Digital Commons Network^™

Dollar Spot Fungus Sclerotinla Homoeocarpa Produces Oxalic Acid, R. C. Venu, Robert A. Beaulieu, Terrance L. Graham, Ainhoa Martinez Medina, Michael J. Boehm

Department of Plant Pathology: Faculty Publications

Dollar spot, caused by Sclerotinia homoeocarpa,. is one of the most devastating diseases of turfgrass worldwide. Many fungi belonging to the genus Sclerotinia produce oxalic acid along with pectolytic cell wall-degrading enzymes. A series of in vitro experiments showed the relationships among temperature, pH, mycelial growth and acid production. Mycelial growth and acid production were most abundant when S. homoeocarpa was grown between 20 and 30°C. Acid production by S. homoeocarpa appeared to be dependent upon the pH of the environment in which it was grown. High performance liquid chromatography analysis of spent broth revealed the presence of oxalic acid. …

Molecular Characterization Of Citrus Tatter Leaf Virus Historically Associated With Meyer Lemon Trees: Complete Genome Sequence And Development Of Biologically Active In Vitro Transcripts, Satyanarayana Tatineni, Mohammad R. Afunian, Mark E. Hilf, Siddarame Gowda, William O. Dawson, Stephen M. Garnsey

Department of Plant Pathology: Faculty Publications

Citrus tatter leaf virus isolated from Meyer lemon trees (CTLV-ML) from California and Florida induces bud union incompatibility of citrus trees grafted on the widely used trifoliate and trifoliate hybrid rootstocks. The complete genome sequence of CTLV-ML was determined to be 6,495 nucleotides (nts), with two overlapping open reading frames (ORFs) and a poly (A) tail at the 3′ end. The genome organization is similar to other capilloviruses, with ORF1 (nts 37 to 6,354) encoding a putative 242-kDa polyprotein which contains replication-associated domains plus a coat protein (CP), and ORF2 (nts 4,788 to 5,750), which is located within ORF1 in …

Plant-Microbes Interactions In Enhanced Fertilizer-Use Efficiency, Anthony O. Adesemoye, Joseph W. Kloepper

Department of Plant Pathology: Faculty Publications

The continued use of chemical fertilizers and manures for enhanced soil fertility and crop productivity often results in unexpected harmful environmental effects, including leaching of nitrate into groundwater, surface runoff of phosphorus and nitrogen runoff, and eutrophication of aquatic ecosystems. Integrated nutrient management systems are needed to maintain agricultural productivity and protect the environment. Microbial inoculants are promising components of such management systems. This review is a critical summary of the efforts in using microbial inoculants, including plant growth-promoting rhizobacteria and arbuscular mycorrhizal fungi for increasing the use efficiency of fertilizers. Studies with microbial inoculants and nutrients have demonstrated that …

Bulked Segregant Analysis Using The Goldengate Assay To Locate The Rpp3 Locus That Confers Resistance To Soybean Rust In Soybean, D. L. Hyten, James R. Smith, Reid D. Frederick, Mark L. Tucker, Qijian Song, P. B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Few resistance loci to soybean rust (SBR), caused by Phakopsora pachyrhizi Syd., have been genetically mapped and linked to molecular markers that can be used for marker assisted selection. New technologies are available for single nucleotide polymorphism (SNP) genotyping that can be used to rapidly map traits controlled by single loci such as resistance to SBR. Our objective was to demonstrate that the highthroughput SNP genotyping method known as the GoldenGate assay can be used to perform bulked segregant analysis (BSA) to fi nd candidate regions to facilitate effi cient mapping of a dominant resistant locus to SBR designated Rpp3 …

Mapping And Confirmation Of A New Allele At Rpp1 From Soybean Pi 594538a Conferring Rb Lesion–Type Resistance To Soybean Rust, Nanda Chakraborty, Joe Curley, Reid D. Frederick, D. L. Hyten, Randall L. Nelson, Glen L. Hartman, Brian W. Diers

