Link to local file: Gediflux Genotype Data It has been claimed that plant breeding reduces genetic diversity in elite germplasm, risking future crop losses and prejudicing the continued ability to improve crops. The objective of this project was to determine any changes to genetic diversity over time in four widely grown agricultural crops: barley, wheat, maize, and potato. Any genetic erosion that might have occurred over the past 50 or more years in these crops was evaluated.The winter wheat collection was divided into ‘Euro-Recommended List’ and ‘UK National List’. The former comprised of 281 entries, selected on the basis each entry occupied at least 5% of the winter wheat acreage in a North European country in the period 1945-2000. The UK NL set was assembled from those varieties in commerce in the late 1990s and consisted of 229 entries. This material was genotyped at 42 mapped SSR (Simple Sequence Repeats) loci by Trait Genetics Gaterslaben Germany (Marcus Wolf) and with SSAP (Sequence Specific Amplified Polymorphism) and NBS (Nucleotide Binding Site) markers at the JIC Norwich UK (Simon Orford).