Italian traditional tomato varieties: a focus on the Campania region

[EN] The long tradition of tomato cultivation in Italy has allowed the evolution of a wide diversity of traditional varieties or landraces that have been cultivated for centuries and many of them are still common in the local markets. Adaptation to peculiar climatic and edaphic conditions, the geographical isolation of several growing areas, the specific agro-technique, the local gardners’ selection, also based on consumers’s sensory preferences, have resulted in groups of landraces distributed not only by region but also by sub-regional areas. In most cases, the cultivation of these Italian landraces covers very limited areas being carried out in family gardens for personal consumption and/or in small-size farms that, therefore, play a key role in the on farm maintenance of this precious germplasm, which in many cases is risking extinction. The Campania region has been, and still is, an important area for tomato production with a long tradition in the selection, cultivation and processing of the crop, resulting in a rich reservoir of valuable tomato landraces. So far, only three Italian tomato landraces have been granted a Protected Geographical Status under European Union law, the PGI “Pomodoro di Pachino” form Sicily, and the two PDOs “Pomodoro S. Marzano dell'Agro Sarnese-Nocerino” and the “Pomodorino del Piennolo del Vesuvio” from Campania. This short review will address some of the most popular landraces of the Campania region, with a particular focus on the two PDOs.[ES] La larga tradición del cultivo del tomate en Italia ha permitido la evolución de una amplia diversidad de variedades tradicionales o variedades autóctonas que han sido cultivadas durante siglos, muchas de las cuales siguen siendo comunes en los mercados locales. La adaptación a las peculiares condiciones climáticas y edáficas, el aislamiento geográfico de varias zonas de cultivo, las técnicas de cultivo específicas, la selección de los agricultores locales, también basada en las preferencias sensoriales de los consumidores, han dado como resultado grupos de variedades locales distribuidas no sólo por regiones, sino por áreas sub-regionales. En la mayoría de los casos, el cultivo de estas variedades autóctonas italianas cubre áreas muy limitadas y se están llevando a cabo en huertos familiares para consumo personal y / o en fincas pequeñas que, por lo tanto, desempeñan un papel clave en el mantenimiento de este valioso germoplasma, que en muchos casos está en peligro de extinción. La región de Campania ha sido, y sigue siendo, un área importante para la producción de tomate con una larga tradición en la selección, cultivo y procesamiento de este cultivo, resultando en un rico reservorio de variedades autóctonas de tomate valiosas. Hasta el momento, sólo tres variedades autóctonas de tomate italiano han obtenido el estatus de protección geográfica conforme a la legislación de la Unión Europea, la IGP “Pomodoro di Pachino” de Sicilia y las dos DOP “Pomodoro S. Marzano dell'Agro Sarnese-Nocerino” y “Pomodorino Del Piennolo del Vesuvio" de Campania. Esta breve revisión abordará algunas de las razas tradicionales más populares de la región de Campania, con especial atención a las dos DOP.This work was supported by the European Commission Horizon 2020 program (TRADITOM grant 634561 to S.G. and P.S.).Sacco, A.; Cammareri, M.; Vitiello, A.; Palombieri, S.; Riccardi, R.; Spigno, P.; Grandillo, S. (2020). Italian traditional tomato varieties: a focus on the Campania region. En I Congrés de la Tomaca Valenciana: La Tomaca Valenciana d'El Perelló. Editorial Universitat Politècnica de València. 179-193. https://doi.org/10.4995/TOMAVAL2017.2017.6526OCS17919

Structural and Functional Genomics of Tomato

Tomato (Solanum lycopersicum L.) is the most intensively investigated Solanaceous species both in genetic and genomics studies. It is a diploid species with a haploid set of 12 chromosomes and a small genome (950 Mb). Based on the detailed knowledge on tomato structural genomics, the sequencing of the euchromatic regions started in the year 2005 as a common effort of different countries. The manuscript focuses on markers used for tomato, on mapping efforts mainly based on exploitation of natural biodiversity, and it gives an updated report on the international sequencing activities. The principal tools developed to explore the function of tomato genes are also summarized, including mutagenesis, genetic transformation, and transcriptome analysis. The current progress in bioinformatic strategies available to manage the overwhelming amount of data generated from different tomato “omics” approaches is reported, and emphasis is given to the effort of producing a computational workbench for the analysis of the organization, as well as the functionality and evolution of the Solanaceae family

