Botany Commons^™

Comparative Transcriptome Analysis Reveals Genetic Mechanisms Of Sugarcane Aphid Resistance In Grain Sorghum, Desalegn D. Serba, Xiaoxi Meng, James Schnable, Elfadil Bashir, J P. Michaud, P V. Vara Prasad, Ramasamy Perumal

Department of Agronomy and Horticulture: Faculty Publications

The sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae) (SCA), has become a major pest of grain sorghum since its appearance in the USA. Several grain sorghum parental lines are moderately resistant to the SCA. However, the molecular and genetic mechanisms underlying this resistance are poorly understood, which has constrained breeding for improved resistance. RNA-Seq was used to conduct transcriptomics analysis on a moderately resistant genotype (TAM428) and a susceptible genotype (Tx2737) to elucidate the molecular mechanisms underlying resistance. Differential expression analysis revealed differences in transcriptomic profile between the two genotypes at multiple time points after infestation by SCA. Six gene …

Fostering A Climate-Smart Intensification For Oil Palm, Juan Pablo Monzon, Maja A. Slingerland, Suroso Rahutomo, Fahmuddin Agus, Thomas Oberthür, José F. Andrade, Antoine Couëdel, Juan I. Rattalino Edreira, Willem Hekman, Rob Van Den Beuken, Fandi Hidayat, Iput Pradiko, Dwi K.G. Purwantomo, Christopher R. Donough, Hendra Sugianto, Ya Li Lim, Thomas Farrell, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Oil palm production in Indonesia illustrates the intense pressure that exists worldwide to convert natural ecosystems to agricultural production. Oil palm production has increased because of expansion of cultivated area rather than due to average-yield increases. We used a data-rich modelling approach to investigate how intensification on existing plantations could help Indonesia meet palm oil demand while preserving fragile ecosystems. We found that average current yield represents 62% and 53% of the attainable yield in large and smallholder plantations, respectively. Narrowing yield gaps via improved agronomic management, together with a limited expansion that excludes fragile ecosystems, would save 2.6 million …

Biocomposites Of Low-Density Polyethylene Plus Wood Flour Or Flax Straw: Biodegradation Kinetics Across Three Environments, Anna K. Zykova, Petr V. Pantyukhov, Elena E. Mastalygina, Christian Chaverri-Ramos, Svetlana G. Nikolaeva, Jose J. Saavedra-Arias, Anatoly A. Popov, Sam E. Wortman, Matheus Poletto

Department of Agronomy and Horticulture: Faculty Publications

The purpose of this study was to assess the potential for biocomposite films to biodegrade in diverse climatic environments. Biocomposite films based on polyethylene and 30 wt.% of two lignocellulosic fillers (wood flour or flax straw) of different size fractions were prepared and studied. The developed composite films were characterized by satisfactory mechanical properties that allows the use of these materials for various applications. The biodegradability was evaluated in soil across three environments: laboratory conditions, an open field in Russia, and an open field in Costa Rica. All the samples lost weight and tensile strength during biodegradation tests, which was …

Physical–Chemical Properties, Droplet Size, And Efficacy Of Dicamba Plus Glyphosate Tank Mixture Influenced By Adjuvants, Estefania Gomiero Polli, Guilherme Sousa Alves, Joao Victor De Oliveira, Greg Robert Kruger

Department of Agronomy and Horticulture: Faculty Publications

Dicamba plus glyphosate tank mixture have been largely adopted for postemergence weed control after the development of dicamba-tolerant crops. Ammonium sulfate is commonly used as water conditioner (WC) to increase glyphosate efficacy, but its use is restricted for dicamba herbicides. The use of non-AMS water conditioner and other adjuvants could be a way to optimize efficacy of this tank mixture while mitigating herbicide off-target movement. The objective of this study was to determine the physical–chemical properties and droplet size distribution of dicamba and glyphosate solutions with and without non-AMS WC alone and tank mixed with other adjuvants and evaluate the …

Critical Time For Weed Removal In Corn As Influenced By Planting Pattern And Pre Herbicides, Dejan Nedeljkovic, Stevan Knezevic, Dragana Bozic, Sava Vrbnicanin

