Marker-assisted introgression of five QTLs controlling fruit quality traits into three tomato lines revealed interactions between QTLs and genetic backgrounds

• Published in: Theoretical and applied genetics 2004-08, Vol.109 (3), p.658-668
• Main Authors: Lecomte, L, Duffe, P, Buret, M, Servin, B, Hospital, F, Causse, M
• Format: Article
• Language: English
• Subjects: additive gene effects; Agriculture - methods; backcrossing; Biological and medical sciences; Chromosome Mapping; Chromosomes, Plant - genetics; Classical genetics, quantitative genetics, hybrids; crop quality; Crosses, Genetic; food quality; Fruit - genetics; Fruit - physiology; Fundamental and applied biological sciences. Psychology; genetic markers; Genetic Markers - genetics; Genetics; Genetics of eukaryotes. Biological and molecular evolution; hybridization; inbred lines; introgression; Life Sciences; Lycopersicon esculentum; Lycopersicon esculentum - genetics; Lycopersicon esculentum - physiology; marker-assisted backcross strategy; Phenotype; plant breeding; Pteridophyta, spermatophyta; quantitative trait loci; Quantitative Trait Loci - genetics; Reproduction - genetics; sensory properties; Solanum lycopersicum var. cerasiforme; Solanum lycopersicum var. lycopersicum; tomatoes; Vegetals
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s00122-004-1674-0

The evaluation of organoleptic quality of tomato fruit requires physical, chemical and sensory analyses, which are expensive and difficult to assess. Therefore, their practical use in phenotypic selection is difficult. In a previous study, the genetic control of several traits related to organoleptic quality of fresh-market tomato fruit was investigated. Five chromosome regions strongly involved in organoleptic quality attributes were then chosen to be introgressed into three different recipient lines through marker-assisted selection. A marker-assisted backcross (MABC) strategy was performed, as all the favorable alleles for quality traits were provided by the same parental tomato line, whose fruit weight (FW) and firmness were much lower than those of the lines commonly used to develop fresh market varieties. Three improved lines were obtained after three backcrossing and two selfing generations. The implementation of the MABC scheme is described. The three improved lines were crossed together and with the recipient lines in a half-diallel mating scheme, and the simultaneous effect of the five quantitative trait locus (QTL) regions was compared in different genetic backgrounds. Significant effects of the introgressed regions and of the genetic backgrounds were shown. Additive effects were detected for soluble solid and reducing sugar content in two genetic backgrounds. A partially dominant effect on titratable acidity was detected in only one genetic background. In contrast, additive to dominant unfavorable effects of the donor alleles were detected for FW and locule number in the three genetic backgrounds. Recessive QTL effects on firmness were only detected in the two firmest genetic backgrounds. Comparison of the hybrids in the half-diallel gave complementary information on the effects of: (1) the alleles at the selected regions, (2) the genetic backgrounds and (3) their interaction. Breeding efficiency strongly varied according to the recipient parent, and significant interactions between QTLs and genetic backgrounds were shown for all of the traits studied.