|Graybosch, Robert - Bob|
Submitted to: International Wheat Quality Conference
Publication Type: Proceedings
Publication Acceptance Date: 4/30/2005
Publication Date: 5/30/2005
Citation: Fufa, H., Baenziger, P.S., Beecher, B.S., Graybosch, R.A., Nelson, I.A. 2005. Genetic improvement trends in agronomic performances and end-use quality characteristics among hard red winter wheat cultivars in nebraska. International Wheat Quality Conference 144:187-188. Interpretive Summary: Evaluation of wheat cultivars from different eras allows breeders an opportunity to estimate breeding progress and to identify traits both amenable and recalcitrant to improvement via selection. This research examined trends in agronomic and end-use quality traits of hard red winter wheat cultivars that made significant contributions to wheat production in Nebraska, or served as parents in the development of such lines. Thirty historically important and popular hard red winter wheat cultivars introduced or released between 1874 and 2000 were tested over a two year period at three Nebraska locations. Older cultivars were found to be low yielding, and were less able to take advantage of favorable environments and respond with increased grain yields. Semi-dwarf cultivars were more stable for plant height than traditional medium to tall cultivars. Modern cultivars, however, were less stable than older cultivars for traits relating to breadmaking quality. However, the quality stability of older cultivars was due to the fact that they were stable for poor quality. Modern cultivars were better able to respond to environmental conditions and produce high quality grain. Protein contents were reduced in modern cultivars but this was offset by increased performance in quality tests. In conclusion, modern cultivars have been tailored to suit the demands of the Nebraska wheat production and marketing industries.
Technical Abstract: Evaluation of wheat cultivars from different eras allows breeders to determine changes in agronomic and end-use quality traits associated with grain yield and end-use quality improvement over time. The objective of this research was to examine the trends in agronomic and end-use quality traits of hard red winter wheat cultivars grown in Nebraska. Thirty historically important and popular hard red winter wheat cultivars introduced or released between 1874 and 2000 were evaluated at Lincoln, Mead and North Platte, Nebraska in 2002 and 2003. An alpha lattice design with 15 incomplete blocks of two plots and three replications was used at all locations. Agronomic (days to flowering, plant height, spike length, culm length, grain yield and yield components, and grain volume weight) and end-use quality (flour yield, SDS-sedimentation value, flour protein content, and Mixograph time and tolerance) traits were measured in each environment. Highly significant differences were observed among environments, genotypes and their interactions for most agronomic and end-use quality traits. Unlike modern cultivars, older cultivars were low yielding, and less responsive to favorable environments for grain yield and yield components. Semi-dwarf cultivars were more stable for plant height than traditional medium to tall cultivars. All cultivars had high grain volume weight since it is part of the grading system and highly selected for in cultivar release. Modern cultivars were less stable than older cultivars for SDS sedimentation and mixing tolerance. However, the stability of older cultivars was attributed to their having weak mixing tolerance and reduced SDS-sedimentation values. The reduced protein content of modern cultivars was offset by increased functionality, as measured by mixograph and SDS sedimentation. In conclusion, breeders have tailored agronomic and end-use quality traits essential for hard red winter wheat production and marketing in Nebraska.