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Thesis - University Access Only
Doctor of Philosophy (PhD)
Bill A. Berzonsky
Wheat market grades and grain prices are primarily determined by test weight (TW). Millers emphasize the importance of TW because it is a general indicator of flour yield and overall end-use quality. Since TW is a measure of weight-per-volume, it is expected to be impacted by attributes, such as; grain length (GL), grain width (GW), size, shape, single grain density (SGD), thousand-grain-weight (TGW) and packing efficiency (PE), which is a measure of the space remaining between grains that are packed into a specific volume. The objectives of this study were to; (i) determine the grain characteristics that contribute to TW, (ii) determine the genotypic (G) and environmental (E) and the G by E interaction (GEI) components of TW, and to (iii) characterize the possible impact of a 1BL.1RS translocation on TW in wheat. Winter and spring wheat cultivars analyzed were from statewide crop performance trials (CPT) and they were grown in 18 and 10 South Dakota environments, in 2011 and 2012, respectively. Near-isogenic lines (NILs) with and without the 1BL.1RS translocation were evaluated in six environments from 2012 to 2013. Single grain density had the highest positive impact on TW for both winter and spring wheat. However, the impact of SGD was higher for winter wheat than for spring wheat. Packing efficiency also had an impact on TW in winter wheat, although the impact was less than SGD. In spring wheat, grain weight (SKGWt) also impacted TW, although its impact also was less than SGD. When evaluated in the absence of SKGWt. GW had the second highest impact on TW. In winter wheat, the high GEI component of SGD and PE may prevent breeders from using either trait to indirectly select for high TW. In spring wheat, SKGWt may be a candidate trait for indirect selection for high TW, but it also exhibits a high GEI component, which may limit its utility as a secondary trait. A NIL with a 1BL.1RS translocation did not exhibit higher TW. However, the NIL with the translocation maintained higher TW compared with the line without the translocation in more water-limiting environments.
Library of Congress Subject Headings
Wheat -- Quality Grain -- Quality
Includes bibliographical references
Number of Pages
South Dakota State University
In Copyright - Educational Use Permitted
Yabwalo, Dalitso Noble, "An Analysis of Grain Characteristics and Their Potential Impact on Test Weight in Wheat (Triticum aestivum L.)" (2015). Electronic Theses and Dissertations. 1865.