Genotyping and phenotyping of grape tomato hybrids aiming at possible genitors for breeding program

ABSTRACT Grape and cherry mini tomatoes have been conquering Brazilian consumers due to their sweet taste, practicality of consumption, and versatility in culinary use. Therefore, the present work aimed to characterize ten grape tomato hybrids based on genetic diversity and physical and biochemical traits to provide information for the development of new genotypes focused on the appearance and enrichment of nutritional factors. The evaluated hybrids were Aiko, BRSIG, BRS Zamir, Carolina, Dolcetto, Dulce, Guaraci, Santa West, SCI-023 and Sweet Heaven. The experiment was conducted in 2019 in a greenhouse at the State University of Londrina, using a completely randomized design with four replications and six plants in each replication. The plants were grown following the practices recommended for cultivating tomatoes. The physical and biochemical characterization data were subjected to analysis of variance by the F test (p<0.05) and Scott & Knott means cluster test (p<0.05), and the molecular characterization data were subjected to analysis of principal coordinates (PCoA) and Bayesian clustering. Aiko presented the highest fruit mass and size as opposed to that observed on SCI-023, while BRSIG was the firmest fruit with the largest pericarp thickness. SCI-023, Dolcetto, and Sweet Heaven had higher sugar content. The soluble solids content ranged from 6.04 to 9.66 °Brix among the genotypes. Hybrids SCI-023, BRSIG, Sweet Heaven, BRS Zamir, and Dulce had the highest antioxidant activity levels. In the phenotypic characterization two groups were formed. The genotypic characterization showed seven groups in which high genetic similarity was verified among BRS Zamir, SCI-023, and Guaraci, as well as between Carolina and Dulce. The greatest dissimilarity was observed between Sweet Heaven and BRSIG. Both characterizations were useful to evaluate the aptitude of these genotypes as outstanding genitors for breeding programs for the Brazilian market.