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Article Excerpt
BOTANY SECTION
CLAUDE BAILEY, CHAIR
DEVELOPMENT AND APPLICATIONS OF GEOREFERENCED HERBARIUM SPECIMENS. Ryan Miller, Andrew Carroll, and Joey Shaw, University of Tennessee, Chattanooga, Chattanooga, Tennessee. Recent advances in Geographic Information Systems (GIS) allow for new methods of conservation, restoration, and general biological inquiry, especially if data from natural history collections are utilized. Currently, we are databasing and georeferencing the approximately 11,000 plant specimens of the University of Tennessee, Chattanooga Herbarium. The primary focus of this research is to create online, interactive county distribution maps for each plant species. The database will include over 50 searchable characteristic fields based on the proposed Darwin Core 2 format Global Positioning System (GPS) coordinates, date collected, locality description, and reproductive state. Other applications of our research include identifying areas of high plant diversity, highlighting areas of endemism, tracking the spread of invasive species, determining locations in need of additional collecting efforts, and studying flowering times in relation to geographic location. However, the full potential of these and other unnamed applications is predicated on the progress of SERNEC's effort to link and share data among southeastern herbaria.
ALL TAXA BIODIVERSITY INVENTORY AT EDGAR EVINS STATE PARK, DEKALB COUNTY, TENNESSEE. Rex R. Barber, Volunteer State Community College, Gallatin, Tennessee. In correlation with the protocol established by the Tennessee State Parks All Taxa Biodiversity Inventory (ATBI), two additional permanent plots were established at Edgar Evins State Park in the spring of 2006. The total is ten established 50 m by 20 m permanent plots. Forest composition of the two new plots was surveyed during the summer of 2006, and the original eight plots were surveyed during the growing season of 2005. Also during the summer of 2006, woody shrubs and saplings were surveyed on all ten plots. Plot number nine, located across Center Hill Lake from the park proper near Indian Creek, is dominated by Acer saccharum, Ailanthus altissima, and Sassafras albidum. Plot number ten, located near the lake edge on Hale's Branch Point, is dominated by Juniperus virginiana, Liquidambar styraciflua, Quercus muehlenbergii, Diospyros virginiana, and Quercus rubra. A summary of forest composition of the original eight plots, as well as physiography, topography, locations, and survey data of the new plots will be presented. Although recent historical anthropogenic factors may be affecting normal forest succession, the park exists with some notable deciduous forest diversity.
EFFECT OF INTER- AND INTRA-SPECIFIC COMPETITION ON GROWTH AND FECUNDITY OF MICROSTEGIUM VIMINEUM. Scott B. Franklin and Christopher A. Henson*, University of Memphis, Memphis, Tennessee. One factor that can greatly influence the success of an invasive species lies in its ability to produce a viable population size in a relatively short period of time. The effects of intraspecific and interspecific competition on growth and fecundity in Microstegium vimineum were examined in situ to determine the degree to which manipulation within separate population parameters would influence reproductive output and resource allocation. A strong increase was observed in both growth and reproductive effort upon removal of intraspecific competitive pressure whereas the degree to which the growth and reproduction of the individuals affected by interspecific competition was less conspicuous. The greater increase in growth and reproductive effort upon the removal of intraspecific pressure in respect to the removal of interspecific competition exhibits one major aspect of the success of Microstegium vimineum as an invasive species.
FITNESS CONSEQUENCES OF VARYING CROSSING SCHEMES IN HELIANTHUS VERTICILLATUS. Jennifer R. Ellis, Vanderbilt University, Nashville, Tennessee. Conservation biologists are often interested in the influence of population size and geographic proximity of populations on fitness. Frequently, studies find there is increased fitness or heterosis in the [F.sub.1] generation when gene flow is from a large to small population or in crosses between populations separated by large distances. However, increased fitness may not carry through to later generations because of a disruption of positive epistatic interactions among parental alleles due to recombination during and beyond the [F.sub.2] generations. Thus, immigration of genetically divergent individuals into a population also can lead to a decrease in fitness owing to dilution of local adaptations or disruption of gene combinations. I present the first generation data of a crossing study of the rare sunflower, Helianthus verticillatus, and find that two types of intrapopulation crosses were the most fit and least fit respectively while the interpopulation crosses were intermediate.
