Effects of a plant-derived biostimulant application on quality and functional traits of greenhouse cherry tomato cultivars

A greenhouse experiment was conducted to study the effects of the application of a plant-derived biostimulant (Bioup® TF) on fruit quality and composition of two clusters (cluster II and cluster VI) of the cherry tomato cultivars 'Eletta', 'Kaucana', and 'Top Stellina'. The biostimulant application promoted fruit yield by 12% (up to 1.3 kg m-2 in 'Kaucana') and increased the concentrations of important functional constituents like phytoene, γ-tocopherol and β-tocopherol by up to 16, 25, and 23%, respectively. Fruits from late-ripe cluster VI showed higher fruit weights, D-fructose, and total sugar contents than those from early-ripe cluster II (by 15, 7 and 5%, respectively), but reduced concentrations of acyclic carotenoids (phytoene and lycopene) and tocochromanols (mainly γ-tocopherol, -44%). 'Top Stellina' showed the highest responsiveness to the biostimulant, as particularly (all-E)-β-carotene, phytofluene, and γ-tocopherol concentrations increased, indicating a genotype-dependent effect of the treatment. However, fruits of all treated genotypes showed a contextual decrease in D-fructose and total sugars in response to the biostimulant (on average by 7 and 10%, respectively), indicating a metabolic load burdening the accumulation of lipophilic antioxidants in cherry tomatoes at the expense of their taste-related C pool.