malcolm.hawkesford@rothamsted.ac.uk

Wheat is an important source of mineral micronutrients for human and livestock nutrition. It is well-established that commercial wheat cultivars exhibit low genetic diversity compared to older varieties, including landraces. Exploiting the A. E. Watkins landrace cultivar collection, a historical germplasm collection dating back a century, we aim to elucidate novel genes controlling the accumulation of essential minerals in wheat grains and identify germplasm for breeding programmes.

The set of 821 Watkins lines, recently sequenced, were grown in two successive years in replicated field trials at Rothamsted in the UK. In addition, selected biparental populations (Paragon x Watkins lines) and NAM panels focused on variation in specific traits were also grown in multiple years and subject to QTL or GWAS analysis. Grain and straw yield were recorded and subsampled for mineral analysis by ICP-AES, as well as grain weight, size and shape.

This enabled total mineral offtake, partitioning from grain straw (mineral harvest index) as well as grain content and concentration to be determined. In addition, in season phenotyping recorded growth and developmental stage. Data will be presented showing the diversity of mineral uptake and partitioning between grain and straw along with variation in phenotype, allowing insights into mechanistic control mineral uptake and distribution. The entire population data is being subjected to GWAS analysis, which may indicate novel loci are involved in these traits, and by exploiting the genomic sequence information, novel candidate genes.

This study is supported by the UK BBSRC to Rothamsted Research and the John Innes Centre through the Designing Future Wheat strategic programme (BB/X011003/1).