Department of Agronomy and Horticulture: Faculty Publications

Soybean rust, caused by Phakopsora pachyrhizi (H. Sydow & Sydow), is a destructive soybean [Glycine max (L.) Merr.] disease and identification of new resistance genes is essential for effective rust management. Our research objectives were to map and confirm the location of resistance gene(s) in PI 594538A using a population of 98 F_3:4 lines from across between PI 594538A (reddish-brown [RB] lesions) and the susceptible cultivar Loda (tan [TAN] lesions). The lines were inoculated with the P. pachyrhizi isolate ZM01-1 from Zimbabwe. The RB resistance in PI 594538A mapped on linkage group G as a single dominant gene. …

Agroecology As A Science, A Movement And A Practice: A Review, A. Wezel, S. Bellon, T. Doré, Charles A. Francis, D. Vallod, C. David

Department of Agronomy and Horticulture: Faculty Publications

Agroecology involves various approaches to solve actual challenges of agricultural production. Though agroecology initially dealt primarily with crop production and protection aspects, in recent decades new dimensions such as environmental, social, economic, ethical and development issues are becoming relevant. Today, the term ‘agroecology’ means either a scientific discipline, agricultural practice, or political or social movement. Here we study the different meanings of agroecology. For that we analyse the historical development of agroecology. We present examples from USA, Brazil, Germany, and France. We study and discuss the evolution of different meanings agroecology. The use of the term agroecology can be traced …

Detection And Validation Of Single Feature Polymorphisms Using Rna Expression Data From A Rice Genome Array, Sung-Hyun Kim, Prasanna R. Bhat, Xinping Cui, Harkamal Walia, Jin Xu, Steve Wanamaker, Abdelbagi M. Ismail, Clyde Wilson, Timothy J. Close

Department of Agronomy and Horticulture: Faculty Publications

Background: A large number of genetic variations have been identified in rice. Such variations must in many cases control phenotypic differences in abiotic stress tolerance and other traits. A single feature polymorphism (SFP) is an oligonucleotide array-based polymorphism which can be used for identification of SNPs or insertion/deletions (INDELs) for high throughput genotyping and high density mapping. Here we applied SFP markers to a lingering question about the source of salt tolerance in a particular rice recombinant inbred line (RIL) derived from a salt tolerant and salt sensitive parent. Results: Expression data obtained by hybridizing RNA to an oligonucleotide array …

Antibiotic Use In Animal Production: Environmental Concerns, Teshome H. Regassa, Richard K. Koelsch, Charles S. Wortmann, Richard F. Randle, Akwasi A. Abunyewa

Department of Agronomy and Horticulture: Faculty Publications

Introduction

Antibiotic1 use in animal production has led to improved feed use efficiency and increased growth rates. In turn, these resulted in reduced food production costs and reduced excrement of manure nutrients which may cause pollution problems.

On the other hand, antibiotic use leads to antibiotic resistance and a possible reduction in effectiveness of treatment options for both animals and humans. This publication addresses these issues.

Disease-causing microorganisms2, including bacteria,are the most diverse and numerous organisms on earth. Diverse in their habitat, environmental adaptation, and mechanisms of reproduction, they have short generations with high multiplication rates. Such characteristics help develop …

Plan To Support Grains Industry Development 2009-2012, Department Of Agriculture And Food, Western Australia

Grain and other field crops published reports

The Plan to Support Grains Industry Development (‘the Plan’) recognises that Western Australian agricultural industries are integral to the economic wellbeing of regional and rural communities. The Plan promotes a progressive and profitable grains industry through modern best practice services and research to enhance continuous improvement in farming and supply chain practices.

The Plan has been developed to align with the Government of Western Australia’s initiatives, strategies and tactics for ‘making every hectare count’ (see Appendix 1) and with grains industry needs as identified by industry stakeholders during a series of consultation forums. These industry needs will be addressed in …

American Chestnut Oral History Project Presentation And Interview Clips, Bethany N. Baxter

American Chestnut Oral History Project

An interview recorded as part of the original research for the thesis entitled, An oral history of the American chestnut in Southern Appalachia, submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Master of Science.

