Plant Breeding and Genetics Commons^™

Molecular Diversity Of Foliar Fungal Endophytes In Relation To Defense Strategies And Disease In Whitebark Pine, Lorinda Bullington

Graduate Student Theses, Dissertations, & Professional Papers

An invasive fungal pathogen, Cronartium ribicola (the causative agent of white pine blister rust) infects and kills whitebark pine (Pinus albicaulis) throughout the western US. Blister rust has decreased whitebark pine populations by over 90% in some areas. Whitebark pine, a keystone species, has been proposed for listing under the Endangered Species Act in the U.S., and the loss of this conifer is predicted to have severe impacts on forest composition and function in high elevations. Hundreds of asymptomatic fungal species live inside whitebark pine tissue, and recent studies suggest that these fungi can influence the frequency and …

Impact Of A High Oil And Protein On Agronomic Traits And Overall Seed Composition In Soybean, Maythem Al-Amery

Theses and Dissertations--Plant and Soil Sciences

New soybean lines have been developed with significantly higher oil, protein + oil and higher meal protein. These soybeans contain a VgD1 gene (highly active acyl-CoA:diacylglycerol acyltransferase, DGAT from Vernonia galamensis (VgDGAT1A) produces much higher oil synthesis and accumulation activity in soybean. Soybean with active DGAT from Vernonia galamensis (VgDGAT1A) has active TAG biosynthesis relative to other DGATs including from soybeans and Arabidopsis. DGATs catalyze the final step of TAG synthesis: DAG (diacylglycerol) + acyl-CoA → TAG + CoASH (Coenzyme A is notable for its role in the synthesis and oxidation of fatty acids, and the oxidation of pyruvate in …

Molecular Characterization Of Spot Blotch And Bacterial Leaf Streak Resistance In Bread Wheat, Girma Ayana

Electronic Theses and Dissertations

Spot blotch (SB), caused by Bipolaris sorokiniana (Sacc.) Shoem, and bacterial leaf streak (BLS), caused by Xanthomonas translucens pv. undulosa (Smith et al.), two important foliar diseases of wheat in the major production regions of the US and the world. Deployment of adequate host resistance against them depends on determining the resistance genes or quantitative trait loci (QTLs) responsible for the trait and identification of genetic markers linked to QTL that facilitate markers assisted breeding. We conducted two independent studies and characterized QTLs for BLS and SB resistance. In the first study, we constructed a genetic linkage map of 1,211 …

Differential Gene Expression In Two Nodule Zones Of Soybean, Sunita Pathak

Electronic Theses and Dissertations

Soybean, a leguminous plant and rhizobia establishes symbiotic relationships, forming root nodules. Nodule organogenesis starts with cortical cell division forming infection and parenchyma zones which houses N-fixing bacteria and block O2 for nitrogenase enzyme function, respectively. The mechanism by which root cortical cells give rise to two structurally and functionally different nodule tissues is not known. One approach to address this knowledge gap is to evaluate global gene expression patterns in these two tissue types during nodule development. Using INTACT method, we developed two promoters, ENOD2 (nodule parenchyma) and ENOD40 (infection zone) driven nuclear envelope biotin tagging constructs and isolated …

Silencing Seed Dormancy Genes To Mitigate Risk Of Transgene Flow To Weedy Rice, Alexander Wireko Kena

Electronic Theses and Dissertations

The flow of fitness-enhancing transgenes from genetically modified crops into wild/weed relatives may cause serious ecological and economic consequences. Seed dormancy (SD) is a key adaptive trait that distributes germination over time, resulting in weed persistence in agroecosystems. Thus, silencing major genes controlling SD would reduce the adaptive fitness of weeds. SD-enhancing genes cloned from weedy rice include SD7-1, SD7-2, SD12a, SD12b, and SD12c. The goal of this study was to develop a transgenic mitigation (TM) strategy using SD gene-silencing structures as mitigating factors to reduce the risk of transgene flow to wild/weed populations. TM vector constructs consisted of the …

Neutral And Adaptive Genetic Variation In North American Hardwood Tree Species, Sudhir Khodwekar

Dissertations, Master's Theses and Master's Reports

'Northern Hardwoods,’ are a characteristic composition of multiple tree species and a part of the rich and diverse northeastern forests. Hardwoods e.g. oaks (Quercus: Fagaceae and Sugar maple), serve as foundation species and offer ecological and economical gains to wildlife and humans. Most of the forest trees go through many biotic and abiotic stresses, for example climate change in their long life span. To overcome these threats and to adapt to changing conditions, tree species need to maintain variation especially in adaptive genes. Therefore, it is necessary to analyze genetic diversity within forest tree populations and take appropriate …

