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An Analysis Of Plant Response To Herbivory, Lawrence Gustavo Seminario-Romero

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Herbivory is often believed to always negatively affect the growth of plants, but there are plant species that can actually benefit from being consumed by herbivores. These plants have a phenotypic trait known as “compensatory growth.” A plant that exhibits compensatory growth is able to increase its intrinsic growth rate as a response to taking damage caused by herbivory, and as a result, produce more biomass. Very few mathematical models used to describe plant-herbivore interactions have accounted for plant compensatory growth. Moreover, these models tend to assume that herbivores follow a Holling type II functional response, which may not necessarily …

Multiple Light Signaling Pathways Control Solar Tracking In Sunflowers, Christopher J. Brooks, Hagop S. Atamian, Stacey L. Harmer

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Sunflowers are famous for their ability to track the sun throughout the day and then reorient at night to face east the following morning. This occurs by differential growth patterns, with the east sides of stems growing more during the day and the west sides of stems growing more at night. This process, termed heliotropism, is generally believed to be a specialized form of phototropism; however, the underlying mechanism is unknown. To better understand heliotropism, we compared gene expression patterns in plants undergoing phototropism in a controlled environment and in plants initiating and maintaining heliotropic growth in the field. We …

Effects Of Fertigation Versus Palletized Fertilizer On Height And Caliper Growth In Oaks, Zachary M. Davis

LSU Master's Theses

The Covid-19 pandemic and ensuing lockdowns led to an increase in revenue and production for green industry products in early 2020. In Study 1. an evaluation of fertigation (liquid feed, quick release) and controlled release fertilizers (CRFs, slow release) were applied to container-grown (7 gallon) live oak (Quercus virginiana) and Nutall oak (Quercus nuttallii) trees (100% Liquid feed, 0% CRF, 67% Liquid feed, 33% CRF, 33% Liquid feed, 67% CRF, 100% Liquid feed, 0% CRF). Live oak trees fertilized with CRFs had increased stem calipers (>30%). Nuttall stem caliper and height were significantly increased by …

Antidiabetic Potential Of Vitex Mombassae Fruits Extract In Streptozotocin-Nicotinamide Induced Diabetic Wistar Rat Model, Mussa B. Mbegeze, Joan J.E. Munissi, Flora Stephano, Ramadhani S.O. Nondo, Stephen S. Nyandoro

Tanzania Journal of Science

Besides changes in life styles and improper dietary patterns, the rapidly increasing burden of diabetes mellitus type 2 is correlated with antidiabetic agents currently in clinical use, which are costly, less effective, and present undesirable side effects. Natural products from plants are promising alternative sources for developing more effective and cost friendly antidiabetic agents. This study therefore investigated the antidiabetic potential of Vitex mombassae fruits extract (VMFE) in streptozotocin-nicotinamide induced diabetic Wistar rat model. Oral acute toxicity test was conducted in male Wistar rat using up and down method by following OECD Guideline 423 (2002). No clinical signs of toxicity …

Activated Carbon Based On Borassus Aethiopum Shells, Hulls, Kernels And Fruits For Removal Of Phenol And 2-Chlorophenol From Water, Ndatiye W. Ndatiye, Lupituko L. Mkayula, Grace A. Kinunda

Tanzania Journal of Science

This study aimed at developing activated carbons from Borassus aethiopum shells (BaS), hulls (BaH), kernels (BaK) and fruits (BaF) for removing phenol (Ph) and 2-chlorophenol (2-CP) from aqueous solution. The preparation of the activated carbons involved carbonization of the starting materials at 500 ºC followed by chemical activation at 600 ºC using 0.5 M H3PO4 acid. The prepared activated carbons were found to be mesoporous having pore sizes and surface areas in the range of 3.2 to 3.5 nm and 644 to 740 m2/g, respectively. Thermogravimetric analysis (TGA) thermograms showed that the prepared activated carbons can be applied in the …

Phytochemical Constituents Of Cissus Oliveri Growing In Pwani Region, Tanzania, Fadhili S. Estomini, Stephen I. Nnungu, Amelia S. Buriyo

