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Effect Of Nitrogen Fertilizer Rate And Harvest Season On Forage Yield, Quality, And Macronutrient Concentrations In Midland Bermuda Grass, Maru K. Kering, John A. Guretzky, Eddie Funderburg, Jagadeesh Mosali Jan 2011

Effect Of Nitrogen Fertilizer Rate And Harvest Season On Forage Yield, Quality, And Macronutrient Concentrations In Midland Bermuda Grass, Maru K. Kering, John A. Guretzky, Eddie Funderburg, Jagadeesh Mosali

Department of Agronomy and Horticulture: Faculty Publications

Bermuda grass [Cynodon dactylon (L.) Pers.] is a major forage for grazing and hay production in the southern United States. The objectives of this study were to determine effects of nitrogen (N) fertilization rate (0, 112, 224, 336, and 448 kg ha−1), split spring and summer applications of N at the 224 and 448 kg ha−1 rates, and harvest periods (spring and summer) on forage yield, crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrients (TDN), and concentrations of phosphorus (P), potassium (K), magnesium (Mg), and calcium (Ca) in Midland Bermuda …


Conceptualizing And Improving Red Wine Grape Cultivars Grown In Kentucky, Matthew Simson Jan 2011

Conceptualizing And Improving Red Wine Grape Cultivars Grown In Kentucky, Matthew Simson

University of Kentucky Master's Theses

Wine sensory attributes are associated with quality of wines. Cabernet Franc did not possess good coloration of its wine. Therefore, in the 2009 and 2010 growing seasons, studies including the sampling of four red wine grape cultivars from the end of flowering throughout the rest of the season and applying treatments to Cabernet Franc grapevines at veraison were commenced to address suitability and color enhancement, respectively. The study examining Cabernet Franc, Cabernet Sauvignon, Chambourcin, and Norton looked at sampling their grapes at two-week intervals from times post-flowering to understand the demands of each cultivar during key stages of berry development, …


Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis: Final Report, Scott R. Abella Dec 2010

Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis: Final Report, Scott R. Abella

Fire Science

Species selection can make the difference between successful revegetation projects and costly failures. Candidate native species for revegetating burned arid lands in the southwestern United States must meet at least two criteria. These species must: (1) be competitive in postfire environments typically dominated by exotic grasses, and (2) be able to become established reliably by seeding or planting. In response to Manager’s Request Task 3 (reestablishment of native vegetation after fires on arid lands) in the 2006 JFS announcement for proposals, this research tackled the problem of selecting native species with the greatest chance of revegetation success by conducting synergistic …


Invasive Species And Climate Change, Invasive Species Advisory Committee Dec 2010

Invasive Species And Climate Change, Invasive Species Advisory Committee

National Invasive Species Council

ISSUE

Climate change interacts with and can often amplify the negative impacts of invasive species. These interactions are not fully appreciated or understood. They can result in threats to critical ecosystem functions on which our food system and other essential provisions and services depend as well as increase threats to human health. The Invasive Species Advisory Committee to the National Invasive Species Council recognizes the Administration’s commitment to dealing proactively with global climate change. However, unless we recognize and act on the impact of climate change and its interaction with ecosystems and invasive species, we will fall further behind in …


Farmers' Markets In Kentucky: A Geospatial, Statistical, And Cultural Analysis, Elizabeth Ann Schmitz Dec 2010

Farmers' Markets In Kentucky: A Geospatial, Statistical, And Cultural Analysis, Elizabeth Ann Schmitz

Masters Theses & Specialist Projects

To assess what factors are driving the exponential growth of farmers’ markets in Kentucky, geospatial and statistical analysis of a database of 121 farmers’ markets was conducted. A statewide survey of market leaders and a case study of a single farmers’ market both identified reasons for growing support of farmers’ markets in Kentucky.

