Botany Commons^™

Intraspecific Variation In The Response Of Elymus Elymoides To Competition From Bromus Tectorum, Rebecca K. Mann

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the western United States, thousands of acres of degraded rangelands are dominated by aggressive invasive species such as cheatgrass (Bromus tectorum), and are seeded by managers with native plants in an attempt to restore species diversity, wildlife habitat, and ecosystem services. There are many options for obtaining seeds of native plants; for instance, they can be collected from the region where restoration is to occur, or they may be purchased through commercial producers. For a given plant species, managers may also select seeds from unique subspecies, cultivars, and populations. Genetic differentiation among these within-species groups can not only affect …

Reproductive Ecology Of Astragalus Filipes, A Great Basin Restoration Legume, Kristal M. Watrous

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Astragalus filipes Torrey ex. A. Gray (Fabaceae) is being studied and propagated for use in rangeland restoration projects throughout the Great Basin. Restoration forbs often require sufficient pollination services for seed production and persistence in restoration sites. Knowledge of a plant's breeding biology is important in providing pollination for maximal seed set.

Reproductive output from four manual pollination treatments (autogamy, geitonogamy, xenogamy, and distant xenogamy) was examined in a common garden. Pod set, seed set, and seed germination were quantified for each of the treatments. Seed set from four wild populations was compared to that of an openly visited common …

Genomic Perspectives On Evolution In Bracken Fern, Joshua P. Der

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The fern genus Pteridium comprises a number of closely related species distributed throughout the world. Collectively they are called bracken ferns and have historically been treated as a single species, Pteridium aquilinum. Bracken is notorious as a toxic weed that colonizes open fields and poisons livestock. Bracken is also easily cultured and has become one of the most intensively studied ferns. Bracken has been used as a model system for the study of the fern life cycle, fern gametophyte development, the pheromonal mechanism of sex determination, toxicology, invasion ecology, and climate change. This dissertation places bracken within a global …

Combining Environmental History And Soil Phytolith Analysis At The City Of Rocks National Reserve: Developing New Methods In Historical Ecology, Lesley Morris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Historical ecology is an emerging and interdisciplinary field that seeks to explain the changes in ecosystems over time through a synthesis of information derived from human records and biological data. The methods in historical ecology cover a wide range of temporal and spatial scales. However, methods for the more recent past (about 200 years) are largely limited to the human archive and dendrochronological evidence which can be subject to human bias, limited in spatial extent or not appropriate for non-forested systems. There is a need to explore new methods by which biological data can be used to understand historic vegetation …

Plant Responses To Clinostating And Mechanical Stress: Growth And Flowering Responses, Chauncy Steed Harris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plants rotated about a horizontal axis show certain growth responses. This research was designed to clarify which of the responses of clinostating are caused by gravity compensation and which are caused by mechanical stresses. Plants used were Xanthium strumarium L. (cocklebur) Chicago strain and Lycopersicon esculentum Mill. (tomato) cv. Rutgers. Six automated treatments that ran for five days were used to separate out the effects. Treatments were: 1) controls, 2) horizontal clinostat, 3) intermittent clinostat, 4) inversion (every 10 min), 5) invert and return, and 6) vertical rotation. Plant height and diameter changes were measured at ink dots with a …

Competition And Spacing Patterns Of Shrubs In The Mojave And Sonoran Deserts, Donald Lundahl Phillips

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spacing patterns of shrubs were studied at a series of sites in the Mojave and Sonoran Deserts. There were significant numbers of occurrences of both aggregation and regularity in dispersion of individuals. These may be due to vegetative reproduction or environmental heterogeneity, and competition between plants, respectively. Different size classes of shrubs tended to follow the trend of aggregated → random → regular with increasing size. This suggests the increasing importance of competition as the plants grow. Further evidence of competition between plants was provided by the correlations of plant size with the distance to their neighbors. Root systems were …

Meiotic And Mitotic Chromosomes Of Fritillaria Atropurpurea Nutt., John Keith Archibald

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this paper is to provide information concerning the number, structure, and behavior of chromosomes in the plant species Fritillaria atropurpurea. The material used for this investigation included both floral buds and root-tips from actively growing naturally occurring plants collected from populations in both Utah and Nevada, and root-tips from seed germinated in the greenhouse. The results obtained include a karyotype analysis of mitotic chromosomes, a discussion of meiosis, a discussion of B-chromosomes, and a series of photographs depicting the stages of mitosis and meiosis in this species.

