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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Chromosome individuality and somatic pairing in Abies grandis

Campbell, John Duncan January 1949 (has links)
One of the phenomena uncovered in cytological studies of Abies grandis LIndley, the Lowland White Fir, was the existence of pairing of chromosomes in somatic cells of the very young ovules. Huskins (1948) has shown that somatic pairing is not rare in the plant world, but is seldom properly recorded. It was thought necessary to undertake a study of the morphology of the Individual chromosomes of the tree. Counts and measurements were made on the chromosomes in several cells, and the measurements reduced to a percentage of the total chromosome length in the cell. Positions of the spindle-fibre attachments or centromeres were also tentatively located and recorded as percentages. The lengths of the twelve chromosomes in the genome are as follows: Chromosome 1, 14.4% units long; 2, 11.3% units; 3, 10.6% units; 4, 9.6% units; 5, 9.1% units; 6, 8.4% units; 7, 8.1% units; 8, 1.2% units; 9, 6.4% units; 10, 6.1% units; 11, 5.5% units; 12, 3.3% units. Two chromosomes have club-shaped ends without any constriction, while five have single terminal knobs. One has three constrictions, one has two, and four have but a single constriction. One chromosome is dicentric, four are approximately isomeral, five are distinctly heteromeral, and two have terminal centromeres. Somatic cells from young ovules showing apparent pairing of chromatin strands at early anaphase were examined. In one cell studied, the pairing is so distinct and the similarity between chromatin threads so striking that It is thought to be indication of some sort of reduced meiosis. The differences between somatic pairing and true meiosis are discussed and also some theories on the reason for somatic pairing. Some problems in technique of conifer cytology and the methods used in this study are set forth. / Science, Faculty of / Botany, Department of / Graduate
22

Study of the needle and cone tissue of alpine fir (Abies lasiocarpa (Hook.) Nutt)

Roller, Kalman Joseph January 1966 (has links)
Alpine fir( Abies lasiocarpa ( Hook ) Nutt. ) needles and cones were studied in natural stands to determine the variability of several traits such as needle length, width, stomatal distance in a row line on the abaxial surface, difference between cone scale and bract lengths, seed-wing areas, etc. Additional histological characteristics of needle, cone scale and bract are presented. Sixty-five stands, located on the West Coast of North America, were sampled. Continuous distribution of variable characteristics has not been found in the 65 stands. Correlation analysis shows that stomatal distance is directly associated with precipitation. Therefore, stomatal frequency increases with higher precipitation. Analysis of variance shows that the difference between cone scale and bract lengths is highly significant between the different stands. These differences indicate actual variations in the cone collection. Varieties and clines are suggested to exist in the natural range of alpine fir. / Science, Faculty of / Botany, Department of / Graduate
23

The effects of timing and of six growth regulators on the rooting of Abies stem cuttings in east-central Indiana and the initiation of callus tissue of Abies concolor by tissue culture techniques