Market distribution, vendor levels, and gross sales were mapped against a backdrop of county urban classification, median household income, and education levels. Kruskal-Wallace analysis was used to identify if Kentucky’s rural, micropolitan, and metropolitan markets differ significantly in terms of their age, number of vendors, and market …


Interclonal Variation Of Primary And Secondary Chemistry In Western Quaking Aspen And Its Influence On Ungulate Selection, Damon A. Winter Dec 2010

Interclonal Variation Of Primary And Secondary Chemistry In Western Quaking Aspen And Its Influence On Ungulate Selection, Damon A. Winter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Quaking aspen (Populus tremuloides) clones within close proximity to one another can exhibit drastically different levels of browsing by ungulates. The objectives of this study were to (1) determine interclonal differences in plant chemistry between adjacent clones exhibiting different degrees of herbivory which may influence the browsing behavior and patterns of ungulates, and (2) determine if correlation exists in the levels of salicortin and tremulacin between current year's suckers and current year's growth on older trees. This second objective was meant to indicate a protocol for land managers for identifying clones meriting increased protection from herbivory after treatment …


Reporting Results Of Data Analysis, Preparing Scientific Manuscripts, And Website Development Efforts, Christopher N. Jacques Dec 2010

Reporting Results Of Data Analysis, Preparing Scientific Manuscripts, And Website Development Efforts, Christopher N. Jacques

The Prairie Naturalist

Preparation of scientific manuscripts and use and presentation of statistics have been topics of several commentaries from previous journal Editors-in-Chief, and have been submitted as invited papers, so I would like to share my perspective as the current Editor-in-Chief (Editor) of The Prairie Naturalist (Journal). Because there is not complete consensus among the experts about when hypothesis testing versus information theoretic methods, or Bayesian versus frequentist methods are suitable, previous Editors have avoided presenting their perspectives (Thompson 2010). I also will avoid presenting my perspective as Editor. I will, however, present my perspective on several of these approaches and then …


Cropland Nesting By Long-Billed Curlews In Southern Alberta, James H. Devries, Steven O. Rimer, Elizabeth M. Walsh Dec 2010

Cropland Nesting By Long-Billed Curlews In Southern Alberta, James H. Devries, Steven O. Rimer, Elizabeth M. Walsh

The Prairie Naturalist

Long-billed curlews (Numenius americanus) are described primarily as a grassland nesting species. However, no studies to date have quantified nest habitat selection among available habitats. During a study of waterfowl nest habitat selection and success in landscapes ranging from cropland to grassland-dominated, we found 9 curlew nests of which 8 were located in active cropland within cropland-dominated landscapes. Cropland nests occurred in fall-seeded winter wheat and spring-seeded barley and nests were clumped in distribution. Four cropland nests and 1 nest in native grass pasture hatched young. Further research is needed to characterize nesting habitat selection and reproductive success …


Review Of Weeds Of The Midwestern United States & Central Canada, Edited By Charles T. Bryson And Michael S. Defelice, James Stubbendieck Dec 2010

Review Of Weeds Of The Midwestern United States & Central Canada, Edited By Charles T. Bryson And Michael S. Defelice, James Stubbendieck

The Prairie Naturalist

This volume is the culmination of work by more than 40 weed scientists and botanists. Its stated purpose is to help identifY the great diversity of weedy and invasive plants that interface with agriculture, industry, and natural ecosystems in central North America. The geographic range covered by this book extends from southeastern Saskatchewan to eastern Kansas, northern Kentucky, northwestern Pennsylvania, and southwestern Quebec. This is a welcome edition because a current book on unwanted plants has not been available for the eastern two-thirds of this region. The book is arranged taxonomically by family and alphabetically by species within each family. …


Summer Activity Pattern And Home Range Of Northern Pocket Gophers In An Alfalfa Field, Jon C. Pigage, Helen K. Pigage Dec 2010

Summer Activity Pattern And Home Range Of Northern Pocket Gophers In An Alfalfa Field, Jon C. Pigage, Helen K. Pigage

