Biology Commons^™

Review Of The Wild Oat Inflorescence And Seed: Anatomy, Development And Morphology, M. V. S. Raju, David M. Sutherland

Biology Faculty Publications

This slim volume describes a detailed study of the reproductive parts of Avena fatua, the wild oat plant-a common weed in the northern plains and the probable ancestor of the cultivated oat. The book integrates the author's own work with information from available literature and includes lengthy technical descriptions of the structure and the growth of the inflorescence, the floret, the ovule, the pollen grain, the embryo, the seed, and the young seedling. Throughout the work, the author relates the wild oat's structure and development to other grasses, other monocotyledons, and other seed plants, offering evolutionary interpretations of many of …

Survivorship And Recruitment In A Long-Lived Prairie Perennial, Ipomoea Leptophylla (Convolvulaceae), Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

Little is known of the lifespans of herbaceous plants, especially in grasslands, although this information is basic to understanding the dynamics of species and ecosystems. Permanently marked plants of the bush morning glory, Ipomoea leptophylla (Convolvulaceae), in Nebraska sandhills prairie were censused annually from 1979-1989. While the average annual death rate was 2.6 per 100, virtually all the mortality was among smaller and probably younger plants. Recruitment varied greatly among years. Of plants of known age, the median age at first flowering was 6 yr. After 9 yr 30% had never flowered. Larger size classes flowered more frequently than smaller …

Primary Productivity And Species Composition Of A Reconstructed Wetland In Eastern Kentucky, Eric C. Webb

Morehead State Theses and Dissertations

A thesis presented to the faculty of the Department of Biological and Environmental Sciences at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Eric C. Webb on May 19, 1991.

Study Of Ferredoxin And Flavodoxin From Tobacco Leaves And Roots Under Normal And Iron-Stressed Conditions, I-Jen Huang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I purified tobacco leaf ferredoxin from normal and iron-stressed leaves. The oxidized form of ferredoxin from normal leaves had absorption maxima at 268, 327, and 422 nm and a shoulder at 463 nm. The oxidized form of ferredoxin from iron-stressed leaves had absorption maxima at 268 and 329 nm but no absorption maxima in the 400-nm range. Higher ferredoxin content was found with higher chlorophyll content in leaves of the same age.

A protein in tobacco root extract was isolated and found to serve as an electron carrier for ferredoxin-requiring nitrite reduction. This protein had a molecular weight and antigenic …

Fungal Development And Host Cell Responses To The Rust Fungus Puccinia Substriata Var. Indica In Seedling And Mature Leaves Of Susceptible And Resistant Pearl Millet [Abstract], Josephine Taylor, C. W. Mims

Faculty Publications

No abstract provided.

A Taxonomic Study Of Variation In Leptochloa Fascicularis (Lam.) Gray In The Central Great Plains, Todd A. Templeton

Biology Faculty Publications

The morphology of Leptochloa fascicularis (Lam.) Gray (Poaceae) was studied in 25 locations in eastern and central Nebraska to determine if this grass was separable into two distinct taxa as suggested in several recent sources. Field collections were supplemented with herbarium specimens from other parts of the Central Great Plains. Glume and lemma lengths, the characters used in published keys, provided no separations useful in dividing the material into two species or varieties. However, individual local populations exhibited significant differences from each other in these characters. Such local differences appear to be reasonable given the high degree of inbreeding that …

New And Corrected Floristic Records For Nebraska, Steven B. Rolfsmeier, Robert B. Kaul, David M. Sutherland

Biology Faculty Publications

Nineteen species (including eight Eurasian ones) are newly recorded for Nebraska: Alopecurus arundinaceus, Amaranthus californicus, Asclepias asperula, A purpurascens, Cardamine {lexuosa*, Centaurea diffusa, Dipsacus laciniatus, Eriochloa villosa, Euclidium syriacum, Gentiana alba, Geranium viscosissimum, Geum vernum, Goodyera oblongifolia, Haplopappus multicaulis, Heterotheca latifolia, Lathyrus tuberosus, Polygonum douglasii, Scirpus saximontanus, Veronica biloba. Twenty-one others are shown to be more widespread in Nebraska than previously known, one has a more restricted range than previously reported, two (Scirpus smithii, S. torreyi) are deleted from the flora based upon corrected identifications, and the status of some rarely-collected species is updated. Thirty-two additions, two …

Woody Plants Of The Lower Rio Grande Valley, Texas, Robert I. Lonard, James H. Everitt, Frank W. Judd

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Description of Common Vegetation of Lower Rio Grande Valley.

