Thesis (M.S.)--Oregon State University, 1985. / Typescript (photocopy). Includes bibliographical references (leaves 87-91). Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 1986. / Typescript (photocopy). Includes bibliographical references (leaves 28-31). Also available on the World Wide Web.

Thesis (Ph. D.)--Oregon State University, 1986. / Typescript (photocopy). Includes bibliographical references (leaves 189-201). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Washington, 1986. / Vita. Bibliography: leaves [128]-135.

The endoplasmic reticulum (ER) molecular chaperone, BiP, plays a role in the translocation and subsequent folding and assembly of newly synthesized proteins targeted to the ER and secretory pathway. The sequence encoding a Douglas-fir (Pseudotsuga menziesii [Mirb] Franco) BiP homologue (PmBiP) was identified by differential screening of a seedling cDNA library. Southern blotting indicated that PmBiP is most likely present as a single copy although other BiP alleles likely exist within a given seedlot. The deduced amino acid sequence of PmBiP contains a HEEL tetrapeptide sequence which functions to retain PmBiP in the ER and is different from HDEL commonly found in angiosperm plant BiPs. Amino acid sequence alignment and phylogenetic analysis show that PmBiP is highly similar to other plant BiPs yet forms a distinct phylogenetic subgroup separate from angiosperm BiPs. Northern and western blotting revealed that PmBiP is subject to developmental regulation during seed development, germination, and early seedling growth and is seasonally regulated in needles of young seedlings. The expression of PmBiP is developmentally regulated during seed development with higher amounts present in seeds prior to embryo development and the deposition of storage proteins. Increased PmBiP expression correlates with seedling growth and developm ent and the mobilization of seed storage proteins. Increased synthesis during germination is likely due to increased synthesis of cell wall proteins and other secretory traffic. This idea is supported by immunolocalization of PmBiP in root tip cells showing staining around the new cell wall in telophase cells and at the periphery of cells in the elongation zone. PmBiP may also play a role in mediating homotypic ER and nuclear envelope membrane fusion during mitosis in actively dividing tissues. PmBiP is seasonally regulated in the needles of young seedlings and increased expression was observed in tissues treated with low temperature suggesting that PmBiP plays an important role in the adaptation of seedlings to low temperatures. This is most likely accomplished through the maintenance of secretory traffic through the ER necessary for the synthesis of proteins with a more direct role in cold acclimation. Proteins were associated with PmBiP in an ATP dependent manner in mature seeds and 2-day-old seedlings but were only detectable in minute amounts. ATP associated proteins were more readily detectable in embryonal suspensor mass (ESM) cultures but only in small amounts unsuitable for N-terminal sequencing and identification. The Douglas-fir BiP promoter (PmBiPProl) contains a variety of cis-acting regulatory elements commonly found in the promoters of storage protein genes, light regulated genes, and phenlypropanoid and cell wall protein genes. The presence of different cis-element groups suggests the transcriptional regulation of PmBiP is controlled by a variety of signal transduction pathways depending upon the developmental and/or physiological state of a given tissue. Transient expression analysis showed that PmBiPProl is functional in germinating Douglas-fir embryos. The expression of PmBiPProl in transgenic Arabidopsis is associated with actively dividing and secretory tissues. Deletion analysis showed that minimal promoter elements lie within a 263 bp region directly upstream of the PmBiP cDNA sequence although upstream flanking sequences are necessary for higher level expression. G-box motifs residing within the 263 bp fragment together with a quantitative activator region (QAR) and a negative regulatory region (NRR) present in upstream areas are likely involved in transcriptional control in young seedlings. PmBiPProl was also wound inducible in transgenic Arabidopsis cotyledons that correlated with similar experiments conducted in Douglas-fir seedlings. Elements involved in conferring wound inducibility are located in PmBiPProl-5 but upstream elements are necessary for higher level expression. G-box motifs may also play a role in the wound inducibility of the Douglas-fir BiP promoter. / Graduate

