Botany Commons^™

The Use Of Rapd To Detect Genetic Variation In Populations Of Liatris Aspera Michx., Duane Joseph Kitchen

Dissertations and Theses @ UNI

The tall grass prairie is one of the most degraded and fragmented ecosystems on earth. Interest in conserving, restoring, and reconstructing tallgrass prairie began early in the 1900s, and has increased dramatically since the 1960s. Early restoration and reconstruction efforts relied primarily on seed collected from prairie remnants near the planting site, but with the increase in prairie planting efforts came a greater demand for large quantities of affordable, viable seed of native prairie species. Following an increase in the use of cultivated varieties (cultivars) of seed, concerns over the loss of genetic integrity of local populations and low genetic …

Effects Of Sludge Application On Prairie Establishment, Brenda Joan Durbahn

Dissertations and Theses @ UNI

Native prairie in Iowa has all but disappeared since the development of agricultural land by European settlers over the past 165 years. Reconstructing prairie is one way to replace some of the acreage that was lost. A byproduct of settling an area is the generation of garbage and other wastes. Currently there is a surplus of sludge, the waste product of waste water treatment facilities. This material is usually disposed of in landfills, used on agricultural land or reclamation projects.

A small area of prairie was reconstructed on the top of a closed portion of the Black Hawk County Solid …

Tapeinosperma Alatum (Myrsinaceae): A Remarkable New Species From Ceram, Diane Holland, P.F. Stevens

Biology Department Faculty Works

A new pachycaul species Tapeinosperma alatum D.E. Holland & P.F. Stevens (Myrsinaceae) is described from South Central Ceram. It is characterized by its huge leaves, over 1 m long, and congested, almost Gunnera-like. inflorescence. The distinctive distribution of the Papuasian pachycaul species of Tapeinosperma is briefly compared with that of a number of other unrelated taxa.

Composition And Change Of Maritime Hammock Flora In East-Central Florida After 20 Years, Donald John Spence

Retrospective Theses and Dissertations

The vegetation of eight east-central Florida maritime hammocks studied in 1997 were compared to similar data collected over 20 years ago. Study sites are located in the northern half of the Indian River Lagoon system mostly within Canaveral National Seashore and Merritt Island National Wildlife Refuge. The upland hammock vegetation throughout the state generally has an oak-palm association, but here these species dominate. Results show that sabal palm, live oak, laurel oak, and pignut hickory, the four dominant tree species in 1976-77, are still dominant in 1997; however, there has been a loss in tree species richness. Most shrub species …

Intraspecific And Diffuse Competition: The Response Of Nassella Pulchra In A California Grassland, Andrew R. Dyer, Kevin J. Rice

Faculty Publications

In inland California grasslands, the high densities of alien annual species have altered the growing environment for native perennial grasses. Using variable-density plots, we measured the influence of intraspecific competition (conspecifics only) and diffuse competition (mixed-composition neighborhoods that include conspecifics) on growth and survival of Nassella pulchra, purple needlegrass. We assessed the effects of intraspecific and diffuse competition in weeded plots and unweeded plots, respectively, across a density gradient of N. pulchra plants (16–356 plants/m2). We used summer fire and spring sheep grazing to reduce diffuse competition in unweeded plots. The potential effect of rooting volume on competitive interactions …

Selection Of Populations Of Puccinia Recondita F. Sp. Tritici For Shortened Latent Period On A Partially Resistant Wheat Cultivar, Jeffery S. Lehman, Gregory Shaner

Biology and Earth Science Faculty Scholarship

Wild-type fungal population 851-WT was selected for shortened latent period on cv. CI 13227 for five uredinial generations to study the adaptation of Puccinia recondita f. sp. tritici to partially resistant wheat cultivars. Differences among wild-type and selected populations for traits contributing to parasitic fitness (i.e., latent period, infection frequency, and uredinium area and growth rate) were assessed in monocyclic infection experiments on susceptible cv. Monon and partially resistant cvs. Suwon 85, Sw 72469-6, L-574-1, and CI 13227. Differences were greatest among fungal populations on cv. CI 13227. The mean latent period of selected population 851-C5 was 2 days shorter …

