The domesticated apple (Malus x domestica Borkh.) of the Rosaceae family is one of the most important commercial fruit worldwide. The quality of this pomaceous fruit is crucial to breeders and farmers as it ultimately determines its acceptance for consumption and determines shelf life. The introduction of marker-assisted selection has allowed hastening of traditional breeding. This book reports the first identification of QTLs associated with nine fruit quality traits using a linkage map derived from ?Golden Delicious'' x ?Dietrich'' population. These loci are of great importance for identification of candidate markers and characterization of genes associated with these quality traits that can be further exploited for new cultivar conception. The book also relates the use of proteomics for comprehensive characterisation of the fruit pulp proteome using 2D-PAGE. Through comparative proteomics analysis of high and low firmness fruits, mechanisms linked with fruit firmness were elucidated. The study sheds light on the mechanisms involved with fruit quality by combining proteomic, genomic and phenotypic data and further link crop biotechnology and fruit breeding.