Trait discovery and editing in tomato.

Tomato (Lycopersicum esculentum), which is used for both processing and fresh markets, is a major crop species that is ranked the first vegetable produced over the world. Tomato is also a model species for research in genetics, fruit development and disease resistances. Genetic resources available in public repositories comprise the 12 wild related species and thousands of landraces, modern cultivars and mutants. In addition, high quality genome sequences are available for cultivated tomato and for several wild relatives, hundreds of accessions have been sequenced, and databases gathering sequence data together with genetic and phenotypic data are accessible to the tomato community. Major breeding goals are productivity, resistance to biotic and abiotic stresses and fruit sensorial and nutritional quality. New traits including resistance to various biotic and abiotic stresses and root architecture are increasingly being studied. Several major mutations and QTLs underlying traits of interest in tomato have been uncovered to date and, thanks to new populations and advances in sequencing technologies, the pace of trait discovery has considerably accelerated. In the recent years, CRISPR/Cas9 gene editing already proved its remarkable efficiency in tomato for engineering favorable alleles and for creating new genetic diversity by gene disruption, gene replacement and precise base editing. Here, we give insights into the major tomato traits and underlying causal genetic variations discovered so far and review the existing genetic resources and most recent strategies for trait discovery in tomato. Further, we explore the opportunities offered by CRISPR/Cas9 and their exploitation for trait editing in tomato. This article is protected by copyright. All rights reserved.Traditional tomato varieties and cultural practices: a case for agricultural diversification with impact on food security and health of European populatio