Phenology Of Apothecium Production In Populations Of Monilinia Vaccinii-Corymbosi From Early- And Late-Maturing Blueberry Cultivars, Jeffery S. Lehman, Peter V. Oudemans

Biology and Earth Science Faculty Scholarship

Pseudosclerotia were evaluated for differences in timing of apothecium development in four controlled experiments conducted over a 2-year period. In a separate experiment, conidia from 10 randomly selected isolates from both of the fungal populations were used to inoculate open flowers. Germination of pseudosclerotia produced from these artificial inoculations also was evaluated. The timing and rate of shoot elongation for cvs. Weymouth and Jersey were assessed in one greenhouse and two field experiments. Average development times for the fungal population from cv. Weymouth were 8 to 15 days earlier or 33 to 42% less than those for the population from …

An Analysis Of The Variation Within Cratoxylum Arborescens (Clusiaceae) In Malesia, A.C. Church, P.F. Stevens

Biology Department Faculty Works

The variation within the widespread West Malesian species Cratoxylum arborescens (Vahl) Blume was analyzed and three distinctive variants were found. These are recognized formally as varieties, var. arborescens, var. miquelii King, and var. borneense A.C. Church & P.F. Stevens. A key and full descriptions are given. The characters employed to delimit the three taxa are discussed and the selection of varietal rank is justified.

Floristics, Plant Community Structure And Bank Profiles, For Five Sites Along The Middle Ohio River, Amy Nicole Morris

Theses, Dissertations and Capstones

Plant community structure, floristics, and bank profiles for five sites along the middle Ohio River were described. Values obtained were compared with a similar study by Clagg and Mills in 1978 on four of the five sites. A total of 186 plant species was observed in the plant community and floristic study. Glenwood Bend had the greatest diversity with 109 plant species. Mason-Pomeroy had the lowest diversity with only 35 plant species. Six species, representing 3.2 percent of the total observed number of species, were present at all five sites. The majority of species, 51 percent, were present at only …

A Second Nitrogenase In Vegetative Cells Of A Heterocyst-Forming Cyanobacterium, T Thiel, E Lyons, J Erker, A Ernst

Biology Department Faculty Works

In many filamentous cyanobacteria nitrogen fixation occurs in differentiated cells called heterocysts. Filamentous strains that do not form heterocysts may fix nitrogen in vegetative cells, primarily under anaerobic conditions. We describe here two functional Mo-dependent nitrogenases in a single organism, the cyanobacterium Anabaena variabilis. Using a lacZ reporter with a fluorescent beta-galactoside substrate for in situ localization of gene expression, we have shown that the two clusters of nif genes are expressed independently. One nitrogenase functions only in heterocysts under either aerobic or anaerobic growth conditions, whereas the second nitrogenase functions only under anaerobic conditions in vegetative cells and heterocysts. …

Reproductive Structure And Organogenesis In A Cottonwood, Populus Deltoides (Salicaceae), Robert B. Kaul

School of Biological Sciences: Faculty Publications

The organogenesis of inflorescences, flowers, and fruits was followed for two years in a male and a female tree of eastern cottonwood, Populus deltoides. Soon after anthesis, an inflorescence for the next year is initiated as a continuation of the apical meristem in most axillary buds of the extension shoot of the current year. Bract and then floral primordia arise helically, and by the end of summer all floral appendages are evident. Individual perianth parts are evident early in ontogeny but not at anthesis; they are vascularized independently by distal traces of discrete vascular strands that also serve the …

The Rare, Serpentine Endemic Streptanthus Morrisonii (Brassicaceae) Species Complex, Revisited Using Isozyme Analysis, Rebecca W. Dolan

Scholarship and Professional Work - LAS

The Streptanthus morrisonii (Brassicaceae) complex is a group of six narrowly-distributed obligate serpentine endemic taxa whose habitat is threatened by geothermal development. Isozyme analysis of this little-studied complex supports the delineation of two species, S. morrisonii and S. brachiatus, but is at odds with the treatment of two subspecies based on morphology. These results may be influenced by small sample sizes but genetic studies of other Streptanthus taxa have shown patterns of relatedness that often transgress subspecies boundaries based on morphology. The present study further shows that members of the S. morrisonii complex share high genetic identity values (mean …