Fritillaria atropurpurea has a diploid chromosome number of 24, …

The Seasonal Pattern Of Cavitation In Five Species Of Trees, Herond R. Hoyt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Five species of trees were studied: Acer glabrum (Hook.) Dippel, maple; Betula fontinalis Sarg., birch; Fraxinus pennsylvanica Marsh., ash; Populus tremuloides Michx., aspen; Pseudotsuga menziesii Britton, Douglas Fir. The trees were taken from naturally growing stands, between 20 and 40 years old, and about 7 m tall. The trees were cut down at eight study dates extending over 18 months. A 1.5 m section of stem and a branch from the upper and lower part of the tree were taken to the laboratory. Small pieces were then cut from these large pieces and were subsequently sliced into sections 200 microns …

Low Temperature Germination And Seed Coat Thickness In Tomatoes, John M. Green

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This investigation has been shown that the thin seed coat of tomato variety P. I. 341988 is not the factor responsible for its ability to germinate at low temperatures. The results support a previous report that low temperature germinating ability is inherited as a simple recessive. Seed coat thickness appears to be conditioned by two or more gene pairs, with dominance lacking. The maternal parent's genes control seed coat thickness, but the embryo's genes control low temperature germinating ability.

Vector Preference Among Varieties Of Lycopersicon Peruvianum And L. Esculentum As Related To Curly Top Virus Resistance, Stanford A. Young

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tests substantiating vector nonpreference as a factor in the ability of certain tomato varieties to escape curly top virus (CTV) infection were conducted and evaluated. Nonpreference is not an effective mode of resistance to CTV in tomatoes under field conditions since leafhoppers feed on and may infect plants before expressing a preference.

Preference of viruliferous leafhoppers was observed on plants of seven tomato varieties arranged both randomly and homogeneously in caged flats. Through observation of curly top symptom development, relative resistance due to vector nonpreference was calculated for each variety.

Up to 23 per cent of the fairly high resistance …

A Comparison Of The Ecological Life Histories Of Delphinium Occidentale S. Wats. And Delphinium Barbeyi Huth, Jere Randolph Holman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two species of the holartic genus Delphinium (D. occidentale S. Wats. and D. barbeyi Huth) were studied in the field and laboratory to determine the factors influencing the life stage development and distribution of these plants.

Delphinium occidentale, more widely distributed geographically and altitudinally than D. barbeyi, is found as a member of aspen and sagebrush communities. Sites are mesic in early spring but turn xeric by midsummer. Delphinium barbeyi, more limited in distribution geographically and altitudinally, appears to be limited to subalpine sites.

Adult biological properties are similar for both species. Morphological and taxonomic differences …

Cytogenetic Effects Of Vitavax Fungicide On Secale Cereale On Allium Cepa, Jack Ernest Staub

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effects of Vitavax fungicide (2,3-dihydro-5-carboxanilido-6-methyl-1,4-oxathiin) on meiotic chromosomes of rye (Secale cereale) and mitotic chromosomes of onion (Allium cepa) and rye were observed.

The principal aberrations recorded in pollen mother cells of rye were: 1-4 univalents at metaphase I; sticky bridges at telophase I; and micronuclei and misshapen nuclei at the quartet stage.

The principal aberrations recorded in root tip mitoses in onion and rye were: chromosome fragmentation, disintegration, clumping, aggregation and inhibition of mitosis.

