Effects of regeneration enhancers on micropropagation of Fragaria vesca L. and phenolic content comparison of field-grown and in vitro-grown plant materials by liquid chromatography-electrospray tandem mass spectrometry (LC–ESI-MS/MS)

Abstract

An efficient in vitro culture protocol of woodland strawberry (Fragaria vesca L., Rosaceae) was developed via multiple shoot formation using MS medium containing different concentrations and combinations of various plant growth regulators (TDZ, BA, Kin, IAA, IBA, NAA and 2,4-d) and regeneration enhancers (silver nitrate (AgNO3), gibberellic acid (GA3), Pluronic F-68, Tween 20 and Tween 80). Although both field-grown plants and sterile seedlings were used as explant source, shoot regeneration was observed with explants obtained from sterile seedlings. Supplementation of medium with Pluronic F-68 was the most efficient treatment which significantly increased shoot number and frequency of shoot formation when compared to treatments supplemented with or without other regeneration enhancers. The best shoot proliferation was obtained with leaf explants cultured on MS media containing 1.0mgl−1 TDZ+0.5mgl−1 IBA+0.1% Pluronic F-68. Regenerated shoots were rooted on MS medium containing different concentrations of IAA, IBA, 2,4-d or NAA. The best root formation was observed with MS basal medium (control). When various auxins were compared for rooting, 0.5mgl−1 IBA and 0.5mgl−1 IAA were found more effective. The phenolic contents in the methanolic extracts of field-grown leaves, fruits and in vitro-grown leaves and callus of F. vesca were analyzed by LC–ESI-MS/MS. Generally, concentrations of phenolic compounds in field-grown leaf extracts were found at least five times higher than in other extracts. Amount of catechin was the highest in all samples, except in vitro callus and fruit extracts. On the other hand, luteolin-7-O-β-d glucoside, vanillic acid, taxifolin and apigenin were the highest phenolics in in vitro-grown callus extract.