Biology Of Ultramafic Rocks And Soils: Research Goals For The Future, R S. Boyd, A R. Kruckeberg, N Rajakaruna

Faculty Publications, Biological Sciences

At this, the 6th International Conference on Serpentine Ecology, it seems timely to review briefly the present status of the field and to project the needs for future research. Although a great deal of serpentine research was done prior to 1960, as summarized by Krause (1958) and discussed briefly by Brooks (1987), much of our progress in learning how serpentine geology affects plant and animal life occurred in the mid- to late 20th century. In that era, it was the landmark studies of several scientists worldwide that initiated a meteoric increase in published serpentine research. Key players in setting the …

Adiantum Viridimontanum, Aspidotis Densa, Minuartia Marcescens, And Symphyotrichum Rhiannon: Additional Serpentine Endemics From Eastern North America, T B. Harris, N Rajakaruna

Faculty Publications, Biological Sciences

Serpentine outcrops around the world are known to harbor disproportionately high rates of plant endemism. Remarkable cases of serpentine endemism occur in New Caledonia and Cuba, with 3178 and 920 endemic taxa, respectively, found solely on serpentine. Despite the patchy occurrence of serpentine in eastern North America from Québec and Newfoundland south to Alabama, only one taxon, Cerastium velutinum var. villosissimum, has been broadly recognized as a serpentine endemic for the region. Based on reports in the literature, we suggest that Adiantum viridimontanum, Minuartia marcescens, and Symphyotrichum rhiannon be considered endemic to serpentine soils from the east coast of North …

Ecology And Molecular Phylogenetics Of Hydnora (Hydnoraceae) In Southern Africa, Jay Francis Bolin

Biological Sciences Theses & Dissertations

The Hydnoraceae are a clade of root holoparasitic angiosperms that contain two small genera, Hydnora and Prosopanche. This study, focused on Hydnora, presents novel data regarding the pollination biology, germination ecology, parasite-host nutritional relationships, and the molecular systematics of this group. Experimental addition of the primary pollinator, Dermestes maculatus to Hydnora africana chamber flowers demonstrated beetle imprisonment during the carpellate stage. Changes in the inner surfaces of the androecial chamber allowed beetle escape after pollen release. Most beetles escaped, dusted with viable pollen, three days after pollen release. To investigate germination ecology, aqueous root extracts of host and …

Evolution And Systematic Significance Of Reproductive Structures In The Genus Cuscuta (Dodders, Convolvulaceae): Pollen And Gynoecium, Mark Welsh

Theses and Dissertations (Comprehensive)

The genus Cuscuta (dodders, Convolvulaceae) is one of the most significant lineages of parasitic plants from economic, conservation, and anthropogenic perspectives. Members of the genus are twining stem parasites with no roots, lacking almost completely chlorophyll or its function, and gather required nutrition from their host via specialized haustorial connections. While there are almost 200 described species, problems with species identification exist because many diagnostic characters are restricted to their tiny flowers. Probably contributing to this identification difficulty is the fact that the group has not received taxonomic attention for over 75 years; even knowledge of its basic reproductive biology …

Integrated Management Strategies For Phytophthora Sojae Combining Host Resistance And Seed Treatments, A. E. Dorrance, A. E. Robertson, S. Cianzo, L. J. Giesler, C. R. Grau, M. A. Draper, A. U. Tenuta, T. R. Anderson

Department of Plant Pathology: Faculty Publications

Phytophthora sojae has re-emerged as a serious soybean pathogen in the past decade. This may be due in part to changes in resistance levels in current cultivars, adoption of P. sojae populations to deployed Rps genes, and highly favorable environments in the past decade. This multilocation study evaluated the effect of seed treatments on the incidence and severity of Phytophthora root and stem rot on soybeans with different combinations of Rps genes and levels of partial resistance. The efficacy of the seed treatments was highly variable across locations. Seed treatments (metalaxyl and mefenoxam) provided protection and increased yields across cultivars …

Joint Fire Science Program – Lake Mead National Recreation Area: Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis, Quarterly Progress Report, October 1 — December 31, 2008, Margaret N. Rees

Fire Science

• Presented poster at Natural Areas Conference in Nashville, TN

• Initiated granivory study at Goodsprings.

