Digital Commons Network^™

The Importance Of Forage Legume Epigenetics In The Anthropocene, J. Brady, J. P. Muir, A. Falk

IGC Proceedings (1997-2023)

As climates change and economic as well as ecological pressures to produce more ruminant product on less land in the Anthropocene increase, the importance of using cutting-edge methods for forage legume improvement grows. The immediate return rate and turnaround on investment is likely greater for multi-species incorporation into grasslands but focusing on intraspecific variability and diversity could also contribute. The role of forage legumes in cultivated pasture and rangeland biodiversity as well as stability depends on genetics as well as management. Their epigenetics, however, may become increasingly important as climatic extremes and ecological pressures grow due to human-induced factors. Unfortunately, …

Targeted Sequencing Of The Panicum Miliaceum Gene Space And Genotyping Of Variant Sites From Population Genetics Studies, Combined In A Single Assay, As A Tool For Broomcorn Millet Assisted Breeding, Gabriele Magris, Serena Foria, Silvano Ciani, Dipak K. Santra, Ombretta Polenghi, Virna Cerne, Michele Morgante, Gabriele Di Gaspero

Department of Agronomy and Horticulture: Faculty Publications

Broomcorn millet (Panicum miliaceum L.) is a prehistorical cereal, today cultivated as a minor crop with low yields but with a renewed interest for its high water use effciency and gluten-free grains. To reverse the downward trend in broomcorn millet cultivation, the crop needs genetic improvement and creation of novel genetic variation to increase productivity. In order to facilitate genomics-assisted breeding, we designed a reduced representation genome-sequencing assay that investigates 1.8% of the nuclear DNA in a targeted and reproducible way, with an intensity of genomic sampling that is a direct function of local recombination rate. We used this …

Identifying Genetic Sources Of Anthracnose Resistance In Global Sorghum Lines, Mary-Frances Behnke

All Theses

Anthracnose of sorghum (causal agent: Colletotrichum sublineola) is the most detrimental disease of sorghum (Sorghum bicolor) worldwide, significantly reducing grain yield. This study includes a literature review of the disease and a meta-analysis of genome-wide association studies (GWAS) of anthracnose-resistance in sorghum as means to elucidate genetic sources of the trait. The meta-analysis includes genotypic and phenotypic data from 5 unique studies and 1,071 sorghum lines. Original genotyping-by-sequencing data from were obtained primarily from National Center for Biotechnology Information’s Sequence Read Archive (NCBI-SRA) and prepared and processed using the Tassel 5 GBS v2. pipeline. Phenotypic data were …

Population Genomic Characterization Of Cercospora Janseana On Rice In The Southern United States, Jacob Searight

LSU Master's Theses

Cercospora janseana is the causative agent of narrow brown leaf spot (NBLS). Effort had been undertaken since the 1940’s to control this disease through resistance breeding in the Southern United States. However, a severe epidemic of NBLS in 2006 inspired renewed focus on managing this disease. One tool for managing this disease has been identified among resistant cultivars, the CRSP-2.1 resistance locus to NBLS. One thing limiting the investment and deployment of CRSP-2.1, and other unknown resistance genes, is the historical observation that resistance to NBLS rapidly breaks-down in the field. Together, the rapid breakdown of resistance to NBLS …

Genomics And Transcriptomics To Protect Rice (Oryza Sativa L.) From Abiotic Stressors: -Pathways To Achieving Zero Hunger, Mushtaq Ahmad

Center for Plant Science Innovation: Faculty and Staff Publications

More over half of the world’s population depends on rice as a major food crop. Rice (Oryza sativa L.) is vulnerable to abiotic challenges including drought, cold, and salinity since it grown in semi-aquatic, tropical, or subtropical settings. Abiotic stress resistance has bred into rice plants since the earliest rice cultivation techniques. Prior to the discovery of the genome, abiotic stressrelated genes were identified using forward genetic methods, and abiotic stress-tolerant lines have developed using traditional breeding methods. Dynamic transcriptome expression represents the degree of gene expression in a specific cell, tissue, or organ of an individual organism at …

Editorial: Genomics-Enabled Triticeae Improvement, Xue-Feng Ma, Xianchun Xia, Shuyu Liu, P. Stephen Baenziger, Hakan Özkan

Department of Agronomy and Horticulture: Faculty Publications

No abstract provided.

