Marker-assisted pyramiding of quantitative trait loci controlling fruit quality traits in tomato

Tomato consumption is considered fundamental for human health for its high nutritional value, mainly ascribed to antioxidant metabolites. In the last few years, we have focused our research on deciphering the genetic control of antioxidant compounds in tomato fruits and to produce superior genetic materials with an increased amount of bioactive compounds in the red ripe berry. For this purpose, we used introgression lines (ILs) obtained from the wild species Solanum pennellii, and we selected lines IL7-3 and IL12-4 for their high content of hydrophilic antioxidants in the fruit. These lines were crossed to combine the identified quantitative trait loci (QTLs) and obtain superior hybrids. A set of species-specific molecular markers was used to clearly distinguish the wild S. pennellii from the cultivated Solanum lycopersicum genome. In the present work, we describe the selection of one double homozygous hybrid (DHO22) and its multilevel characterization in comparison with its parental genotypes and with the cultivated genotype M82. The selected hybrid DHO22 exhibits high contents of ascorbic acid and phenolics, combined with good performances in terms of yield and other fruit quality traits, and clearly resembles the cultivated genotype M82. In future, this line could be used as pre-breeding material to obtain a new cultivar improved for nutritional traits.