The Prairie Naturalist

AIlocation of time for feeding, resting and reproduction in subterranean animals is difficult to determine. Although pocket gophers (Thomomys spp.) are among the most widely studied subterranean rodents, there are conflicting reports on activity measurement in these animals. Activity studies have included opening gopher burrows (Tryon 1947), laboratory studies of activity (Vaughan and Hansen 1961), telemetry studies (Anderson and McMahon 1981, Bandoli 1987, and Cameron et al. 1988), and subcutaneously implanted radioactive gold wires (Gettinger 1984). The diversity of techniques reflects the difficulty of generalizing results from different species of pocket gophers in natural and artificial environments. Patton and …


Review Of Grouse Of The Plains And Mountains - The South Dakota Story, By Lester D. Flake, John W. Connelly, Thomas R. Kirschenmann, And Andrew J. Lindbloom., Brent E. Jamison Dec 2010

Review Of Grouse Of The Plains And Mountains - The South Dakota Story, By Lester D. Flake, John W. Connelly, Thomas R. Kirschenmann, And Andrew J. Lindbloom., Brent E. Jamison

The Prairie Naturalist

Grouse are a fascinating group of birds that offer elaborate breeding displays for birders in the spring, provide sporting opportunities for hunters in the fall, and serve as indicators of grassland health. Though the authors claim that the book targets those who enjoy the outdoors, bird watching, and upland game bird hunting, there is ample reason for ecologists, ornithologists, and grouse researchers to reference this book as well. The book contains general information of interest to a broad audience, but often moves beyond the introductory information to greater detail. Many details are supported by peer-reviewed literature. This book strikes a …


Is Orthoptera Abundance And Distribution Across A Small Grassland Area Affected By Plant Biomass, Plant Species Richness, And Plant Quality?, Caitlin Falcone Dec 2010

Is Orthoptera Abundance And Distribution Across A Small Grassland Area Affected By Plant Biomass, Plant Species Richness, And Plant Quality?, Caitlin Falcone

Department of Environmental Studies: Undergraduate Student Theses

The choice of a specific microhabitat represents a compromise among a number of different factors organisms use to monitor habitat suitability. Grassland vegetation structure can vary widely along environmental gradients over a relatively small area. This vegetation structure can have a large influence on habitat selection by grasshoppers (Orthoptera). However, it is not clear which vegetation characteristics are most important in determining grasshopper abundance. We found that plant biomass, plant species richness, and plant quality all have an effect on grasshopper abundance and distribution. We observe that these affects vary both within and among the two years of data collection. …


Current Distribution Of Rare Fishes In Eastern Wyoming Prairie Streams, Christina E. Barrineau, Elizabeth A. Bear, Anna C. Senecal Dec 2010

Current Distribution Of Rare Fishes In Eastern Wyoming Prairie Streams, Christina E. Barrineau, Elizabeth A. Bear, Anna C. Senecal

The Prairie Naturalist

Distributions of native fishes have declined throughout the Great Plains region. Over 50% of native fishes within the Missouri River drainage in Wyoming have experienced declines in distributions. Thus, the primary goal of our study was to assess current distribution of rare native fishes in eastern Wyoming prairie streams. Of the 10 rare fishes sampled, goldeye (Hiodon alosoides), western silvery minnow (Hybognathus argyritis), plains minnow (H. hankinsoni), and Iowa darter (Etheostoma exile) have experienced declines in distribution over the last decade. Plains topminnow (Fundulus sciadicus) appears to be expanding to areas outside …


Examination Of Owl Pellets For Northern Pocket Gophers At Crescent Lake National Wildlife Refuge, Nebraska, Stacey L. Bonner, Keith Geluso Dec 2010

Examination Of Owl Pellets For Northern Pocket Gophers At Crescent Lake National Wildlife Refuge, Nebraska, Stacey L. Bonner, Keith Geluso

The Prairie Naturalist

Analysis of regurgitated pellets from owls is a well-known and nondestructive method that provides useful information regarding diet (Errington 1930). This technique also is used to examine composition of small mammal communities and distribution of prey species (e.g. Kamler et al. 2003, Torre et al. 2004, Poole and Matlack 2007). In western Nebraska, two species of owls that regularly breed in the region are the common barn owl (Tyto alba) and great horned owl (Bubo virginianus). In the early 1970s, Rickart (1972) studied the diet of both species at Crescent Lake National Wildlife Refuge (CLNWR), Garden …