THE STATUS OF PRENANTHES BARBATA, BARBED RATTLESNAKE ROOT, IN KENTUCKY AND TENNESSEE. Edward W. Chester, Austin Peay State University, Clarksville, Tennessee. Prenanthes harbata (Torrey and Gray) Milstead (Asteraceae), Barbed Rattlesnake Root, is a rare, short-lived perennial known from eight southern states (AL, ARK, GA, KY, LA, MISS, TN, TX). It is regarded as a species of concern in all states with known occurrences. It is known from one county in Kentucky (Trigg) and from 10 counties in Tennessee, mostly on the Western Highland Rim. Literature reports indicate that plants from west of the Mississippi River are most often found on floodplains, while those eastward are most often found on drier, upland sites, especially barrens and prairies. Studies on the northwestern Highland Rim of Tennessee and Kentucky showed that the species is usually found in barrens, thickets, or open oak woods surrounding barrens. The number of stems is always small and fluctuates yearly, with or without burning or other disturbance. However, disturbance appears to provide the open habitat where best growth occurs.
THE DISCOVERY AND STATUS OF QUERCUS MARGARETTA (SAND POST OAK) IN SOUTHWEST TENNESSEE. Claude J. Bailey, Jackson State Community College, Jackson, Tennessee. In 2004 several specimens of Quercus margaretta (Sand Post Oak) were collected along sandy hill bluffs of the Wolf River in Fayette County, Tennessee. This is the first report of Sand Post Oak from Tennessee. The habitat and current range of Sand Post Oak includes deep sands and gravels of the Gulf and Atlantic Coastal plains historically from New York to Central Texas and north into northern Mississippi and Alabama. The closest known locality to Tennessee occurrence is ca. 100 km to the south in Calhoun County, Mississippi. Currently, no collections are known from neighboring county of Benton in Mississippi. The Tennessee occurrence is the northern-most occurrence known to date and represents a range extension for the species.
ECOLOGY OF AMERICAN CHESTNUT AT MAMMOTH CAVE NATIONAL PARK, AN UPDATE. Louis J. Schibig, Jeramie Tinsley*, Anne M. Osborn*, and Lloyd Fly*, Volunteer State Community College, Gallatin, Tennessee. The purpose of this study was to continue the inventory of native populations of Castanea dentata at Mammoth Cave National Park. This entailed the gathering of these data: coordinates for each C. dentata specimen, site conditions, measurements of stem diameter at breast height (dbh) and height, blight status, flowering status, and associated tree and shrub species. All data were entered into an Excel spreadsheet and analyzed to determine size class distributions, site preferences, and the incidence of blight and flowering. From 2003 to 2005, 1381 American chestnut trees were inventoried in the Park. During the summer of 2006, over 300 new specimens were recorded. Most were blight-free, less than 2.5 cm dbh and under 3 m in height, and many were growing on dry, acidic, sandstone soils on upper south to west-facing slopes in association with Acer rubrum, Oxydendrum arboreum, Quercus velutina, Quercus coccinea, Carya spp., Vaccinium spp, and Kalmia latifolia.
ECOLOGY OF FLOWERING AMERICAN CHESTNUT TREES IN KENTUCKY AND TENNESSEE. Louis J. Schibig, Volunteer State Community College, Gallatin, Tennessee. From 2002 to 2005 data were recorded on 59 native flowering American chestnut trees in Kentucky and Tennessee. Three were found in the Unaka Mountains, 1 in the Ridge and Valley region, 4 in the Cumberland Plateau and Cumberland Mountains region, 2 in the Knobs region, 32 on the Eastern Highland Rim, 11 on the Western Highland Rim, 3 in the Western Coal Fields, 2 on the West Tennessee Uplands, and 1 on the Coastal Plain. The flowering trees represented only 2% of the 2067 chestnut trees recorded. Eighty percent of the flowering trees were on relatively dry sites (south to west-facing slopes and ridges). Most (75%) of the flowering trees were blighted. Many of these have been pollinated using hybrid pollen from The American Chestnut Foundation. The progeny will be used to develop blight-resistant American chestnut trees adapted to various regions of Kentucky and Tennessee.
