Did Modern Plant Breeding Lead to Genetic Erosion in European Winter Wheat Varieties

The objective of this study was to assess whether modern plant breeding has led to any loss of genetic diversity in modern European winter wheat varieties (Triticum aestivum L.). For this purpose, a collection of 511 widely grown winter wheat varieties of Central and Northern Europe was genotyped with 42 microsatellite markers. In the varieties representing the National List of the UK during the 1980s and 1990s the allelic richness and gene diversity were lower than in the varieties of Recommended Lists covering the time period 1945-2000. However, no apparent quantitative loss of genetic diversity was found by comparing the different decadal groups of varieties present in the Recommended Lists. Analysis of molecular variance (AMOVA) showed that the variance component among varieties within decadal groups accounted for 96.41% of the genetic variation, but among decadal groups only for 3.59%. The Fst values increased from the 1950s to the 1990s compared to the 1940s with a slight decrease in the 1970s. These results suggested that modern plant breeding has resulted in changes of alleles present in the germplasm; however, it appears that modern plant breeding has resulted in no apparent loss of allele numbers, or genetic diversity, in the investigated European wheat varieties over time.