Volatile compounds of traditional and virus-resistant breeding lines of Muchamiel tomatoes

Abstract

Currently, sensory quality is the primary objective for almost all tomato breeding programs. In this study, postharvest behaviour of a breeding line with genetic resistance to important viruses (ToMV, TSWV, and TYLCV) has been compared with the original traditional landrace (Muchamiel) from an aromatic point of view. The breeding line has been obtained by backcrossing, introgressing three resistance genes but trying to keep the aromatic characteristics of the traditional variety. The main aim was to obtain qualitative (solid phase microextraction, SPME) and semi-quantitative (simultaneous steam-distillation extraction, SDE, and hydrodistillation, HD) volatile compositions of Muchamiel tomatoes. Fruits were randomly picked at a green-immature stage and stored at 10 °C during 13 days. Volatile compositions of tomatoes in two stages of ripening (green-immature and red-mature) were obtained by three different extraction methods: SDE, HD, and SPME. Besides, sensory evaluation with a trained panel was carried out on both types of tomatoes at two ripening stages. Main fresh tomato aroma compounds (cis-3-hexenal, hexanal, cis-3-hexanol, 6-methyl-5-hepten-2-one, 2-isobutylthiazole and β-ionone) were found at similar concentrations in both types of samples, confirming the success of the breeding program. Finally, SPME could be considered as a useful tool to get realistic values on fresh tomato odour, while HD and SDE results correlated better with fresh tomato aroma. Although a long time has been required to develop the breeding line, results indicate that sensory quality has been recovered through backcrossing, confirming the success of the breeding program