Investigation of the Physiological and Biochemical Responses of Echinacea purpurea under Salinity Stress

Abstract

Echinacea purpurea is an important medicinal plant that contains valuable medicinal compounds that have a tremendous effect on stimulating the body’s immune system to fight off viral and bacterial agents. To evaluate salinity stress tolerance in Echinacea purpurea, an experiment was conducted using a diverse population. The seeds used in this experiment were the result of selecting superior genotypes in terms of chicoric acid content and drought tolerance. Considering the medicinal value of Echinacea purpurea and the high area of saline soils in Iran, the purpose of this study was to investigate the possibility of cultivating this plant in saline soils. In this experiment, salinity stress at two levels of 0 and 60 mM of NaCl started when the plant was at the six-leaf stage and continued for 14 days. The results showed a significant decrease in the amounts of photosynthetic pigments and potassium under salinity stress. Under saline conditions, the amount of sodium ions in the shoots, ion leakage, and total phenols increased, but there was no significant change in the amount of proline, antioxidant capacity, and chlorophyll fluorescence parameters. It seems that among the genotypes under salinity stress, based on the results obtained under stress, Genotypes 34, 46, 90, 89, 79, and 165 have high levels of proline and phenolic compounds, and strong antioxidant properties. These genotypes were in a better position in terms of these parameters and were placed in a separate cluster in cluster analysis, so these can be selected as tolerant genotypes.