Plant Breeding and Genetics Commons^™

Nodule Zone-Specific Gene Expression In Soybean, Sadikshya Aryal

Electronic Theses and Dissertations

Nitrogen is one of the most limiting nutrients for plant growth and yield. Leguminous plants such as soybean (Glycine max) have developed the ability to form a symbiotic association with nitrogen fixing rhizobia. This symbiotic association results in the formation of unique structures called nodules that originate from root cortex via de novo cell differentiation. During soybean nodule development, two major nodule zones, the Nodule primordium (Npr) in the center and the nodule parenchyma (Npa) in the periphery, are clearly distinguishable. Npr gives rise to infection zone (IZ), and the Npa holds vascular bundles. However, it is not clear what …

Comparison Of Three Assembly Strategies For A Heterozygous Seedless Grapevine Genome Assembly, Sagar Patal, Zhixiu Lu, Xiaozhu Jin, Padmapriya Swaminathan, Erliang Zeng, Anne Y. Fennell Dr

Agronomy, Horticulture and Plant Science Faculty Publications

Background
De novo heterozygous assembly is an ongoing challenge requiring improved assembly approaches. In this study, three strategies were used to develop de novo Vitis vinifera ‘Sultanina’ genome assemblies for comparison with the inbred V. vinifera (PN40024 12X.v2) reference genome and a published Sultanina ALLPATHS-LG assembly (AP). The strategies were: 1) a default PLATANUS assembly (PLAT_d) for direct comparison with AP assembly, 2) an iterative merging strategy using METASSEMBLER to combine PLAT_d and AP assemblies (MERGE) and 3) PLATANUS parameter modifications plus GapCloser (PLAT*_GC).
Results
The three new assemblies were greater in size than the AP assembly. PLAT*_GC had the …

Genetic Component Effects Of Two Loci On Seed Dormancy, Awn, Low-Temperature Germination, Plant Height, And Flowering Time In Rice (Oryza Sativa L.), Ugur Korkmaz

Electronic Theses and Dissertations

Seed dormancy (SD) is an adaptive trait of both ecological and agricultural importance. Cereal crops have been selected for reduced SD to promote germination, which also caused the pre-harvest sprouting (PHS) problem in crop production. The previous research identified a set of quantitative trait loci (QTL) for SD, including qSD1- 2 and qSD8, in the conspecific weedy and cultivated rice (Oryza sativa). qSD1-2 carries a dormancy-enhancing allele from the cultivated rice and has a pleiotropic effect on plant height. qSD8 carries a dormancy-enhancing allele from the weedy rice and tightly links to qAL8 for awn length. The …

Exploiting The Genetic Diversity Of Wild Ancestors And Relatives Of Wheat For Its Improvement, Jagdeep Singh Sidhu

Electronic Theses and Dissertations

Wheat is the third most staple food worldwide but current 1% annual improvement in the wheat production is insufficient to meet the growing demands in future. The narrow genetic base of wheat limits continuous improvement in wheat productivity and tolerance to biotic and abiotic stresses under changing climate. Wild ancestors and relatives of wheat hold a potential in widening the genetic pool of wheat and enhance its resilience to biotic and abiotic stresses. This study was focused towards characterizing the genetic diversity in wild relatives of wheat for disease resistance and efficient association with diazotrophs. In the first study, we …

Map-Based Cloning And Molecular Characterization Of The Seed Dormancy 10 Locus In Rice (Oryza Sativa L.), Wirat Pipatpongpinyo

Electronic Theses and Dissertations

Seed dormancy is a key adaptive trait of both ecological and agricultural importance. Although many quantitative trait loci (QTL) have been associated with seed dormancy in cereal crops or model plants, a majority of them remain unknown for molecular identities and functions. Cereal crops and wild/weedy relatives usually have weak and strong seed dormancy, respectively, such as Asian cultivated rice vs. weedy rice (Oryza sativa L.). Previous research identified a set of seed dormancy QTL, including qSD10, in single plant-derived BC₁F₂ and BC₁F₃ populations from the backcross between the weedy rice line SS18-2 …

Identification Of Qtl Modifying The Activity Of The Tcb1-S Locus And Characterization And Sequencing Of Two Plutonium-Beryllium Induced Reduced Gametophyte Transmission Mutants In Maize, Merritt Bryer Burch

Electronic Theses and Dissertations

This thesis is split into two independent projects both involving the male gametophyte generation of maize. The first project looks at how pollen interacts with the female gametophyte to reduce its transmission in cross-incompatible reactions controlled by the unilateral cross-incompatibility system, teosinte crossing barrier 1. The second project explores two plutonium-beryllium induced male gametophyte mutants and attempts to uncover their genetic basis.

