Life Sciences Commons^™

Flower Visitation In Relation To Pollen And Nectar Nutrition: Implications For Pollinator Habitat And Conservation, Megan E. Leach

Electronic Theses and Dissertations

Pollination of both wild and crop plants is at a crossroads; honey bee populations are experiencing losses at a higher rate than ever before, and some native bee species are declining in abundance to the point of being listed as endangered species. A few examples of these threats include pesticide exposure, habitat loss, and climate change. In response to bee population declines, conservation efforts have been initiated to increase habitat quality for bees by planting pollinator reservoirs or gardens. Plants provide nutrition to bees in the form of pollen and nectar. Several studies have shown links between higher nutritional quality …

Tripartite Interactions Of Legumes With Arbuscular Mycorrhizal Fungi And Rhizobial Bacteria: Insight Into Plant Growth, Seed Yield, And Resource Exchange, Arjun Kafle

Electronic Theses and Dissertations

Under natural conditions, legumes, such as alfalfa (Medicago) and soybean (Glycine max) are colonized with arbuscular mycorrhizal (AM) fungi and rhizobial bacteria forming tripartite interactions. Legumes are important crop species due to their high nutritional and economic values. Most of the previous literatures focused on experiments with an individual symbiont: either AM fungi or rhizobial bacteria, but not with both symbionts at the same time, thus our current understanding of resource exchange in tripartite interactions is limited. It has been reported that AM fungi primarily provide phosphate (P), nitrogen (N), and other nutritional and non-nutritional benefits while rhizobial bacteria solely …

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 …

Regulation Of Local Auxin Metabolism During Soybean Nodule Development, Suresh Damodaran

Electronic Theses and Dissertations

Legume-rhizobia symbiosis leads to the development of secondary root organs called nodules. Rhizobia bacteria housed inside nodules assimilate atmospheric nitrogen and convert them into plant usable forms thereby reducing the need for fertilizer application in crop legumes like soybean. Nodule development is a coordinated process orchestrated by multiple plant hormones. In soybean, the auxin responsive gene expression was detected in nodule primordia and in the periphery of mature nodules, primarily in nodule vasculature. Auxin hypersensitivity reduces nodule formation in soybean and also polar auxin transport inhibition at the site of nodule development is not crucial for determinate nodule formation. Therefore, …

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. …