Tanzania Journal of Science

Cissus oliveri (Engl.) Gilg ex Engl. is among the plant species of the family Vitaceae widely used in traditional medicine for management of different ailments. This study aimed at assessing the phytochemicals of C. oliveri parts in order to provide scientific validation for its use as a therapeutic agent. Qualitative analysis of water and ethanolic extracts was conducted by using standard methods and the results revealed that all the parts possess alkaloids, flavonoids, phenols and tannins. Similarly, glycosides and saponins were only present in leaf and root. Quantitative analysis performed by gravimetric and spectrophotometric methods showed that all parts contain …

Anticancer Potential Of The Leaf Extracts From The Selected Croton Species, Peter V. Fayyu, Joan J.E. Munissi, Stephen S. Nyandoro, Flora Stephano

Tanzania Journal of Science

The reported investigations were aimed at establishing anticancer potential of the leaf extracts from Croton dictyophlebodes (CDE), C. kilwae (CKE) and C. longipedicellatus ssp austrotanzanicus (CLE). In vitro cytotoxicity assays of the extracts were performed against human laryngeal cancer cell line (HEp-2) and human breast cancer cell line (MCF-7), while in vivo toxicological studies were done using Swiss albino mice (Mus musculus) following the Organization for Economic Cooperation and Development guideline number 423 of 2001. Results for in vitro assays revealed that CDE and CLE induced cytotoxicity to MCF-7 and HEp-2 cell lines at EC50 values of 86 and 63 …

Genetic Analysis Of Basal Stalk Rot Resistance Introgressed From Wild Helianthus Petiolaris Into Cultivated Sunflower (Helianthus Annuus L.) Using An Advanced Backcross Population, Zahirul I. Talukder, William Underwood, Christopher G. Misar, Xuehui Li, Gerald J. Seiler, Xiwen Cai, Lili Qi

Department of Agronomy and Horticulture: Faculty Publications

Introduction: Sclerotinia sclerotiorum is a serious pathogen causing severe basal stalk rot (BSR) disease on cultivated sunflower (Helianthus annuus L.) that leads to significant yield losses due to insufficient resistance. The wild annual sunflower species H. petiolaris, commonly known as prairie sunflower is known for its resistance against this pathogen. Sunflower resistance to BSR is quantitative and determined by many genes with small effects on the resistance phenotype. The objective of this study was to identify loci governing BSR resistance derived from H. petiolaris using a quantitative trait loci (QTL) mapping approach.

Methods: BSR …

Effects Of Rootstock And Location On Open Field ‘Bhn 589’ And ‘Nebraska Wedding’ Grafted Tomato Yield, Raihanah H. Shonerd, Ashley A. Thompson, Samuel E. Wortman

Department of Agronomy and Horticulture: Faculty Publications

Grafted tomato (Solanum lycopersicum) production is popular, particularly in high tunnels, because grafted plants can mitigate soilborne disease incidence in highly infested soils and increase water and nutrient use efficiency and crop yield and quality. However, these potential benefits are not as well documented in open field production systems with less disease pressure. The objective of this study was to quantify the effect of tomato grafting on fruit yield, number, and size across 2 years (2018 and 2019) and three diverse open-field production environments in Nebraska (Lincoln, North Platte, and Dwight). At each location, a scion from one …

Evaluation Of Land Preparation Methods For Soil Stabilization, Revegetation, And Renewed Productivity In Semi-Arid Climates, Jarrett Lardy, North Dakota State University, Miranda Meehan, Aaron L. M. Daigh, James Staricka, Nathan Derby

Department of Agronomy and Horticulture: Faculty Publications

In the Williston Basin, land-preparation treatments have not been compared in side-by-side trials to evaluate performance for parameters such as runoff, erosion, and vegetation establishment. Thus, four treatments of wheat-straw crimping, land imprinting, wood-fiber hydromulch, and the combination of land imprinting and hydromulch were evaluated against a bare soil control in a replicated and randomized completed block field experiment near Williston, ND. Rainfall simulations were performed in September 2020 and June 2021 to examine the effectiveness of the treatments to reduce runoff and sediment losses. Vegetation establishment was also evaluated in August 2021. The wheat straw treatment reduced the equivalent …

Irrigation Increases On-Farm Soybean Yields In Water-Limited Environments Without A Trade-Off In Seed Protein Concentration, Walter D. Carciochi, Patricio Grassini, Seth Naeve, James E. Specht, Mitiku Mamo, Ron Seymour, Aaron Nygren, Nathan Mueller, Sarah Sivits, Christopher A. Proctor, Jenny Rees, Todd Whitney, N. Cafaro La Menza

Department of Agronomy and Horticulture: Faculty Publications

Context or problem: A trade-off between seed protein concentration (SPC) and yield has been reported for soybean. Therefore, assessing management practices that can nullify this trade-off is relevant to avoid further declines in SPC in the future as yield continues to increase. While the positive effect of irrigation on yield is well documented, only a few studies have assessed the impact of irrigation on SPC, showing conflicting results.