Seasonal Yellow Perch Harvest In Two Dissimilar South Dakota Fisheries, Casey W. Schoenebeck, Michael L. Brown, David O. Lucchesi Dec 2010

Seasonal Yellow Perch Harvest In Two Dissimilar South Dakota Fisheries, Casey W. Schoenebeck, Michael L. Brown, David O. Lucchesi

The Prairie Naturalist

Angler effort and fish harvest in South Dakota have historically been quantified through summer and winter creel surveys. However, the late-summer, pulsed recruitment of yellow perch (Perea flavescens) into a fishery combined with an increase in fall movement and feeding activity suggested September and October could be significant periods of perch harvest in South Dakota lakes. Seasonal trends in angler effort and yellow perch harvest during 2005-2007 were compared for high- and low-quality yellow perch fishery types commonly found in eastern South Dakota glacial lakes. High-quality yellow perch fisheries are characterized by fast growth (mean total length at age-3 greater …


Resource Selection Of Greater Prairie-Chicken And Sharp-Tailed Grouse Broods In Central South Dakota, Mark A. Norton, Kent C. Jensen, Anthony P. Leif, Thomas R. Kirschenmann, Gregaory A. Wolbrink Dec 2010

Resource Selection Of Greater Prairie-Chicken And Sharp-Tailed Grouse Broods In Central South Dakota, Mark A. Norton, Kent C. Jensen, Anthony P. Leif, Thomas R. Kirschenmann, Gregaory A. Wolbrink

The Prairie Naturalist

Habitat use of sympatric greater prairie-chicken (Tympanuchus cupido) and sharp-tailed grouse (T. phasianellus) broods during the brood-rearing season has not been quantified for stable prairie grouse populations in large contiguous grassland landscapes in the Northern Great Plains. Characteristics of habitats used by prairie grouse broods were described based on data collected from 35 broods (18 greater prairie-chicken and 17 sharp-tailed grottse) during the breeding seasons of 2004 and 2005. Greater prairie-chicken and sharp-tailed grouse broods used vegetation with visual obstruction heights 2:26 cm and 37 cm, respectively. Greater prairie-chicken broods selected western wheatgrass (Pascopyrum smithii …


Diets Of Nesting Swainson's Hawks In Relation To Land Cover In Northwestern North Dakota, Robert K. Murphy Dec 2010

Diets Of Nesting Swainson's Hawks In Relation To Land Cover In Northwestern North Dakota, Robert K. Murphy

The Prairie Naturalist

Relationships between land use practices and types of prey used by Swainson's hawks (Buteo swainsoni) in the Northern Great Plains is of increasing interest as the quantity and quality of habitat in the region declines. I recorded 1,284 prey items at 18 Swainson' s hawk nesting areas throughout northwestern North Dakota during summer 1986-1987. After correcting for detectability biases and food needs of adults, I estimated (90% CI) 2,087-2,859 total prey individuals and 138.3-206.7 kg of prey biomass (x = 69.8 g/item) were consumed by adult and nestling Swainson's hawks during my study. Major prey (>10% overall …


Effect Of Mica Content On Surface Infiltration Of Soils In Northwestern Kern County, California, Steven Keyes Stakland Dec 2010

Effect Of Mica Content On Surface Infiltration Of Soils In Northwestern Kern County, California, Steven Keyes Stakland

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A soils infiltration rate (IR) is the measured rate that soil is able to absorb water, either from precipitation or irrigation. A low IR can cause damage to crops if the necessary amount of water cannot penetrate to the plant roots in the time needed. The damage can be common in permanent plantings such as almond and pistachio orchards where regular tillage is avoided. This indicates a physical aspect to the problem because tillage increases IR. However, there is also an electrochemical side to infiltration problems because certain calcium surfactant treatments can increase IR. Various other methods have been used …


