Fine Mapping and Genetic Interactions of Nearly-Isogenic Allelic Series Representing Yield and Quality QTLs Derived from Wild Tomato Species

Wild germplasm represents a rich source of QTLs capable of enhancing productivity of crop plants. Using the molecular linkage map of tomato in conjunction with novel population structures, we have identified QTLs from five Lycopersicon species that improve key yield and quality associated traits of processing tomatoes. In this research we employed multi-testing sites for fine mapping analysis of the different components of the affected traits combined with genetic interaction studies. Our results demonstrate that 'exotic libraries', which comprise of marker-defined genomic regions taken from wild species and introgressed onto the background of elite crop lines, provide an important opportunity for improving of the agricultural performance of modem crop varieties. Furthermore, we showed that these genetic resources can also serve as reagents for the discovery and characterization of genes that underlie traits of agricultural value. The results set the stage for using the QTLs in marker assisted programs and for applying map-based cloning of the targeted QTL/genes. The cloning of QTLs revealed genes that control pathways for agricultural yield in tomato that may be common for other crop species.