Objective or research question: The objective was to determine if the trade-off between seed yield and SPC persists when irrigation is applied and how management, soil, and weather factors influence the trade-off. …

Deleterious Mutations Predicted In The Sorghum (Sorghum Bicolor) Maturity (Ma) And Dwarf (Dw) Genes From Whole‑Genome Resequencing, Nathan P. Grant, John J. Toy, Deanna L. Funnell, Scott E. Sattler

Department of Agronomy and Horticulture: Faculty Publications

In sorghum [Sorghum bicolor (L.) Moench] the Maturity (Ma1, Ma2, Ma3, Ma4, Ma5, Ma6) and Dwarf (Dw1, Dw2, Dw3, Dw4) loci, encode genes controlling flowering time and plant height, respectively, which are critical for designing sorghum ideotypes for a maturity timeframe and a harvest method. Publicly available whole-genome resequencing data from 860 sorghum accessions was analyzed in silico to identify genomic variants at 8 of these loci (Ma1, Ma2, Ma3, Ma5, Ma6, Dw1, Dw2, Dw3) to identify novel loss …

The Silver Bullet That Wasn’T: Rapid Agronomic Weed Adaptations To Glyphosate In North America, Christopher Landau, Kevin Bradley, Erin Burns, Michael Flessner, Karla Gage, Aaron Hager, Joseph Ikley, Prashant Jha, Amit Jhala, Paul O. Johnson, William Johnson, Sarah Lancaster, Travis Legleiter, Dwight Lingenfelter, Mark Loux, Eric Miller, Jason Norsworthy, Micheal Owen, Scott Nolte, Debalin Sarangi, Peter Sikkema, Christy Sprague, Mark Vangessel, Rodrigo Werle, Bryan Young, Martin M. Williamsii

Department of Agronomy and Horticulture: Faculty Publications

The rapid adoption of glyphosate-resistant crops at the end of the 20th century caused a simplification of weed management that relied heavily on glyphosate for weed control. However, the effectiveness of glyphosate has diminished. A greater understanding of trends related to glyphosate use will shed new light on weed adaptation to a product that transformed global agriculture. Objectives were to (1) quantify the change in weed control efficacy from postemergence (POST) glyphosate use on troublesome weeds in corn and soybean and (2) determine the extent to which glyphosate preceded by a preemergence (PRE) improved the efficacy and consistency of weed …

Bryophyta Sensu Stricto Presence And Function In The Epiphytic Ecosystems Of The Tropical Montane Cloud Forests Of El Valle De Anton, Teaghan Duff

Independent Study Project (ISP) Collection

Bryophyta sensu stricto, colloquially known as moss, is often found growing epiphytically in cloud forest ecosystems. Under these conditions, moss may fulfill a secondary foundational species (FS) role, supporting increased habitat for other organisms while remaining dependent on the primary FS host tree. Exploring the dual relationship of moss as both a dependent and supportive organism allows for better understanding of its connective role within ecosystems. Research in the cloud forests of El Valle de Anton focused on relative abundance, environmental surroundings, morphology, and microclimate of mosses to offer baseline data on these connections. Mosses along four different trails within …

Soil Succession: Short And Long-Term Impacts Of Grazing On Soil Properties In A Tropical Montane Cloud Forest, June Curtis

Independent Study Project (ISP) Collection

Cattle ranching is the leading cause of deforestation in South America, causing long-lasting alterations to the continent's landscape and ecology. Tropical montane cloud forests (TMCFs) are a rare ecosystem particularly vulnerable to the effects of land conversion to pasture, a process which has implications ranging from biodiversity loss to soil degradation. Grazing is known to significantly alter soils' physical structure through processes of compaction and erosion as well as significant additions of organic matter. Silvopasture, or the integration of pasture and forest, has emerged as an alternative to traditional grazing practices with the hope of mitigating environmental and soil degradation. …