The Vascular Flora, Rare Species And Plant Migrations Of New River Gorge National River, West Virginia, Dale William Suiter

Theses, Dissertations and Capstones

In 1978, the United States Congress designated 83.5 km/53 mi. of the New River in southern West Virginia as New River Gorge National River. The vascular flora of selected sites in NRGNR was surveyed from September 1992 through October 1994. A total of 904 taxa of vascular plants was recorded, 79.2% of which are native to West Virginia. Currently, 1337 vascular plant taxa have been documented from the New River Gorge as a result of this work as well as the work of Grafton and McGraw and Phillips. A comparison of species with the West Virginia Natural Heritage Program's rare …

Meristic And Organogenetic Variation In Ruppia Occidentalis And R. Maritima, Robert B. Kaul

School of Biological Sciences: Faculty Publications

Floral meristic and organogenetic variation was sampled in Ruppia occidentalis from an alkaline lake of the Nebraska Sandhills and in Ruppia maritima var. rostrata from a saline, non-Sandhills lake nearby. The androecium is meristically stable, always having two stamens, but the gynoecium is not. Seventy-two percent of the flowers of R. maritima had four carpels and the others had three, and in 80% of inflorescences the two flowers had the same number. In about one-third of inflorescences having dissimilar carpel numbers, the four-carpellate flower was uppermost. The number of carpels in each flower of R. occidentalis ranged from four to …

Molecular Approaches For Control Of Tomato Bushy Stunt Virus, H. B. Scholthof, M. Borja, Thomas Jack Morris, A. O. Jackson

School of Biological Sciences: Faculty Publications

I N this overview strategies are discussed that are currently being tested in our laboratory in an effort to engineer resistance against tomato bushy stunt virus (TBSV) in plants. TBSV is chosen as a model-system since this is an economically important RNA virus that is well characterized at the molecular level and the virus has some interesting and potentially useful features that can be exploited to produce resistant plants. Moreover, we anticipate that the information derived from our studies with TBSV will be applicable in developing resistance to other plant viruses. Some approaches that we are attempting to apply to …

Multivariate Analysis Of The Carex Brevior Group In Iowa, Scott C. Zager

Dissertations and Theses @ UNI

In Iowa, the most troublesome sedges to identify are Carex brevior, C. festucacea, C. molesta, C. normalis, C. tenera, and C. tenera var. echinodes. These taxa form the C. brevior group--part of an even larger aggregate of species associated with C. straminea. Their morphological features are indistinct and intergrade into one another. Botanists have had difficulty classifying members of this aggregate for nearly 200 years. Some authors have viewed the taxa as separate species, others as polymorphic forms of a single species. Much of the contention has centered upon the variation of taxonomic characters used to delimit and distinguish species. …

Factors Related To The Occurrence Of Certain Prairie Graminoid Species In Black Hawk County, Iowa, Roadsides, Pauline Mary Drobney

Dissertations and Theses @ UNI

The native vegetation of Iowa was primarily tallgrass prairie and currently exists only in small isolated parcels, including some remnants occurring in roadsides. Roadside prairie remnants are important for historical, environmental, aesthetic, scientific, and economic reasons. Information about factors influencing the occurrance of roadside prairie vegetation could be useful to roadside vegetation managers in development of initial vegetation surveys and subsequent to restoration of roadside prairie vegetation.