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. …

The Short-Term Effects Of Manganese Toxicity On Ribulose 1,5 Biophosphate Carboxylase In Tobacco Chloroplasts, Kerrie Elliott

Masters Theses & Specialist Projects

The short-term effects of manganese toxicity on ribulose 1,5 bisphosphate carboxylase (Rubisco) activity and concentration in tobacco chloroplasts were examined. The activity of the enzyme from both manganese-treated and control plants was determined 6, 12, 18, 24 , and 48 h after introduction of manganese (80 mg/Li. Enzyme activity was determined by monitoring rates of radioactive CO₂ fixation into acid stable products. A slight stimulation of the enzyme's activity was noted in experimental plants after 18 h of exposure to manganese as compared with control plants. A decrease in the enzyme's activity in experimental plants was noted after 48 …

The Effect Of Plant Growth Regulators On The Growth Of Closterium Moniliferum, Cynthia Lehua Warnock Christensen

Dissertations and Theses

Physiologic responses to Gibberellic Acid (GA), 1-Naphthalene Acetic Acid (NAA), Benzylaminopurine (BAP), and Abscisic Acid (ABA), suggest that Closterium moniliferum has the ability to utilize these plant growth factors. The growth promoters NAA and GA both increased growth when added to the media. The cell division regulator BAP (a synthetic cytokinin). also had a promotive effect on growth. Abscisic acid was found to be inhibitive to growth.

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 …

Introduction And Enhancement Of Vegetative Cover At Lake Mead, Jennifer S. Haley, Lisa K. Croft, Suzanne E. Leavitt, Larry J. Paulson

Publications (WR)

Studies done by the Nevada Department of Wildlife (NDOW) and the Arizona Fish and Game between 1978 and 1981 indicate that inadequate cover may be limiting the production and survival of largemouth bass at the Lake Mead National Recreation Area (LMNRA). As a result of these studies, NDOW initiated a contract in 1986 with the Lake Mead Research Center (LMRC) to investigate means of improving habitat for game fish by introducing natural and/or artificial cover. During Phase I (1986-1987) of this contract, the shoreline of Lake Mead was surveyed for aquatic and terrestrial plant growth. Also during this time, submerged …

Vegetation And Environment In An Adjacent Post Oak Flatwoods And Barrens In Indiana, Rebecca W. Dolan, Eric S. Menges

Scholarship and Professional Work - LAS

To compare adjacent post oak flatwoods and barrens communities in south-western Indiana, we used vegetational, environmental and fire history data in multivariate analyses. Barrens had greater dominance by post oak and lower tree species richness, but variation in tree species composition was not strongly related to soil moisture, litter depth or other environmental gradients measured. Tree growth has been slow and variable, with little difference between the barrens and flatwoods. Barrens and flatwoods differ in herb species composition, but with considerable overlap. In the barrens, herbaceous vegetation composition was correlated with tree basal area, litter depth and soil moisture; in …

Temporal Patterns Of Nectar And Pollen Production In Aralia Hispida: Implications For Reproductive Success, James D. Thomas, Mary A. Mckenna, Mitchell B. Cruzan

Biology Faculty Publications and Presentations

Large plants of Aralia hispida present their pollen and nectar in hundreds of small flowers than open sequentially over 2—3 wk in a pattern of synchronized protandry that alternates male and female phases. The primary pollinators, bumble bees, are able to discover individual plants with elevated levels of either nectar or pollen, and to return to them more often than to less rewarding plants. Both pollen and nectar are presented gradually over time in such a way as to favor traplining behavior by the bees, with many, frequent visits. In controlled environments, lifetime sugar production per flower varies among plants, …

The Effects Of Varying Light Exposure Times On The Colonization And Sporulation Of Gigaspora Margarita In The California Pepper, Mary E. Kirker

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Arts and Sciences at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science in Biology by Mary E. Kirker on July 24, 1989.

