Year of Publication

2007

Document Type

Dissertation

College

Agriculture

Department

Crop Science

First Advisor

David Van Sanford

Abstract

Increased interest in value-added traits of soft winter wheat (SWW; Triticum aestivum L.), such as white-seed coat and gluten strength, has resulted from economic incentives for these traits. The first objective of this study was to determine whether differences existed between red- and white- seeded progeny of 17 populations. When abiotic and biotic stresses were negligible, significant differences were not detected between red- and white-seeded progeny, except for yield: red-seeded progeny had a significantly higher yield than the white-seeded progeny. However, when abiotic and biotic stresses were larger, the yield of white-seeded progeny was not significantly different from red-seeded progeny and the white-seeded progeny accumulated a significantly greater amount of deoxynivalenol (DON) than red-seeded progeny. Therefore, Kentucky producers should be cautious when considering production of white-seeded cultivars. The second objective of this study was to determine whether early- or late- generation selection for white-seeded progeny produced a higher frequency of superior white-seeded lines. Three selection methods were studied. Late-generation bulk selection produced a significantly lower frequency of superior white-seeded lines (1.7%) than single seed descent (SSD; 13.9%); the early-generation bulk (9.6%) did not differ statistically from either method. Although SSD produced the most superior lines, the utility of SSD breeding will have to be assessed by SWW breeders to justify additional labor and space requirements. The final objective was to determine whether early-generation selection of wheat quality, as determined by wheat meal-based assays, was effective. A cross between a strong gluten soft red winter and a weak gluten soft white winter wheat was examined. Significant correlations and regressions between wheat meal assays and flour-based assays were found. High heritability and realized genetic gains were also observed. Therefore, early-generation selection for quality characteristics appears to be effective.

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