Restriction Fragment Polymorphisms in Biological Species of Armillaria mellea

Mycologia ◽  
1987 ◽  
Vol 79 (1) ◽  
pp. 69 ◽  
Author(s):  
James B. Anderson ◽  
Dawna M. Petsche ◽  
Myron L. Smith
Keyword(s):  
Restriction Fragment ◽  
Biological Species ◽  
Armillaria Mellea

Restriction Fragment Polymorphisms in Biological Species of Armillaria Mellea

Mycologia ◽  
1987 ◽  
Vol 79 (1) ◽  
pp. 69-76 ◽  
Author(s):  
James B. Anderson ◽  
Dawna M. Petsche ◽  
Myron L. Smith
Keyword(s):  
Restriction Fragment ◽  
Biological Species ◽  
Armillaria Mellea

Restriction fragment length polymorphisms demonstrate single origin of infection centers in Phellinus weirii

1994 ◽  
Vol 72 (4) ◽  
pp. 440-447 ◽  
Author(s):  
Hanhong Bae ◽  
Everett M. Hansen ◽  
Steven H. Strauss
Keyword(s):  
Mitochondrial Dna ◽  
Restriction Fragment ◽  
Ribosomal Dna ◽  
Fragment Length ◽  
Host Species ◽  
Root Rot ◽  
Biological Species ◽  
Douglas Fir ◽  
Dna Probes ◽  
Restriction Fragment Length

Restriction fragment length polymorphism (RFLP) markers were used to study genetic variation in the basidiomycete fungus Phellinus weirii (Murr.) Gilbertson, the cause of laminated root rot of conifers. In an initial study, three isolates each from the Douglas-fir type and the cedar-type biological species were surveyed with 12 restriction enzymes and 20 random, mitochondrial, and nuclear-ribosomal gene probes. The two biological species were distinct with most probe–enzyme combinations (91%). Variation within biological species was detected for the random and ribosomal DNA probes but not for the mitochondrial DNA probes. In a subsequent study 65 probe–enzyme combinations (13 × 5) that had detected variation within the Douglas-fir type biological species were used to analyze 27 isolates derived from six infection centers, two host species, and two geographic areas in western Oregon. Infection centers differed from one another in numerous probe–enzyme combinations but were nearly genetically uniform within. Isolates from the two host species, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and mountain hemlock (Tsuga mertensiana (Bong.) Carr.), showed few RFLP differences. Initiation of infection centers, and subsequent vegetative or basdiospore initiated immigration, appear to be rare events. Key words: ribosomal DNA, mitochondrial DNA, RFLP, root rot, conifer.

Nature of the "black line" produced between different biological species of the Armillaria mellea complex

1986 ◽  
Vol 64 (11) ◽  
pp. 2588-2590 ◽  
Author(s):  
K. I. Mallett ◽  
Y. Hiratsuka
Keyword(s):  
Light Microscopy ◽  
Agar Medium ◽  
Biological Species ◽  
Malt Agar ◽  
Black Line ◽  
Armillaria Mellea

The zone of antagonism or black line, formed between the confronting margins of different biological species of the Armillaria mellea complex when paired on malt agar medium, was investigated. Light microscopy showed that the black line was composed of melanized hyphal cells from both species and was bordered on either side by the bladderlike cells of the pseudosclerotial plate of each species.

Biological Species of Armillaria mellea in North America

Mycologia ◽  
1979 ◽  
Vol 71 (2) ◽  
pp. 402 ◽  
Author(s):  
James B. Anderson ◽  
Robert C. Ullrich
Keyword(s):  
North America ◽  
Biological Species ◽  
Armillaria Mellea

Restriction fragment length polymorphisms of the mitochondrial DNA of Phytophthora megasperma isolated from soybean, alfalfa, and fruit trees