All meiotic phases were significantly affected by 1,000, 5,000,10,000, 33,300, 66,600 ppm Vitavax at the 48, 72, and 96 hour …

Temperature Effect On Leaf Water Potential Measurements, Rex J. Prosser

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Silver foil psychrometers were used to monitor water potential in different portions of maize leaves which were subjected to temperature gradients. The psychrometers were preliminarily calibrated over standard NaCI solutions at temperatures ranging from 5°C to 45°C in an aluminum plate apparatus designed to provide uniform temperatures within each psychrometer even while overall temperature was changing. Based on the calibrations, empirical temperature correction equations were derived and used to correct psychrometer readings at different temperatures to equivalent values at 25°C. Temperatures on a single maize leaf were varied by placing the long leaf through an insulated box with several compartments …

Xanthium Strumarium L.: Extraction And Assay Of Floral Promotive Principles And Additional Investigations Into Inhibition Of Flowering, David D. Gibby

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

New techniques in extraction and assay of florigenic substances were tested. Initial response to the buffer-PVP extracts proved promising, but after several successful experiments, results could not be duplicated. Possible reasons for the failure are discussed.

A long-day inhibitory effect, demonstrated earlier by Gibby and Salisbury (25), was further investigated. Experiments with ¹⁴C-labled assimilates disproved the hypothesis that the inhibition is a result of assimilate translocation. Other experiments pointed to the probability of phytochrome involvement as well as protein synthesis as part of the inhibitory process. The nature of inhibition was ascribed to a localized inhibitory condition, probably a …

The Action Of Antibiotics And Antimetabolites On The Tobacco Mosaic Virus Infection Process In Bean Leaves, Virendra Nayyar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The action of 28 antibiotics and antimetabolites at varying concentrations was studied in coincidence with the bioassay of tobacco mosaic virus on detached bean leaves by using an ultrasonic method of inoculation developed by Lamborn, Cochran and Chidester.¹ All tested chemicals were classified, in regard to the virus infection process, as inhibitory or stimulatory and their optimal concentrations in the inoculum were determined. Of the 28 antibiotics and antimetabolites studied, eight were found to stimulate while twenty inhibited TMV infection in bean leaves. From the results of these experiments, an attempt was made to characterize the nature of the …

An Isolation And Partial Purification Of A Small Tobacco Mosaic Virus Nucleoprotein Unit And A Study Of Its Polymerization By Carbodiimides, Alicia Bruna De Tosso

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A small tobacco mosaic virus nucleoprotein unit, thought to be the basic infectious unit of TMV, was isolated and purified from systemically-infected Turkish tobacco leaves. This small TMV particle was characterized by a doughnut shaped form as shown in the electron micrographs and by the induction of gray lesions when inoculated on Scotia bean leaves. Four carbodiimides, organic chemical condensing reagents, were compared for effectiveness in inducing polymerization of this starting material into longer rod-shaped viral particles. Dicyclohexyl carbodiimide, a wax-like solid, was found to be the most suitable reagent when used with an organic solvent such as ethanol in …

Effects Of Six Herbicides On Three Common Fresh Water Algae, Mridulika Virmani

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Six herbicides (diuron, karbutilate, propham, chloropropham, atrazine and simazine) were tested for their effects on Chlorocuccum hypnosporum, Chlorella pyrenoidosa and Anabaena sp. Experiments were conducted to determine minimum lethal dosages, algicidal versus algistatic concentrations and the uptake of ¹⁴CO₂ fixation by diuron containing cultures, as well as the uptake of radioactive diuron.

All three investigated species have shown a high degree of sensitivity to diuron at or below 1 ppm. Karbutilate was found to inhibit the growth of Chlorella pyrenoidosa and Anabaena sp. at lower concentrations than were required in the case of Chlorococcum hypnosporum.

Chloropropham …

A Taxonomic Study Of Single Spikelet Elymus Species Of Western United States, Earl R. Jensen Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two single-spikelet species, including three varieties, of naturally occurring wild-ryes of the genus Elymus native to the Rocky Mountain and Intermountain West were investigated using morphological, anatomical, ecological, and cytogenetical methods to determine their biosystematic relationships.

One species, Elymus ambiguus Vasey and Scribn., was found to be a distinct species without any recognizable varieties. This species had been previously recognized with three varieties.

