Identifying the genes controlling the variation of quantitative traits is a key goal for breeders. Genetic variations underlying quantitative traits (QTL) have been mapped by traditional linkage mapping for years and positional cloning identified several QTLs. However linkage mapping is limited to the analysis of traits differing between two lines and the impact of genetic background on QTL effect has been underlined. Thanks to the increase in molecular markers, genome-wide association studies were then proposed to circumvent QTL limitations. ln tomato, a self-pollinated crop, we have shown that association studies are possible, using the admixed nature of cherry tomato genomes that limits the impact of population structure in such an approach. Nevertheless, the results might be limited by linkage disequilibrium, which varies greatly along the genome. Multi-allelic Advanced Generation Inter-Cross (MAGIC) populations allow a wide range of variability to be analyzed and avoid dealing with population structure.