Department of Agronomy and Horticulture: Faculty Publications

Determining the critical time for weed removal (CTWR) is essential for the development of an integrated weed management plan. Therefore, field experiments were conducted to evaluate the effects of two planting patterns (standard and twin-row) with and without PRE-applied herbicides on CTWR in corn. Experiments were laid out in a split-plot arrangement with two main plots: (i) standard row planting (SRP) that is 70 cm wide, and (ii) twin-row planting (TRP) with 50 cm distance between each set of double rows. Each main plot was divided into two sub-plots (with and without PRE herbicides). The sub-sub-plots consisted of seven weed …

Sweet Sorghum Genotypes Tolerant And Sensitive To Nitrogen Stress Select Distinct Root Endosphere And Rhizosphere Bacterial Communities, Lucas Dantas Lopes, Yen Ning Chai, Ellen L. Marsh, John F. Rajewski, Ismail Dweikat, Daniel P. Schachtman

Department of Agronomy and Horticulture: Faculty Publications

The belowground microbiomes have many beneficial functions that assist plant growth, including nutrient cycling, acquisition and transport, as well as alleviation of stresses caused by nutrient limitations such as nitrogen (N). Here we analyzed the root endosphere, rhizosphere and soil bacterial communities of seven sweet sorghum genotypes differing in sensitivity to N-stress. Sorghum genotypes were grown in fields with no (low-N) or sufficient (high-N) N. The dry shoot weight ratio (low-N/high-N) was used to determine N-stress sensitivity. Our hypothesis was that genotypes tolerant and sensitive to N-stress select distinct bacterial communities. The endosphere and rhizosphere bacterial community structure were significantly …

Derivation Of The Generic Names Of North American Grasses (Names In Current Or Recent Use), James P. Smith Jr

Botanical Studies

No abstract provided.

Rhizosphere Microbiomes In A Historical Maize-Soybean Rotation System Respond To Host Species And Nitrogen Fertilization At The Genus And Subgenus Levels, Michael A. Meier, Martha G. Lopez-Guerrero, Ming Guo, Marty Schmer, Josh Herr, James Schnable, James R. Alfano, Jinliang Yang

Department of Agronomy and Horticulture: Faculty Publications

Root-associated microbes are key players in plant health, disease resistance, and nitrogen (N) use efficiency. It remains largely unclear how the interplay of biological and environmental factors affects rhizobiome dynamics in agricultural systems. In this study, we quantified the composition of rhizosphere and bulk soil microbial communities associated with maize (Zea mays L.) and soybean (Glycine max L.) in a long-term crop rotation study under conventional fertilization and low-N regimes. Over two growing seasons, we evaluated the effects of environmental conditions and several treatment factors on the abundance of rhizosphere- and soil-colonizing microbial taxa. Time of sampling, host plant species, …

Reciprocal Transplant And Machine Learning Study Of Oak Mistletoe On Three Host Oak Species In Santa Margarita, California, Ella Abelli-Amen

Master's Theses

At Santa Margarita Ranch, California, oak mistletoe (Phoradendron villosum) parasitizes valley oak and blue oak but cannot be found growing on coast live oak despite its abundance and ability to parasitize coast live oak in other areas. It seems as though this species of mistletoe is specializing on certain host oak trees, but the mechanisms of this specialization are unknown. In order to investigate this pattern, we utilized a type of machine learning in GIS called supervised classification as well as a reciprocal transplant study in the field. The three species of oak trees were classified with 87% accuracy using …

Using Thermal Imaging To Measure Water Stress In Creeping Bentgrass Putting Greens, Joseph G. Foral Jr.

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

Thermal imaging is a developing tool that can help turf managers reduce water consumption and improve irrigation scheduling, but in-depth studies are needed to maximize this potential. This study evaluated the ability of thermal imaging to identify water stress in a creeping bentgrass (Agrostis stolonifera ‘007’) putting green. Water use and canopy temperature (T_c) were measured for plots subjected to three levels of measured water replacement (full, half, and none) to evaluate changes over a range of soil water potentials (SWP). Water use was consistent across the irrigation treatments up to several days before observed wilt …

Dna Barcoding Of The High-Altitude Artemisia And Nepeta Species, Vyacheslav Dushenkov, Csanad Gurdon, Shukhratdzhon Satorov

Publications and Research

DNA barcoding was performed for four medicinal plant species from the mountain region of Tajikistan. The nucleotide sequences for Artemisia sieberi, Artemisia scoparia, Artemisia vulgaris, and Nepeta glutinosa were deposited into the GenBank at the National Center for Biotechnology Information.

