Regular consumption of tomatoes has been associated with decreased risk of chronic degenerative diseases. Epidemiological findings confirm the observed health effects are due to the presence of different antioxidant molecules such as carotenoids, particularly lycopene, ascorbic acid, vitamin E and phenol compounds, particularly flavonoids. In this work, eight components contributing to the healthy quality of tomato (i. e. lycopene, beta-carotene, other carotenoids, flavonoids, phenolic acids, vitamins C and E, dry residue) were studied in the framework of breeding programs aiming to develop nutritional superior genotypes. Twelve tomato advanced breeding lines and six open pollinated cultivars were grown in strictly controlled conditions and analysed for their content of antioxidants. Among the 18 genotypes analysed, 10 showed a high level of total carotenoids, 6 high level of beta-carotene, 9 high lycopene levels, 15 high flavonoids and 2 relevant concentration of vitamin E. Based on such data and on a literature survey on tomato composition, an index, called index of antioxidant nutritional quality (I(QUAN)), was proposed as a tool to address the breeding programs in selecting tomato genotypes with antioxidant nutritional qualities.

BackgroundOne of the main tomato breeding objectives is to improve fruit organoleptic quality. However, this task is made somewhat challenging by the complex nature of sensory traits and the lack of efficient selection criteria. Sensory quality depends on numerous factors, including fruit colour, texture, aroma, and composition in primary and secondary metabolites. It is also influenced by genotypic differences, the nutritional regime of plants, stage of ripening at harvest and environmental conditions. In this study, agronomic, biochemical and sensory characterization was performed on six Italian heirlooms grown in different environmental conditions.ResultWe identified a number of links among traits contributing to fruit organoleptic quality and to the perception of sensory attributes. PCA analysis was used to highlight some biochemical, sensory and agronomic discriminating traits: this statistical test allowed us to identify which sensory attributes are more closely linked to environmental conditions and those, instead, linked to the genetic constitution of tomato. Sweetness, sourness, saltiness and tomato flavour are not only grouped in the same PCA factor, but also result in a clear discrimination of tomato ecotypes in the three different fields. The three different traditional varieties cluster on the basis of attributes like juiciness, granulosity, hardness and equatorial diameter, and are therefore more closely related to the genetic background of the cultivar.ConclusionThis finding suggests that a different method should be undertaken to improve sensory traits related to taste perception and texture. Our results might be used to ascertain in what direction to steer breeding in order to improve the flavour characteristics of tomato ecotypes.

The long-term objective of tomato breeders is to identify metabolites that contribute to defining the target flavour and to design strategies to enhance it. This paper reports the results of network analysis, based on metabolic phenotypic and sensory data, to highlight important relationships among such traits. This tool allowed a reduction in data set complexity, building a network consisting of 35 nodes and 74 links corresponding to the 74 significant (positive or negative) correlations among the variables studied. A number of links among traits contributing to fruit organoleptic quality and to the perception of sensory attributes were identified. Modular partitioning of the characteristics involved in fruit organoleptic perception captured the essential fruit parameters that regulate interactions among different class traits. The main feature of the network was the presence of three nodes interconnected among themselves (dry matter, pH, and °Brix) and with other traits, and nodes with widely different linkage degrees. Identification of strong associations between some metabolic and sensory traits, such as citric acid with tomato smell, glycine with tomato smell, and granulosity with dry matter, suggests a basis for more targeted investigations in the future.

Tomato (Solanum lycopersicum) is one of the world’s most important vegetable crops. Managing the health of this crop can be particularly challenging; crop resistance may be overcome by new pathogen races while new pathogens have been introduced by global agricultural markets. Tomato is extensively used as a model plant for resistance studies and much has been attained through both genetic and biotechnological approaches. In this paper, we illustrate genomic methods currently employed to preserve resistant germplasm and to facilitate the study and transfer of resistance genes, and we describe the genomic organization of R-genes. Patterns of gene activation during disease resistance response, identified through functional approaches, are depicted. We also describe the opportunities offered by the use of new genomic technologies, including high-throughput DNA sequencing, large-scale expression data production and the comparative hybridization technique, whilst reporting multifaceted approaches to achieve genetic tomato disease control. Future strategies combining the huge amount of genomic and genetic data will be able to accelerate development of novel resistance varieties sustainably on a worldwide basis. Such strategies are discussed in the context of the latest insights obtained in this field.

