H2020 TRADITOM Project: Traditional tomato varieties and cultural practices: an argument for agricultural diversification with an impact on food security and the health of the European population

TRADITOM has achieved the following results:

1. The project assembled the largest collection of traditional European tomato varieties by soliciting seeds from scattered seed banks, research laboratories, and farmers' associations. The current collection exceeds 1,800 different varieties (500 more than initially planned). Passport data on growing regions has been collected, and a web repository with detailed information and materials has been created.
2. The assessment of genotypic and phenotypic variability in TRADITOM has been completed for 1691 non-redundant varieties. Valuable information has been obtained for 141 quantitative and 43 qualitative traits, covering the interests of farmers, breeders, food technologists, and consumers. The high degree of variability identified corroborates the value of TRADITOM for diverse applications, from variety selection based on traits of interest (e.g., fruit size, shape, color, yield, post-harvest behavior, etc.) to its use in variety protection, detection of duplicate varieties, etc. The effect of environmental and growing conditions on the expression of these traits has also been analyzed in trials with almost 32,000 plants and their fruits (4 limited-stress conditions tested in 12 different locations).
3. In terms of breeding, the introduction of disease resistance genes (DRGs) into 422 new F1 hybrids has revealed which traditional traits are retained and which are lost depending on the specific cross. In total, more than 1,691 varieties, 422 F1 breeding lines, and more than 28 BCs have been evaluated. In close collaboration with academic and industrial partners, we identified the best materials and crosses to increase the resilience of heirloom tomatoes while maintaining their traditional flavor. The identification of genes flanking the DRG with negative effects on quality prompted us to reduce the size of the introgression to eliminate any negative linkage effects. This strategy has proven effective in TRADITOM, and farmers are currently using new derived varieties.
4. Valorization was made possible by first optimizing the most powerful metabolite profiling platform to date for a single crop (more than 700 metabolites identified). It was then used to profile the complement of health and flavor metabolites of a core set of TRADITOM varieties (11,124 samples analyzed). The improved set of health and flavor metabolites has been used to define varieties that will represent different combinations of these metabolites and, over time, will be preferred by different types of consumers. We also assessed consumer preferences, postharvest behavior, and socioeconomic factors restricting the commercialization of heirloom tomatoes. This valorization has already been used in case studies at TRADITOM, resulting in quality certifications and addressing the needs of consumers and restaurateurs.
5. TRADITOM involved representatives from all stakeholders, from farmers, breeders, and scientists to food experts, chefs, consumers, and others. Joint activities included active participation in research and technical work, discussions, and dissemination of results. The partners published their work in various articles, participated in international conferences, local food fairs, and held training workshops with farmers. The consortium engaged the public by disseminating the project's vision and mission through our website, social media, press releases, and interviews.