Document Type

Thesis - Open Access

Award Date

2016

Degree Name

Doctor of Philosophy (PhD)

Department / School

Plant Science

First Advisor

Sharon Clay

Keywords

maize, response, teosinte, transcriptomic, weed

Abstract

Sweet corn (Zea mays L. convar. saccharata var. rugosa) and modern dent variants (field maize, Zea mays L. indentata) have varying degrees of weed tolerance (ability to maintain yield under weed stress). Maize retains ~30% of its ancestral teosinte’s (Zea mays ssp parviglumis) genetic base. Transcriptomic response to weed pressure in maize and teosinte can lead to manipulation of the maize genome to minimize crop yield loss due to weed presence. In maize and teosinte under weed-free and weedstressed conditions, the objectives of this study were: 1) to evaluate transcriptomic responses of 2 teosinte lines; 2) to evaluate transcriptomic response in 5 maize selections in 4 different growing seasons; 3) to determine if mid-season growth parameters (chlorophyll, height, stem diameter, leaf area, or biomass) correlate with crop tolerance; and, 4) to compare and contrast transcriptomic responses among maize and teosinte selections. Four maize selections and 2 teosinte lines suffered grain yield (maize) or harvest biomass (teosinte) loss due to weed stress ranging from 13-44%. Each evaluated selection had a unique response to weeds, with 3 gene ontologies (jasmonic acid response/signaling, UDP-glucosyl and glucuronyltransferases, and quercetin glucosyltransferase) common to all selections evaluated. These common ontologies were not directly related to light depravation or quality, nutrient depravation, nor water stress, which were expected to be the primary mechanisms in weed response. This research suggests individual maize and teosinte selections have distinctive responses to weed stress.

Library of Congress Subject Headings

Corn -- Morphology.
Corn -- Varieties.
Corn -- Genetics.
Weeds.
Stress (Physiology)

Description

Includes bibliographical references (pages 173-190)

Format

application/pdf

Number of Pages

202

Publisher

South Dakota State University

Included in

Weed Science Commons

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Rights Statement

In Copyright