Community Complexity Of A Pollination Network: Analysis Of Plant-Pollinator Interactions In The Eastern Ecuadorian Cloud Forest, Anisa López-Ruiz

Independent Study Project (ISP) Collection

Global declines in pollinators and temporal/spatial mismatches between plants and pollinators threaten the integrity of plant-pollinator networks. Ecological network analysis provides a powerful framework for understanding the dynamics of plant-pollinator networks and measures of community complexity that can help inform areas of priority in conservation. This study observed a plant-pollinator network in a secondary forest close to the Río Zuñac Reserve in the eastern Ecuadorian cloud forest to identify assemblages of plants and pollinators and evaluate measures of community complexity, including specialization and nestedness. Flowering plants were identified and observed along a 1.2 km transect, and floral visitors to these …

Friends In High Places: Establishing Pollination Networks For The Páramos Of Central Ecuador, Emma Diaz

Independent Study Project (ISP) Collection

Well-known for being a global biodiversity hotspot, the Andean Páramos hosts a unique array of floristic diversity seen nowhere else in the world (Luteyn, n.d.). With the resiliency of this ecosystem dependent on the successful reproduction of these plants, it is crucial to understand the pollination network which sustains them. Modern-day research has outlined networks in the Chilean, Venezuelan, and Argentinean Páramos, but one has yet to be defined for Ecuador, despite being the suspected home to nearly half of floristic diversity in the Páramos (Arroyo et al., 1985; Pelayo et al., 2021; Medan et al., 2023; Caranqui et al., …

Variation Of Carbon Stock Of Boca Del Drago Mangrove Forests Based On Salinity And Seaward Proximity, Fiona Wyrtzen

Independent Study Project (ISP) Collection

Mangrove forests, at the intersection of land and sea, are considered one of the most important marine environments for their variety of ecosystem services and their ability to sequester large amounts of carbon in their biomass and adjacent soils. With a changing climate, many of the abiotic and biotic factors influencing mangroves will begin to shift, potentially impacting resilience, growth capacity, and distribution of mangroves worldwide. This study aimed to examine the influence of changing salinity on the carbon stock capacity for Rhizophora mangle and Laguncularia racemosa forests, and the distribution of biomass in each species relative to salinity in …

Optimizing Crop Productivity And Fertility Practices In Intermediate Wheatgrass, Roberta Bianchin Rebesquini

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

The intensive management associated with many annual crops often includes recurring tillage, fertilization, and pesticide applications, which contribute to environmental concerns such as water pollution and soil erosion. Intermediate wheatgrass (Thinopyrum intermedium), recognized under the trade name Kernza®, is a perennial grass that can be managed to produce grain and biomass while providing desired environmental benefits such as soil conservation and nutrient cycling. There has been limited research on best management practices and crop productivity for this alternative dual-use crop in Nebraska. A field experiment was conducted beginning in 2021 to assess nitrogen (N), phosphorus (P), and potassium …

Bryophyte (Sl) Growth And Environmental Factors Along An Altitudinal Gradient On Cerro Gaital, El Valle, Coclé, Panamá, Julian Grace-Martin

Independent Study Project (ISP) Collection

Research on bryophytes (SL) in the tropics has been lacking compared with the high number of species found there and the potential benefit of bryophytes (SL) as indicators of pollutants and other forms of human disturbance. This study investigated whether or not bryophyte (SL) growth patterns showed relation when compared with environmental factors on the mountain Cerro Gaital in El Valley, Panamá. Whether or not bryophytes (SL) are present, extent of the area covered by their growth, and height of their growth are all aspects of bryophyte (SL) growth that were used. In this study, these three aspects are compared …

Evaluation Of The Inhibitive Properties Of Silver Nanoparticles In Senna Occidentalis Root Extract As Corrosion Inhibitor Of Mild Steel, Victor O. Egbeneje, Samuel E. Okhale, Chinyere Imoisi, Isaac O. Ogbogo, Omolade Ojo