Chromomap: An R Package For Interactive Visualization Of Multi-Omics Data And Annotation Of Chromosomes, Lakshay Anand, Carlos M. Rodriguez Lopez

Horticulture Faculty Publications

BACKGROUND: The recent advancements in high-throughput sequencing have resulted in the availability of annotated genomes, as well as of multi-omics data for many living organisms. This has increased the need for graphic tools that allow the concurrent visualization of genomes and feature-associated multi-omics data on single publication-ready plots.

RESULTS: We present chromoMap, an R package, developed for the construction of interactive visualizations of chromosomes/chromosomal regions, mapping of any chromosomal feature with known coordinates (i.e., protein coding genes, transposable elements, non-coding RNAs, microsatellites, etc.), and chromosomal regional characteristics (i.e. genomic feature density, gene expression, DNA methylation, chromatin modifications, etc.) of organisms …

Quantifying Contributions Of Climate, Geography, And Gene Flow To Divergence: A Case Study For Three North American Pines, Constance E. Bolte

Theses and Dissertations

Long-lived species of trees, especially conifers, often display weak patterns of reproductive isolation, but clear patterns of local adaptation and phenotypic divergence. Discovering the evolutionary history of these patterns is paramount to a generalized understanding of speciation and the processes that confer population persistence versus those that compromise adaptive potential under rapidly changing environments. Forest trees have long generation times and low migratory potential making them especially vulnerable to population fragmentation and reductions of genetic diversity due to insufficient tracking of niche optima and adaptational lags. Within clades of the genus Pinus, evolutionary histories appear to be riddled with hybridization …

Transgenesis And Genomics In Molecular Breeding Of Forage Plants, G. Spangenberg, R. Kalla, A. Lidgett, T. Sawbridge, E. K. Ong, U. John

IGC Proceedings (1997-2023)

Forage plant breeding has been largely based on phenotypic selection following sexual recombination of natural genetic variation found between and within ecotypes. Advances in plant genetic manipulation over the last 15 years have provided convincing evidence that these powerful technologies can complement and enhance plant breeding programs. Significant progress in the establishment of the methodologies required for the molecular breeding of forage plants has been made. Examples of current products and approaches for the application of these methodologies to forage grass and legume improvement are outlined. Large-scale genomic analysis of many organisms is under way with human, arabidopsis and rice …

Chloroplast Genome Evolution In The Klebsormidiophyceae And Streptofilum, Sarah Glass

Theses

The Klebsormidiophyceae are a class of green microalgae found globally in both freshwater and terrestrial habitats. Morphology-based classification schemes of this class have been shown to be insufficient, particularly due to the simple morphology of these algae, the tendency of morphology to vary in culture versus in field conditions, and rampant morphological homoplasy. Molecular studies revealing cryptic diversity have renewed interest in this group. We sequenced the complete chloroplast genomes of taxa in the Klebsormidiophyceae representing the known taxonomic breadth of this class, as well as the chloroplast genomes of three strains of Streptofilum, a recently discovered algal lineage …

Genomic Resources In Plant Breeding For Sustainable Agriculture, Mahendar Thudi, Rajeev K. Varshney, James C. Schnable

Department of Agronomy and Horticulture: Faculty Publications

Climate change during the last 40 years has had a serious impact on agriculture and threatens global food and nutritional security. From over half a million plant species, cereals and legumes are the most important for food and nutritional security. Although systematic plant breeding has a relatively short history, con- ventional breeding coupled with advances in technology and crop management strategies has increased crop yields by 56 % globally between 1965− 85, referred to as the Green Revolution. Nevertheless, increased demand for food, feed, fiber, and fuel necessitates the need to break existing yield barriers in many crop plants. In …

Molecular Genetic Analysis Of Drought Resistance And Productivity Traits Of Rice Genotypes, Yheni Dwiningsih

Graduate Theses and Dissertations

Rice (Oryza sativa L.) is the staple food for a majority of the world’s population, and uses 30% of the global fresh water during its life cycle. Drought at the reproductive stage is the most important abiotic stress factor limiting grain yield. The United States is the third largest exporter of rice, and Arkansas is the top rice-producing state. The Arkansas rice-growing region in the Lower Mississippi belt is among the 10 areas with the highest risk of water scarcity. Adapted U.S. rice cultivars were screened for drought resistant (DR) traits to find sources for breeding U.S. rice cultivars for …

