Plant Breeding and Genetics Commons^™

Integrating Genomic And Phenomic Breeding Tools For Wheat Stem Sawfly Resistance In Hard Winter Wheat, Sydney E. Graham

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

The wheat stem sawfly (WSS; Cephus cinctus) is an insect pest that affects wheat (Triticum aestivum) in the Northern Great Plains. This pest causes stem cutting that makes the plants susceptible to lodging and results in up to 30% yield loss. The primary management strategy for producers is utilizing host plant resistance, for which the main trait is stem solidness. This trait increases the pith thickness and provides resistance to the WSS by increasing larval mortality and reducing stem cutting. While stem solidness is largely controlled by a known major gene (SSt1), the phenotypic expression is also …

Leveraging Historical Data For Estimating Genetic Gain And Implementing Genomic Selection In A Student Led Barley Breeding Program, Sydney Graham

Department of Statistics: Dissertations, Theses, and Student Research

In Nebraska, winter feed barley presents an emerging market for producers and an opportunity to diversify cropping systems. The University of Nebraska Barley Breeding Program aims to develop high-yielding, winter-hardy varieties. A unique aspect of this program is that doctoral students serve as barley breeders and are responsible for crossing, data collection, and advancement decisions. While this provides hands-on experience for the students, the impact of student leadership has not been examined.

This study used a historical data set to evaluate the realized genetic gain of the breeding program, and as a training population for genomic selection. The dataset consisted …

Understanding The Impact Of Fall Armyworm (Spodoptera Frugiperda) Feeding, And Drought Stress On Drought-Tolerant And Drought-Resistant Soybean (Glycine Max)., Adriana G. Peissel

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Drought and insect herbivory are two major stressors on high-value crops like soybean (Glycine max). However, few studies have explored how these stressors interact, despite their presence in tandem under field conditions. We investigated how drought stress and fall armyworm (Spodoptera frugiperda) caterpillar herbivory impact Magellan (drought-tolerant) and Blackhawk (drought-susceptible) soybean cultivars. The soybean plants were subject to four treatment groups (1. Drought 2. Herbivory 3. Drought + Herbivory 4. Well-Watered) during a treatment period of 7 days in a greenhouse. We then measured plant height, physiological traits, trichome density, soil moisture, and larval mass gain. …

Identification And Characterization Of Intermediate Phenotypes To Decipher Genetic Architecture Of Stalk Lodging Resistance In Maize (Zea Mays L.), Bharath Kunduru

All Dissertations

Maize is a key contributor to global food security and incurs severe yield losses due to stalk lodging, the permanent displacement of plants from an upright growth habit due to mechanical damage to the stem (stalk). Stalk lodging resistance, an indicator of the stalk ability to resist lodging, is a complex trait and determined by several structural, geometric, and material properties of stalks, collectively referred to as intermediate phenotypes, whose identity and genetic framework are poorly understood. Therefore, progress in resolving the genetic architecture of stalk lodging resistance was impeded by a lack of standardized phenotyping methodologies and a poor …

Understanding The Genetic And Metabolic Underpinnings Of Complex Traits In C4 Grasses, Manwinder Singh Brar

All Dissertations

Maize (Zea mays L.) and sorghum (Sorghum bicolor (L.) Moench) are two important cereal crops cultivated worldwide for food, animal feed, and industrial products. Productivity of these crops is significantly impacted by various biotic and abiotic stresses, such as diseases, insect pests, drought, salinity, and heat. Among factors influencing crop performance under stress, the regulation of leaf longevity plays a critical role in determining yield. Leaf senescence is a highly regulated process essential for nutrient remobilization through the degradation of cellular components in aging leaves, but premature or accelerated senescence reduces photosynthetic efficiency and yield. Staygreen, a phenotype …

Investigating The Effects Of Gibberellin Treatments On Different Dwarf Millet Genotypes And Identifying The Mechanism Responsible For Genetic Dwarfism, Macie Mccarty, Audrie Miller, Quinn Calvert, Abi Waters, Dania Creary, Justin Coleman

