Abstract
The relationship between root morphometry, growth stages, and total saponin content (TS) by a vanillin-sulfuric acid method in the wild-growing Gypsophila paniculata (n 43), G. perfoliata (n 35), and Acanthophyllum pungens (n 47) from southeastern Kazakhstan was studied and a preliminary assessment of their inhibitory activity against Bacillus sp., Erwinia amylovora, Agrobacterium sp., Fusarium sp., and Aspergillus niger was conducted by the disk-diffusion method. ANOVA and correlation analysis of root parameters and TS content during the vegetation revealed: G. perfoliata exhibited consistent TS level and similar root indices during all phases; G. paniculata showed maximum TS at the flowering coinciding with minimal root diameter values; A. pungens—high TS accumulation and high root growth indices at the end of the vegetation. The differences among species indicate varying root growth dynamics during the growing season, which influence the TS accumulation. The variability in morphometry and TS at separately phase of growth may be associated with intrapopulation heterogeneity. The antibacterial activity of the extracts (10:1) varied depending on the target bacterial species and the extract dose. Gypsophila extracts did not differ in their activity against G+ Bacillus sp., G– Er. amylovora, and Fusarium sp. The A. pungens activity range additionally included G-Agrobacterium sp. and Aspergillus niger. These results may serve as a basis for further study of these species as promising sources of saponins with antimicrobial activity.