Primers For Castilleja And Their Utility Across Orobanchaceae: I. Chloroplast Primers, Maribeth Latvis, Sebastian M. E. Mortimer, Diego F. Morales-Briones, Samuel Torpey, Simon Uribe-Convers, Sarah J. Jacobs, Sarah Mathews, David C. Tank

Natural Resource Management Faculty Publications

Premise of the study: Chloroplast primers were developed from genomic data for the taxonomically challenging genus Castilleja. We further tested the broader utility of these primers across Orobanchaceae, identifying a core set of chloroplast primers amplifying across the clade.
Methods and Results: Using a combination of three low-coverage Castilleja genomes and sequence data from 12 Castilleja plastomes, 76 primer combinations were specifically designed and tested for Castilleja. The primers targeted the most variable portions of the plastome and were validated for their applicability across the clade. Of these, 38 primer combinations were subsequently evaluated in silico and then validated across …

Midwest Vegetable Trial Report For 2016, Elizabeth Maynard, Brad Bergefurd

Purdue Fruit and Vegetable Research Reports

This is a compilation of 21 research trial reports from six land-grant universities in the midwestern United States. Crops include dry beans, cantaloupe, cucumber, pepper, pumpkin, sweet corn, summer squash, winter squash, strawberry, tomato, watermelon, and winter melon. Several crops were evaluated in high tunnels or hoop houses. Most trials evaluated different cultivars or varieties. Three reports addressed specific growing practices: the use of poly-coated urea to supply nitrogen to sweet corn, potassium fertilization for high tunnel tomatoes, and use of cereal rye cover crop in butternut squash.

Midwest Vegetable Trial Report For 2016, Elizabeth Maynard, Brad Bergefurd

Midwest Vegetable Trial Reports

This is a compilation of 21 research trial reports from six land-grant universities in the midwestern United States. Crops include dry beans, cantaloupe, cucumber, pepper, pumpkin, sweet corn, summer squash, winter squash, strawberry, tomato, watermelon, and winter melon. Several crops were evaluated in high tunnels or hoop houses. Most trials evaluated different cultivars or varieties. Three reports addressed specific growing practices: the use of poly-coated urea to supply nitrogen to sweet corn, potassium fertilization for high tunnel tomatoes, and use of cereal rye cover crop in butternut squash.

Association Mapping Of Seed Weight, Protein, And Sucrose Content; And Kinetics Of Edamame Under Infrared Treatment, Laura Melissa Lara Santisteban

Graduate Theses and Dissertations

Edamame is a specialty large-seeded soybean (Glycine max L. Merr.) harvested at an immature stage (R6) that has become the second largest consumed soyfood. Although United States is the largest soybean producer, majority of edamame is imported from Asia, highlighting the importance of developing new edamame varieties. Association mapping (AM) provides an alternative to bi-parental linkage mapping method to detect quantitative trait loci (QTL) adding higher resolution and broader germplasm information. Seed weight, sucrose, and protein are quantitative traits of value when selecting edamame lines. However molecular mechanisms controlling each of these traits are still inconclusive and have not been …

Development Of Highly Variable Microsatellite Markers For The Tetraploid Silene Stellata (Caryophyllaceae), Juannan Zhou, Michele R. Dudash, Charles B. Fenster, Elizabeth A. Zimmer

Natural Resource Management Faculty Publications

Premise of the study:We designed and tested microsatellite markers for the North American native species Silene stellata (Caryophyllaceae) to investigate its population genetic structure and identify selection on floral design through male reproductive success.

Methods and Results: A total of 153 candidate microsatellite loci were isolated based on next-generation sequencing. We identified 18 polymorphic microsatellite loci in three populations of S. stellata, with di- or trinucleotide repeats. Genotyping results showed the number of alleles per locus ranged from six to 45 and expected heterozygosity ranged from 0.511 to 0.951. Five of these loci were successfully amplified in S. …

Quantitative Trait Loci Mapping, Genome-Wide Association Analysis, And Gene Expression Of Salt Tolerance In Soybean, Ailan Zeng

Graduate Theses and Dissertations

Salt stress is a common abiotic stress causing yield reduction in soybean. There are differential responses, namely tolerance (excluder) and intolerance (includer), among soybean germplasm. However, the genetic and physiological mechanism for salt tolerance is not clear. Identification of novel QTL for salt tolerance and genes that are differentially expressed under salt stress would help elucidate the salt tolerance mechanism and facilitate the development of salt tolerant cultivars through marker assisted selection (MAS). The objectives of this study were to identify new QTL or genes responsible for salt tolerance using three approaches: QTL mapping, association analysis, and RNA sequencing (RNA-seq). …