Tanzania Journal of Science

The use of nanoparticles as corrosion inhibitors has gained popularity because of its increased corrosion efficiency due to increase surface to volume ratio. Nanoparticles which undergo physisorption/chemisorption to the corrosion metal surface and inhibit the corrosion efficiently also have low toxicity, low cost and easy production. In this research work, weight lost method was applied to study the inhibitive properties of silver nanoparticles (AgNPs) synthesized using Senna occidentalis root extract as environmentally benign corrosion inhibitor of mild steel in 0.5 M H2SO4 medium at 298 K and 308 K. It was observed that the corrosion rate of the steel sample …

Did Cover Crop Or Animal Manure Ameliorate Corn Residue Removal Effects On Soil Mechanical Properties After 10 Years?, Hans W. Klopp, Humberto Blanco-Canqui, Michael Sindelar, Virginia L. Jin, Marty R. Schmer, Richard B. Ferguson

Department of Agronomy and Horticulture: Faculty Publications

Crop residue removal may negatively affect soil mechanical properties, which are key components of soil quality. To evaluate potential long-term effects, we assessed the 10-yr impact of corn (Zea mays L.) residue removal (59 % of non-grain biomass annually) on surface soil mechanical properties (0–20 cm). We also evaluated whether adding carbon (C) amendments, such as using a winter rye (Secale cereale L.) cover crop or surface-applying cattle manure (24 Mg ha− 1 biannually) can ameliorate the effects of crop residue removal. This long-term study was under irrigated no-till continuous corn on a silt loam soil in south-central …

Design Of A Cooling System Integrated With Ultraviolet Light For Preservation Of Fruits And Vegetables At Variable Tropical Weather Conditions: A Case Study Of Arusha, Tanzania, John Pyuza Gunda, Alexander Pogrebnoi, Baraka Kichonge

Tanzania Journal of Science

Post-harvest losses of fruits and vegetables pose significant challenges, especially in tropical climates. This study introduces the development and performance evaluation of a solar-powered evaporative cooling storage system integrated with ultraviolet light (UV) designed for preservation of perishable fruits and vegetables. The cooling chamber supplied with ultraviolet lamp was developed using locally available materials such as sisal, sponge, and bricks. The performance of the system was evaluated in terms of air temperature decrease, relative humidity increase, and evaporative cooling power capacity both for sunny and cloudy tropical weather conditions. The study reveals that activating the UV light considerably extends the …

Microplastics In Marine Sediments From Dar Es Salaam Coast: Spatial Distribution And Characterization, Macarius P. Mtega, Matobola J. Mihale, Kessy F. Kilulya

Tanzania Journal of Science

The purpose of the research was to determine the spatial distribution and characterization of microplastics in marine sediments of beaches along the Indian Ocean of Dar es Salaam coast. The sediment samples were extracted in triplicate using floatation method followed by digestion of organic debris, then analyzed using At-FTIR spectrophotometer and stereomicroscope. The mean concentrations of microplastics for Kijichi Beach were 700 ± 907 particles/m2 at 1 cm, 859 ± 839 particles/m2 at 5 cm and 590 ± 782 particles/m2 at 10 cm; from Palm Beach were 157 ± 15 particles/m2 at 1 cm, 130 ± 182 particles/m2 at 5 …

Effects Of Bacillus Thuringiensis, Beauveria Bassiana, Neem, And A Tomato Inter-Crop On Diamondback Moth (Plutella Xylostella L.) (Lepidoptera: Plutellidae) In Tharaka-Nithi County, Kenya, Ceciliah N. Ngugi, Jesca N. Mbaka Mbaka, Hellen W. Muthengi

Tanzania Journal of Science

Cabbage (Brassica oleracea var. capitata) is an important crop in Kenya, ranked 3rd among the exotic vegetables. Diamondback moth (DBM) is a major cabbage pest that can cause a 100% loss in yield if not well managed. Farmers indiscriminately use synthetic pesticides associated with environmental, health, and pest resistance concerns to manage the DBM. To increase the availability of technologies for effective management of DBM in Kenya, three biopesticides; BioPower (Beauveria bassiana 1.0 x 108 CFUs/g), Dipel DF® (Bacillus thuringiensis subsp. kurstaki), Neemraj Super 3000 (Azadirachtin 0.3% EC), and a tomato inter-crop were evaluated. Cabbages (30 plants) spaced at 40 …