Sensory traits and consumer’s perceived quality of traditional and modern fresh market tomato varieties: A study in three European countries

Consumer dissatisfaction with the flavor quality of many modern fresh market tomato varieties has fostered breeders’ interest in sensory quality improvement, and the demand for traditional varieties, which are generally associated with better flavor. To achieve further knowledge on the factors influencing the sensory quality and consumers’ preferences and perception, European traditional and modern fresh market tomato varieties were grown and evaluated in France, Italy, and Spain. Different growing conditions were tested in France (soilless vs. soil) and in Spain (open field vs. greenhouse), while in Italy fruits were evaluated at two ripening stages. Fruit quality was assessed by integrating physicochemical analyses, sensory profiles, and consumer tests. In all three countries, overall modern varieties were perceived as having more intense “tomato flavor” and “overall flavor” than traditional ones. In France and Spain, consumers’ preferences were more oriented towards modern varieties than traditional ones. Significant growing condition effects were found on sensory and physicochemical traits, while the effect on consumers’ overall liking was not significant, largely depending on the genotype. A fair agreement between product configurations from descriptive analysis by trained assessors and Check-All-That-Apply (CATA) questions by consumers was observed. Penalty-lift analysis based on CATA allowed identifying positive and negative drivers of liking.Postprint (published version

Sensory Traits and Consumer’s Perceived Quality of Traditional and Modern Fresh Market Tomato Varieties: A Study in Three European Countries

Consumer dissatisfaction with the flavor quality of many modern fresh market tomato varieties has fostered breeders’ interest in sensory quality improvement, and the demand for traditional varieties, which are generally associated with better flavor. To achieve further knowledge on the factors influencing the sensory quality and consumers’ preferences and perception, European traditional and modern fresh market tomato varieties were grown and evaluated in France, Italy, and Spain. Different growing conditions were tested in France (soilless vs. soil) and in Spain (open field vs. greenhouse), while in Italy fruits were evaluated at two ripening stages. Fruit quality was assessed by integrating physicochemical analyses, sensory profiles, and consumer tests. In all three countries, overall modern varieties were perceived as having more intense “tomato flavor” and “overall flavor” than traditional ones. In France and Spain, consumers’ preferences were more oriented towards modern varieties than traditional ones. Significant growing condition effects were found on sensory and physicochemical traits, while the effect on consumers’ overall liking was not significant, largely depending on the genotype. A fair agreement between product configurations from descriptive analysis by trained assessors and Check-All-That-Apply (CATA) questions by consumers was observed. Penalty-lift analysis based on CATA allowed identifying positive and negative drivers of liking

Diversity and genetic architecture of agro-morphological traits in a core collection of European traditional tomato

European traditional tomato varieties have been selected by farmers given their consistent performance and adaptation to local growing conditions. Here we developed a multipurpose core collection, comprising 226 accessions representative of the genotypic, phenotypic, and geographical diversity present in European traditional tomatoes, to investigate the basis of their phenotypic variation, gene×environment interactions, and stability for 33 agro-morphological traits. Comparison of the traditional varieties with a modern reference panel revealed that some traditional varieties displayed excellent agronomic performance and high trait stability, as good as or better than that of their modern counterparts. We conducted genome-wide association and genome-wide environment interaction studies and detected 141 quantitative trait loci (QTLs). Out of those, 47 QTLs were associated with the phenotype mean (meanQTLs), 41 with stability (stbQTLs), and 53 QTL-by-environment interactions (QTIs). Most QTLs displayed additive gene actions, with the exception of stbQTLs, which were mostly recessive and overdominant QTLs. Both common and specific loci controlled the phenotype mean and stability variation in traditional tomato; however, a larger proportion of specific QTLs was observed, indicating that the stability gene regulatory model is the predominant one. Developmental genes tended to map close to meanQTLs, while genes involved in stress response, hormone metabolism, and signalling were found within regions affecting stability. A total of 137 marker–trait associations for phenotypic means and stability were novel, and therefore our study enhances the understanding of the genetic basis of valuable agronomic traits and opens up a new avenue for an exploitation of the allelic diversity available within European traditional tomato germplasmThis work was supported by European Commission H2020 research and innovation program through TRADITOM grant agreement no. 634561, G2P-SOL, grant agreement no. 677379, and HARNESSTOM grant agreement no. 101000716. Networking activities were funded by COST Actions “EUROCAROTEN CA15136 and ‘RoxyCOST’ CA18210 ‘RoxyCOSTPostprint (published version