1989 ◽  
Vol 67 (2) ◽  
pp. 529-537 ◽  
Author(s):  
Helga Förster ◽  
T. G. Kinscherf ◽  
S. A. Leong ◽  
Douglas P. Maxwell
Keyword(s):  
High Temperature ◽  
Restriction Fragment ◽  
Fragment Length ◽  
Phylogenetic Analyses ◽  
Fruit Trees ◽  
Biological Species ◽  
Polymorphism Analysis ◽  
Phytophthora Megasperma ◽  
Restriction Patterns ◽  
Restriction Fragment Length

The mtDNAs from 24 small oogonial soybean-specific Phytophthora megasperma f.sp. glycinea (Pmg) isolates, 10 small oogonial alfalfa-specific P. megasperma f.sp. medicaginis (Pmm) isolates, 2 small oogonial nonhost-specific P. megasperma isolates from apple, 6 large oogonial nonhost-specific P. megasperma isolates from alfalfa or cherry, and 1 high-temperature P. megasperma isolate from alfalfa were investigated by restriction fragment length polymorphism analysis. Restriction patterns of the mtDNAs obtained by digestion with six restriction endonucleases showed limited variation within isolates of Pmg and Pmm. However, restriction patterns of Pmg and Pmm mtDNAs were very different. All nonhost-specific isolates of P. megasperma and the high-temperature isolate had restriction patterns that differed from each other and from those of Pmg and Pmm. The restriction patterns of the nuclear DNAs also distinguished these isolates from Pmg and Pmm. Phylogenetic analyses indicate that Pmg and Pmm are genetically distinct subgroups that represent biological species of P. megasperma and that several additional subgroups, possibly biological species, are present in the P. megasperma complex.

Morphological characterization of Armillaria ostoyae and Armillaria sinapina sp.nov.

1988 ◽  
Vol 66 (10) ◽  
pp. 2027-2034 ◽  
Author(s):  
J. A. Bérubé ◽  
M. Dessureault
Keyword(s):  
Root Rot ◽  
Morphological Characteristics ◽  
Morphological Characterization ◽  
Biological Species ◽  
Broad Sense ◽  
Fruiting Bodies ◽  
Armillaria Mellea ◽  
Armillaria Ostoyae ◽  
Mating Tests

In Quebec, the root rot fungus Armillaria mellea (Vahl: Fr.) Kummer in the broad sense was found to be composed of three intersterile groups or biological species by using mating tests with standard voucher strains. Monosporous cultures of our specimens were compatible with strains of groups I, V, and VI. Groups I and V corresponding to A. ostoyae (Romagn.) Herink and A. sinapina sp.nov., respectively, are described and their occurrence and ecology documented. Morphological characteristics of fruiting bodies and of vegetative isolates can be used to differentiate A. ostoyae, A. sinapina, and A. mellea s.str. Armillaria ostoyae and A. sinapina are mild pathogens or saprotrophs on declining trees or stumps, whereas A. mellea s.str. appears to be an aggressive pathogen.

A TEM study of electron tunneling in biological macromolecules

1987 ◽  
Vol 45 ◽  
pp. 140-141
Author(s):  
J. A. Panitz
Keyword(s):  
Stark Effect ◽  
Electron Tunneling ◽  
Imaging Modality ◽  
Tunneling Current ◽  
Biological Species ◽  
Scanning Tunneling ◽  
Biological Macromolecules ◽  
Flat Surfaces ◽  
Virus Particles ◽  
Stm Images

Tunneling is a ubiquitous phenomenon. Alpha particle disintegration, the Stark effect, superconductivity in thin films, field-emission, and field-ionization are examples of electron tunneling phenomena. In the scanning tunneling microscope (STM) electron tunneling is used as an imaging modality. STM images of flat surfaces show structure at the atomic level. However, STM images of large biological species deposited onto flat surfaces are disappointing. For example, unstained virus particles imaged in the STM do not resemble their TEM counterparts.It is not clear how an STM image of a biological species is formed. Most biological species are large compared to the nominal electrode separation of ∼ 1nm that is required for electron tunneling. To form an image of a biological species, the tunneling electrodes must be separated by a distance that would normally be too large for a tunneling current to be observed.

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