One taxon, Elymus salina (C. L. Hitchc.) E. Jensen, often considered a variety of Elymus ambiguus, was found to be a distinct species. It shared features with both Elymus ambiguus and Elymus salina but was sufficiently …

An Analysis Of The Taxonomic Status Of A New Taxon In The Genus Salsola, H. Lamont Arnold

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An attempt was made to determine the taxonomic status of a Salsola taxon new to Utah but found quite extensively in parts of Nevada, and California. The disciplines of cytogenetics, morphology, anatomy, chemotaxonomy, and palynology were employed.

It is the consensus of some taxonomists that this new taxon, referred to as Salsola X and which has lax perianth tips, is a variant of the Salsola Salsola paulsenii Litv. or barbwire Russian thistle taxon. Accepted taxonomic authorities on the Cheopodiaceae, Aellen and Botschantzev, consider the erect, spinose perianth tips to be a morphological character used in delimiting S. paulsenii. If …

Inorganic Mercury Uptake And Mercury Tolerance Demonstrated By Several Species Of Algae, Daniel S. Filip

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The inhibition by low concentrations of inorganic mercury has been established for several species of freshwater algae, and a method has been developed to determine mercury levels in algal cells, having good precision at levels as low as one hundred parts per billion.

Rapid sorption of inorganic mercury by glassware was minimized by using heavy algal cultures and short term incubations. The rates and extent of mercury uptake by three species of freshwater green algae were delineated under laboratory conditions. Replicate mercury containing cultures yielded slightly different mercury concentrations upon analysis due to analytical errors and glass sorption. Therefore, percent …

The Relationship Between Matric Water And Related Physiological Properties, Hussain Ali Al-Saadi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Matric water was measured as the water retained by plant material on a pressure membrane or ultra filter after equilibration under 20 bars nitrogen gas pressure and the removal of free water. At increasing pressures lesser amounts of water are held by matric or colloidal surface forces. Twenty bars pressure, supplied by cylinder nitrogen for 48 hours, was used in this study. Matric water was expressed as a percent of either (a) the dry weight or (b) the original water content. Plant material was oven dried, ground, and then saturated with water prior to the determination.

The matric water values …

Investigations Of Unusual Curly Top Symptoms In Grafted Tomato Plants And Early Leafhopper Feeding Effects Upon Tomato Seedlings, Donald Eldon Gardner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To determine possible unusual effects of resistant plants upon symptom expression of curly top disease in susceptible tomato plants (Lycopersicon esculentum Mill.), tops of susceptible plants were grafted to lower stems and roots of resistant plants and inoculated. The resistant plants used were wild relatives of L. esculentum: L. peruvianum var. dentatum Dun. and L. peruvianum var. humifusum C. H. Mul. Reciprocal grafts, in which tops of dentatum plants were grafted to lower stems and roots of L. esculentum, were also made and inoculated.

External symptoms in the grafted plant tops were observed and compared with those of nongrafted, …

Low Temperature Modification Of Cell Ultrastructure In Hardy And Nonhardy Grass Species, Steven L. Kimball

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Studies were conducted to determine the influence of different temperatures (25, 10, 0, or -5 C) upon plant growth and cell ultrastructure, and to determine if physical changes within cells might block growth activities even though individual biochemical processes were potentially active.

Secale cereale L. was found to be most hardy, followed by Cynodon dactylon (L) Pers. and Paspalum notatum Flugge, whose responses were quite similar. Secale grew normally at 25 and 10 C, with reduced activity at 0 C and a slight delay before resuming normal growth when placed at 25 C again. All three species were killed at …

Polymerization Of Tobacco Mosaic Virus, Fabian Crespo V.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An organic chemical condensing reagent, 1-cyclohexyl-3-(2-morpholinoethyl)-carbodiimide metho-p-toluene sulfonate (CMC) was tested for effectiveness in inducing polymerization of short lengths of tobacco mosaic virus (TMV) nucleoprotein particles isolated from systemically infected Turkish tobacco leaves. It appeared that the chemical induced the formation of phosphodiester linkages between the viral RNA helices in the joining nucleoprotein fragments. Because the polymerization reaction liberates a hydroxyl ion with each joining event the kinetics of the polymerization can be followed with time using a pH meter. The number of hydroxyl ions liberated is equal to the number of polymerizations. Physical evidence of polymerization was obtained by …