Orm Expression Alters Sphingolipid Homeostasis And Differentially Affects Ceramide Synthase Activity, Athen N. Kimberlin, Gongshe Han, Kyle D. Luttgeharm, Ming Chen, Rebecca E. Cahoon, Julie M. Stone, Jennifer E. Markham, Teresa M. Dunn, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty Publications

Sphingolipid synthesis is tightly regulated in eukaryotes. This regulation in plants ensures sufficient sphingolipids to support growth while limiting the accumulation of sphingolipid metabolites that induce programmed cell death. Serine palmitoyltransferase (SPT) catalyzes the first step in sphingolipid biosynthesis and is considered the primary sphingolipid homeostatic regulatory point. In this report, Arabidopsis (Arabidopsis thaliana) putative SPT regulatory proteins, orosomucoidlike proteins AtORM1 and AtORM2, were found to interact physically with Arabidopsis SPT and to suppress SPT activity when coexpressed with Arabidopsis SPT subunits long-chain base1 (LCB1) and LCB2 and the small subunit of SPT in a yeast ( …

Influence Of Source Credibility On Consumer Acceptance Of Genetically Modified Foods In China, Mingyang Zhang, Chao Chen, Wuyang Hu, Lijun Chen, Jintao Zhan

Agricultural Economics Faculty Publications

This paper examines the reasoning mechanism behind the consumer acceptance of genetically modified foods (GMFs) in China, and investigates influence of source credibility on consumer acceptance of GMFs. Based on the original Persuasion Model—which was developed by Carl Hovland, an American psychologist and pioneer in the study of communication and its effect on attitudes and beliefs—we conducted a survey using multistage sampling from 1167 urban residents, which were proportionally selected from six cities in three economic regions (south, central, and north) in the Jiangsu province through face to face interviews. Mixed-process regression that could correct endogeneity and ordered probit model …

Pengaruh Berbagai Dosis Pupuk Silika Organik Dan Tingkat Kekerasan Biji Terhadap Pertumbuhan Dan Hasil Tanaman Hanjeli Pulut (Coix Lacryma- Jobi.L) Genotip 37”, Tati Nurmala, Anni Yuniarti, N. Syahfitri

Jurnal Kultivasi

Penelitian ini bertujuan untuk mengetahui dosis silika organik dan tingkat kekerasan biji yang dapat memberikan pengaruh terbaik terhadap pertumbuhan dan hasil tanaman hanjeli pulut (Coix lacryma- Jobi.L). Penelitian ini dilaksanakan pada bulan Desember 2015 sampai dengan bulan Mei 2016 di Kebun Percobaan Ciparanje Fakultas Pertanian Universitas Padjadjaran, Jatinangor, Sumedang. Rancangan percobaan yang digunakan adalah Rancangan Acak Kelompok (RAK) yang terdiri dari enam perlakuan dan empat kali ulangan, yaitu: Kontrol; Silika dosis (4,50 g/tanaman); (9,00 g/tanaman); (13,50 g/tanaman); (18,00 g/tanaman); (22,50 g/tanaman), sehingga diperoleh 24 petak percobaan. Hasil penelitian menunjukkan bahwa, perlakuan tanpa pupuk silika organik berpengaruh terhadap biomassa total tanaman …

Transcriptome Response Of Cassava Leaves Under Natural Shade, Zehong Ding, Yang Zhang, Yi Xiao, Fangfang Liu, Minghui Wang, Xinguang Zhu, Peng Liu, Qi Sun, Wenquan Wang, Ming Peng, Tom Brutnell, Pinghua Li

Center for Plant Science Innovation: Faculty Publications

Cassava is an important staple crop in tropical and sub-tropical areas. As a common farming practice, cassava is usually cultivated intercropping with other crops and subjected to various degrees of shading, which causes reduced productivity. Herein, a comparative transcriptomic analysis was performed on a series of developmental cassava leaves under both full sunlight and natural shade conditions. Gene expression profiles of these two conditions exhibited similar developmental transitions, e.g. genes related to cell wall and basic cellular metabolism were highly expressed in immature leaves, genes involved in lipid metabolism and tetrapyrrole synthesis were highly expressed during the transition stages, and …

Phenotypic And Gene Expression Analysis Of Diverse Rice Genotypes In Response To Drought, Miranti Rahmaningsih