Population And Diet Assessment Of White Bass In Lake Sharpe, South Dakota, Andrew E. Ahrens, Travis W. Schaeffer, Melissa R. Wuellner, David W. Willis Dec 2010

Population And Diet Assessment Of White Bass In Lake Sharpe, South Dakota, Andrew E. Ahrens, Travis W. Schaeffer, Melissa R. Wuellner, David W. Willis

The Prairie Naturalist

White bass (Morone chrysops) have been introduced into all 4 South Dakota Missouri River reservoirs and compose a substantial proportion of the annual recreational harvest. To date, limited studies have examined white bass population dynamics and food habits in South Dakota Missouri River reservoirs. Our objective was to examine population dynamics and food habits of white bass in Lake Sharpe, a South Dakota mainstem Missouri River reservoir. White bass consistently consumed invertebrates during May but switched to a more piscivorous diet later in the growing season; most of the fish consumed were gizzard shad (Dorosoma cepedianum). …


Correlation Of Mature Walleye Relative Abundance To Egg Density, Jordan D. Katt, Casey W. Schoenebeck, Keith D. Koupal, Brian C. Peterson, W. Wyatt Hoback Dec 2010

Correlation Of Mature Walleye Relative Abundance To Egg Density, Jordan D. Katt, Casey W. Schoenebeck, Keith D. Koupal, Brian C. Peterson, W. Wyatt Hoback

The Prairie Naturalist

Knowledge of spawning areas can benefit fisheries management (Marsden et al. 1991). Identification of spawning areas allows managers to protect, enhance, and/or restore critical habitat (Gunn et al. 1996, Thompson 2009), examine important biotic and abiotic conditions necessary for reproduction (Quist et al. 2003), and to efficiently collect broodstock for production (Satterfield and Flickinger 1996). The most effective method to directly identify spawning areas of fish with demersal eggs is to sample the substrate for eggs (Marsden et al. 1991). This method has been used to locate spawning areas of several species (Michaletz 1984, Zorn et al. 1998, Martin 2008). …


The Prairie Naturalist, Vol. 42, Issue 3/4, December 2010, The Great Plains Natural Science Society Dec 2010

The Prairie Naturalist, Vol. 42, Issue 3/4, December 2010, The Great Plains Natural Science Society

The Prairie Naturalist

EDITOR'S NOTE: REPORTING RESULTS OF DATA ANALYSIS, PREPARING SCIENTIFIC MANUSCRIPTS, AND WEBSITE DEVELOPMENT EFFORTS • Christopher N. Jacques

Current Distribution of Rare Fishes in Eastern Wyoming Prairie Streams • Christina E. Barrineau, Elizabeth A. Bear, and Anna C. Senecal

Diets of Nesting Swainson's Hawks in Relation to Land Cover in Northwestern North Dakota • Robert K. Murphy

Resource Selection of Greater Prairie-Chicken and and Sharp-Tailed Grouse Broods in Central South Dakota • Mark A. Norton, Kent C. Jensen, Anthony P. Leif, Thomas R. Kirschenmann, and Gregory A. Wolbrink

Population Characteristics of Central Stonerollers in Iowa Streams • Scott M Bisping, …


Population Characteristics Of Central Stonerollers In Iowa Streams, Scott M. Bisping, Jesse R. Fischer, Michael C. Quist, Andrew J. Schaefer Dec 2010

Population Characteristics Of Central Stonerollers In Iowa Streams, Scott M. Bisping, Jesse R. Fischer, Michael C. Quist, Andrew J. Schaefer

The Prairie Naturalist

The central stoneroller (Campostoma anomalum) is a herbivore that can have substantial effects on algal communities, nutrient dynamics, and energy flow in streams. Despite its importance in lotic ecosystems, little is known about its population dynamics in streams of the Great Plains. Our objective was to describe age structure, age-specific mortality, and growth rates of central stonerollers in three Iowa streams. We sampled fish from 41 reaches during June-August 2007. We sampled 466 central stonerollers, of which we aged 192. Fish varied in length from 32 to 130 mm and in age from age 0 to 4 years. …


