EFFECTIVENESS OF BIOLOGICAL PREPARATIONS IN ENHANCING SALINITY TOLERANCE IN STEVIA: MODERN APPROACHES

Soil salinity is one of the major abiotic stress factors causing reductions in crop yield and product quality in agriculture. Stevia rebaudiana Bertoni is a high-value sweetener and medicinal plant whose leaves accumulate steviol glycosides widely used in the food and pharmaceutical industries. However, stevia is considered relatively sensitive to salinity, and salt stress conditions suppress growth, photosynthesis, mineral nutrition, and metabolic processes. This review analyzes the physiological and biochemical effects of salinity stress in stevia and examines the protective mechanisms of biological preparations, including plant growth-promoting rhizobacteria (PGPR), arbuscular mycorrhizal fungi (AMF), and seaweed-based bio stimulants. The literature indicates that biological preparations mitigate the negative effects of salt stress by improving ion homeostasis, activating antioxidant systems, enhancing osmotic regulation, and stimulating root development. As a result, vegetative growth, leaf biomass accumulation, and quality traits become more stable under saline conditions. Nevertheless, the molecular-level effects of biological preparations on steviol glycoside biosynthesis remain insufficiently studied. Biological approaches are therefore considered environmentally safe and promising strategies for stevia cultivation in saline soils.