Extent and side effects of wild introgressions in cultivated tomato
General Genetics and Functional Genome Biology
Plant Breeding and Plant Pathology
Final Report Abstract
Introgression of wild alleles into cultivated tomato has been a common practice during tomato improvement programs over the last century. These introgressions have allowed the improvement of important traits like pathogen resistance or fruit diversity. However, because these introgressions can have unwanted consequences, such as suppression of recombination or dragging of unfavourable genes along the beneficial ones. In this project we perform a catalogue of the introgressions present in hundreds of tomato accessions and we study their effect on the tomato genome. These results highlight advantages and disadvantages of the breeding techniques used up until now. In this project we used public genome sequences from more than 700 tomato accessions encompassing 13 different species to establish the first comprehensive catalogue of wild introgressions in cultivated tomato. To do this, we developed new methods that allow unequivocal identification of wild introgressions and determine their origin and the number of genes contained. The resulting catalogue was used to select nine cultivars displaying the most common introgressions, to generate populations of hundreds of tomato individuals segregating for the introgressions. These populations were then used to study the effect of the most common introgressions on the suppression of meiotic recombination. Finally, transcriptomic datasets from more than 400 tomato accessions were used to study the effect of wild introgressions in the modification of the transcriptional landscape in tomato.