MONITORING RARE PLANT SPECIES IN TENNESSEE. David A. Lincicome, Tennessee Department of Environment and Conservation, Division of Natural Areas. Nashville, Tennessee. The Tennessee Department of Environment and Conservation, Division of Natural Areas houses the state's Rare Plant Protection Program. This program is responsible for accomplishing the recovery of plants listed on the Federal Endangered Species Act of 1973. A key component of this program's recovery efforts is the monitoring of rare plants. Monitoring, to various degrees, is conducted on twenty-five rare plant species. Examples of monitoring efforts include intense demographic monitoring for Astragalus bibullatus; population size/condition monitoring for Lesquerella stonensis, Pityopsis ruthii, Conradina verticillata and Lesquerella perforata; and presence/absence monitoring for Arabis perstellata and Spiraea virginiana. Generally six monitoring projects are completed for rare plants each year. Routine monitoring of rare plant populations aids resource managers in making recovery decisions. Management actions are often implemented or modified in response to trends revealed by monitoring results. Monitoring will continue to be an integral component of the Rare Plant Protection Program's recovery efforts.
DETERMINATION OF SOIL NUTRIENTS, MICROBIAL DIVERSITY, AND LEVELS OF HERBIVORY TO ASSESS THE IMPACT OF VINCA ON A GOLDENSEAL POPULATION. Amanda Simpson* and A. Darlene Panvini, Belmont University, Nashville, Tennessee. Exotic plants compete with native species, altering native communities. Vinca, an exotic vine, is found throughout the Warner Parks in Nashville, Tennessee, including areas where the native and threatened Hydrastis canadensis, goldenseal, occurs. The number, height, and width of goldenseal plants were compared with percent cover of Vinca. To determine if Vinca changes the ecosystem dynamics where goldenseal grows, leaf herbivory, light variation, soil nutrients, and soil functional microbial diversity were assessed. Goldenseal is more prevalent in areas with minimal Vinca, and shows significant levels of herbivory compared to Vinca. The amount of Fe in the soil is positively correlated to the percent cover of Vinca. The percent cover of Vinca was greatest in areas with reduced light levels. Understanding how Vinca changes the ecosystem and impacts goldenseal populations might help prevent the demise of goldenseal in Warner Parks and aid in the preservation of native ecosystems.
ECOLOGICAL IMPACT OF LONICERA MAACKII AS DETERMINED BY SOIL NUTRIENTS, FUNCTIONAL MICROBIAL DIVERSITY, LIGHT, AND HERBIVORY. Neeley Osteen* and A. Darlene Panvini, Belmont University, Nashville, Tennessee. While we know that invasive exotic plants alter native plant communities, less is known about the impact of exotics on ecosystems. Lonicera maackii, bush honeysuckle, can be found throughout the Warner Parks in Nashville, Tennessee. Thirty areas, representing high, medium, and low densities of honeysuckle, were assessed for soil functional microbial diversity, soil nutrients, and light levels. Levels of herbivory on honeysuckle leaves were compared to leaf herbivory on native species. Areas with fewer honeysuckles had greater levels of soil functional microbial diversity and less shade. Differences in Fe were noted in areas with high densities of honeysuckle compared to less dense areas. More herbivory was found on native leaves than on honeysuckle leaves. Our understanding of the impact of exotic species on native plant communities is enhanced when we know whether or not honeysuckle changes ecosystem dynamics.