• Outplanted 2376 plants for Experiment 1 at Lake Mead nursery.

• Presented poster at Wildfires and Invasive Plants in American Deserts conference in Reno, NV.

• Submitted manuscript covering our distance from road - microsite invasibility study to Journal of Arid Environments.

A High-Oleic-Acid And Low-Palmitic-Acid Soybean: Agronomic Performance And Evaluation As A Feedstock For Biodiesel, George L. Graef, Bradley J. Lavallee, Patrick Tenopir, Mustafa Tat, Bruce Schweiger, Anthony J. Kinney, Jon H. Van Gerpen, Thomas E. Clemente

Department of Agronomy and Horticulture: Faculty Publications

Phenotypic characterization of soybean event 335-13, which possesses oil with an increased oleic acid content (> 85%) and reduced palmitic acid content (< 5%), was conducted across multiple environments during 2004 and 2005. Under these conditions, the stability of the novel fatty acid profile of the oil was not influenced by environment. Importantly, the novel soybean event 335-13 was not compromised in yield in both irrigated and non-irrigated production schemes. Moreover, seed characteristics, including total oil and protein, as well as amino acid profile, were not altered as a result of the large shift in the fatty acid profile. The novel oil trait was inherited in a simple Mendelian fashion. The event 335-13 was also evaluated as a feedstock for biodiesel. Extruded oil from event 335-13 produced a biodiesel with improved cold flow and enhanced oxidative stability, two critical fuel parameters that can limit the utility of this renewable transportation fuel.

Ecotypic Variation In Elymus Elymoides Subspecies Brevifolius Race C In The Northern Intermountain West, Matthew C. Parsons

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Little information is available on the extent of local adaptation for many native grass species. This is the case for squirreltail (Elymus section Sitanion), despite this group's prevalence and importance in rangeland restoration efforts. I evaluated 32 populations of E. elymoides ssp. brevifolius race C, a phylogenetic subdivision of bottlebrush squirreltail (E. elymoides) centered in the northern Intermountain West, for phenotypic variables and neutral genetic markers to measure their association with geographical origin. Phenotypic traits were measured in common field and greenhouse environments, and genetic diversity was assessed using Amplified Fragment Length Polymorphism. Three factors were extracted from the phenotypic …

Aminoglycosides And Syringomycin E As Fungicides Against Fusarium Graminearum In Head Blight Disease, Yukie Kawasaki

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fusarium graminearum is one of the most problematic phytopathogens in US agriculture. This fungus causes head blight, foot rot, and damping off on wheat and barley. The infection lowers the grain yield and causes contamination of the grain product with mycotoxins. Effective control measures are lacking, and new fungicides that kill F. graminearum but remain safe and economical to use are needed. Newly synthesized aminoglycosides (JL22, JL38, JL39, JL40, NEOF004, NEOF005), classic aminoglycosides (amikacin, gentamicin, kanamycin A, kanamycin B, neomycin, and ribostamycin), and a lipopeptide, syringomycin E (SRE), were studied to determine their antifungal potential to control F. graminearum. …

Abundance And Diversity Of Seagrass And Macrofauna In The Intertidal Areas With And Without Seaweed Farming Activities In The East Coast Of Zanzibar, Thomas J Lyimo, Esther F Mvungi, Yunus D Mgaya

Tanzania Journal of Science

The diversity and abundance of seagrass and associated macrofauna were studied in transects with and without seaweed farms at Chwaka Bay and Jambiani, in the East Coast of Zanzibar. Eight seagrass species, namely Cymodocea rotundata, Cymodocea serrulata, Thalassia hemprichii, Thalassodendron ciliatum, Syringodium isoetifolium, Halodule uninervis, Halophila ovalis and Enhalus acoroides were recorded in the transects. The mean total biomass of seagrass at Chwaka Bay ranged from 142.4 ± 70.71 to 1652 ± 772.7 g dw/m2 and 212.9 ± 146.2 to 1829 ± 1692 g dw/m2 in station with and without seaweed farms, respectively. At Jambiani, the mean total biomass ranged …