Graduate Theses and Dissertations

Drought is one of the most limiting factors for rice (Oryza sativa L.) growth and development with vegetative and reproductive stages the most sensitive and distinct phases. During the vegetative stage, drought can cause reduction in growth and biomass accumulation. Moreover, water stress at reproductive stage can reduce yield significantly. Plants are protected against drought by three different mechanisms: drought avoidance, drought tolerance, and drought escape. An integrated approach combining physiology, breeding, and genomics could be an effective way to characterize and mitigate this problem. The objectives of this research were to (1) screen a diverse set of rice genotypes …

Genetic Basis Of Biosynthesis And Cytotoxic Activity Of Medicago Truncatula Triterpene Saponins, Brynn Kathleen Lawrence

Graduate Theses and Dissertations

Saponins are a large family of specialized metabolites produced in many plants. They can have negative effects on a number of plant pests and are thought to play a role in plant defense. With current and possible future uses in industry and agriculture, saponins have also been shown to be hypocholesterolemic, hypoglycemic, immunostimulatory, antioxidative, anti-inflammatory, and cytotoxic. In spite of their usefulness, our understanding of the genetic basis for saponin biosynthesis is still incomplete. We generated recombinant populations with parents from genetically distinct accessions of Medicago truncatula, with either high or low accumulation and varying profiles of saponins. Primers for …

Comparative Evolutionary Analysis Of Organellar Genomic Diversity In Green Plants, Weishu Fan

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

The mitochondrial genome (mitogenome) and plastid genome (plastome) of plants vary immensely in genome size and gene content. They have also developed several eccentric features, such as the preference for horizontal gene transfer of mitochondrial genes, the reduction of the plastome in non-photosynthetic plants, and variable amounts of RNA editing affecting both genomes. Different organismal lifestyles can partially account for the highly diverse organellar genomes across the tree of green plants. For example, endosymbiotic and parasitic lifestyles can dramatically affect the genomic architectures of plant mitochondria and plastids. In this study, the organellar genomes of several green plants with atypical …

Reducing Pollen Dispersal Using Forest Windbreaks, Carol Auer, Thomas Meyer, Vernie Sagun

Plant Science Articles

The adoption of genetically engineered (GE) crops has created a demand for practical methods to mitigate pollen dispersal and gene flow. The goal of this project was to measure the ability of a narrow forest windbreak to reduce downwind pollen fluxes from switchgrass (Panicum virgatum L.), a North American grass and model biofuels feedstock. Switchgrass fields were established in two identical plots where one had a forest windbreak and the other was in an open (control) site. Switchgrass reproduction, pollen dispersal, wind speed, and wind direction were measured over two years. Daily release of switchgrass pollen peaked at 11:00-13:30 …

A Heavy Metal P-Type Atpase Oshma4 Prevents Copper Accumulation In Rice Grain, Xin-Yuan Huang, Fenglin Deng, Naoki Yamaji, Shannon R.M. Pinson, Miho Fujii-Kashino, John Danku, Alex Douglas, Mary Lou Guerinot, David Salt, Jian Feng Ma

Dartmouth Scholarship

Rice is a major source of calories and mineral nutrients for over half the world's human population. However, little is known in rice about the genetic basis of variation in accumulation of copper (Cu), an essential but potentially toxic nutrient. Here we identify OsHMA4 as the likely causal gene of a quantitative trait locus controlling Cu accumulation in rice grain. We provide evidence that OsHMA4 functions to sequester Cu into root vacuoles, limiting Cu accumulation in the grain. The difference in grain Cu accumulation is most likely attributed to a single amino acid substitution that leads to different OsHMA4 transport …

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 …

Rna-Seq Based Analysis Of Population Structure Within The Maize Inbred B73, Zhikai Liang, James C. Schnable

Center for Plant Science Innovation: Faculty Publications

Recent reports have shown than many identically named genetic lines used in research around the world actually contain large amounts of uncharacterized genetic variation as a result of cross contamination of stocks, unintentional crossing, residual heterozygosity within original stocks, or de novo mutation. 27 public, large scale, RNA-seq datasets from 20 independent research groups around the world were used to assess variation within the maize (Zea mays ssp. mays) inbred B73, a four decade old variety which served as the reference genotype for the original maize genome sequencing project and is widely used in genetic, genomic, and phenotypic research. Several …

Regeneration: An Overlooked Aspect Of Trait-Based Plant Community Assembly Models, Julie Larson, Jennifer L. Funk

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Despite the disproportionate influence that propagule production, dispersal, seed to seedling recruitment, and vegetative reproduction can have on plant population and community dynamics, progress has been slow in the directed collection of regeneration traits to inform community assembly outcomes.