Identification of QTL Modifying the Activity of the Tcb1-s Locus
Teosinte crossing barrier 1 (Tcb1) is a unilateral cross-incompatibility system present in maize that provides a pre-zygotic pistil barrier to plants carrying Tcb1-s (strong allele) from pollen …

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 …

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 …

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. …

Next Generation Mapping Of Enological Traits In An F2 Interspecific Grapevine Hybrid Family, Shanshan Yang, Jonathan Fresnedo-Ramírez, Qi Sun, David C. Manns, Gavin L. Sacks, Anna Katherine Mansfield, James L. Luby, Jason Londo, Bruce I. Reisch, Lance Cadle-Davidson, Anne Y. Fennell

Agronomy, Horticulture and Plant Science Faculty Publications

In winegrapes (Vitis spp.), fruit quality traits such as berry color, total soluble solids content (SS), malic acid content (MA), and yeast assimilable nitrogen (YAN) affect fermentation or wine quality, and are important traits in selecting new hybrid winegrape cultivars. Given the high genetic diversity and heterozygosity of Vitis species and their tendency to exhibit inbreeding depression, linkage map construction and quantitative trait locus (QTL) mapping has relied on F₁ families with the use of simple sequence repeat (SSR) and other markers. This study presents the construction of a genetic map by single nucleotide polymorphisms identified through genotyping-by-sequencing …

A Molecular Genetic And Physiological Comparison Of The Hybrid Necrosis Response In Wheat (Triticum Aestivum L.) To Biotic And Abiotic Stress Responses, Devi R. Kandel

Electronic Theses and Dissertations

Expression of hybrid necrosis in plants can lead to a significant reduction in productivity, or even lethality. Epistatic interactions between divergent loci that have evolved through evolution are proposed as being responsible for the genetic incompatability that is expressed as hybrid necrosis. Hybrid necrosis can also represent an obstacle to the transfer of desirable traits from wild, related species to domesticated bread wheat. In wheat, expression of dominant complementary genes Ne1 and Ne2, located to chromosomes 5B and 2B in a hybrid results the production of necrotic leaf tissue, stunted plant growth, and reduced grain yield, which are similar plant …

Evaluation And Identification Of Soybean Aphid Resistance Sources And Mapping Of Soybean Aphid Resistance Loci In Early Maturing Soybean Germplasm Accessions, Siddhi Jeewan Bhusal

Electronic Theses and Dissertations

Soybean aphid (Aphis glycines Matsumura) has been a major pest of soybean [Glycine max (L.) Merr.] in North America particularly in the northern United States and three Canadian provinces. At least four biotypes of soybean aphid have been confirmed in the United States. Identification of soybean aphid resistance sources in early-maturing soybeans and genetic characterization of new sources of resistance will facilitate to expand the gene pool of soybean aphid resistance and thus will help to develop soybean aphid resistant cultivars. To identify new sources of resistance in early maturing soybeans, 330 soybean germplasm accessions from Maturity Group (MG) I, …

Toward The Elucidation Of Cytoplasmic Diversity In North American Grape Breeding Programs, Jonathan Fresnedo-Ramirez, Qi Sun, Chin-Feng Hwang, Craig A. Ledbetter, David W. Ramming, Anne Fennell, M. Andrew Walker, James J. Luby, Matthew D. Clark, Jason P. Londo, Lance Cadle-Davidson, Gan-Yuan Zhong

Agronomy, Horticulture and Plant Science Faculty Publications

Plants have an intriguing tripartite genetic system: Nuclear genome 9 Mitochondria 9 Plastids and their interactions may impact germplasm breeding. In grapevine, the study of cytoplasmic genomes has been limited, and their role with respect to grapevine germplasm diversity has yet to be elucidated. In the present study, the results of an analysis of the cytoplasmic diversity among 6073 individuals (comprising cultivars, interspecific hybrids and segregating progenies) are presented. Genotyping by sequencing (GBS) was used to elucidate plastid and mitochondrial DNA sequences, and results were analyzed using multivariate techniques. Single nucleotide polymorphism (SNP) effects were annotated in reference to plastid …

Short Day Transcriptomic Programming During Induction Of Dormancy In Grapevine, Anne Fennell, Karen A. Schlauch, Satyanarayana Gouthu, Laurent G. Deluc, Vedbar Khadka, Lekha Sreekantan, Jerome Grimplet, Grant C. Cramer, Katherine L. Mathiason