Morphophysiological And Molecular Characterization Of Millet (Panicum Miliaceum L.) Varieties For Crop Improvement In Western Europe, Massimo Vischi, Nicola Zorzin, Maria Bernhart, Johanna Winkler, Dipak Santra, Carla Pappalardo, Stefano Marchetti

Department of Agronomy and Horticulture: Faculty Publications

Background

Global warming and issues in favour of a more sustainable agriculture suggest a reconsideration of minor cereals in European agrosystems. Compared to other summer crops, proso millet has a remarkable drought resistance and could be used to improve crop rotation and biodiversity. Proso millet is also increasingly sought by industry to produce novel foods such as those designed for celiac patients. In this study, a thorough characterization of 11, commercially available, proso millet (Panicum milliaceum L.) varieties was carried out as a preliminary step for crop reintroduction and breeding in Western Europe.

Methods

The cultivars under evaluation were …

Evolution And Development Of The Seed Coat In Gymnosperms, Cecilia Zumajo

Dissertations, Theses, and Capstone Projects

Gymnosperms and angiosperms are the most abundant plant lineages on earth and constitute a turning point in the evolution of plants because they are at the origin of the seed, a key morphological and developmental novelty in the evolution of land plant. Although the morphological variation of the seed, across seed plants, may on its own, explain the complexity of this structure, the origin, and evolution are even more, the understanding of these topics is still under discussion. Evidence shows that previous studies have often lacked the component of gene expression, particularly in species that are not model species. The …

Improved Taste And Texture In Novel Popcorn Varieties Compared To Conventional Lines, Leandra Parsons, Oscar Rodriguez, David R. Holding

Department of Agronomy and Horticulture: Faculty Publications

Abstract Quality Protein Popcorn (QPP) varieties were bred out of a unique germplasm pool derived from Quality Protein dent Maize and conventional popcorn lines. To identify and compare distinctive characteristics within this population, a new sensory method was employed that coupled hedonic numeric rankings of common sensory traits appearance, aroma, texture, and taste with an “overall likability” score while requiring the selection of specific descriptors for taste and texture. Participants tasted six popcorn cultivars, rated each sample based on sensory factors, and offered specific descriptors for taste and texture. This sensory method identified two QPP hybrids with higher overall likability …

Analysis Of Symptom Expressions And Transmission Rates Caused By The Plant Pathogen Phytophthora Ramorum On Native Chaparral Plants From The Genus Arctostaphylos, Bharati Gaonker

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Phytophthora ramorum is the causal agent of Sudden Oak death (SOD), ramorum dieback and ramorum leaf blight which affect both forest environments and nurseries. This oomycete pathogen has had a huge economic impact on the nursery and lumber industry. Forests in California have experienced substantial mortality of oaks affecting the forest dynamics and diversity. Our research investigates four native species and two ornamental cultivars of plants, which belong to the genus Arctostaphylos (manzanita) and are considered to be new hosts for P. ramorum in the chaparral ecosystem of California. Symptom expression and transmission rates were analyzed on Arctostaphylos glauca, …

The Garden Of Extraterrestrial Deee-Lites, Jessica Bremehr

Graduate School of Art Theses

I present a delusion where you, the reader, are a hitchhiker on a journey toward an alternate realm guided by a god-like buffoon. While I take you on a journey through my daydreams and my musings on an alternate existence, a tour guide will lead the way to an otherworldly realm called The Garden of Extraterrestrial Deee-Lites, reflective of a tourist experience to a faraway destination. The tour will culminate in an uncanny space where curious life forms converge with familiar objects to encourage a sense of wonder while promoting ideas of interconnectedness within the world around us.

Coleoptile Length Comparison Of Three Winter Small Grain Cereals Adapted To The Great Plains, M. Alam, M. Kashif, Amanda Easterly, F. Wang, J. D. Boehm Jr., P. Stephen Baenziger

Department of Agronomy and Horticulture: Faculty Publications

Successful crop stand establishment is critical to realize high yield potential, which is dependent on depth of seed placement to access soil moisture. The coleoptile determines sowing depth by its length and ability to emerge from depth. This study was conducted to assess coleoptile length among three sets of three Great Plains winter small grain cereals—wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and triticale (X triticosecale Wittm.)—and to evaluate the effect of the Rht-B1b dwarfing allele on coleoptile length in wheat and triticale. Fifty seeds of each genotype were sown in wet germination paper in two …