Effects Of Dmso And Propham On Mitosis In Root Tips Of Secale Cereale, Max Rosequist

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

DMSO (dimethyl sulfoxide) and propham (isopropyl carbanilate) were investigated to determine their effect singly and in combination on mitoses in rye (Secale cereale) root tip cells. Root tips were prepared for observation by the paraffin and aceto-carmine squash methods. Results showed DMSO caused the following abnormalities: arrested metaphases, multipolar spindles, multinucleate cells, stickiness, shortened chromosomes, and mitotic inhibition. Cells from propham treated root tips exhibited the same abnormalities as those treated with DMSO. In addition, propham treatments resulted in polyploid cells and chromosome granulation. In combination, DMSO and propham caused all the abnormalities mentioned above except polyploidy. In …

Survey Of The Matric Potential Of Various Plant Groups, Hussain Ali Al-Saadi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Matric potentials of leaves or photosynthetic stem tissues from sixty species, including hydrophytes, xerophytes, and halophytes, were measured by the pressure membrane apparatus. The matric potentials of different families and other plant groupings were compared; the correlation between matric potentials and other properties, such as estimated drought and salt tolerance, tissue moisture content, and mineral ion composition were also determined.

High matrix potential values and tissue moisture content were measured in species of Chenopodiaceae, considered more salt and drought tolerant than species in other families.

Low matric potential values were found in the coniferous tree leaves, which also have low …

The Role Of Stomata In Gaseous Fluoride Injury To Plants And Several Enzymatic Changes Associated With That Injury, Bachettira Wthappa Poovaiah

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect of fluoride fumigation on water relations and several enzymes of Glycine max and Pelargonium zonale plants were studied.

Glycine Max leaves absorbed 600 parts per million fluoride from an atmosphere of 15 parts per billion fluoride during 96 hours fumigation. Lower, fully expanded leaves were always more severely damaged than the upper younger leaves. In day versus night fumigation experiments, although daytime fumigated plants absorbed less fluoride than continuously fumigated plants, they had two to three times more fluoride than the nighttime fumigated ones and also exhibited more severe damage.

Transpiration of fumigated plants decreased markedly, presumably due …

A Rapid Serological Bean Blight Test And Antibiotic Control Measures, Terry Dee Miller

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The detection and identification of bacterial pathogens in bean tissues can be accomplished with relative ease and certainty by utilizing antiserum prepared against specific bean pathogens. This test requires only fifteen minutes to complete, and a minimum amount of equipment. In addition to speed and ease, it eliminates the difficult process of isolating the bacterial pathogens from the many contaminants that will grow in nutrient culture techniques. The advantage of this technique is primarily based on the utilization of the bacterial population already present in the diseased plant tissues.

The effectiveness of this method has been demonstrated by diagnosing beans …

Effect Of Phenology, Clipping, And Moisture Stress On Translocation In Grass, Ronald Eugene Sosebee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect of phenology on the pattern of photosynthate distribution was studied in crested wheatgrass (Agropyron cristatum (L.) Gaertn.) plants grown in a nursery under semi-natural environmental conditions. A set of plants was transferred every fourth week (April 13, 1968, through December 2, 1968) from the nursery to a growth room where the temperature was maintained at approximately 24 C with 16-hour photoperiods. A single leaf per plant received 1.5x10^-3 ml of either NaH₂³²PO₄ or KH₂³²PO₄. Approximately 24 hours after the ³²P application, the plants were harvested and …

Overwintering Of Erwinia Amylovora Inside Living Host Tissue In Cache Valley, Utah, G. Doyle Morrill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Experiments were conducted to see if Erwinia amylovora (Burrill) Winslow et al. overwinters inside living host tissue in Utah. Bacteria, collected from apple, pear, mountain ash, chokecherry and Pyracantha, were used in the experiment. Isolates taken from buds and inner bark plated on nutrient yeast dextrose agar, we re tested by serological and bacteriophage techniques. Those showing positive tests were then inoculated into Bartlett pear seedlings to test virulence.

Both virulent and avirulent isolates were isolated from each species of plant in the experiment. Pathogenic bacteria were isolated from diseased tissue near cankers, as well as from apparently healthy inner …