While seed mass is globally available and linked to growth and reproductive output, there are limits to its explanatory ability. In this essay, we call for expanded efforts to integrate a more diverse set of regeneration traits into community assembly models.

First, we extend an existing community assembly framework to conceptualize regeneration as a series of transitional processes whose outcomes are …

Dawn Or Doom: The Risks And Rewards Of Emerging Technologies, Diana Hancock, Steve Tally, Gerry Mccartney, Michele Arthur

Purdue P-12 Networking Summit & Poster Session

Dawn or Doom is a free and open to the public conference at Purdue where we focus on benefits and risks surrounding some of the technologies that are both the most disruptive to current practices and being adopted the fastest. A collection of Purdue faculty experts and some outside speakers showcase their many perspectives related to this technology explosion, explore conditions that will foster innovation and investment into the next generation, and address the big-picture issues where both optimism and pessimism are warranted.

A Brief History Of Corn: Looking Back To Move Forward, Jon Derek Pruitt

Doctor of Plant Health Program: Dissertations and Student Research

Maize was domesticated from teosinte in Mexico some 7,000 to 10,000 years ago and quickly spread through the Americas. It has become one of the most important crops at a local and global level. Two types, Northern Flint corn and Southern Dent corns provided the basis of the genetic background of modern maize hybrids. The development of hybrids, first double-cross and later single-cross hybrids, along with a transition to high input farming provided huge yield increases, which have continued to improve with improving technology.

Increase in maize production also caused a rise in Western corn Rootworm (Diabrotica virgifera virgifera …

Genetic Determinism Of Xanthomonas Arboricola Pv. Pruni (Xap) Resistance, Fruit Quality, And Phenological Traits In Peach And Incorporation Of Marker-Assisted Selection (Mas) In The University Of Arkansas Peach And Nectarine Breeding Program, Terrence James Frett

Graduate Theses and Dissertations

For over two decades the incorporation of marker-assisted selection (MAS) has been discussed as an innovative approach to increase peach breeding efficiency. Although hundreds of quantitative trait loci (QTLs) have been identified, only a few have been converted into usable MAS tools. This highlights a disconnect between genomic discoveries and practical application in breeding programs, which has delayed use of MAS.

In this dissertation, three sequential steps were performed with the objective to bridge this gap and develop breeding-relevant DNA tests for MAS of fruit bacterial spot resistance (Xap1 and Xap6), fruit quality [blush (Rf), acidity (D), and acidity and …

Screening Strawberry Clones For Anthracnose Disease Resistance Using Traditional Techniques And Molecular Markers, Melinda A. Miller-Butler

Dissertations

Cultivated strawberry, Fragaria x ananassa Duchesne, is host for many pathogens. One of the most destructive diseases of strawberry is anthracnose, whose symptoms include fruit rot, leaf and petiole lesions, crown rot, wilt, and death. Three species of Colletotrichum are considered causative agents of anthracnose diseases of strawberry. Colletotrichum acutatum causes anthracnose fruit rot, has a broad host range, and occurs in most areas of the world where strawberries are grown. Colletotrichum fragariae, the primary causal fungus of anthracnose crown rot, may infect all aboveground parts of the strawberry plant, and has restricted host and geographic ranges. Colletotrichum gloeosporioides …

Consumer Willingness To Pay For Genetically Engineered Edamame, Elijah John Wolfe

Graduate Theses and Dissertations

This study examined the effect of GM labeling on consumer willingness to pay (WTP) for edamame. It also investigated how people reacted to different messages and whether the order of receiving positive or negative information about GM technology impacted their willingness to pay (WTP). The study had three components: (1) a sensory test of GM and non-GM labeled products; (2) a non-hypothetical experimental auction to assess WTP for GM, non-GM and unlabeled products; and (3) a questionnaire to collect demographics and other information from the participants. Results of the sensory evaluation revealed no statistically significant difference between GM and non-GM …

Gene Expression And Physiological Analysis To Study Differences Between Oryza Sativa Cultivars Susceptible And Resistant To Chalky Grain Formation Subjected To High Nighttime Temperatures., Nicholas Lawson

Graduate Theses and Dissertations

Starch composition and grain quality of rice is greatly influenced by genotype and environmental factors. The detrimental effects of high nighttime temperatures on rice yield and quality has recently become apparent, with some of the warmest average nighttime temperatures being recorded in the past few years. One of the most notable effects of this stress, an increase in grain chalk formation, correlates with a decrease in quality. This effect varies greatly between cultivars as some show less temperature-sensitive quality reduction than others. The goal of this research is to elucidate fundamental changes that occur in developing plants and grains as …