Physiological and Biochemical Responses of Pimpinella anisum L.to Salinity Stress

Salinity stress represents a significant abiotic constraint that adversely affects growth, physiological performance, and secondary metabolite production in medicinal and aromatic plants. This study evaluated the impact of varying salinity levels (۰, ۳۰, ۶۰, ۹۰, ۱۲۰, and ۱۵۰ mM NaCl) on the physiological traits and yield components of Pimpinella anisum under greenhouse conditions using a completely randomized design. Salinity significantly influenced all measured parameters. Increasing NaCl concentrations induced a progressive decline in chlorophyll a and b contents, while relative water content (RWC) remained relatively stable up to ۱۲۰ mM before dropping sharply at ۱۵۰ mM. Proline accumulation exhibited a threshold-dependent response, decreasing at ۳۰ mM but increasing significantly from ۶۰ mM onward. Notably, plants subjected to ۱۲۰ and ۱۵۰ mM NaCl failed to reach harvest stage due to severe stress-induced mortality. Essential oil content in both seeds and leaves peaked at ۶۰ mM NaCl, indicating that moderate salinity stimulates secondary metabolite biosynthesis, whereas ۹۰ mM NaCl caused a marked decline, particularly in seeds. These findings highlight the sensitivity of P. anisum to high salinity and suggest that controlled, moderate saline conditions may enhance phytochemical yield, underscoring the need for optimized irrigation management in anise cultivation under saline environments.

کلیدواژه ها:

Salinity stress ، Pimpinella anisum ، essential oil ، photosynthetic pigments ، Proline