Olsen, Richard Wayne 03 June 2011 (has links)
The purpose of this study was twofold. The first purpose was to determine the time of year when representative Abies stem cuttings will root most successfully in east-central Indiana. The second purpose was to identify a suitable nutrient medium and the appropriate environmental conditions for the initiation and maintenance of Abies concolor callus by tissue culture techniques.A review of the literature indicated that there have been few studies conducted on either the propagation of Abies species.Included in the review of literature is a summary of the studies concerning the propagation of Abies cuttings and the tissue culturing of Abies species, and also a core of background literature pertaining to the methods utilized in propagating other coniferous species.This study was conducted in two phases. The first phase involved the propagation of Abies stem cuttings. From September 1967 to May 1968, stem cuttings were taken at two-week intervals from terminal branches of mature Abies concolor trees. Abies stem cuttings or on tissue culturing of Abies species.The bases of the cuttings in the treatment groups were dusted with one percent growth regulator powders of B-naphthoxyacetic acid, parachlorophenoxyacetic acid, ethyl-3-indoleacetate, indole-3-acetic acid, 3-indolepropionic acid, or B-2-furylacrylic acid. The cuttings were rooted in a coarse sand propagating medium. The propagation bench was equipped with both controlled bottom temperature regulation and an intermittent mist system. The rooting results of these cuttings were recorded in November 1968. Based on these results, stem cuttings were taken weekly during January and February of 1969 from terminal branches of mature Abies concolor and Abies balsamea trees. These cuttings received the same treatment as did those taken in 1967 and 1968. The rooting results of these cuttings were recorded in November 1969.The second phase of this study involved the tissue culturing of Abies concolor. Inocula were prepared from terminal stem sections taken from mature trees. The stem sections were deneedled while immersed in ethyl alcohol and then sterilized in household bleach for ten minutes. The stem sections were cut into inocula approximately 8-10end up, on several different types of defined and undefined media. The cultures were maintained in the dark at a temperature of 27.5 + 2° C. under saturated humiditymillimeters in length.The inocula were inserted, basal conditions. Results of the cutting propagation phase indicated that optimal rooting of Abies concolor cuttings occurred when taken from the middle of January to the middle of February. Cuttings in the treatment groups formed better root systems than did the control cuttings. One hundred percent rooting occurred on all Abies concolor cuttings taken on January 29, 1968. Rooting results obtained from the Abies balsamea cuttings were poorer than those from Abies concolor. None of the Abies balsamea cuttings in the control groups rooted. In no instance was the percentage of rooting of Abies balsamea cuttings greater than forty percent.Results of the tissue culturing phase indicated that callus can be initiated from inocula prepared from terminal stem sections of mature Abies concolor trees on a modified Winton medium. The successful cultures were initiated in the dark at a temperature of 27.5 + 2° C. under saturated humidity conditions. At six weeks, each callus was transferred to fresh medium where it continued to grow. After the initial transfer, the callus was transferred to fresh medium every three weeks. At the end of ninety days the callus was still growing on the undefined medium.
24

Effects of vegetation and soil organisms on soil nutrient dynamics in subalpine Abies lasiocarpa forests /

Johnson, Kathleen A., January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 1999. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.
25

Ecological conditions limiting the distribution of 'Fagus silvatica' L. and 'Abies alba' Mill. near Schwarzenberg (Lucerne) Switzerland /

Gadekar, Hirasa. January 1975 (has links)
Diss. Nr. 5408 Naturwiss. ETH Zürich. / SA aus: Veröffentlichungen des Geobotanischen Institut ETH, Stiftung Rübel, Band 541975.
26

Změny jadérka v průběhu buněčné smrti

Juráň, Stanislav January 2013 (has links)
No description available.
27

Morthological variation and habitat relations of intergradient Grand Fir (Abies grandis)/ White Fir (Abies concolor) populations in the Wallowa Mountains, Oregon

Craig, Scott J. 31 January 1989 (has links)
Graduation date: 1989
28

Thinning and urea fertilization effects on emerging grand fir (Abies grandis) foliage and growth of western spruce budworm (Choristoneura occidentalis) larvae /

Savage, Thomas J. January 1987 (has links)
Thesis (M.S.)--Oregon State University, 1988. / Typescript (photocopy). Includes bibliographical references (leaves 35-41). Also available on the World Wide Web.
29

Growth of subalpine fir (Abies lasiocarpa) in the Olympic Mountains, Washington : response to climate and genetic variation /

Ettl, Gregory John. January 1995 (has links)
Thesis (Ph.D.)--University of Washington, 1995. / Vita. Includes bibliographical references (leaves [110]-144).
30

Dormancy in Abies seedlings /

Tung, Chao-hsiung. January 1987 (has links)
Thesis (Ph. D.)--Oregon State University, 1988. / Typescript (photocopy). Includes bibliographical references (leaves 101-114). Also available on the World Wide Web.

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