End-use quality of CIMMYT-derived soft kernel durum wheat germplasm: I. Grain, milling, and soft wheat quality

Authors: BOEHM, J - Washington State University; IBBA, M - Washington State University; Kiszonas, Alecia; Morris, Craig

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/12/2017
Publication Date: 6/16/2017
Citation: Boehm, J.D., Ibba, M.I., Kiszonas, A., Morris, C.F. 2017. End-use quality of CIMMYT-derived soft kernel durum wheat germplasm: I. Grain, milling, and soft wheat quality. Crop Science. 57:1475-1484.

Interpretive Summary: In 2014, 33.5 million tons of durum wheat (Triticum turgidum subsp. durum) were harvested worldwide, which was dwarfed by the 729 million tons of common wheat (T. aestivum). There are two important reasons to explain this production difference: (1) durum grain, which has the hardest kernel texture of all wheats, requires specialized processing, and (2) the semolina produced from the specialized milling of durum grain lacks the culinary versatility of common wheat flour. As a result, durum wheat is simply less versatile than common wheat, and thus has lower consumer demand. Yet, durum is widely grown and is a competitive crop agronomically in regions with low annual rainfall such as Northern Africa, the Mediterranean basin, the Middle East, India, Canada, Australia, and Mexico due to its tolerance of biotic and abiotic stresses and adaptability to semi-arid climates. This research in this manuscript indicates that the traditional view of durum wheat -- its kernel texture, milling performance and end-use quality -- needs to be modified relative to soft durum wheat. The radical change in kernel texture has greatly modified the mechanical processing, utilization and functionality of durum grain and suggests that a paradigm shift is needed in order to determine a new market fit for the multitude of food product possibilities surrounding this exciting brand-new classification of wheat. Without question, soft durum grain may now be milled conventionally alongside common wheat to produce durum flour, not semolina, with kernel texture, break flour yield, flour yield, flour particle size and starch damage befitting that of common wheat flour, all of which illustrate the transformative nature of the Puroindoline genes functioning in Triticum turgidum ssp. durum. Moreover, new agricultural possibilities with soft durum are also exciting. If near isogenic lines of soft durum are able to be developed and grown in tandem with other durum cultivars and landraces in developing countries that presently rely on durum as a staple crop, then those countries may be able to locally source and produce soft durum flour, which could reduce flour imports and improve food security.

Technical Abstract: Wheat kernel texture is used in part to define U.S. wheat market class due to its importance in end-use quality and utilization. Durum wheat (Triticum turgidum subsp. durum) has lower demand and fewer culinary end-uses compared to bread wheat because of its extremely hard kernel texture, which precludes conventional milling. Recently a new durum cultivar with soft kernel texture, cv. Soft Svevo, was developed by the Ph1b-mediated homoeologous transfer of the Puroindoline genes at the Ha locus from the D genome of T. aestivum. The objective of this research was to evaluate soft kernel durum germplasm developed from crossing Soft Svevo to selected entries of the CIMMYT 44th International Durum Yield Nursery. Forty-six F2:5 soft durum full and half sib lines were grown in replicated field plots in two locations. Grain samples were evaluated for grain, milling and soft wheat end-use quality. Significant differences (p<0.05) were detected amongst lines for all grain traits including SKCS kernel hardness (2.0-25.7 HI), break flour yield (37.7-43.8 g 100 g-1), flour yield (58.9-65.9 g 100 g-1), starch damage (1.11 – 1.77 g 100 g-1), flour protein (11.5-13.5 g 100 g-1), SRC water (49.1 – 57.0 g 100 g-1), SRC carbonate (59.8 g 100 g-1 – 68.8 g 100 g-1), SRC sucrose (90.6 – 105.0 g 100g-1 ), and cookie diameter (8.7-9.6 cm). No differences were detected for flour ash concentration. These results indicate that soft kernel texture is easily transferrable and that differences among hard kernel durum parents confer significant differences in end-use quality when evaluated using traditional soft wheat parameters.