Agronomy, Horticulture and Plant Science Faculty Publications

Bud dormancy in grapevine is an adaptive strategy for the survival of drought, high and low temperatures and freeze dehydration stress that limit the range of cultivar adaptation. Therefore, development of a comprehensive understanding of the biological mechanisms involved in bud dormancy is needed to promote advances in selection and breeding, and to develop improved cultural practices for existing grape cultivars. The seasonally indeterminate grapevine, which continuously develops compound axillary buds during the growing season, provides an excellent system for dissecting dormancy, because the grapevine does not transition through terminal bud development prior to dormancy. This study used gene expression …

Landscape Features Impact On Soil Available Water, Corn Biomass, And Gene Expression During The Late Vegetative Stage, Stephanie Hansen, Sharon A. Clay, David E. Clay, C. Gregg Carlson, Graig Reicks, Youssef Jarachi, David Horvath

Agronomy, Horticulture and Plant Science Faculty Publications

Crop yields at summit positions of rolling landscapes often are lower than backslope yields. The differences in plant response may be the result of many different factors. We examined corn (Zea mays L.) plant productivity, gene expression, soil water, and nutrient availability in two landscape positions located in historically high (backslope) and moderate (summit and shoulder) yielding zones to gain insight into plant response differences. Growth characteristics, gene expression, and soil parameters (water and N and P content) were determined at the V12 growth stage of corn. At tassel, plant biomass, N content, ¹³C isotope discrimination (Δ), and …

Comparative Analysis Of Grapevine Whole-Genome Gene Predictions, Functional Annotation, Categorization And Integration Of The Predicted Gene Sequences, Jerome Grimplet, John Van Hemert, Pablo Carbonell-Bejerano, Jose Diaz-Riquelme, Julie Dickerson, Anne Fennell Dr, Mario Pezzotti, Jose M. Martinez-Zapater

Agronomy, Horticulture and Plant Science Faculty Publications

Background: The first draft assembly and gene prediction of the grapevine genome (8X base coverage) was made available to the scientific community in 2007, and functional annotation was developed on this gene prediction. Since then additional Sanger sequences were added to the 8X sequences pool and a new version of the genomic sequence with superior base coverage (12X) was produced.
Results: In order to more efficiently annotate the function of the genes predicted in the new assembly, it is important to build on as much of the previous work as possible, by transferring 8X annotation of the genome to the …

Vitisnet: ‘‘Omics’’ Integration Through Grapevine Molecular Networks, Jerome Grimplet, Grant R. Cramer, Julie A. Dickerson, Kathy Mathiason, John Van Hemert, Anne Y. Fennell Dr

Agronomy, Horticulture and Plant Science Faculty Publications

Background: Genomic data release for the grapevine has increased exponentially in the last five years. The Vitis vinifera genome has been sequenced and Vitis EST, transcriptomic, proteomic, and metabolomic tools and data sets continue to be developed. The next critical challenge is to provide biological meaning to this tremendous amount of data by annotating genes and integrating them within their biological context. We have developed and validated a system of Grapevine Molecular Networks (VitisNet). Methodology/Principal Findings: The sequences from the Vitis vinifera (cv. Pinot Noir PN40024) genome sequencing project and ESTs from the Vitis genus have been paired and the …

Gene Family Encoding Hordeum Vulgare Translation Elongation Factor 1 Alpha (Ef-1a): Assignment Based On Bioinformatic Analysis Of Cdna Sequences, Jackson Moeller

The Journal of Undergraduate Research

Search of international DNA database, Genbank, produced eight barley cDNA EFlα sequences with unique accession numbers. The length of these sequences varied from an incomplete 502 bp to a full length 1646 bp encoding a 447 amino acid protein. The knowledge that there are four EF-lα gene family members in barley led us to query whether all four genes were represented in the group of eight database submitted sequences. Also of great importance was the correct assignment of gene family member to its mRNA and protein expression profiles. Before we could begin to address the expression studies, we undertook the …

Breaking Seed Dormancy In Three Poaceae Species, Heidi Jo Larson

Electronic Theses and Dissertations

Seed dormancy is a major impediment to germination testing in seed testing laboratories. Dormant seeds are alive but do not germinate under conditions favorable for germination of non-dormant seeds of the same species. Dormancy in many p􀊆ant species can be broken using a single ·treatment or a combination of treatments. Treatments commonly used are light or dark, various temperature regimes, prolonged exposure to cold treatments (pre-chilling), and the use of growth hormones or other chemicals. Three Poaceae species, winter wheat (Triticum aestiivum), prairie drop seed V (Sporobolus heterolepis), and prairie cordgrass (Spartina pectinata), were the subject …