Widths of 22,734 bands of earlywood and latewood were measured systematically along the average radii at the centers of the annual height increments of 18 Douglas fir trees. Shapes of the annual growth layers of earlywood and of latewood, respectively, formed during an accrued growth period of 589 years were investigated: (i) using relative measures embodied in diagramatic computer outputs; (ii) using absolute measures by statistical and graphical techniques; (iii) by computing Hohenadl's form factor (lambda 0.9) for each year's growth of; a) imaginary "earlywood stems" consisting of layers of earlywood; b) imaginary "latewood stems" consisting of layers of latewood; c) actual stems consisting of total annual layers. The form of earlywood layers differed markedly and consistently from that of latewood layers. The maximum width of earlywood layers in individual trees occurred within a zone located in the upper portion of the live crown; in the stand it was within a zone parallel with the surface of crown canopy. Width of earlywood was at its minimum at some distance above the stem base. This distance increased with tree age. Latewood layers were usually widest along the basal portion of the stem. As a result, the form factors of "earlywood stems" were considerably higher than those of "latewood stems". The shapes of the growth layers, and hence the form of stems consisting of these layers, could not be reconciled satisfactorily with the tenets of Schwendener - Metzger's mechanistic, or Hartigfs nutritional, or Jaccard's water conductive, or hormonal theories of stem formation. Therefore, a new scheme was proposed using the following concepts: (1) Heating of stems by solar energy constitutes a purely physical process; the rate of energy transfer between a tree and its environment determines the temperature of its cambial tissues. (2.) Because trees are not homoiothermous organisms, at a given time various parts of the cambial cylinder may possess different temperatures even in an isothermal environment. (3) A pronounced stratification of the environment due to gradients in air temperature or in length of time of positive net flux of energy has been observed in forests throughout the world. (4) Radial growth may proceed at varying rates for unequal periods of time within the different parts of the cambial cylinder, depending largely on the levels of subcortical temperatures. (5) Consequently, the shapes of the annual layers of earlywood and latewood may reflect the respective spring and summer environmental energy gradients. (6) Then the average form of trees from forests of the temperate latitudes, which is that of a quadratic paraboloid, may reflect the average microclimatic structure prevailing in these forests during the growing season. Form of open-grown trees, eccentricity of stems, roots and branches, and other so far unexplained anomalies in radial growth may be clarified similarly. Indirect and some preliminary direct evidence supporting the proposed conceptual scheme of stem formation was presented. In addition, influence of some selected factors of macroclimate on the amount of radial growth expressed in terms of the average widths of growth layers was analysed. Individual trees have been used as sampling units. The trends in the growth series were removed by analysis of covariance: average layer width indices were derived by calculating deviations from the straight lines fitted by least squares to the adjusted mean layer widths. The degree of autocorrelation of both growth and weather series was largely nonsignificant. Correlations between the growth indices of earlywood and latewood were nonsignificant or low. In the individual trees, six weather variables accounted for from 10 to 48 per cent of the total variability observed in the radial growth of latewood. Temperatures of the previous summer could not be related to the amount of radial growth of earlywood of the current year. Since the approximate minimum true correlation in the universe was zero the general influence of macroclimate was nonsignificant. It appears that other studies have neglected the influence on growth of microenvironmental factors and that there is need for research on the means by which distribution and amount of radial growth are controlled by the net flow of energy. / Forestry, Faculty of / Graduate

The cellulose fraction in 100-micron thick microtome sections from three growth increments of a Douglas fir tree was sytematically degraded through random scission of chains by means of 0.1, 1.0, 10.0, and 15.0 megarad doses of gamma irradiation. Degree of cellulose polymerization (DP) was estimated from results of intrinsic viscosity measurements on dilute solutions of cellulose nitrate in acetcne. Control and irradiated samples were tested in tension parallel to grain by employing a micro-scale test method. Tests were done at 25, 50, and 70°C temperatures in combination with moisture-free, air-dry, and water-saturated conditions of test specimens. Ultimate tensile strength, an elastic constant, ultimate tensile strain, and work to maximum tensile load have been calculated from experimental data. Results were statistically analyzed in relation to cellulose chain length, temperature and moisture content. Regression equations based on experimental results have been constructed. These explained a large part of the variations in tensile strength properties and are reported as three-dimensional diagrams. It is shown that tensile strength behavior of Douglas fir earlywood and latewood are distinctly different. Strength properties of latewood are not only higher by a factor of approximately 2 to 8 than those of early-wood, but also the response of the two growth zones to changes in cellulose chain length, temperature, and moisture content at test is different. The above characteristics are due to different deformation mechanisms in tension parallel to grain of the two growth zones. It is suggested that deformation in earlywood is intra-cellular, whereas in latewood it is primarily an inter-tracheid, phenomenon. Decrease in cellulose DP reduced strength, ultimate strain, and work to maximum load more in the low than in the high DP regions. This is explained by the increasing importance of inter-chain and/or inter-fibrillar slippage with decreasing chain length. Elastic properties are but little affected by changes in cellulose DP if the crystalline-amorphous ratio of cellulose in wood is not altered significantly by the treatment applied, such as accompanies gamma irradiation. A change in wood moisture content at time of test from the moisture-free to the water-saturated condition reduced strength properties of Douglas fir by approximately 20 to 50 per cent. The reductions in late-wood strength were significantly higher than in earlywood. A convex upward curve configuration relating strength and elasticity to moisture content is suggested from the experimental data. Effect of temperature on strength properties of Douglas fir within the range of 25 to 70°C is minor in comparison with that of moisture content. The relationship is probably linear. Tensile strength characteristics of Douglas fir wood with degraded cellulose are more sensitive to changes in moisture content than are those of wood having cellulose of long-chain structure. This behavior of wood in tension is also explained by the slippage mechanism of deformation. / Forestry, Faculty of / Graduate

