Potential of genomic selection in rapeseed (Brassica napus L.) breeding

Genomic selection employs genome-wide marker data to predict genomic breeding values. In this study, a population consisting of 391 lines of elite winter oilseed rape derived from nine families was used to evaluate the prospects of genomic selection in rapeseed breeding. All lines have been phenotyped for six morphological, quality- and yield-related traits and genotyped with genome-wide SNP markers. We used ridge regression best linear unbiased prediction in combination with cross-validation and obtained medium to high prediction accuracies for the studied traits. Our results illustrate that among-family variance contributes to the prediction accuracy and can lead to an overestimation of the prospects of genomic selection within single segregating families. We also tested a scenario where estimation of effects was carried out without individuals from the family in which breeding values were predicted, which yielded lower but nevertheless attractive prediction accuracies. Taken together, our results suggest that genomic selection can be a valuable genomic approach for complex agronomic traits towards a knowledge-based breeding in rapeseed.