2025 Student Academic Showcase

Gibberellins (GAs) are essential plant hormones involved in regulating growth and development, particularly in stem elongation, seed germination, and flowering. In cereal crops like millet, dwarf genotypes are of agricultural interest due to their potential for increased stability and yield efficiency. However, the genetic mechanisms underlying dwarfism in millet remain unclear. This study investigates the response of various dwarf millet genotypes to gibberellin treatments and seeks to determine the genetic basis of their dwarfism. We hypothesize that genotypes with gibberellin biosynthesis deficiencies will exhibit increased stem elongation when treated with gibberellin, while genotypes with signal transduction defects will show minimal …

The Effect Of Gibberellins On Dwarf Millet Growth, Rylee Deckard, Reed Morrison, Chase Christopher, Amy Brice, Sanduni Galbokka Hewa, Malina Roberson, Matthew Palmer

2025 Student Academic Showcase

Dwarf and semidwarf variants of agricultural plants are used to decrease lodging without decreasing crop yield. Some dwarf genotypes lack the ability to produce the growth hormone gibberellin, and others lack complete receptor pathways. Exogenous gibberellic acid (GA) was applied to four dwarf millet genotypes over the course of six weeks to determine what pathway for dwarfism each dwarf genotype was. Statistical analysis was done to analyze the relationship between GA applications and increased plant growth. It was found that all genotypes had some response to the treatment, though some were more extreme than others. Additionally, the treatment group had …

Arkansas Cotton Variety Tests 2024, F. Bourland, J. Gann, B. Lovelady, B. Guest Jr., J. Mcalee, L. Martin, Z. Treadway, C. Henderson

Arkansas Agricultural Experiment Station Research Series

The primary goal of the Arkansas Cotton Variety Tests is to provide unbiased data regarding the agronomic performance of cotton varieties and advanced breeding lines in the major cotton-growing areas of Arkansas. This information helps seed companies establish marketing strategies and assists producers in choosing varieties to plant. These annual evaluations will then facilitate the inclusion of new, improved genetic material in Arkansas cotton production. Adaptation of varieties is determined by evaluating the lines at five University of Arkansas System Division of Agriculture research sites (Manila, Keiser, Judd Hill, Marianna, and Rohwer). The 2024 tests at Keiser were adversely affected …

Crispr-Induced Mutagenesis Of Arabidopsis Thaliana Gene Apetala3, Hazel Frans, Tara Phelps-Durr

SACAD: Scholarly Activities

This project aims to create CRISPR-CAS9 mutations in the APETELA3 (AP3) gene of the model plant Arabidopsis thaliana. AP3 is a class B gene critical to the petal and stamen development of Arabidopsis flowers. AP3 is defined in a MADS domain, which binds directly to DNA and may be responsible for the expression of the CaRG-box genes. AP3 works in conjunction with PISTILLATA (PI), AGAMOUS (AG), APETALA1 (AP1), and SEPALLATA (SEP) genes to specify the development in the second and third whorls of the flower. While several alleles of AP3 already exist, these alleles are strong alleles that knockout gene …

Hordeum I Genome Unlocks Adaptive Evolution And Genetic Potential For Crop Improvement, Hao Feng, Qingwei Du, Ying Jiang, Yong Jia, Tianhua He, Yibin Wang, Brett Chapman, Jiaxin Yu, Hiawen Zhang, Mengxue Gu, Mengwei Jiang, Shanshan Gao, Xinjie Zhang, Yameng Song, Vanika Garg, Rajeev K. Varshney, Jianhua Wei, Chengdao Li, Xingtan Zhang, Ruifen Li