Genome-Wide Identification And Analysis Of Heterotic Loci In Three Maize Hybrids, Hongjun Liu, Qin Wang, Mengjiao Chen, Yahui Ding, Xuerong Yang, Jie Liu, Xiaohan Li, Congcong Zhou, Qilin Tian, Yiqi Lu, Danlin Fan, Junpeng Shi, Lin Zhang, Congbin Kang, Mingfei Mingfei Sun, Fangyuan Li, Yujian Wu, Yongzhong Zhang, Baoshen Liu, Xiang Yu Zhao, Qi Feng, Jinliang Yang, Bin Han, Jinsheng Lai, Xian Sheng Zhang, Xuehui Huang

Department of Agronomy and Horticulture: Faculty Publications

Heterosis, or hybrid vigour, is a predominant phenomenon in plant genetics, serving as the basis of crop hybrid breeding, but the causative loci and genes underlying heterosis remain unclear in many crops. Here, we present a large-scale genetic analysis using 5360 offsprings from three elite maize hybrids, which identifies 628 loci underlying 19 yield-related traits with relatively high mapping resolutions. Heterotic pattern investigations of the 628 loci show that numerous loci, mostly with complete–incomplete dominance (the major one) or overdominance effects (the secondary one) for heterozygous genotypes and nearly equal proportion of advantageous alleles from both parental lines, are the …

A Bioinformatic Approach To Exploring Land Plant Evolution, Lauren Margaret Orton

Graduate Research Theses & Dissertations

Today, researchers are inundated with an overwhelming amount of data due to advances in DNA sequencing technologies. This has benefited the fields of both bioinformatics and phylogenomics substantially. With the ability to increase sampling at both the taxonomic and molecular levels, we are now able to produce robust phylogenomic reconstructions and better discern relationships between taxa.

The goals of this dissertation are in two distinct parts: 1) to advance the understanding of land plant terrestrialization and evolution through examination of the closest relative to the land plant lineage, a species of green algae; and 2) to explore evolution among a …

Leveraging Genome-Enabled Growth Models To Study Shoot Growth Responses To Water Deficit In Rice, Malachy T. Campbell, Alexandre Grondin, Harkamal Walia, Gota Morota

Department of Agronomy and Horticulture: Faculty Publications

lucidating genotype-by-environment interactions and partitioning its contribution to phenotypic variation remains a challenge for plant scientists. We propose a framework that utilizes genome-wide markers to model genotype-specific shoot growth trajectories as a function of time and soil water availability. A rice diversity panel was phenotyped daily for 21 d using an automated, high-throughput image-based, phenotyping platform that enabled estimation of daily shoot biomass and soil water content. Using these data, we modeled shoot growth as a function of time and soil water content, and were able to determine the time point where an inflection in the growth trajectory occurred. We …

Genome Of The Tropical Plant Marchantia Inflexa: Implications For Sex Chromosome Evolution And Dehydration Tolerance, Rose A. Marks, Jeramiah J. Smith, Quentin Cronk, Christopher J. Grassa, D. Nicholas Mcletchie

Biology Faculty Publications

We present a draft genome assembly for the tropical liverwort, Marchantia inflexa, which adds to a growing body of genomic resources for bryophytes and provides an important perspective on the evolution and diversification of land plants. We specifically address questions related to sex chromosome evolution, sexual dimorphisms, and the genomic underpinnings of dehydration tolerance. This assembly leveraged the recently published genome of related liverwort, M. polymorpha, to improve scaffolding and annotation, aid in the identification of sex-linked sequences, and quantify patterns of sequence differentiation within Marchantia. We find that genes on sex chromosomes are under greater …

Intraspecific Variation In Dehydration Tolerance: Insights From The Tropical Plant Marchantia Inflexa, Rose A. Marks

Theses and Dissertations--Biology

Plants are threatened by global change, increasing variability in weather patterns, and associated abiotic stress. Consequently, there is an urgent need to enhance our ability to predict plant community dynamics, shifts in species distributions, and physiological responses to environmental challenges. By building a fundamental understanding of plant stress tolerance, it may be possibly to protect the ecological services, economic industries, and communities that depend on plants. Dehydration tolerance (DhT) is an important mechanism of water stress tolerance with promising translational applications. Here, I take advantage natural variation in DhT to gain a deeper insight into this complex trait. In addition, …

Natural Selection For Disease Resistance In Hybrid Poplars Targets Stomatal Patterning Traits And Regulatory Genes., Karl Christian Fetter