This study was conducted to determine what factors most affected the percent coverage of prairie graminoids in roadsides; particularly soil moisture availability, drainage, soil disturbance, and availability of a prairie seed sources. Prairie …

Sulfur Accumulation In Xylem Tissue Of Forest Trees From Kentucky & Tennessee & Its Relation To Yearly Growth, Jennifer Sharp

Masters Theses & Specialist Projects

The levels of sulfur present in xylem tissue of Quercus alba (white oak) show a statistically significant increase from 1970 to 1983. This increase was found in trees from three different sites in Kentucky and Tennessee. The levels of sulfur present in Tsuga canadensis (hemlock) show a statistically significant increase from 1955 to 1970. Sensitivity, growth response to the tree's environment, decreased in oaks from 1933 to 1968 but increased slightly in hemlocks during the same time period. The data tend to support a direct relationship between increasing sulfur levels and a reduction in growth. Physiological and ecological studies of …

Patterns Of Sulfur Deposition In The Wood Of Pinus Echinatia Mill. From The Cumberland Plateau In Kentucky, Darrell Ray

Masters Theses & Specialist Projects

Air pollution and acid precipitation have long had an influence on plant and animal life. In this study, the level of sulfur in the stem tissue of Pinus echinata Mill. was measured in trees from various sites along the western edge of the Cumberland Plateau to determine the presence and pattern of sulfur deposition in this species. Overall, a 40.28% increase in sulfur levels was observed from four sites along the plateau with levels increasing from 0.072 mgS/gdwt in the 1962-66 growth increment to 0.101 mg in the 1982-86 increment. According to a computer generated analysis of variance, the differences …

Cupular Structure In Paleotropical Castanopsis (Fagaceae), Robert B. Kaul

School of Biological Sciences: Faculty Publications

The structure and some developmental aspects of the cupules of 22 species of paleotropical Castanopsis are discussed and illustrated. Some species have cupules massively invested with strong, sharp spines, but others are less spiny, and some are nearly smooth. Most cupular armament results from spines produced axillary to the valvular scales and basally adnate to them. Columns of scales straddling the sutures between the cupular valves do not become spines, but the numerous scales elsewhere on the valves become somewhat spiny with age. Dehiscence in the spiny-valved species is mostly along the sutures. The smooth cupules of some species have …

Reproductive Structure Of Lithocarpus Sensu Lato (Fagaceae): Cymules And Fruits, Robert B. Kaul

School of Biological Sciences: Faculty Publications

Seventy-three species were examined for structural and developmental details of the cymules and fruits. The cymules bear one to seven or more flowers and are subtended by one to nine or more bracteoles. Generally, the number of flowers and bracteoles in the pistillate cymules is the same or less than in the staminate ones. Some of the latter have an inner set of bracteoles that could be homologous to the pistillate cupule. Scales are present at anthesis on the cupules of all species examined, but in some species they fail to enlarge, are torn or disintegrate, or fall away as …

Nebraska Plant Distribution, David M. Sutherland, Robert B. Kaul

Biology Faculty Publications

Distribution notes based on recent collections and herbarium work are provided for 46 Nebraska plant taxa, including 43 flowering plants, two ferns, and one liverwort. The list includes several plants that are new to the State and provides range extensions within the State for many others. Several previously- published distribution records believed to be erroneous are also discussed.

Evolution And Reproductive Biology Of Inflorescences In Lithocarpus, Castanopsis, Castanea, And Quercus (Fagaceae), Robert B. Kaul

School of Biological Sciences: Faculty Publications

Of Lithocarpus, Castanopsis, Castanea, and Quercus, only Lithocarpus frequently bears branched spikes suggestive of the primitive condition in the Fagaceae; the other genera sometimes have them in some individuals. Simple and branched spikes can occur on the same tree. Evolution of the simple spike is interpreted as the loss of branching capacity in the branched spikes. The Fagaceae show various transitional stages from perfect, entomophilous to imperfect, anemophilous flowers and from mixed-sex to unisexual spikes. Complete separation of staminate from pistillate function into separate spikes and catkins occurs only in Quercus, which is also the only …

Extrafloral Nectaries On Plants In Communities Without Ants: Hawaii, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

Since the Hawaiian Islands lack native ants, it was hypothesized that extrafloral nectaries, an ant-related mutualistic trait, should be lacking on native species. Presence of extrafloral nectaries (EFNs) on plants was determined by direct observation and related to vegetation structure and floral composition. Frequency of plants with EFNs was low by all possible comparisons. However, several endemic species had functional EFNs. The hypotheses to explain these anomalies are (1) phylogenetic inertia or (2) mutualism with some other organism than ants.