Estimation Of Household Smoke-Exposure Risk Using Demographic And Health Survey (Dhs) Data, Mazbahul G. Ahamad, Fahian Tanin

Department of Agronomy and Horticulture: Faculty Publications

We introduce Stata and R codes to estimate the household smoke-exposure risk (SER) variable using cooking fuel- and cooking place-related information obtained from country-level demographic and health survey (DHS) data. Two categories of cooking fuels (smoke-producing and non-smoke producing fuels) and two categories of cooking places (indoor and outdoor) are used to estimate the household SER. Finally, household SER is classified into four levels of risk: high (cooking indoor using smoke-producing fuels), medium (cooking outdoor using smoke-producing fuels), low (cooking indoor using non-smoke-producing fuels), and very low (cooking outdoor using non-smoke-producing fuels). An example of a household SER calculation using …

The Vascular Flora Of Cleburne County, Alabama, Melanie T. Spaulding

Theses

Cleburne County is located in Northeast Alabama and measures 145,298 hectares. Approximately one-third of the county lies within the Talladega National Forest, more than any other county covered by the Talladega National Forest. The county has two physiographic regions: Piedmont and Ridge and Valley. A floristic survey of Cleburne County, Alabama, was conducted on public and private lands from 2014– 2020. Sporadic field collections took place from March 2014 – April 2019, with extensive fieldwork conducted from May 2019 – October 2020. A total of 1,302 vascular plant taxa are reported, including 266 taxa not previously documented for the county. …

Agrobacterium Mediated Transformation Optimizations For Sugarcane (Saccharum Officinarum L.) Cultivar Spf-234 With Direct Organogenesis, Muhammad Nawaz, Naeem Iqbal, Rabia Hameed, Mehwish Mehwish, Shakra Jamil

Journal of Bioresource Management

Sugarcane (Saccharum officinarum L.) is the most important food and energy crop worldwide. In the present study, an efficient Agrobacterium mediated transformation and regeneration system for sugarcane cultivar SPF-234 was established. Agrobacterium tumefaciens strains EHA101and LBA4404 using vector pIG121 Hm, having GUS, HPTII and NPTII genes were used. Polymerase chain reaction (PCR) and histochemical assays confirmed the GUS gene expression. A 620 bp fragment from GUS positive plants was amplified. The GUS expressing putative transformants were 35% of the total plants formed under 30 minute immersion time and 72 hr of incubation period. The co-cultivation media having 60 …

Responses Of The Carnivorous Pink Spoonleaf Sundew (Drosera Capillaris) To Nitrogen Addition, Phosphorus Addition, And Simulated Fire, Karina Rodriguez Castillo

Honors Theses

This study investigated how the carnivorous plant, Drosera capillaris(pink sundew), responded to changes in the resources of its habitat, the fire-prone, nutrient-poor wet savannas. It is of interest to determine what soil nutrient(s), nitrogen or phosphorus, limits the survival and growth of pink sundew, and to what extent, if any, does fire affect the survival and growth of this carnivorous plant. My field experiments had twenty plots with two replicate groups consisting of four pink sundews in each plot. From the fall of 2017 to the fall of 2019, only half of the plots were clipped annually, and there …

Evaluating Silicon Foliar Sprays As A Strategy To Improve Postproduction Performance Of Potted Basil (Ocimum Basilicum L.), Joshua Tebow

Horticulture Undergraduate Honors Theses

The objective of the study was to evaluate foliar silicon (Si) applications for effects on the growth and performance of container-grown basil during production and resistance to postproduction wilt in retail. Basil (Ocimum basilicum ‘Genovese’ L.) seedling plugs were transplanted into 10-cm diameter plastic containers with peat-based substrate and grown for 42 d in a polycarbonate greenhouse. Plants were irrigated with fertilizer solution consisting of a 17.0 nitrogen (N)-1.3 phosphorus-14.1 potassium water-soluble fertilizer dissolved in tap water at 150 mg∙L-1 N. Foliar sprays containing sodium silicate at 0, 50, 100, 200, and 400 mg∙L-1 Si mixed with deionized water were …

The Effect Of Anionic Surfactants On Herbicide Mixtures And Solutions, Ely Daniel Anderson

