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Document Type

Dissertation - University Access Only

Award Date

2014

Degree Name

Doctor of Philosophy (PhD)

Department

Plant Science

First Advisor

William A. Berzonsky

Abstract

Wheat bran is an important source of dietary fiber, and according to consumers, they prefer the appearance and taste of whole-wheat products made from white wheat compared to those made from red wheat. However, since the predominant Fusiarium Head Blight (FHB) mycotoxin, deoxynivalenol (DON) accumulates primarily in the bran layer of kernels, the bran may be a significant source of DON, especially in products made using white wheat. Moreover, differences in bran characteristics between white and red kernels may impact the DON in whole-wheat products, and pose a potential food safety risk. Near-isogenic lines (NILs) of red and white winter wheat were developed for use in this study to examine kernel bran differences and identify the impact of any genetic differences on the accumulation of DON in bran. In four greenhouse trials, parents, NILs, and control cultivars were inoculated with Fusarium graminearum (teleomorph Gibberella zeae) to induce FHB symptoms, and kernel samples were collected from both infected and uninfected plants. To compare accumulation of DON in the kernel bran layers, the samples were pearl-milled to produce bran and non-bran fractions. Regardless of genotype, DON accumulation in bran fractions was significantly higher than in non-bran fractions. Though the differences were not always statistically significant, generally, DON accumulation was higher in the bran fractions of red kernel genotypes compared to the bran fractions of white kernel genotypes. Red kernel genotypes had a significantly thicker bran layer than white kernel genotypes, and this may be partially responsible for the red bran generally having a higher DON content. At least as suggested by these comparisons, bran from red kernel genotypes may represent a higher DON contamination risk in whole-wheat products compared with bran from white kernel genotypes.

Library of Congress Subject Headings

Wheat -- Genetics
Wheat -- Varieties
Mycotoxins
Bran

Description

Includes bibliographical references (pages 58-74)

Format

application/pdf

Number of Pages

88

Publisher

South Dakota State University

Rights

In Copyright - Non-Commercial Use Permitted
http://rightsstatements.org/vocab/InC-NC/1.0/

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