Seed Longevity Of Dominant Plant Species From Degraded Savanna In Semi-Arid Tanzania, Hvm Lyaruu

Tanzania Journal of Science

Artificially buried seeds were followed by periodic exhumation and germination during 21 months in Kondoa Irangi Hills, central Tanzania. Viable seeds from thirteen selected species were buried in polythene envelopes at a depth of 15 cm below woodland vegetation. Lethal germination, fungal decay and insect infestation were singled out as the most important contributors to loss of viability among seeds. Hierarchical clustering based on a seed’s mean viability, seed shape and presence or absence of dispersal appendages, produced three distinct groups: (1) non-dormant seeds (2) seeds with enforced dormancy and (3) seeds with seed coat imposed dormancy. The low decay …

The Performance Of Maize Crop During Acid Amelioration With Organic Residues In Soils Of Mtwara, Tanzania, Ae Majule, Jo Omollo

Tanzania Journal of Science

This study evaluated acid ameliorative potential and their effects on maize growth of four organic residues namely wild spikenard, cordia, cowpea and pigeon peas through incubations with or without sulphur. This was done in order to recommend potential organic residue source that could ameliorate soil acidity associated with sulphur dusting. Increased levels of sulphur in the soils reduced the growth and dry matter yields of maize due to intense acidification while maize growth and dry matter yields in soils which organic residues were incorporated was enhanced. Enhancement in maize performance may be a result of reduced soil acidity due to …

First Report Of Soybean Rust Caused By Phakopsora Pachyrhizi In Nebraska, S. R. Watson, L. J. Giesler, A. D. Ziems, T. E. Brovont

Department of Plant Pathology: Faculty Publications

Soybean rust caused by Phakopsora pachyrhizi Sydow was first observed in the continental United States in Louisiana in November 2004 (2). As part of the national soybean rust monitoring effort, samples were collected on 3 October 2007 during the scouting of fields with green leaves in southeastern Nebraska. After incubation at room temperature for 24 h, uredinea and urediniospores were observed with microscopic examination. Urediniospores were obovoid, hyaline to pale brown, and measured 20 to 30 × 18 to 20 μm.

Enhanced Plant Nutrient Use Efficiency With Pgpr And Amf In An Integrated Nutrient Management System, A. O. Adesemoye, H. A. Torbert, J. W. Kloepper

Department of Plant Pathology: Faculty Publications

A 3-year field study was conducted with field corn from 2005 to 2007 to test the hypothesis that microbial inoculants that increase plant growth and yield can enhance nutrient uptake, and thereby remove more nutrients—especially N, P, and K—from the field as part of an integrated nutrient management system. The field trial evaluated microbial inoculants, which include a commercially available plant growth-promoting rhizobacteria (PGPR), arbuscular mycorrhiza fungi (AMF), and their combination across 2 tillage systems (no-till and conventional till) and 2 fertilization regimes (poultry litter and ammonium nitrate). Data were collected on plant height, yield (dry mass of ears and …

Joint Fire Science Program – Lake Mead National Recreation Area: Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis, Quarterly Progress Report, July 1 — September 30, 2008, Margaret N. Rees

Fire Science

• Cones monitored and reseeded to obtain plants for nursery study.

• Goodsprings revegetation studies monitored.

• Website developed for JFS study.

• Writing short communication for Journal of Arid Environments.

• Working on poster for NAA conference in October.