Benthic Diatom Community Dynamics In The Colorado River: Interactive Effects Of Periodic Dessication And Current Regime, Christopher Gerard Peterson

Publications (WR)

The response to periodic desiccation of periphyton communities developed in eddy environments or in areas exposed to variable, direct current was examined. Algal communities were incubated on clay tiles for between 2 and 12 weeks in the Colorado River, directly below Hoover Dam from October, 1983 - January, 1984. Mean daily discharge from the dam decreased over this period. To assess the influence of these discharge changes on community dynamics, samples collected over the first 12 weeks of the investigation were compared to samples of the same age collected over the final 8 weeks.

The small diatom taxon Achnahthes spp …

Ua66/6 Brigadoon Nature Preserve Survey Phase I, Wayne Mason, Jeff Jenkins, Kenneth Nicely, Herbert Shadowen

WKU Administration Documents

A preliminary report of an ongoing survey on the mammals, birds, vascular plants, and fungi that have been recorded at the Brigadoon Nature Preserve from November, 1983 - September, 1984.

An Evaluation Of Naturally Occurring Populations Of Magnolia Tripetala L. In Indiana, Kemuel S. Badger

All-Inclusive List of Electronic Theses and Dissertations

Magnolia tripetala L. occurs in Indiana as a disjunct from the Appalachian mountains populations. Currently, the known distribution of ~· tripetala in Indiana is confined to seven sites in Crawford County. The current status of ~· tripetala and the surrounding plant community was evaluated to aid in the future study, protection and management of this species, which is endangered in Indiana. Systematic random sampling of the tree stratum was done with belt transects. The sapling and seeding strata were sampled with subplots, placed along the belt transects. Permanent plots were established to enable future monitoring of what is currently prime …

Phenotypic Differences In Populations Of Euonymus Americanus L. From The Central United States & Autecological Studies Of This Species In A Deciduous Forest Of Kentucky, Paul Bayer

Masters Theses & Specialist Projects

The concentrations of sodium and potassium in the leaves of Euonymus americanus collected from a relict hardwood forest during a four month period showed a possible winter conditioning pattern. Seeds collected from this same relict stand would not germinate, even though they were subjected to a wide variety of germination experiments. Phenotypic differentiation in fully developed leaves was not found; however, differences related to the length of the growing season were noted. Autecological studies of Euonymus americanus should be continued to investigate the role of this plant in relict hardwood stands.

An Ultrastructural Study Of Transmitting Tissue Development In The Pistil Of Lilium Leucanthum, Stanley R. Gawlik

Biology Faculty/Staff Publications

A study of developing transmitting tissue of Lilium Leucanthum pistils was undertaken in order to correlate structure with function. Lining the stylar canal are stigmatoid cells which contain a secretory zone consisting of a labyrinth of wall ingrowths characteristic of transfer cells. The functional feature of the labyrinth is a high surface-to-volume ration that facilitates an intensive transmembrane flux of solutes. Stigmatoid cells in various stages of development and maturation have been investigated with the aid of electron and light optics in conjunction with cytochemical techniques. During the development of the secretory zone, vesicles, formed by hypersecretory dictyosomes, fuse with …

Seasonal Shifts Of Photosynthesis In Portulacaria Afra (L.) Jacq., Lonnie J. Guralnick, Patricia A. Rorabaugh, Zac Hanscom

Arts & Sciences Faculty Publications

Portulacaria afra (L.) Jacq., a perennial facultative Crassulacean acid metabolism (CAM) species, was studied under natural photoperiods and temperatures in San Diego, California. The plants were irrigated every fourth day throughout the study period. Measurements of ¹⁴CO₂ uptake, stomatal resistance, and titratable acidity were made periodically from July 1981 through May 1982. P. afra maintained C₃ photosynthesis during the winter and the spring. Diurnal acid fluctuations were low and maximal ¹⁴CO₂ uptake occurred during the day. The day/night ratio of carbon uptake varied from 5 to 10 and indicated little nocturnal CO₂ uptake. CAM …