Grain and Other Field Crops Research Articles

Crop wild relatives (CWRs) are invaluable for crop improvement. Among these, Hordeum I-genome species exhibit exceptional tolerance to alkali and salt stresses. Here we present a chromosome-scale genome assembly of Hordeum brevisubulatum (II, 2n = 2x =14) and genome resequencing of 38 diploid germplasms spanning 7 I-genome species. We reveal that the adaptive evolution of the H. brevisubulatum genome is shaped by structural variations, some of which may contribute to its adaptation to high alkali and salt environments. Evolutionary duplication of the stress sensor-responder module CaBP-NRT2 and the horizontally transferred fungal gene Fhb7 were identified as novel alkaline–saline …

Inter-Simple Sequence Repeats Application On The Identification Of Genetic Variation Of A New Indonesian Melon Cultivar “Melona”, Tantri Ajeng Salma Salsabila, Adib Fakhruddin Yusuf, Wiko Arif Wibowo, Prima Sekti Kusnanda, Budi Setiadi Daryono

Makara Journal of Science

The field of identification of molecular markers has seen significant advancements, with the Inter-Simple Sequence Repeat (ISSR) emerging as a prominent tool for characterizing genetic variation within species. This study focuses on the new Indonesian melon cultivar “Melona,” developed through selective breeding of commercial melons. This study aimed to assess the utility of ISSR markers in evaluating the genetic variation and stability of the “Melona” cultivar. Comparisons were made with established cultivars—‘Inthanon,” “Rich Sweetness,” “Chamoe,” and “Hikapel”—using five ISSR primers: UBC 807, UBC 808, UBC 810, UBC 812, and UBC 826. A total of 70 DNA fragments with a high …

Morphological Characterization, Pollen Viability, And Germinability Evaluation Of Two Plumeria Species In The University Of The Philippines Los Baños, Darel Kenth S. Antesco, Maria Charito E. Balladares, Alangelico O. San Pascual, Pablito M. Magdalita, Fernando C. Sanchez Jr

The Philippine Agricultural Scientist

The genus Plumeria, locally known as kalachuci, is a popular ornamental tree belonging to the Apocynaceae family. The University of the Philippines Los Baños (UPLB) maintains a collection of Plumeria trees scattered across its campus; however, the origin of these trees remains unclear due to a lack of proper documentation. This study conducted morphological characterization and pollen analysis to provide information for further research. Results revealed the presence of 2 Plumeria species in the campus. P. obtusa has a linear leaf shape with acute tips and revolute margins while P. rubra has a lanceolate leaf shape. Additionally, P. …

Arkansas Soybean Performance Tests 2024, J. F. Carlin, R. D. Bond, T. C. Swanson, J. C. Mccoy

Arkansas Agricultural Experiment Station Research Series

Soybean variety and strain performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture’s Arkansas Crop Variety Improvement Program. The tests provide information to companies developing varieties and/ or marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating variety recommendations for soybean producers.

Arkansas Soybean Research Studies 2023, Jeremy Ross

Arkansas Agricultural Experiment Station Research Series

The 2023 Arkansas Soybean Research Studies includes research reports on topics pertaining to soybean across several disciplines from breeding to post-harvest processing. Research reports contained in this publication may represent preliminary or only data from a single year or limited results; therefore, these results should not be used as a basis for long-term recommendations.

Several research reports in this publication will appear in other University of Arkansas System Division of Agriculture’s Arkansas Agricultural Experiment Station publications. This duplication is the result of the overlap in research coverage between disciplines and our effort to inform Arkansas soybean producers of the research …

A Barley Pan-Transcriptome Reveals Layers Of Genotype-Dependent Transcriptional Complexity, Wenbin Guo, Miriam Schreiber, Vanda B. Marosi, Paolo Bagnaresi, Morten Egevang Jorgensen, Katarzyna B. Braune, Ken J. Chalmers, Brett Chapman, Viet Hoang Dang, Christoph Dockter, Anne Fiebig, Geoffrey B. Fincher, Agostino Fricano, John Fuller, Allison Haaning, Georg Haberer, Axel Himmelbach, Murukarthick Jayakodi, Yong Jia, Nadia Kamal, Peter Langridge, Chengdao Li

