In this work, cultures of callus and suspension cells originating from leaves of sterile highbush blueberry (Vaccinium corymbosum L.) plants were obtained and characterized. For their active growth and production of phenolic compounds, a combination of 2,4-D at a concentration of 0.34–2.25 µM and BAP at a concentration of 0.45–2.25 µM is effective. An increase in the phytohormone concentration leads to a slowdown in culture formation and reduces their ability to synthesize phenolic compounds. When cultivating V. corymbosum suspension cells over a year (12 passages), they not only retain the ability to synthesize phenolic compounds but also enhance it. By the 12th passage, the content of TSPC in suspension cells reaches 150 mg/g DW, the content of flavonoids reaches 100 mg/g DW, the content of flavans reaches 40 mg/g DW, and the content of proanthocyanidins reaches 30 mg/g DW. The high content of phenolic compounds may be due to the high expression of genes in flavonoid biosynthesis enzymes. V. corymbosum suspension cells accumulate a high level of phenolic compounds during a passage. The ability of V. corymbosum callus and cell suspension cultures in the presence of low concentrations of phytohormones to grow and accumulate biologically active phenolic compounds determines their high economic significance and prospects for organizing a biotechnological method for obtaining phenolic compounds.

In leaves, berries, calluses, and suspension cells of highbush blueberry Vaccinium corymbosum L. it was photometrically determined content of phenolic compounds (i.e. soluble phenolic compounds, flavonoids, flavans, and proanthocyanidins). It was shown that highbush blueberry callus and suspension cultures retain the ability to accumulate phenolic compounds, which is comparable to the species leaves and berries. In particular, content of soluble phenolic compounds in leaves is about 270 mg/g dry weight, in berries it is about 70 mg/g dry weight, in calluses it reaches 35–102 mg/g dry weight, and in suspension cultures it reaches 125–150 mg/g dry weight depending on cultures origin (on explant type). In phenolic complex of callus and suspension cultures, as well as in those of leaves, flavonoids predominate (25–146 mg/g dry weight and 180 mg/g dry weight, respectively), and in suspension cultures, initiated from calluses of leaf origin, flavans and proanthocyanidins accumulation increases in comparison with leaves. This study indicates that highbush blueberry suspension cultures, initiated from calluses of leaf origin, may serve as an alternative to plants from greenhouse for production of economically valuable phenolic compounds characteristic of heather plants.