Graduate College Dissertations and Theses

The evolution of disease resistance in plants occurs within a framework of interacting

phenotypes, balancing natural selection for life-history traits along a continuum of

fast-growing and poorly defended, or slow-growing and well-defended lifestyles. Plant

populations connected by gene flow are physiologically limited to evolving along a

single axis of the spectrum of the growth-defense trade-off, and strong local selection

can purge phenotypic variance from a population or species, making it difficult to

detect variation linked to the trade-off. Hybridization between two species that have

evolved different growth-defense trade-off optima can reveal trade-offs hidden in either

species by introducing phenotypic and …

The Evolution And Domestication Genetics Of The Mango Genus, Mangifera (Anacardiaceae), Emily Warschefsky

FIU Electronic Theses and Dissertations

Domesticated species are vital to global food security and have also been foundational to the formulation and advancement of evolutionary theory. My dissertation employs emerging molecular genomic tools to provide an evolutionary context for crop improvement. I begin by providing a contemporary perspective on two components of domestication biology that have long been used to improve crop production: wild relatives of crop species and grafted rootstocks. First, I propose a method to systematically introgress crop wild relative diversity into crop breeding programs. Then, I explore rootstocks, the lesser-known half of the perennial crop equation, documenting prevalence and diversity, cataloging rootstock …

Conservation And Variation Of Dna Methylation In Lactuca Sativa And Lactuca Serriola, Trudi A. Baker

Graduate Doctoral Dissertations

Molecular techniques for guiding plant breeding have successfully used wild progenitors of domestic crops as sources of genetic variants conveying desirable traits. However, epigenetic variation, in particular DNA methylation, is a significant source of phenotypic variation and epigenetic effects of plant domestication are poorly understood. Described herein are the first single-base pair resolution methylomes of the highly valued crop iceberg lettuce (Lactuca sativa cv. Salinas) and its close relative, and ubiquitous weed, L. serriola. This work suggests several roles for acquisition and inheritance of methylation in the evolution of Lactuca spp. in response to stress. The Lactuca spp. have conserved …

Genomic Approaches For Improvement Of Understudied Grasses, Keenan Amundsen, Gautam Sarath, Teresa Donze-Reiner

Teresa Donze-Reiner

No abstract provided.

Dissecting The Genetic Basis Of Salt Tolerance In Rice (Oryza Sativa), Malachy Thomas Campbell

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

Excessive salt is a major factor limiting crop productivity. Rice is an important food crop worldwide, and provides a major source of calories for billions of people in tropical and subtropical developing countries. In many regions throughout Southeast Asia, rice is grown in low-lying coastal regions, which are prone to ingress by seawater. Rice is highly sensitive to salt stress, with mild salinity resulting in large reductions in yield. Improving salt tolerance in rice is essential for ensuring food security for many individuals throughput the developing world.

In this work, the overall goals were to characterize a diverse collection of …

Genomic Approaches For Improvement Of Understudied Grasses, Keenan Amundsen, Gautam Sarath, Teresa Donze-Reiner

Biology Faculty Publications

No abstract provided.

A Comparative Genomic Analysis Of Putative Pathogenicity Genes In The Host-Specific Sibling Species Colletotrichum Graminicola And Colletotrichum Sublineola, Ester A. S. Buiate, Katia Viana Xavier, Neil Moore, Maria F. Torres, Mark L. Farman, Christopher L. Schardl, Lisa J. Vaillancourt

Plant Pathology Faculty Publications

Background: Colletotrichum graminicola and C. sublineola cause anthracnose leaf and stalk diseases of maize and sorghum, respectively. In spite of their close evolutionary relationship, the two species are completely host-specific. Host specificity is often attributed to pathogen virulence factors, including specialized secondary metabolites (SSM), and small-secreted protein (SSP) effectors. Genes relevant to these categories were manually annotated in two co-occurring, contemporaneous strains of C. graminicola and C. sublineola. A comparative genomic and phylogenetic analysis was performed to address the evolutionary relationships among these and other divergent gene families in the two strains.