Grain and Other Field Crops Research Articles

A pan-transcriptome describes the transcriptional and post-transcriptional consequences of genome diversity from multiple individuals within a species. We developed a barley pan-transcriptome using 20 inbred genotypes representing domesticated barley diversity by generating and analyzing short- and long-read RNA-sequencing datasets from multiple tissues. To overcome single reference bias in transcript quantification, we constructed genotype-specific reference transcript datasets (RTDs) and integrated these into a linear pan-genome framework to create a pan-RTD, allowing transcript categorization as core, shell or cloud. Focusing on the core (expressed in all genotypes), we observed significant transcript abundance variation among tissues and between genotypes driven partly by RNA …

Arkansas Corn And Grain Sorghum Performance Tests 2024, J. F. Carlin, R. D. Bond, J. C. Mccoy, T. C. Swanson

Arkansas Agricultural Experiment Station Research Series

Corn and grain sorghum performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture. The tests provide information to companies marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating recommendations for producers.

The 2024 corn performance tests contained 44 hybrids and were conducted at the Northeast Rice Research and Extension Center (NERREC) at Harrisburg, the Lon Mann Cotton Research Station (LMCRS) near Marianna, the Rohwer Research Station (RRS) near Rohwer, and the Rice Research and Extension Center (RREC) near Stuttgart. The 2024 grain sorghum performance tests contained 16 …

Spatial Analysis Of American Chestnut (Castanea Dentata) Distribution And Ecology In Kentucky’S Federal Lands, Jacob Raymond Pease

Murray State Theses and Dissertations

Anthropogenic factors have been the cause of the decline of tree species across the globe. From unsustainable logging and development to disease and improper management, threats to forests have taken their toll. The American chestnut (Castanea dentata) was once an integral basal tree species in Appalachian forests, but chestnut blight drove the species to functional extinction by the mid-1900s. The recent creation of genetically modified chestnuts gives hope for future restoration of the species throughout its historical range. Despite blight resistance, effective restoration will require optimal site selection for finding and planting chestnuts, which will maximize limited resources. …

Identification Of A Stable Qtl For Juice Color In A Vitis Interspecific Hybrid ‘Chambourcin’- Based Population, Qiuni Yang

Graduate Theses/Dissertations

Berry juice color is one of the key factors influencing grape and wine quality, consumer preference, and marketability. While most previous studies on berry color have focused on the skin, research on juice color remains limited. This study investigated the genetic basis of berry juice color in a hybrid population derived from the Vitis interspecific hybrid ‘Chambourcin’ and V. vinifera ‘Cabernet Sauvignon’. A new nine-category visual scoring system was developed to assess juice color based on OIV 225. To achieve comprehensive precision and quantitative analysis, CIELAB parameters (L*, a*, b*), Hue, and Chroma were extracted from image-based measurements. Using berries …

2025 Standard-Sized Seedless Watermelon Cultivar Evaluation In Indiana, Wenjing Guan, Dennis Nowaskie, Cesar Escalante

Midwest Vegetable Trial Reports

Indiana ranked fifth in watermelon production in the United States. In 2024, Indiana growers planted approximately 8,100 acres of watermelons. Watermelon cultivar evaluation trials have been conducted annually at the Southwest Purdue Agricultural Center (SWPAC) in Vincennes, IN, for over 30 years. In 2025, 25 standard-sized seedless watermelons were evaluated, and yield and fruit quality parameters were assessed.

Optimization Of Transformation And Regeneration In The Sunflower (Helianthus Annuus), Sara M. Kilar

Masters Theses

In addition to their value as prized ornamentals, sunflowers are important crop species due to the nutritional value and high oil content of the seeds. Sunflower oil is a significant contributor to global seed oil production, which can be used as a food additive and cooking agent as well as a raw material for biodiesel production. While traditional breeding efforts have led to the development of many unique cultivars, genetically modified variations have proven more difficult due to the recalcitrance of sunflower plants to genetic transformation. As a result, facile and efficient transformation methods for sunflowers have the potential to …