Genetic estimates of antioxidant properties in the conventionally and in vitro propagated strawberry (Fragaria × ananassa Duch.)

•Strawberry fruits are a good source of bioactive compounds.•In vitro propagation had an impact on the strawberry antioxidant properties.•Higher heritability and genetic gain of antioxidant activity was exhibited in microplants.•In vitro plants are suitable for breeding focused on an enhancement of berry antioxidant potential. This study was undertaken in order to estimate the effect of in vitro propagation on antioxidant activity in strawberry. Results of this research exhibited differences between conventionally and in vitro propagated plants in respect of all traits analyzed. In spite of the decrease in range and mean content of vitamin C and polyphenols as well as antioxidant activity, the genetic gain expressed as percent of mean was higher in microplants regarding phenolics, flavonoids and antioxidant activity in contrast to conventional plants (22.39–20.83, 21.79–15.61, 9.52–3.39; resp.). Correlation and path coefficients showed changes of antioxidants inter-relations between micropropagated and conventional plants. Phenolics and vitamin C correlated positively with antioxidant activity in all genotypes. The highest positive direct effect on antioxidant activity was observed via vitamin C in microplants (0.705), while in conventional plants via phenolics (0.834). Flavonoids affected directly and positively antioxidant activity in microplants (0.103) and negatively in conventional plants (−0.143).