Reducing in vitro phenolic oxidation in grape explants through ascorbic acid treatment and etiolation

Abstract

N. Zelenianska*, O. Gogulinska, M. Artiukh, V. Borun, M. Samofalov and M. Riabyi

Micropropagation of grapes is a common method of propagation in grape nurseries. Phenolic oxidation of explants causes significant problems at the initial stage of introducing explants into in vitro culture. The purpose of this research was to determine the effectiveness of ascorbic acid and etiolation in reducing phenolic oxidation during culture establishment. To reduce in vitro phenolic oxidation, grape explants of ‘Arkadia’ and ‘Zagadka’ varieties were treated with the Ascorbic Acid (AA) solution for one hour before sterilization and subsequently propagated on the Murashige and Skoog (MS) growth medium with ascorbic acid, while the inoculated explants were cultivated under lighting conditions with a 12-hour photoperiod or etiolated for the first 15 days. The most favorable conditions for the proliferation of axillary buds were treatment with the ascorbic acid solution (200 mg/L) before sterilization, cultivation on a growth medium with 5 mg/L of ascorbic acid, or on a standard MS growth medium with 15-day etiolation. The polyphenol content in green tissues of the experimental explants was lower than in the control by 42.2-48.4% 30 days after their inoculation (3.20 ± 0.10, 2.86 ± 0.07 mg/g of tissue), while shoot length was 1.9-2.5 times higher than in the control (2,40 ± 0,14, 1,85 ± 0,32 cm).