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Physiological traits influencing hardness and vitreosity in wheat grain - AR0908


Policy relevance
This project is relevant to MAFF’s policy objectives through improving the arable industry’s competitiveness. It aims to focus on a fundamental property of grains of Triticum aestivum (common wheat), namely endosperm texture, which is under genetic control but varies markedly in response to environment. While a significant proportion of the variation in endosperm texture between hard and soft wheats is due to the Ha gene on chromosome 5D, up to 40% of the variation in hardness is due to other unknown factors, with evidence for a strong genotype x environment (G x E) interaction. The environmental component of the variation is known to show a strong correlation with the visual endosperm characteristic of vitreosity (translucency); indicative of an effect on the physical structure of the endopserm. Variation in endosperm texture influences the end-use properties of wheat grain, and hence value for 1) export, through its effects on water absorption and Alveograph values, 2) milling and baking, through its effects on water absorption of flours and 3) animal feed, where hardness influences starch digestibility in poultry and the degree of rumen degradable starch. As a consequence, this project encourages the competitive position of UK wheat in world markets, and also supports MAFFs policy objectives, through a potential reduction in digestive and health problems particularly in the case of poultry thus leading to more efficient agricultural systems.

Main objective
Grain hardness and vitreosity are strongly affected by environmental conditions during grain growth and drying, but there is no knowledge of whether varietal types which are more suited to growth under droughted conditions are more or less uniform in terms of the grain’s textural properties in response to environmental stress.

Through an examination of 34 doubled-haploid lines of winter wheat formed from a cross between two contrasting parents; Beaver, (+1B1R, soft endosperm type and drought susceptible) and Soissons, (-1B1R, hard endosperm type and drought tolerant) grown under irrigated and unirrigated field conditions, our objectives are:
- to study the relationships among grain hardness, grain size and vitreosity in UK wheats,
- to assess the relative importance of drought resistance and quality traits on the stability of grain hardness under drought stress, and
- by comparison with an existing AFLP map, search for QTL associated with new sources of stability in end-use quality.

This study would be the first to link quality traits to physiological traits of UK wheats in field conditions.

Intended use of results
Results emanating from this project will be disseminated freely as guidance for the relevant sectors:
For growers
Information from this project will give them a means of deciding which varieties are best suited to drought-prone situations for particular end-use requirements. This will give them the option of either minimising variability in vitreousity or directing grain for a particular end-use to one or other extremes of vitreousity.
For plant breeders
Information about crop ideotypes which combine traits conferring yield stability and grain quality in drought-prone environments and ensure that in the future, yield-enhancing traits are improved in line with improvement in grain quality.
For end-users
Improved quality of crops for particular processes due to targeted production arising from the enhanced understanding of factors which affect wheat endosperm texture. This will also improve the efficiency of wheat trading as clearer specifications for the particular quality issues addressed can be identified and agreed.
1. Establish robust relationships between grain hardness, vitreosity, N content and grain size in winter wheat.
2. Identify desirable combinations of drought-resistance/quality traits in winter wheat that confer more stable end-use quality under drought stress conditions for specific end-use markets.
3. Assist UK breeders to maintain current rates of grain quality improvement by providing them with information on genes and with selection methods for traits conferring more stable end-use quality under drought stress conditions.
4. By mapping genes controlling characters conferring improved end-use quality under stress, provide them as targets for further biochemical and molecular analysis.
Project Documents
• Final Report : Physiological Traits Influencing Hardness and Vitreosity In Wheat Grain   (290k)
Time-Scale and Cost
From: 2001

To: 2004

Cost: £245,540
Contractor / Funded Organisations
John Innes Centre (BBSRC), University - Nottingham, ADAS UK Ltd., Campden Technology Ltd
Arable Farming              
Crop Improvement              
Sustainable Production              
Wheat Production              
Fields of Study
Arable Crops