Detection on chromosomes 1, 3, 5 and 7 of QTL for AF trait using a single trait or multi-trait model. The multi-trait model concerned the AF trait combined with the HMGCS1 gene or the synthetic variable combining the 660 gene-set or the 5 gene-set. The chromosome-wide significance threshold at the 5% level for the AF QTL analysis (- - -) is indicated by a dashed blue horizontal line. On chromosome 5, the 1‰ level threshold (-) for the multivariate QTL analysis using AF and the synthetic variable combining the 5 gene-set is indicated by a red line. The genetic markers and genetic distances (cM) are shown on the X-axis. The likelihood ratio test (LRT) is shown on the Y-axis.