Isolation & Characterization Of A Type I Topoisomerase From The Hypocotyls Of Etiolated Soybeans, Rick Dye

Masters Theses & Specialist Projects

Topoisomerases are enzymes of critical biological significance. Despite this fact, little data specific to the topoisomerases of higher plants has been published. This research was undertaken to isolate and characterize a higher plant topoisomerase from soybean hypocotyls to further the understanding of the structure and function of these enzymes.

Nuclei were isolated from frozen hypocotyls of 4 day old etiolated soybeans by homogenization and centrifugation, then lysed by gentle stirring in the presence of 1.5 mM ammonium sulfate. The resultant extract was desalted and purified by column chromatography on DEAF sepharose, 5-200 sephacryl and CM cellulose. The components of the …

Historical Biogeography: Geography As Evolution, Evolution As Geography, Charles H. Smith

DLPS Faculty Publications

Despite a number of advances in recent years, biogeography remains a field with a poorly developed philosophical core. As a result, its historical and ecological sides remain as isolated from one another as ever. In this essay I argue that a more unified approach to biogeographic studies will become possible only when workers realise that it is necessary to reject absolute space, "geography as handmaiden" approaches to distribution problems in favour of structuralist models compatible with both probabilistic spatial interaction and deterministic phylogenetic kinds of thinking. Pros and cons of regionalist, vicariance, and panbiogeographic approaches are weighed in this regard; …

Ultrastructure Of The Early Stages Of Infection Of Peanut Leaves By The Rust Fungus Puccinia Srachidis [Abstract], C. W. Mims, Josephine Taylor, E. A. Richardson

Faculty Publications

No abstract provided.

Expression Of Holo And Apo Forms Of Spinach Acyl Carrier Protein-I In Leaves Of Transgenic Tobacco Plants, M. A. Post-Beittenmiller, Katherine M. Schmid, J. B. Ohlrogge

Scholarship and Professional Work - LAS

Acyl carrier protein (ACP) is a chloroplast-localized cofactor of fatty acid synthesis, desaturation, and acyl transfer. We have transformed tobacco with a chimeric gene consisting of the tobacco ribulose-1,5-bisphosphate carboxylase promoter and transit peptide and the sequence encoding the mature spinach ACP-I. Spinach ACP-I was expressed in the transformed plants at levels twofold to threefold higher than the endogenous tobacco ACPs as determined by protein immunoblots and assays of ACP in leaf extracts. In addition to these elevated levels of the holo form, there were high levels of apoACP-I, a form lacking the 4'-phosphopantetheine prosthetic group and not previously detected …

Tallgrass Prairie Remnants Of Eastern Nebraska, Judith F. Boettcher, Thomas B. Bragg

Biology Faculty Proceedings & Presentations

Ten eastern Nebraska tallgrass prairie remnants were evaluated up to four times during the 1979 growing season to assess vegetative composition and the effects of mowing, topographic and size differences, and season of evaluation. Frequent mowing resulted in a reduced canopy cover of some species, such as big bluestem (Andropogon gerardii Vitman) (21% lower with frequent mowing), but increased cover of others, particularly the introduced species smooth brome (Bromus inermis Leyss. subsp. inermis) (35% higher cover with frequent mowing). In addition, frequent mowing resulted in a higher proportion of disturbance species. Comparing the time of mowing, canopy …

Effect Of Eastern Red Cedar On Seedling Establishment Of Prairie Plants, Dan J. Stipe, Thomas B. Bragg

Biology Faculty Proceedings & Presentations

To test the hypothesis that eastern red cedar (Juniperus virginiana L.) is allelopathic, seedling establishment of five herbaceous prairie species was evaluated by growing seeds in soil collected beneath and adjacent to a stand of this tree species. While four species showed no significant effect, the germination of one species, finger coreopsis (Coreopsis palmata Nutt.), was significantly reduced. Since eastern red cedar is an early invader of unburned prairie, such an allelopathic effect, even on only a few species, is of particular concern in that it has the potential to hasten degradation of invaded prairie sites.

