The distribution of Endocronartiumharknessii and Cronartiumquercuum on jack pine in Minnesota

1985 ◽  
Vol 15 (6) ◽  
pp. 1045-1048 ◽  
Author(s):  
R. A. Dietrich ◽  
R. A. Blanchette ◽  
C. F. Croghan ◽  
S. O. Phillips
Keyword(s):  
Germ Tube ◽  
Jack Pine ◽  
Germination Characteristics ◽  
The Future

In 1984, a survey was done to determine the distribution of pine–pine gall rust (Endocronartiumharknessii (J. P. Moore) Y. Hiratsuka) and pine–oak gall rust (Cronartiumquercuum (Berk) Miyabe ex Shirai f.sp. banksianae Burdsall and Snow) on jack pine (Pinusbanksiana Lamb.) throughout its range in Minnesota. Sporulating globose galls (960 galls from 257 stands) were collected in May and June and the pathogens were identified on the basis of aeciospore germ tube morphology. The relative usefulness of aeciospore germination characteristics that have been used to separate these rusts was examined. Endocronartiumharknessii predominated in the northeastern and Cronartiumquercuum in the southwestern portions of the range of jack pine. This information will be useful in selecting and growing rust-resistant trees and for monitoring changes in the distribution of these rusts in the future.

WALLROTHIELLA ARCEUTHOBII, A PARASITE OF THE JACK-PINE MISTLETOE

1931 ◽  
Vol 5 (2) ◽  
pp. 219-230 ◽  
Author(s):  
E. Silver Dowding
Keyword(s):  
British Columbia ◽  
Germ Tube ◽  
Jack Pine ◽  
Maximum Development ◽  
Lower Compartment

Arceuthobium, the host of Wallrothiella Arceuthobii, has been found in British Columbia, Alberta, Manitoba, and Ontario and Wallrothiella Arceuthobii has been found in Manitoba and Alberta.Arceuthobium fruits become infected in Canada in the spring, about a week after fertilization. The fungus and the infected fruits then increase in size, and they attain their maximum development by the summer of the following year.The ascospores are not violently discharged into the air. The spores ooze out into water when the perithecia are wet.The mature perithecium is made up of two compartments, the lower compartment containing the asci, and the upper compartment into which the ascospores are discharged and where they collect.It is suggested that insects are agents which disperse the ascospores.Ascospores sown in Arceuthobium decoction commence to germinate, but growth ceases after the germ tube has reached the length of about one millimetre.Attempts to inoculate the stigmas of healthy Arceuthobium with "sprout-mycelium" have so far been unsuccessful.

Nuclear condition and germination characteristics of the aeciosporesof Cronartium comandrae and C. comptoniae

1969 ◽  
Vol 47 (12) ◽  
pp. 1961-1963 ◽  
Author(s):  
J. M. Powell ◽  
Y. Hiratsuka
Keyword(s):  
Germ Tube ◽  
Tube Growth ◽  
Nuclear Behavior ◽  
Germination Characteristics ◽  
Germ Tubes ◽  
Germ Tube Growth ◽  
Nuclear Condition

Two pine stem rusts, Cronartium comandrae Pk. and C. comptoniae Arth., had binucleate mature aeciospores which produced non-septate branched or unbranched germ tubes. No nuclear divisions occurred, and the two nuclei migrated together towards the tip of the germ tube and into an appressorium, if formed. This type of nuclear behavior and germ-tube growth is characteristic of host-alternating races, and distinguishes them from pine-to-pine races. Aeciospores of C. comandrae characteristically produced two or more germ tubes, unlike other pine stem rusts which usually produced one germ tube per spore.

International determination of the total motion of the pole

1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  
Secular Motion ◽  
The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

Status of the Lick Proper Motion Program

1978 ◽  
Vol 48 ◽  
pp. 387-388
Author(s):  
A. R. Klemola
Keyword(s):  
Proper Motion ◽  
The Future

Second-epoch photographs have now been obtained for nearly 850 of the 1246 fields of the proper motion program with centers at declination -20° and northwards. For the sky at 0° and northward only 130 fields remain to be taken in the next year or two. The 270 southern fields with centers at -5° to -20° remain for the future.

Some Structural Features of Metaphase Chromosomes of Mice and Men

1967 ◽  
Vol 25 ◽  
pp. 190-191
Author(s):  
Godfrey C. Hoskins ◽  
Betty B. Hoskins
Keyword(s):  
Electron Microscopy ◽  
Electron Micrographs ◽  
Structural Features ◽  
Metaphase Chromosomes ◽  
The Future ◽  
Of Mice And Men ◽  
Mouse Cells ◽  
Human And Mouse

Metaphase chromosomes from human and mouse cells in vitro are isolated by micrurgy, fixed, and placed on grids for electron microscopy. Interpretations of electron micrographs by current methods indicate the following structural features.Chromosomal spindle fibrils about 200Å thick form fascicles about 600Å thick, wrapped by dense spiraling fibrils (DSF) less than 100Å thick as they near the kinomere. Such a fascicle joins the future daughter kinomere of each metaphase chromatid with those of adjacent non-homologous chromatids to either side. Thus, four fascicles (SF, 1-4) attach to each metaphase kinomere (K). It is thought that fascicles extend from the kinomere poleward, fray out to let chromosomal fibrils act as traction fibrils against polar fibrils, then regroup to join the adjacent kinomere.

Freeze-fracture cytochemistry: A goal set by Russell Steere in 1957

1993 ◽  
Vol 51 ◽  
pp. 60-61
Author(s):  
Nicholas J Severs
Keyword(s):  
Chemical Nature ◽  
Biological Systems ◽  
Freeze Fracture ◽  
Structural Components ◽  
Major Goal ◽  
Membrane Biology ◽  
Routine Application ◽  
The Future ◽  
Freeze Etching

In his pioneering demonstration of the potential of freeze-etching in biological systems, Russell Steere assessed the future promise and limitations of the technique with remarkable foresight. Item 2 in his list of inherent difficulties as they then stood stated “The chemical nature of the objects seen in the replica cannot be determined”. This defined a major goal for practitioners of freeze-fracture which, for more than a decade, seemed unattainable. It was not until the introduction of the label-fracture-etch technique in the early 1970s that the mould was broken, and not until the following decade that the full scope of modern freeze-fracture cytochemistry took shape. The culmination of these developments in the 1990s now equips the researcher with a set of effective techniques for routine application in cell and membrane biology.Freeze-fracture cytochemical techniques are all designed to provide information on the chemical nature of structural components revealed by freeze-fracture, but differ in how this is achieved, in precisely what type of information is obtained, and in which types of specimen can be studied.

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