CORRELATION OF LONICERA MAACKII DENSITY WITH SOIL NUTRIENTS, MICROBIAL DIVERSITY, LIGHT, HERBIVORY, AND POPULATION GROWTH. Rejana Wells* and A. Darlene Panvini, Belmont University, Nashville, Tennessee. Lonicera maackii, bush honeysuckle, is an invasive exotic plant found in the Warner Parks in Nashville, Tennessee, including a parcel referred to as the Northwest Reserve. This study examined the population growth of honeysuckle over a one year period in this reserve, as well as several factors to assess the ecological impact of honeysuckle on the ecosystem. The number of honeysuckle plants and dbh were determined in twelve 10 [m.sup.2] plots in 2005 and 2006. Herbivory, soil functional microbial diversity, soil nutrients, and shading were analyzed in 2006. The number of recruits increased significantly in the southern and western plots, which contained the greatest number of honeysuckle. The levels of Fe and Mn in the soil were correlated to the quantity of honeysuckle in each plot. Honeysuckle exhibited less leaf herbivory than native species. These data suggest the presence of exotic species like honeysuckle can change the ecology of ecosystems.
CAN FESCUE OR ZUCCHINI BE EMPLOYED EFFECTIVELY TO PHYTOREMEDIATE POLYCYCLIC AROMATIC HYDROCARBONS FROM THE FLOOD PLAINS OF THE CHATTANOOGA CREEK? Joseph Frellen Simpson*, Eric Matthew Cohen*, David S. Percy*, and Stephen Julius Halperin, University of Tennessee, Chattanooga, Chattanooga, Tennessee. Polycyclic aromatic hydrocarbons are a major toxicant in the floodplain of Chattanooga Creek, and there is great interest at the federal, state and local levels for clean up of this contaminated site. We are testing two possible candidates for phytoremediation: zucchini (Cucurbita pepo) and tall fescue (Festuca arundinacea). Plants of either species were grown in six window boxes; three window boxes contained pyrene-enriched soil and three contained untreated soil. Multiple soil samples were taken from each window box before the seeds were added and then two weeks after planting. Pyrene was extracted from the soil samples and analyzed via reverse-phase HPLC. Tall fescue caused a significant reduction in pyrene in the soil whereas zucchini did not. This suggests that tall fescue may be suitable for use in the phytoremediation of the floodplains of Chattanooga Creek.
GENETIC VARIABILITY OF THE RARE CEDAR GLADE ENDEMIC ASTRAGALUS BIBULLATUS: COMPARING ESTIMATES BASED ON AMPLIFIED FRAGMENT LENGTH POLYMORPHISM MARKERS AND ISOZYMES. Carol J. Baskauf and John M. Burke, Austin Peay State University, Clarksville, Tennessee and University of Georgia, Athens, Georgia. Amplified fragment length polymorphism (AFLP) markers were used to investigate the population genetics of the endangered plant Astragalus bibullatus (Fabaceae), endemic to limestone cedar glades in Tennessee. Estimates based on 143 AFLP markers indicate that populations of this species are genetically very similar, with genetic identity values between 0.971-0.990. The [F.sub.ST] estimate indicates that about 12% of the total genetic variability of the species is due to differences among the seven sites sampled. Averaging across populations, about 40% of the AFLP markers are polymorphic, and mean expected heterozygosity is estimated to be 0.125. These estimates based on AFLP markers are compared with an earlier study of this same species based on 15 isozyme loci in which populations were genetically similar to each other (genetic identities of 0.981 to 1.000, [F.sub.ST] of 0.089) but genetic variability estimates were lower (25.6% polymorphic loci, 0.063 for expected heterozygosity).
