Understanding the Physiological and Molecular Basis for Differences in Nitrogen Use Efficiency in the Parents of a Winter Wheat MAGIC Population.

The need to improve both the cost of food production and lower the environmental impact of food production is key to being able to sustainably feed the projected growth of the human population. To attempt to understand how to improve yields under lower nitrogen (N) inputs, a diverse set of UK winter wheats encompassing ~80% of the genetic diversity in current winter wheats in the UK were grown under a range of N levels and their performance measured under various levels of N. This population has parents which encompass all four end-use categories to understand how breeding for differences in NUE may change across different end-use types of wheat. The growth of the eight parents of a MAGIC population showed significant differences in biomass per plant, ear number, yield and protein content of the grain when grown with differing levels of N. No consistent response to N was seen for the lines tested for all of the traits measured. However, the underlying difference in response to N was not due to N uptake or N translocation, as short-term