Global Protein Interactome Exploration Through Mining Genome-Scale Data In Arabidopsis Thaliana, Feng Xu, Guang Li, Chen Zhao, Yuhua Li, Peng Li, Jian Cui, Youping Deng, Tieliu Shi Nov 2010

Global Protein Interactome Exploration Through Mining Genome-Scale Data In Arabidopsis Thaliana, Feng Xu, Guang Li, Chen Zhao, Yuhua Li, Peng Li, Jian Cui, Youping Deng, Tieliu Shi

Faculty Publications

Background

Many essential cellular processes, such as cellular metabolism, transport, cellular metabolism and most regulatory mechanisms, rely on physical interactions between proteins. Genome-wide protein interactome networks of yeast, human and several other animal organisms have already been established, but this kind of network reminds to be established in the field of plant.

Results

We first predicted the protein protein interaction in Arabidopsis thaliana with methods, including ortholog, SSBP, gene fusion, gene neighbor, phylogenetic profile, coexpression, protein domain, and used Naïve Bayesian approach next to integrate the results of these methods and text mining data to build a genome-wide protein interactome …


2010 Warbonnet Ranch Botanical Survey, Robert F. Steinauer Oct 2010

2010 Warbonnet Ranch Botanical Survey, Robert F. Steinauer

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

The Nebraska Natural Legacy Project (Schneider et al, 2005), a statewide comprehensive wildlife conservation strategy developed by the Nebraska Game and Parks Commission (NGPC), identified the Pine Ridge and Oglala Grasslands of northwestern Nebraska as “Biologically Unique Landscapes” (BULs). Native plant community and rare plant surveys were conducted on the approximately 8,000-acre privately-owned Warbonnet Ranch. The Ranch occurs within both of the above mentioned BULs and is topographically and geologically diverse. The primary goal of this survey was to document the botanical resources of a well-managed, privately-owned, western Nebraska range and determine its potential for conservation of Nebraska’s biological diversity. …


Mojave Applied Ecology Notes Fall 2010, Adria Decorte, Sharon Altman, Alex Suazo Oct 2010

Mojave Applied Ecology Notes Fall 2010, Adria Decorte, Sharon Altman, Alex Suazo

Mojave Applied Ecology Notes

Adria DeCorte defense, Mojave desert inventory and monitoring mapping project, effect of burial depth on Brassica tournefortii seeds


Traditional Plant Use Of The Raglay In Cãu Gãy Village, Núi Chúa National Park, Alex Greene Oct 2010

Traditional Plant Use Of The Raglay In Cãu Gãy Village, Núi Chúa National Park, Alex Greene

Independent Study Project (ISP) Collection

Members of the Raglay community of Cãu Gãy Village were interviewed to determine the extent and nature of their traditional reliance on plants. This community, located in the buffer zone of Núi Chúa National Park, was found to utilize 64 plant species for a wide variety of uses. Botanical specimens and photographs were used to identify 42 plants to species level, 13 to genus level, and 6 to family level, while 3 remained unidentified. For each plant, the Raglay name, local Vietnamese name, use, specific application, and preparation were documented, as well as any details of ritual or commercial significance. …


Guano Exploitation In Madagascar, Christina Buliga Oct 2010

Guano Exploitation In Madagascar, Christina Buliga

Independent Study Project (ISP) Collection

Agriculture in Madagascar continues to remain largely undeveloped. Out of the eighty percent of Malagasy individuals that live in rural areas an overwhelming sixty five percent practice subsistence agriculture. With respect to the country as a whole this means that out of Madagascar's 58.2 million hectares of available land only 5.2 percent (3 million hectares) are farmed. And out of these 3 million hectares only 67% are cultivated permanently and only 11% are fertilized.