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

Herbicide mixtures are popular for farmers to delay the evolution of herbicide-resistant biotypes from occurring and control existing herbicide-resistant weeds. Glufosinate is a contact herbicide that has been observed as a mixture partner with many herbicides. In many cases, antagonistic interactions have occurred when using glufosinate in mixture with other herbicides. The antagonistic interactions have resulted in applications with incomplete weed control. Adjuvants have been known to impact an herbicide application by increasing herbicide penetration, spreadability, and efficacy. Adjuvants added to glufosinate mixtures can impact spray applications and increase weed control. The objectives of this research were: (1) investigate the …

An Analysis Of The Pollinators Of Echinacea Purpurea In Relation To Their Perceived Efficiency And Color Preferences, Carmen Black

Honors Theses

This study aimed to better understand how insects interacted with species of Echinacea in Tennessee and specifically their preference to floral color. Based on previous studies I expected the main visitors to be composed of various bees, beetles and butterflies. Based on previous studies, I hypothesized that most bees (especially social bees) would most likely pollinate the purple/violet morphs of the flower versus the white morph. I also expected the bees would have the most visits to the coneflowers versus any other taxonomic group. I believe bees to be the majority of pollinators based upon the results of Stucky, Gadd, …

Not All Pollinator Gardens Are Created Equally: Determining Factors Pertinent To Improving Pollinator Garden Effectiveness, Travis Watson

Electronic Theses and Dissertations

Increasing evidence documenting the decline of insect populations, resulting from increasing human disturbances has resulted in efforts to establish pollinator gardens to provide additional resources for insect populations. However, our understanding of biotic and abiotic garden characteristics important for attracting and sustaining pollinator diversity is limited. Here, we evaluated 17 pollinator gardens to evaluate the effect of five biotic and three abiotic garden characteristics on pollinator species richness, abundance, and proportional representation of four pollinator functional groups. Plant species richness positively influenced pollinator richness and negatively influenced flower visitation. Bombus proportional abundance responded to several variables (distance to vegetation, plant …

Seaweed Monitoring In The Great Bay Estuary, Nh: 2020 Annual Report, Andrew Payne, David M. Burdick, Gregg Moore, Natalie White, Christopher Peter, Arthur Mathieson

Jackson Estuarine Laboratory

As water temperatures rise due to global warming and nitrogen inputs change, it is important to understand how these changes are impacting vegetative communities that form the basic habitat structure in the Great Bay Estuary, NH. The abundance and taxa of intertidal seaweeds have been monitored at fixed locations throughout the Estuary since 2013. In 2020, percent cover and biomass were collected from five intertidal and four subtidal sampling locations. Data from 2013-2020 show appreciable amounts of nuisance seaweeds (primarily reds), including several introduced species. Cover of green seaweeds decreased significantly over time at the two intertidal sites (Depot Road …

Photographs Of Seaweeds In Intertidal Monitoring Plots, 2020, David M. Burdick, Gregg Moore

Jackson Estuarine Laboratory

Records of photographs of intertidal seaweed sampling plots for cover (50 by 50 cm) and biomass (25 by 25 cm) collected by Jackson Estuarine Laboratory research staff in 2020.

Subtidal Seaweed And Eelgrass Monitoring Photographs 2020, David M. Burdick, Gregg E. Moore

Jackson Estuarine Laboratory

Records of photographs of subtidal seaweed and eelgrass sampling plots for cover (50 by 50 cm) collected by Jackson Estuarine Laboratory research staff in 2020.

Sciadopitys Verticillata (Japanese Umbrella Pine), #1065-1067, Grace C. Kubat

BIO 140 Arboretum Project

Over the course of the 2021 spring semester, I observed a grove of Japanese Umbrella Pines. These trees are a part of the University's arboretum. In addition to making weekly observations, I researched the cultural significance of the Umbrella Pines. My research will hopefully contribute to future projects regarding the trees and help to enrich the University's arboretum project.

Phenotypic Plasticity Of Diverse Sorghum Varieties In Response To Nitrogen Deficit Stress, Mackenzie Zwiener

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

The movement of nutrients from old vegetative tissue to young leaves and reproductive organs is known as senescence. Senescence can be influenced by the environment of a plant, such as, drought, heat, and nutrient stress. These environmental stressors can also influence canopy architecture. Crop canopy consists of several traits including: leaf number, angle, length and width. Past research in crops like maize and rice have shown significant influences of more erect leaves, including, the ability for increased planting density, which optimizes light interception and increases yield. In a field trial of a sorghum association panel including 345 different sorghum varieties …