Whole-genome re-sequencing of two Italian tomato landraces reveals sequence variations in genes associated with stress tolerance, fruit quality and long shelf-life traits

Tomato is a high value crop and the primary model for fleshy fruit development and ripening. Breeding priorities include increased fruit quality, shelf life and tolerance to stresses. To contribute towards this goal, we re-sequenced the genomes of Corbarino (COR) and Lucariello (LUC) landraces, which both possess the traits of plant adaptation to water deficit, prolonged fruit shelf-life and good fruit quality. Through the newly developed pipeline Reconstructor, we generated the genome sequences of COR and LUC using datasets of 65.8M and 56.4M of 30–150bp paired-end reads, respectively. New contigs including reads that could not be mapped to the tomato reference genome were assembled, and a total of 43, 054 and 44, 579 gene loci were annotated in COR and LUC. Both genomes showed novel regions with similarity to Solanum pimpinellifolium and Solanum pennellii. In addition to small deletions and insertions, 2, 000 and 1, 700 single nucleotide polymorphisms (SNPs) could exert potentially disruptive effects on 1, 371 and 1, 201 genes in COR and LUC, respectively. A detailed survey of the SNPs occurring in fruit quality, shelf life and stress tolerance related-genes identified several candidates of potential relevance. Variations in ethylene response components may concur in determining peculiar phenotypes of COR and LUC

Identification, introgression, and validation of fruit volatile QTLs from a red-fruited wild tomato species

[EN] Volatile organic compounds (VOCs) are major determinants of fruit flavor, a primary objective in tomato breeding. A recombinant inbred line (RIL) population consisting of 169 lines derived from a cross between Solanum lycopersicum and a red-fruited wild tomato species Solanum pimpinellifolium accession (SP) was characterized for VOCs in three different seasons. Correlation and hierarchical cluster analyses were performed on the 52 VOCs identified, providing a tool for the putative assignation of individual compounds to metabolic pathways. Quantitative trait locus (QTL) analysis, based on a genetic linkage map comprising 297 single nucleotide polymorphisms (SNPs), revealed 102 QTLs (75% not described previously) corresponding to 39 different VOCs. The SP alleles exerted a positive effect on most of the underlying apocarotenoid volatile QTLs-regarded as desirable for liking tomato-indicating that alleles inherited from SP are a valuable resource for flavor breeding. An introgression line (IL) population developed from the same parental genotypes provided 12 ILs carrying a single SP introgression and covering 85 VOC QTLs, which were characterized at three locations. The results showed that almost half of the QTLs previously identified in the RILs maintained their effect in an IL form, reinforcing the value of these QTLs for flavor/aroma breeding in cultivated tomato.We thank Erika Moro for valuable help in volatile analysis of the ILs. WB was supported by a fellowship granted by the Universidad de Costa Rica and CSIC-Spain by way of a collaboration agreement between CSIC/UCR. Volatile profiling was performed in the Metabolomic facilities of the IBMCP, CSIC (Spain). This work was supported in part by the Spanish MINECO Project AGL2015-65246-R co-financed by EU FEDER, MINECO Project AGL2011-26957, and the Bilateral agreements of Scientific and Technological Cooperation between the Spanish National Research Council (CSIC) and the Italian National Research Council (CNR). Funding for this project was provided through TRADITOM. TRADITOM has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 634561. Networking activities were supported by COST action Fruit Quality FA 1106.Rambla Nebot, JL.; Medina, A.; Fernández Del Carmen, MA.; Barrantes, W.; Grandillo, S.; Cammareri, M.; López Casado, G.... (2016). Identification, introgression, and validation of fruit volatile QTLs from a red-fruited wild tomato species. Journal of Experimental Botany. 68(3):429-442. https://doi.org/10.1093/jxb/erw455S429442683Alba, J. M., Montserrat, M., & Fernández-Muñoz, R. (2008). 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Multi-omics data integration provides insights into the post-harvest biology of a long shelf-life tomato landrace

