The paper focuses on the growth dynamics and biosynthetic characteristics of the microshoot culture of Spiraea betulifolia ssp. aemiliana obtained in vitro in agar-solidified and liquid media. Microshoots cultured in either type of media showed similar growth dynamics. The most active culture growth was observed from day 35 to day 60. A comparative analysis of the contents of flavonoids and phenol carboxylic acids showed a higher level of phenol carboxylic acids (5.3–6.84%) and a stronger 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical–scavenging activity (half-maximal inhibitory concentration: 341 µg/mL) in S. betulifolia ssp. aemiliana microshoots grown in the liquid medium compared to the microshoots cultured in the solid medium. The flavonoid content of the cultured microshoot did not depend on the consistency of the medium. High-performance liquid chromatography (HPLC) was employed to study the profile and levels of phenolic compounds in microshoots, intact plants, and ex vitro–acclimated S. betulifolia ssp. aemiliana plants. The concentration of kaempferol glycosides was found to be higher in microshoots (1.33% in the solid medium, 1.06% in the liquid medium) compared to intact plants and ex vitro–acclimated plants. Thus, the microshoots of S. betulifolia ssp. aemiliana cultured in the liquid medium rapidly increase their biomass and are an inexpensive promising source of biologically active antioxidant substances, mainly phenol carboxylic acids and kaempferol glycosides.

The relationship between the morphological variability of the productivity characteristics and the genetic variability of the electrophoretic spectra of seed polypeptides in the valuable medicinal species Hedysarum theinum Krasnob was established based on analyzing six cenopopulations. The protocols for the microclonal propagation of advanced samples were developed. The most efficient multiplication was achieved in an MS medium supplemented with 5 μM BAP, 200 mg/L⁻¹ glutathione, and 200 mg/L⁻¹ casein hydrolyzate. The shoots were successfully rooted on the half-strength MS basal medium supplemented with 7 μM NAA.

Sorbaria pallasii is an endemic species of the Far East and Siberia and grows along the Goltsy altitudinal belt. Data on micropropagation and phytochemical characteristics of this plant are not available, probably because of the inaccessibility of the plant material. Morphogenesis initiation from flower buds of S. pallasii in vitro and micropropagation were performed here in the Murashige and Skoog medium supplemented with 5.0 µM 6-benzylaminopurine and 0.0–1.0 µM α-naphthylacetic acid; elongation was implemented in the same medium without the hormones. A well-growing sterile culture of S. pallasii was obtained; the number of microshoots per explant reached 5.7 ± 1.2. Phytochemical analyses of in vitro propagated S. pallasii detected 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity in a water-ethanol extract from its microshoots and revealed phenolic compounds in it. The phenolic compounds that likely contribute to its biological activity are tannins (74.9 mg/g), phenolcarboxylic acids (30.8 mg/g), and catechins (13.3 mg/g). In the microshoot extract, high-performance liquid chromatography identified three catechins. Microshoots showed the highest concentration of (±)-catechin (3.03 mg/(g of absolutely dry mass; ADM)). Concentrations of epigallocatechin gallate (0.38 mg/(g of ADM)) and (−)-epicatechin (0.55 mg/(g of ADM)) were significantly lower. This study paves the way for further biotechnological and phytochemical research on S. pallasii.