While there are several reasons for why Madagascar’s agriculture has remained largely undeveloped and for why Madagascar continues to rely on imported crops to meet its …


Empirical Geographic Modeling Of Switchgrass Yields In The United States, Henriette I. Jager, Latha M. Baskaran, Craig C. Brandt, Ethan B. Davis Sep 2010

Empirical Geographic Modeling Of Switchgrass Yields In The United States, Henriette I. Jager, Latha M. Baskaran, Craig C. Brandt, Ethan B. Davis

Dartmouth Scholarship

Switchgrass (Panicum virgatum L.) is a perennial grass native to the United States that has been studied as a sustainable source of biomass fuel. Although many field‐scale studies have examined the potential of this grass as a bioenergy crop, these studies have not been integrated. In this study, we present an empirical model for switchgrass yield and use this model to predict yield for the conterminous United States. We added environmental covariates to assembled yield data from field trials based on geographic location. We developed empirical models based on these data. The resulting empirical models, which account for spatial …


Temporal And Spatial Assessment Of Evaporation, Transpiration, And Soil Moisture Redistribution, Brian M. Bird Aug 2010

Temporal And Spatial Assessment Of Evaporation, Transpiration, And Soil Moisture Redistribution, Brian M. Bird

UNLV Theses, Dissertations, Professional Papers, and Capstones

At a native stand of creosote bush (Larrea tridentata) in North Las Vegas, a rainfall simulation study was conducted over a 12 month period from October 2005 to October 2006. Simulated rainfall occurred during the winter, spring, summer, and fall periods. Rainfall simulation systems were positioned on each of 12 plots, each containing a single creosote bush. Simulated rainfall events occurred at night with multiple short pulses designed to maximize infiltration while minimizing ponding. Yearly simulated rainfall amounts were set at 0, 15, 30 and 60 cm (replicated three times) and were approximately 0, 1.5, 3.0 and 6.0 times the …


Genetic Mapping Of Quantitative Trait Loci Associated With Bioenergy Traits, And The Assessment Of Genetic Variability In Sweet Sorghum (Sorghum Bicolor (L.). Moench), Aatshwaelwe Lekgari Lekgari Aug 2010

Genetic Mapping Of Quantitative Trait Loci Associated With Bioenergy Traits, And The Assessment Of Genetic Variability In Sweet Sorghum (Sorghum Bicolor (L.). Moench), Aatshwaelwe Lekgari Lekgari

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Sweet sorghum, a botanical variety of sorghum is a potential source of bioenergy because high sugar levels accumulate in its stalks. The objectives of this study were to explore the global diversity of sweet sorghum germplasm, and map the genomic regions that are associated with bioenergy traits. In assessing diversity, 142 sweet sorghum accessions were evaluated with three marker types (SSR, SRAP, and morphological markers) to determine the degree of relatedness among the accessions. The traits measured (anthesis date [AD], plant height [PH], biomass yield [BY], and moisture content [MC]) were all significantly different (P< 0.05) among accessions. Morphological marker clustered the accessions into five groups based on PH, MC and AD. The three traits accounted for 92.5% of the variation. There were four and five groups based on SRAP and SSR data respectively classifying accessions mainly on their origin or breeding history. The observed difference between SSR and SRAP based clusters could be attributed to the difference in marker type. SSRs amplify any region of the genome whereas SRAP amplify the open reading frames and promoter regions. Comparing the three marker-type clusters, the markers complimented each other in grouping accessions and would be valuable in assisting breeders to select appropriate lines for crossing. In evaluating QTLs that are associated with bioenergy traits, 165 recombinant inbred lines (RILs) were planted at four environments in Nebraska. A genetic linkage map constructed spanned a length of 1541.3 cM, and generated 18 linkage groups that aligned to the 10 sorghum chromosomes. Fourteen QTLs (6 for brix, 3 for BY, 2 each for AD and MC, and 1 for PH) were mapped. QTLs for the traits that were significantly correlated, colocalized in two clusters on linkage group Sbi01b. Both parents contributed beneficial alleles for most of traits measured, supporting the transgressive segregation in this population. Additional work is needed on exploiting the usefulness of chromosome 1 in breeding sorghum for bioenergy.