An analysis was made of the distribution of and interactions between three major species of insects in cones of Douglas fir. This was based on over 3,500 cones from 93 trees in 1961 and 4,000 cones from 97 trees in 1962. High variation in damage was found among trees for each of the three insect species studied (Contarinia oregonensis Foote, Megastigmus spermotrophus Wachtl., and Dioryctria abietella D.&S.) In C. oregonensis this variation was significantly related to the height of the trees and dates when cones became pendent. The percentage of filled seeds and average cone size of the trees were important in M. spermotrophus. The average cone size of the trees and duration of vegetative bud flushing were significantly associated with D. abietella. The within tree-variation of damage by C. oregonensis was highly significant and consistant from tree to tree and year to year. Damage increased significantly from the bottom to the top of live crown. Suggestions are made to help increase the seed yield by chemical control of insects by selection of uninfested or slightly infested trees by sequential sampling, and by selection of cone and seed insect resistant trees for seed orchards. Although no tree was wholly resistant to all three insects the best, with only 4.8 per cent of its seeds damaged, was so much better than average that it may be of considerable economic importance. The great range in apparent resistance of trees to attack by cone and seed insects should be recognized in further studies and attempts be made to determine biologically sound reasons for the observed differences. / Forestry, Faculty of / Graduate

This paper presents a study of three phases of the flight of the Douglas-fir beetle, viz: flight preparation and response, flight attitude and movements, and flight capacity. A room equipped with temperature and humidity controls was used for some of the experiments. The wing movements were studied with a stroboscope and flash photography. Flight mills were used in the studies involving flight duration and velocity. The only effect of nemic and mite associates was reduction of the duration of the initial flight caused by internal nematodes. Temperature played an important role in all phases of flight studied. Temperatures from 72° to 89° F. were optimum for spontaneous flight, while 68° F. seemed to be the lower limit of flight in the absence of additional stimuli. In sunlight, spontaneous flights occurred at 63° F. Increasing temperature caused a rapid increase in the wing-beat frequency up to the threshold for spontaneous flight, then increased only slightly to the level of heat prostration. Lower temperatures greatly reduced the duration of the initial flight and caused a broken flight pattern, but failed to influence the over-all flight duration. The effects of relative humidity followed a similar pattern to those of temperature inasmuch as evaporational cooling of the insect occurred at low relative humidities not at high relative humidities. Increased light intensity increased the speed of the flight response and caused slight increases in the wing-beat frequency; both results being attributed to increased nervous stimulation. Studies on the effect of the ehange in the beetles’ activity from dispersal to gallery construction to re-emergence, on the response to flight stimulation, showed that once gallery construction had begun the females became flight refractory, some regaining their inclination to fly after 15 days. On the other hand, the males could be expected to be either flight positive or refractory throughout the duration of gallery construction. The number of individuals responding positively to flight stimulation by tossing increased greatly following the first toss, then diminished until no further change occurred after six tosses. Wing mutilation and loading produced changes in the wing-beat frequency similar to those found by other workers, and indicated that the changes were probably due to altering the inertia of the oscillating system. Fatigue caused a gradual reduction in the wing-beat frequency over a four hour period although the final per cent decrease attributable to fatigue was much lower than that reported for other insects. The flight velocity was of the order of 90 to 115 metres per minute or 3.3 to 4.2 miles per hour, changes in the flight velocity seemingly being related directly to changes in wing-beat frequency. It is concluded from these studies that the Douglas-fir beetle is a strong uniform flier despite the complexity of components affecting several phases of flight. The various thresholds for spontaneous flight were consistently above the levels required for continuation of the activity. The flight of the Douglas-fir beetle can be expected to vary greatly from year to year and from season to season depending on the environmental factors. Of the flight movements it is the wing-beat frequency which is affected the most by environmental changes, thus varying the strength, velocity and magnitude of the flight. The Douglas-fir beetle is capable of an average flight of up to 10 miles immediately following take-off and from between 15 to 20 miles a day for several days; favourable air currents would increase these figures substantially. / Science, Faculty of / Zoology, Department of / Graduate

A study was made to determine if there is a growth response in Douglas-fir seedlings to the presence of mycorrhizal associations. Nursery, potted and pure culture experiments were carried out to induce the formation of mycorrhiza on Douglas-fir seedlings. Seedlings from natural areas were examined to give an indication of the types of mycorrhiza which occur and the age at which they are formed. Variation in the number and type of mycorrhiza as determined by site factors was studied. Well-developed mycorrhiza were found in natural seedlings as young as three months old. Most of the seedlings examined showed well-developed mycorrhiza by the end of the first growing season. Only typical ectotrophic mycorrhiza were found in Douglas-fir seedlings. They occurred in a range of sites, but the occurrence could not be correlated with variation in site factors. In the nursery and potted experiments there were no significant differences between the treatments as indicated by the height, root volume or number of mycorrhiza of the seedlings. All attempts to induce the formation of mycorrhiza on Douglas-fir seedlings in pure culture were unsuccessful. / Science, Faculty of / Botany, Department of / Graduate