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Cereal Grain Biochemistry

The University of Adelaide Grain Biochemistry Program lead by Associate Professor Daryl Mares focuses on the biochemistry, genetics and molecular biology of traits or factors that cause deterioration of quality prior to harvest or that influence marketability and nutritional value of Australian wheat. The group is funded primarily by the Grains Research and Development Corporation to provide new knowledge, improved germplasm and screening technologies needed by breeders to develop improved cultivars required for a sustainable wheat industry and better financial returns to growers. Additional research funding is provided by the South Australian Grains Industry Trust.

The Grain Biochemistry Group is the lead agency in the national Grain Defect Elimination program and a major centre for research on quality, in particular colour, for Asian noodles.

Research Staff & Students

• Associate Professor Daryl Mares
• Dr Kolumbina Mrva
• Dr Robert Asenstorfer
• Dr Imelda Soriano
• Mr Michael Quinn
• Ms Judith Rathjen
• Mrs Christine Kusznir
• Ms Hai Yunn Law
• Mrs Cindy Anderson
• Ms Nicole Kempster
• Mr Daniel Smith

Major Research Themes

Grain defects: pre-harvest sprouting (PHS), late maturity a-amylase (LMA) and black point (BP) that arise as a result of unfavourable weather conditions during grain development and prior to harvest.

• Introgress tolerance to sprouting (grain dormancy) from landraces into locally adapted cultivars.
• Assist wheat breeders to improve tolerance to sprouting and black point and eliminate late maturity a-amylase (LMA).
• Develop improved and efficient screening technologies, including molecular markers.
• Understand the genetic, biochemical, molecular and environmental mechanisms involved in expression of these grain defects.

Asian noodle colour and colour stability

• Characterise grain and flour constituents that contribute to colour and colour stability in white salted (WSN) and yellow alkaline noodles (YAN).
• Develop phenotype screening based on small-scale noodle sheets and measurement of individual constituents: xanthophyll (lutein & lutein esters) and flavonoid (apigenin-C-diglycoside) contents, polyphenol oxidase (PPO), non-PPO oxidation, peroxidase and lipoxygenase activities.
• Develop molecular markers for noodle colour traits.
• Understand genetic and molecular control of synthesis of colour compounds and enzymes.
• Develop germplasm for YAN that eliminates the need for colour additives.

Durum adaptation and pasta quality

• Identify and introgress tolerance to grain defect traits, hostile soils (boron toxicity, high bicarbonate, salinity, zinc deficiency), root diseases (crown rot and nematodes).
• Improve semolina and pasta brightness and yellowness.

High lutein wheat

• An adequate intake of the natural yellow pigment lutein, and other xanthophylls, is associated with a reduced risk of macular degeneration, the major cause of age-related blindness. High lutein bread wheat has been developed for application in noodles and breads with a defined health benefit and noodles (YAN) that are free from colour additives.

Collaborative Linkages

• Australian wheat breeding companies.
• SARDI & the MPB CRC molecular marker laboratory at the Waite Campus.
• CSIRO Plant Industry, Canberra.
• Murdoch University.
• Victorian Department of Primary Industries.
• Various scientists in the UK, USA, China, Japan and South Africa.

Key Recent Papers

• Mares,D.J., Mrva,K. and Fincher,G.B. (2004) Enzyme activities. Encyclopedia of Grain Science. C.Wrigley, H.Corke and C.Walker (eds). Elsevier Science, London, UK Vol 1, 357-365.
• Mrva,K., Wallwork,M. and Mares,D.J. (2006) a-Amylase and programmed cell death in aleurone of ripening wheat grains. J Exp Botany 57: 877-885.
• Asenstorfer,R.E. and Mares,D.J. (2006) 4,4’-dihydroxy-3,3’, 5,5’-tetramethoxyazodioxybenzene, an unexpected product formed during extraction of wheat flour with hydroxylamine. Tetrahedron Lett. 62: 9289-9293.
• Asenstorfer,R.E., Wang,Y. and Mares,D.J. (2006) Chemical structure of flavonoid compounds in wheat (Triticum aestivum L.) flour that contribute to the yellow colour of Asian alkaline noodles. J Cereal Sci 43:108-119.
• Mares,D.J., Mrva,K., Cheong,J., Williams,K., Watson,B., Storlie,E., Sutherland,M. and Zou,Y. (2005) A QTL located on chromosome 4A associated with dormancy in white- and red-grained wheats of diverse origin. Theor Appl Genetics 7: 1357-1364.
• Biddulph,T.B., Mares,D.J., Plummer,J.A. and Setter,T.L. (2005) Drought and high temperature increases preharvest sprouting tolerance in a genotype without grain dormancy. Euphytica 134:277-283.