Results: Inoculation of maize with C. sublineola …

Editorial: Genomic Approaches For Improvement Of Understudied Grasses, Keenan Amundsen, Gautam Sarath, Teresa Donze-Reiner

Department of Agronomy and Horticulture: Faculty Publications

Grasses are diverse, spanning native prairies to high-yielding grain cropping systems. They are valued for their beauty and useful for soil stabilization, pollution mitigation, biofuel production, nutritional value, and forage quality; grasses encompass the most important grain crops in the world. There are thousands of distinct grass species and many have promiscuous hybridization patterns, blurring species boundaries. Resources for advancing the science and knowledgebase of individual grass species or their unique characteristics varies, often proportional to their perceived value to society. For many grasses, limited genetic information hinders research progress. Presented in this research topic is a brief snapshot of …

Understanding Plant Response To Stress Using Gene Model Quality Evaluation And Transcriptome Analysis, Karthik Ramaswamy Padmanabhan

Open Access Dissertations

The overall aim of the project was to understand how plants reacted to environmental stress and evolved to overcome it. The land plants that we see today evolved from a green algal ancestor around 510 million years ago. Plants had to make significant changes to their cellular, morphological, regulatory and physiological processes during their adaptation to the terrestrial environment from an aquatic environment. The first part of the project was to find out how these changes were reflected on the protein makeup of the early land plants. The gene model sequence data of two early land plants, Physcomitrella patens (moss) …

Distribution Of Genomic Variation In The Usda Soybean Germplasm Collection And Relationship With Phenotypic Variation, Nonoy Batiller Bandillo

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

The USDA Soybean Germplasm Collection harbors a large stock of genetic diversity with potential to accelerate soybean cultivar development. The extent and nature of favorable alleles contained in the collection are not well known nor is the distribution of genetic variation and how it relates to phenotypic variation. The genotyping of the entire USDA Soybean Germplasm Collection marked the beginning of a systematic exploration of genetic diversity for genetic research and breeding. In this research, we conducted the first comprehensive analysis of population structure on the collection of ~14,400 soybean accessions [Glycine max (L.) Merr. and G. soja Siebold …

Transcriptome Sequencing Of Mung Bean (Vigna Radiate L.) Genes And The Identification Of Est-Ssr Markers, Honglin Chen, Lixia Wang, Suhua Wang, Chunji Liu, Matthew Wohlgemuth Blair, Xuzhen Cheng

Agricultural and Environmental Sciences Faculty Research

Mung bean (Vigna radiate (L.) Wilczek) is an important traditional food legume crop, with high economic and nutritional value. It is widely grown in China and other Asian countries. Despite its importance, genomic information is currently unavailable for this crop plant species or some of its close relatives in the Vigna genus. In this study, more than 103 million high quality cDNA sequence reads were obtained from mung bean using Illumina paired-end sequencing technology. The processed reads were assembled into 48,693 unigenes with an average length of 874 bp. Of these unigenes, 25,820 (53.0%) and 23,235 (47.7%) showed significant …

Recent Advances In Potato Genomics, Transcriptomics, And Transgenicsunder Drought And Heat Stresses: A Review, Emre Aksoy, Ufuk Demi̇rel, Zahi̇de Nesli̇han Öztürk, Sevgi̇ Çalişkan, Mehmet Emi̇n Çalişkan

Turkish Journal of Botany

Sustainable potato production practices are crucial for food security and social sustainability in the future since potato is a highly nutritious food and it is considered as one of the most promising crops to reduce human hunger and poverty in the world due to its high yield potential. However, being a temperate crop, potato is exposed to various environmental stresses, including extended periods of drought and heat. The majority of potato genomics, transcriptomics, and transgenics studies concentrate on the characterization of molecular mechanisms governing cold hardiness of tubers and response and tolerance mechanisms against diseases. Likewise, potato breeding studies focus …

An Exploration Of Fern Genome Space, Paul G. Wolf, Emily B. Sessa, D. Blaine Marchant, Fay-Wei Li, Carl J. Rothfels, Erin M. Sigel, Mathew A. Gitzendanner, Clayton J. Visger, Jo Ann Banks, Douglas E. Soltis, Pamela S. Soltis, Kathleen M. Pryer, Joshua P. Der

An Exploration of Fern Genome Space

Ferns are one of the few remaining major clades of land plants for which a complete genome sequence is lacking. Knowledge of genome space in ferns will enable broad-scale comparative analyses of land plant genes and genomes, provide insights into genome evolution across green plants, and shed light on genetic and genomic features that characterize ferns, such as their high chromosome numbers and large genome sizes. As part of an initial exploration into fern genome space, we used a whole genome shotgun sequencing approach to obtain low-density coverage (1X to 2X) for six fern species from the Polypodiales (Ceratopteris …