In this study we investigated the transcriptome and epigenome dynamics of the tomato fruit during post-harvest in a landrace belonging to a group of tomatoes (Solanum lycopersicum L.) collectively known as "Piennolo del Vesuvio", all characterized by a long shelf-life. Expression of protein-coding genes and microRNAs as well as DNA methylation patterns and histone modifications were analysed in distinct post-harvest phases. Multi-omics data integration contributed to the elucidation of the molecular mechanisms underlying processes leading to long shelf-life. We unveiled global changes in transcriptome and epigenome. DNA methylation increased and the repressive histone mark H3K27me3 was lost as the fruit progressed from red ripe to 150 days post-harvest. Thousands of genes were differentially expressed, about half of which were potentially epi-regulated as they were engaged in at least one epi-mark change in addition to being microRNA targets in ~5% of cases. Down-regulation of the ripening regulator MADS-RIN and of genes involved in ethylene response and cell wall degradation was consistent with the delayed fruit softening. Large-scale epigenome reprogramming that occurred in the fruit during post-harvest likely contributed to delayed fruit senescence

Genetic and physiological analysis of tomato fruit weight and composition: influence of carbon availability on QTL detection

Throughout tomato domestication, a large increase in fruit size was associated with a loss of dry matter and sugar contents. This study aims to dissect the contributions of genetic variation and the physiological processes underlying the relationships between fruit growth and the accumulation of dry matter and sugars. Fruit quality traits and physiological parameters were measured on 20 introgression lines derived from the introgression of Solanum chmielewskii into S. lycopersicum, under high (HL, unpruned trusses) and low (LL, trusses pruned to one fruit) fruit load conditions. Inter- and intra-genotypic correlations among traits were estimated and quantitative trait loci (QTL) for size, composition, and physiological traits were mapped. LL increased almost all traits, but the response of sugar content was genotype-dependent, involving either dilution effects or differences in carbon allocation to sugars. Genotype×fruit load interactions were significant for most traits and only 30% of the QTL were stable under both fruit loads. Many QTL for fresh weight and cell or seed numbers co-localized. Eleven clusters of QTL for fresh weight and dry matter or sugar content were detected, eight with opposite allele effects and three with negative effects. Two genotypic antagonistic relationships, between fresh weight and dry matter content and between cell number and cell size, were significant only under HL; the second could be interpreted as a competition for carbohydrates among cells. The role of cuticular conductance, fruit transpiration or cracking in the relationship between fruit fresh weight and composition was also emphasized at the genetic and physiological levels

European traditional tomatoes galore: a result of farmers’ selection of a few diversity-rich loci

A comprehensive collection of 1254 tomato accessions, corresponding to European traditional and modern varieties, early domesticated varieties, and wild relatives, was analyzed by genotyping by sequencing. A continuous genetic gradient between the traditional and modern varieties was observed. European traditional tomatoes displayed very low genetic diversity, with only 298 polymorphic loci (95% threshold) out of 64 943 total variants. European traditional tomatoes could be classified into several genetic groups. Two main clusters consisting of Spanish and Italian accessions showed higher genetic diversity than the remaining varieties, suggesting that these regions might be independent secondary centers of diversity with a different history. Other varieties seem to be the result of a more recent complex pattern of migrations and hybridizations among the European regions. Several polymorphic loci were associated in a genome-wide association study with fruit morphological traits in the European traditional collection. The corresponding alleles were found to contribute to the distinctive phenotypic characteristic of the genetic varietal groups. The few highly polymorphic loci associated with morphological traits in an otherwise a low-diversity population suggests a history of balancing selection, in which tomato farmers likely maintained the morphological variation by inadvertently applying a high selective pressure within different varietal types.This work was supported by the European Commission H2020 research and innovation program through TRADITOM grant agreement no. 634561, G2P-SOL, grant agreement no. 677379, and HARNESSTOM grant agreement no. 101000716. MP is grateful to the Spanish Ministerio de Ciencia e Innovación for a postdoctoral grant (IJC2019-039091-I/AEI/10.13039/501100011033).Postprint (published version