Marker-assisted selection for the transfer of QTLs controlling fruit quality traits into tomato elite lines

Marker assisted selection (MAS) should increase the efficiency of plant breeding both for the introgression of major genes and for the simultaneous transfer of favorable alleles of many QTLs. After a review of the various MAS strategies, a MAS scheme for the improvement of tomato fruit quality is presented. Improving organoleptic quality of fresh market tomato fruit has become an important objective for tomato breeders. Several QTLs controlling the variation of tomato quality traits have been detected using a recombinant inbred line population derived from a cross between a cherry tomato chosen for its good flavor and a line with bigger fruits but poor taste. A MAS scheme was then set in order to transfer the five most important QTLs involved in fruit quality into three recurrent lines. The backcross optimisation (population size, number and position of markers) is presented, taking into account both theoretical and practical aspects.