Diversity assessment in the Portuguese genebank collection of tomato (Solanum lycopersicum L.) accessions: Insights for breeding and sustainable conservation

•Morphological, agronomic, molecular and chemical data of 20 accessions were collected.•Citric and ascorbic acids, C18:2n6, C16:0, α-tocopherol, fructose were major compounds.•The size and shape of the fruits were associated with distinct compositional features.•Nineteen alleles were detected at the 7 SSR loci, capturing 77.5% of the total alleles.•The greater the heterozygosity, the greater the compositional variance among accessions. Tomato germplasm is source of variability used by plant breeders to develop improved cultivars and part of the natural heritage to be preserved. In this study, the diversity among twenty Portuguese tomato accessions was evaluated, considering morphological and agronomic descriptors, molecular data, and compositional aspects. The tomato accessions captured 77.5% of the total 19 alleles detected. Important information on the selection of SSR loci in diversity analysis for the tomato genotypes was provided. The studied genotypes were rich in carbohydrates and source of ascorbic acid. Citric acid and palmitic, linoleic, oleic, stearic, and α-linolenic acids were the major organic and fatty acids, respectively. The four tocopherol isoforms were detected and α-tocopherol was the most abundant. When correlating molecular and compositional data, it seemed that the greater the heterozygosity, the greater the compositional variance. However, despite the genetic distance that characterized these accessions, some were chemically similar. Overall, the genetic differentiation among genotypes provided useful information for parental selection in breeding and other genetic studies. [Display omitted]