Life Sciences Commons^™

Identification Of Loci Influencing Teosinte Crossing Barrier 1 (Tcb1) Efficacy In Maize By Quantitative Trait Loci (Qtl) Mapping And Genome-Wide Association Study (Gwas), Namrata Maharjan

Electronic Theses and Dissertations

Pollen cross-contamination has been a major problem for maize breeders. Various mechanical methods applied to avoid the contaminations are ineffective. The genetic factors related to maize fertilization can be used to develop an effective method to prevent pollen contamination. Pollen rejection ability controlled by Teosinte crossing barrier 1 (Tcb1) is such a genetic system. Silks possessing dominant Tcb1-s reject pollen possessing the recessive allele (tcb1). Successful fertilization occurs when Tcb1-s pollen falls upon tcb1 silks. The efficacy of dominant Tcb1-s was, however, reduced when repeatedly backcross with maize inbred lines, which suggests that there are modifiers to Tcb1-s. To find …

Validation Of Candidate Loci For Maize Regrowability And Selection Of Near Isogenic Lines For The Loci, Tajbir Raihan

Electronic Theses and Dissertations

Developing perennial grain crops is an effective way for sustainable agriculture and it can be a tool for the betterment of the overall ecosystem. To understand how perenniality works in perennial species, we made a cross between Zea diploperennis and maize (Z. mays) inbred line B73. F1 hybrids produced from this cross were selfed to get the F2 population and later the F2 population underwent Genotyping-By- Sequencing (GBS) analysis. Based on the candidate loci identified on chromosome 2 and chromosome 7 from GBS, SNP-specific markers were developed from the candidate locus interval and used to genotype the F2 …

Grass-Specific Mechanisms Of Iron Uptake: Investigation Of Phytosiderophore Transporters And Discovery Of Novel Iron Deficiency Loci, David Chan Rodriguez

Doctoral Dissertations

Iron-deficiency anemia is one of the most prevalent forms of malnutrition worldwide, affecting 1.62 billion people, with the population in developing countries being the most affected. Iron is equally vital in plants to perform essential functions such as photosynthesis. Crop grasses form part of everyday human nutrition, contribute fundamentally to human caloric intake, and, in some parts of the world, are the primary source of food. Grasses acquire iron from the soil by secreting chelator molecules called phytosiderophores to solubilize iron, making it available to be transported by the Yellow Stripe1 (YS1) transporter. In this dissertation, I studied aspects of …

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 …

Expression Analyses And Identification Of Key Molecular Participants In Plant Responses To Environmental Cues, Praveena Kanchupati

Electronic Theses and Dissertations

Plants constantly engage and interact with the environment and respond to the changes in conditions like temperature, water, and photoperiod, by regulating expression of genes of multiple regulatory and signaling pathways. Insight into these pathways and their participants has provided and will provide candidates to improve various agronomically important traits in crops through marker-assisted breeding and genetic manipulation. With this aim in mind, in the present study, I attempted to identify key candidate genes that are involved in the regulation of; i) plant response to low temperature stress, ii) plant roots’ response to soil moisture content and iii) flowering time. …

Uncovering Tasselsheath3. A Genomic And Phenotypic Analysis Of A Maize Floral Mutant., Thompson Zhang

Masters Theses

In the modern era, maize has become the most successful crop grown in the United States. According to the USDA over 90 million acres of land are planted to corn and 96.2% of the U.S feed grain production is made up of the cereal. Part of the success of maize is due to its floral architecture, and its pollination technique in which the flower opens, exposing stamens containing pollen into the air. A unique organ called the lodicule functions as a release mechanism, forcing the flower to open. Lodicules from grasses and eudicot petals are homologous, yet there is little …

Investigation Of Candidate Loci Associated With Maize Perennialism, Anjun Ma

Electronic Theses and Dissertations

Developing perennial grain crops is an effective and crucial way to prevent soil erosion caused by conventional agriculture of using annual crops while meeting the increasing need of global food demand. We hypothesized that the regrowth in Zea might be controlled by two dominant complementary genes. F1 hybrids were created by crossing Zea diploperennis Iltis, Doebley & R. Guzman with annual Zea mays L. ssp. mays inbred line B73. A Total of 134 F2 plants derived from nine F1 were planted and phenotyped. A subpopulation of 94 F2 plants were genotyped with Genotype-by- Sequencing (GBS) and called 10,431 SNPs after …

Sequence Analysis Of Maize Yellow Stripe3 Candidate Genes, Dennis B. Depaolo

Masters Theses

The work presented here focuses on the molecular mechanism of phytosiderophore secretion in graminaceous plants. In maize, yellow stripe3 (ys3) is a mutant that is deficient in its ability to secrete iron-chelating compounds of the mugineic acid family known as phytosiderophores. Phytosiderophores are specific to grasses and are used for the acquisition of iron. Genetic linkage mapping of the ys3 locus lead to a region of interest on chromosome 3 defined by marker UMC1773. The sequence of eleven candidate genes (GRMZM2G390345, GRMZM2G390374, GRMZM2G342821, GRMZM5G800764, GRMZM2G502560, GRMZM5G849435, GRMZM2G105766, GRMZM5G876835, GRMZM2G036976, GRMZM2G502563, miR167g) revealed several small deletions …

Molecular And Biochemical Mechanisms Of Pathogenesis In The Maize Foliar Pathogen Cercospora Zeae-Maydis, Winfred-Peck Dorleku

Graduate Theses and Dissertations

GLS is a serious foliar disease of maize, a major staple crop grown commercially in the USA for both human and animal feed production, and increasingly, for ethanol production. The disease is caused by two Cercospora species, C. zeae-maydis and C. zeina, both of which infect maize in the USA and in other parts of the world, with yield losses potentially greater than 50%, depending on local conditions. In culture, C. zeae-maydis produces a phytotoxic, host non-specific perylenequinone, cercosporin, and abscisic acid (ABA), for which there is no known pathological or physiological function in the fungus. Experimental evidence indicates …