Wheat breeding for quality: An historical review

Authors: Kiszonas, Alecia; Morris, Craig

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/9/2017
Publication Date: 2/6/2018
Publication URL: https://handle.nal.usda.gov/10113/5922781
Citation: Kiszonas, A., Morris, C.F. 2018. Wheat breeding for quality: An historical review. Cereal Chemistry. 95:17–34.

Interpretive Summary: Wheat, more so than any other species, has risen to be the global leader in directly sustaining humankind in terms of calories and nutrition. The world currently produces about 770 mmt of wheat annually. A key reason for this rise is the ability of wheat to be used as the main ingredient in a plethora of products. The most notable of these are breads, noodles and pasta—each of which has a near-limitless number of variations. Why wheat? In the simplest of terms, gluten. Gluten is that ‘rubbery’ substance that forms when wheat endosperm proteins are mixed with water, and energy is supplied by mixing. Since the dawn of civilization, humans have been cultivating, preparing and consuming wheat. For the majority of that time, ca. 12,000 years, humans have likely had little direct involvement in “improving” the milling and baking (end-use) quality of wheat. Rather, natural selection and human intervention improved responses to biotic and abiotic stresses, and certainly humans selected for domestication traits, adaptation to cultivation and increased grain yield. These locally adapted (and often culinarily preferred) strains are referred to as ‘land races’. This paper is a historical review on wheat breeding for quality. One important lesson from the studies cited here is that we as a wheat breeding community have collected numerous markers and QTLs, but very few of them are being used for the improvement of wheat. Technology continues to advance; SNP chips and genotyping-by-sequencing studies are certainly less laborious than running countless gels. However, in the breakneck speed of genetic technology advancement, the wheat improvement community has failed to apply the vast majority of QTLs and markers to improve end-use quality. We have collected hundreds of QTLs for quality traits, yet very few have been implemented as markers that are used routinely for MAS. Collecting countless QTLs is rather meaningless unless we take the next step and develop and use markers to improve the quality and consistency of wheat. It is time to stop collecting QTLs, and time to start using all that we have learned to develop stable, robust markers that can be used to capture the full genetic potential of wheat and end-use quality.

Technical Abstract: Wheat (Triticum spp. L.) is a leading cereal contributing to the nourishment of humankind. Since its domestication ca. 12 000 years ago, humans have profoundly influenced its evolution. In the more recent past, breeding via cross-hybridization and the selection of progeny with superior end-use quality have moved from solely phenotyping (for example, bread baking quality), to a more detailed genetic approach of selecting genes, alleles and whole genome structure for desirable traits. The present review provides a brief historical summary of wheat improvement for end-use quality. In the last ~150 years, wheat improvement has benefited from advances in genetics, chemistry and biotechnology. In the past couple decades, rapid advances in DNA and next-generation sequencing technology have promised a revolution in wheat improvement. The various technologies are reviewed here. The ‘future’ of wheat improvement may involve the whole-genome-based analysis, ‘genomic selection’. However, to date, the plethora of QTL generated over the recent years have largely remained unused.