefly discussed.

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