PHTOINHIBITION-INDUCED HETEROGENEITY OF QUINONE-B REDUCTION IN PHOTOSYSTEM II. Jefferson G. Lebkuecher and Brittany N. Hopkins*, Austin Peay State University, Clarksville, Tennessee. Reduced photosynthetic capacity following exposure to bright light results from damage to photosystem II and/or dissipation of excitation energy by photoprotective mechanisms. To determine the effects of short-term, full-sunlight exposure the green alga Chorella vulgaris commonly experiences due to sunflecks and/or changes of location in the water column, cells cultured at 200 [micro]mol photons x [m.sup.-2] x [s.sup.-1] were exposed to 30 min of 2000 [micro]mol photons x [m.sup.-2] x [s.sup.-1]. Electron-transport dynamics and photoprotective transduction of excitation energy to heat via the xanthophyll cycle of bright-light treated and control cells were investigated using chlorophyll fluorescence. The results demonstrate that exposure to 30 min of 2000 [micro]mol photons x [m.sup.-2] x [s.sup.-1] overwhelmed the xanthophyll photoprotective mechanism, inhibited electron transport from quinon[e.sub.A] to quinon[e.sub.B], and damaged the water-oxidation apparatus. Nonsignificant differences in the photochemical quenching coefficient indicates charge recombination between pigmen[t.sub.680.sup.+1] and pheophyti[n.sup.-1] in photoinhibited photosystem II allows for continuous quenching of excitation energy by repeated [P.sub.680] oxidation.
A PRELIMINARY FLORA OF THE NORTH CHICKAMAUGA CREEK GORGE STATE NATURAL AREA. Stacy Huskins and Joey Shaw, University of Tennessee, Chattanooga, Chattanooga, Tennessee. The North Chickamauga Creek Gorge State Natural Area (NCCG) consists of 4,864 acres and is located in Hamilton and Sequatchie counties in eastern Tennessee. The NCCG is on the eastern edge of the Cumberland Plateau and is bordered by the Ridge and Valley physiographic province. Broadly defined habitat types support a diverse assemblage of plants on the NCCG's upper plateau surface, gorge slopes, stream banks, and ruderal areas. Floras of nearby areas comprised of similar habitat types have reported over 1,000 species. Ten species with either a state or federal listing are known to occur in the NCCG: Scutellaria montana, Spiraea virginiana, Nestronia umbellula, Phemeranthus mengesii, Sabatia capitata, Diervilla sessilifolia var. rivularis, Lonicera dioica, Panax quinquefolius, Viola tripartita and Glyceria acutifolia. Nineteen collecting trips were made during the spring and early summer of 2006 and 180 species of vascular plants in 72 families were documented, including several populations of Scutellaria montana.
ASSESSING THE MIGRATORY VIGOR OF LOLIUM ARUNDINACEUM IN ASSOCIATION WITH A NOVEL ENDOPHYTIC SYMBIONT USING MICROSATELLITE MARKERS. Sheri M. Mersch*, Middle Tennessee State University, Murfreesboro, Tennessee. Tall fescue toxicity in livestock caused by the endophyte Neotyphodium coenophialum has been managed by the introduction of Lolium arundinaceum varieties with novel endophyte associations, such as MaxQ[R]). This research effort seeks to determine how steadfast this variety of fescue will be on a long-term basis in areas dominated by local endophyte infected L. arundinaceum by tracking the population with microsatellite molecular markers. Primers for PCR genotyping were obtained from published studies on similar species with the goal of finding a genetic polymorphism between local varieties (Ky-31) and MaxQ[R]. One such primer set has revealed a polymorphism that has allowed the MaxQ[R] endophyte to be distinguished from the local endophyte molecularly. Fescue samples collected from recently renovated MaxQ[R] paddocks at the Agribusiness/Agriscience Miller Center at Middle Tennessee State University are currently being genotyped with consistent results, making this methodology useful for better understanding the population dynamics of these fescue varieties.
CELL AND MOLECULAR BIOLOGY
D. GRANT WILLHITE, CHAIR
DEMONSTRATION OF CELL PROLIFERATION IN ESTROGEN RECEPTOR POSITIVE HUMAN BREAST CANCER CELL LINE T47D BY SYNTHETIC FOOD COLORANTS. Payel Datta* and Sarah Lundin-Schiller, Austin Peay State University, Clarksville, Tennessee. Breast cancer may be induced by exposure to estrogen and xenoestrogens. These compounds stimulate proliferation of estrogen responsive breast cancer through nuclear-hormone pathway. This study evaluated synthetic food colorants, Sudan 1 (Solvent Orange R) and Tartrazine (FD & C Yellow 5), as potential xenoestrogens. T47D cells,...
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