Effect Of Burning On Germination Of Tallgrass Prairie Plant Species, Sherry R. Rohn, Thomas B. Bragg

Biology Faculty Proceedings & Presentations

Seeds from 10 prairie plant species of burned and unburned portions of three tallgrass prairies were collected and tested for germinability. Germination of big bluestem (Andropogon gerardii Vitman) consistently averaged higher with burning. Indiangrass (Sorghastrum nutans L.) and sideoats grama [Bouteloua curtipendula (Michx.) Torr.] averaged 5% higher with burning on two of the three sites, although for indiangrass average germination for all three sites was 7% lower. Species for which germination declined with burning were false sunflower [Heliopsis helianthoides (L.) Sweet var. scabra (Dun.) Fern.], -13%; whole leaf rosinweed (Silphium integrifolium Michx.), -10%; and white …

Establishing Warm-Season Grasses And Forbs Using Herbicides And Mowing, Thomas B. Bragg, David M. Sutherland

Biology Faculty Proceedings & Presentations

The objective of this study was to provide a preliminary assessment of the use of selected herbicides in establishing a diverse stand of prairie grasses and forbs. An upland and a lowland site in eastern Nebraska, consisting of well-drained, fine-silty clay, loess-derived soils, were seeded with 23 native prairie grass and forb species and subsequently mowed or treated at rates of 0.6, 1.1, 1.7, and 2.2 kg/ha with atrazine [6-chloro-Nethyl- N' -(l-methylethyl)-l ,3,S-triazine-2,4-diamine] or 2,4-0 (2,4-dichlorophenoxyacetic acid). Treatments were applied at one and two-year intervals. Canopy cover in unreplicated treatment areas (12 x 30 m) was evaluated in ten randomly …

An Annotated List Of The Vascular Plants Of Keith County, Nebraska, David M. Sutherland, Steven B. Rolfsmeier

Biology Faculty Publications

This study provides an annotated list of the vascular plants known to exist outside of cultivation in Keith County, Nebraska. Listed are a total of 599 species, subspecies and varieties belonging to 302 genera of 87 families. Notes are included about frequency and habitat for each of the taxa. 264 (44.1 %) of the taxa listed were previously unreported for Keith County. Additionally, the paper discusses vegetation regions in the county and gives information in tabular form about numbers of the flora in different taxa, the ten largest families, numbers of taxa of different growth habits, and numbers of taxa …

The Short Term Effects Of Manganese Toxicity On Isocitrate Dehydrogenase In Wheat & Tobacco, Juergen Pfeiffer

Masters Theses & Specialist Projects

The short term effects of high manganese levels (80 mg/L) on wheat and tobacco isocitrate dehydrogenase (IDH) activity were compared. The change in activity was then compared to the concentrations of manganese in the tissues.

As the time of manganese exposure increased, the fresh weight IDH activities in wheat and tobacco decreased. In contrast both control groups had similar enzyme activities every 6 hr over the 24 hr test period. The decrease in IDH activity of wheat and tobacco plants in experimental groups seemed to be related to an increase of the manganese in the leaf tissue. The slower decrease …

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 …

New And Corrected Floristic Records For Nebraska, Steven B. Rolfsmeier, Robert B. Kaul, Marjorie M. Garabrandt, David M. Sutherland

Biology Faculty Publications

New distributional data are given for 54 species of vascular plants in Nebraska. Twenty are newly recorded for the State. 23 are shown to be more widespread than was previously known, seven are shown to have more restricted ranges than previously reported. the records of one species attributed to the State are shown to be based on misidentifications. and the presence in the State of three species collected long ago is confirmed by recent collections.