Fruit Xavour of traditional tomato ecotypes diVers from that of modern varieties, the latter being often blamed for lack of Xavour. To respond to consumer complaints breeders should know the range of genetic variability available in tomato resources, including local ecotypes, for improving Xavour. For this purpose, multitrait characterization, including biochemical, sensorial and molecular analyses, was performed on 12 Italian tomato ecotypes that belong to diVerent types (San Marzano, Sorrento, and Vesuvio). The ecotypes showed a signiWcant variation both in glucose and citric acid content. As for amino acid determination, lysine, aspartic acid and serine showed signiWcant variation among the three types analyzed. Sensory analysis clearly evidenced diVerences among genotypes: the San Marzano ecotypes revealed sensory proWles that diVer from the control processing variety in perception of sweetness and sourness, whereas the Sorrento and Vesuvio ecotype proWles were similar to the fresh market control. In particular, Vesuvio genotypes exhibited a good intensity of tomato aroma and sweetness and an intermediate level of acidity. Finally, molecular characterization performed through AFLP markers provided evidence for a very high level of polymorphism: an ecotype-speciWc AFLP pattern was identiWed for at least 11 genotypes, thus deWning their molecular Wngerprints.

Tomato is challenged by several pathogens which cause loss of production. One such pathogen is the oomycete Phytophthora infestans which is able to attack all the aerial parts of the plant. Although a wide range of resistance sources are available, genetic control of this disease is not yet successful. Pyramiding R-genes through genetic transformation could be a straightforward way to produce tomato and potato lines carrying durable resistance to P. infestans. In this work the R1 potato gene was transferred into tomato lines. The tomato transgenic lines were analyzed by using q-RT-PCR and progeny segregation to determine the gene copy number. To test the hypothesis that R1 represents a specifically regulated R-gene, transgenic tomato plants were inoculated with P. infestans isolate 88133 and IPO. All the plants containing the R1 gene were resistant to the late blight isolate IPO-0 and susceptible to isolate 88133. These results provide evidence for specific activation of the R1 gene during pathogen challenge. Furthermore, evidence for enhancement of PR-1 gene expression during P. infestans resistance response was obtained.

Tomato is a food of great relevance both\ud due to its large-scale consumption and its richness in\ud bioactive components. It is an important component\ud of the traditional Mediterranean diet as well as of\ud other diets. Nowadays, concerns about human health\ud and environment preservation have changed the\ud objectives of tomato breeding. In this study, eight\ud tomato F1 hybrids and their parental lines were\ud analyzed for nutritional properties and agronomic\ud traits using a new selection method that combines\ud biochemical and agronomic evaluation. Eight traits\ud contributing to the nutritional quality of tomato\ud (lycopene, b-carotene, other carotenoids, flavonoids,\ud phenolic acids, vitamins C and E, dry residue) and\ud average yield were assessed in fifteen tomato genotypes.\ud Furthermore the pathogen resistances possessed\ud from these genotypes were, also, considered.\ud In order to select valuable tomato hybrids, a nutritional\ud index (IQUAN) and an agronomic index (AI)\ud were calculated. Our results suggested that the IQUAN\ud nutritional index may be very useful to forecast the\ud nutritional value of F1 hybrids based on parental\ud performance. Combining the use of the IQUAN and AI\ud indexes, we were able to select two hybrids (MR 48\ud and MR 47) that contain considerable amounts of\ud antioxidants and acceptable parameters for commercial\ud production

In Solanaceae family several plant resistant genes to pathogen (R-genes) have been mapped and cloned. Most of them encode Nucleotide Binding Site Leucine Rich Repeat domain (NBS-LRR) protein. However, little is known about the resistance genes variability pattern and the evolutionary process acting on different species belonging to the same family. The aims of the present work, was to genotype and study the evolutionary relationship of fifty wild tomato accessions using the <i>I</i>2 resistance gene sequences. Thirty-three new candidate homologues <i>I</i>2 resistance gene nucleotide sequence were obtained from wild tomato species. Nucleotide polymorphisms in <i>I</i>2-NBS domain was detected in wild tomato species: diversity could have accumulated over a long time and species sorting could have produced new variants. In order to study the NBS-LRR domain variability we analyzed the evolution process acting on the amino acid sequence. The FEL method (codon Model) based on dN/dS, was used to estimate the presence of positive, negative and neutral selection acting on each codon. The <i>I</i>2-NBS domain sequence data studied seems to be under a general purification process of evolution. However, intermittent bouts of positive selection sites were detected in high variable regions. Phylogenetic analysis conducted within the Solanaceae family shows that the Solanum genus is under a rapid adaptative divergence process and Nicotiana and Capsicum clustered separately; Solanum peruvianum, in particular, displayed to be the most polymorphic specie. These results might be important for the identification of new sources of resistance genes to tomato pathogens