Ethnobotanical Survey On The Knowledge And Use Of Medicinal Plants For Malaria Management Among University Students, Felista W. Mwingira, Deokary J. Matiya, Neema G. Mogha

Tanzania Journal of Science

Malaria remains a public health problem in Tanzania, escalated by the emergence of both parasite and vector resistance. Plant-based traditional medicines have been widely utilized as alternatives to malaria management. However, proper documentation is minimal, especially among the younger generation. This study assessed the knowledge of medicinal plants for malaria management among 532 Dar es Salaam University College of Education students. Overall, twenty-four plant species, most belonging to the family Asteraceae, were identified with Azaradichta indica being the most dominant species. These results reveal a substantial knowledge of medicinal plants for malaria management among university students.

Effective Enhancement Of Post-Harvest Tomato Storage Through Wrapping Using Deacetylated Chitin Nanofibril-Plasticized Honey Films, Ngesa Ezekiel Mushi, Edina Meela, Divina Kaombe

Tanzania Journal of Science

As one of the most grown seasonal fruit, tomato is widely consumed for making food products, drugs and ornaments. However, poor post-harvest handling system, transport and storage facilities deteriorate the quality of tomato fruits resulting into post-harvest losses. These problems have been addressed by the use of nanotechnology in this study. The combination of a chitosan surface and the core shell chitin results into novel deacetylated chitin nanofibril (DeChNF) with good biological activity and mechanical strength. The effectiveness of the DeChNF films for food preservation as an alternative material to chitosan is investigated. The DeChNF with degree of acetylation (DA) …

Dynamic Reconfiguration Of Switchgrass Proteomes In Response To Rust (Puccinia Novopanici) Infection, Nathan A. Palmer, Sophie Alvarez, Michael J. Naldrett, Anthony Muhle, Gautam Sarath, Serge J. Edmé, Satyanarayana Tatineni, Robert B. Mitchell, Gary Yuen

Department of Plant Pathology: Faculty Publications

Switchgrass (Panicum virgatum L.) can be infected by the rust pathogen (Puccinia novopanici) and results in lowering biomass yields and quality. Label-free quantitative proteomics was conducted on leaf extracts harvested from non-infected and infected plants from a susceptible cultivar (Summer) at 7, 11, and 18 days after inoculation (DAI) to follow the progression of disease and evaluate any plant compensatory mechanisms to infection. Some pustules were evident at 7 DAI, and their numbers increased with time. However, fungal DNA loads did not appreciably change over the course of this experiment in the infected plants. In total, 3830 …

Cercocarpus Ledifolius Var. Intricatus ‘Doubledown’, Asmita Paudel, Youping Sun, Larry A. Rupp

Plants, Soils, and Climate Faculty Publications

Bonsai (tray landscape, potted scenery, potted landscape, miniature trees, and rockery) is an artistic horticulture practice of developing aesthetically formed trees and landscapes in miniature with appropriately aesthetic containers. This has been practiced over a few thousand years in oriental cultures, including the ancient Chinese tradition of penzai or penjing, from which the art originated; the miniature living landscapes of Vietnamese hòn non bộ; and the Japanese variations of bonsai and “tray planting” (Gustafson 1995). To produce bonsai plants that share similar shapes and styles of mature, full-size trees, cultivation techniques are used, including leaf trimming, …

Overcoming Genetic Paucity Of Camelina Sativa: Possibilities For Interspecific Hybridization Conditioned By The Genus Evolution Pathway, Rostyslav Y. Blume, Ruslan Kalendar, Liang Guo, Edgar B. Cahoon, Yaroslav B. Blume

Center for Plant Science Innovation: Faculty Publications

Camelina or false flax (Camelina sativa) is an emerging oilseed crop and a feedstock for biofuel production. This species is believed to originate from Western Asian and Eastern European regions, where the center of diversity of the Camelina genus is located. Cultivated Camelina species arose via a series of polyploidization events, serving as bottlenecks narrowing genetic diversity of the species. The genetic paucity of C. sativa is foreseen as the most crucial limitation for successful breeding and improvement of this crop. A potential solution to this challenge could be gene introgression from Camelina wild species or from …