The Very-Long-Chain Hydroxy Fatty Acyl-Coa Dehydratase Pasticcino2 Is Essential And Limiting For Plant Development, Liên Bach, Louise V. Michaelson, Richard Haslam, Yannick Bellec, Lionel Gissot, Jessica Marion, Marco Da Costa, Jean-Pierre Boutin, Martine Miquel, Frédérique Tellier, Frederic Domergue, Jennifer E. Markham, Frederic Beaudoin, Johnathan A. Napier, Jean-Denis Faure

Department of Biochemistry: Faculty Publications

Very-long-chain fatty acids (VLCFAs) are synthesized as acyl-CoAs by the endoplasmic reticulum-localized elongase multiprotein complex. Two Arabidopsis genes are putative homologues of the recently identified yeast 3-hydroxy-acyl-CoA dehydratase (PHS1), the third enzyme of the elongase complex. We showed that Arabidopsis PASTICCINO2 (PAS2) was able to restore phs1 cytokinesis defects and sphingolipid long chain base overaccumulation. Conversely, the expression of PHS1 was able to complement the developmental defects and the accumulation of long chain bases of the pas2–1 mutant. The pas2–1 mutant was characterized by a general reduction of VLCFA pools in seed storage triacylglycerols, cuticular waxes, …

Shrub-Interspace Dynamics Alter Relationships Between Microbial Community Composition And Belowground Ecosystem Characteristics, Rebecca E. Drenovsky, Z. T. Aanderud, M. I. Shuldman, J. H. Richards

Biology

In desert ecosystems, belowground characteristics are influenced chiefly by the formation and persistence of “shrub-islands of fertility” in contrast to barren plant interspaces. If soil microbial communities are exclusively compared between these two biogeochemically distinct soil types, the impact of characteristics altered by shrub species, especially soil C and N, are likely to be overemphasized and overshadow the role of other characteristics in structuring microbial composition. To determine how belowground characteristics influence microbial community composition, and if the relative importance of these characteristics shifts across the landscape (i.e., between and within shrub and interspace soils), changes in microbial communities across …

Gender Variation In The Prezygotic Reproductive Effort Of The Common Silver Moss, Kimberley Horsley, Lloyd Stark

Undergraduate Research Opportunities Program (UROP)

The bryophyte Bryum argenteum is a vigorous moss with a cosmopolitan distribution and high tolerance to desiccation and temperature stress. Due to its widespread nature, B. argenteum has been highly investigated (e.g., Chopra and Bhatla 1981). However, very little research has been done on the reproductive aspects of this moss with respect to gender differences. This project will address the prefertilization reproductive efforts of the moss, and look for any differences in the rate of growth and sexual expression between the sexes. The hypothesis to be tested is that males actually have a higher prefertilization reproductive effort than females and …

Decoding The Protein Interaction Network - An Approach Integrating Biology And Math, Ryan Huang, Lingkun Gu, Qingxi J. Shen

Undergraduate Research Opportunities Program (UROP)

The WRKY super family is known to play a major role during the plant stress response and development. My project focuses on the protein-protein interaction of an Oryzasativa (rice) transcription factor, OsWRKY71 which functions as the repressor of gibberellins signaling pathway. Previous literature revealed that OsWRKY71 can interact with itself or OsWRKY51 to form dimmers by using bimolecular fluorescence complementation (BiFC). To confirm this result, we use yeast two-hybrid system. As our data showed, OsWRKY71 seems to suppress the reporter gene expression of the conventional yeast two-hybrid system, so we use a modified yeast two-hybrid, Mating-based Split Ubiquitin System (MbSUS). …

Genetic Diversity In Native And Invasive Rubus (Rosaceae), Ashley A. Wint

Masters Theses & Specialist Projects

Invasive species are an increasing threat to biological diversity as well as a leading cause of recent species’ extinctions. Invasives spread quickly and efficiently, and the U.S spends millions of dollars annually in the control and eradication of these species. More information is necessary in order to predict which species may become invasive. Rubus (Rosaceae) was chosen for study because this genus includes various ploidy levels, reproductive modes, and species that are invasive as well as native.

Three Rubus species were chosen to represent apomictic and tetraploid invasives (Rubus armeniacus), a sexual and diploid native species (R. occidentalis), and a …