Effects of cadmium stress on growth and physiological characteristics of Panax ginseng / 中草药

ABSTRACT

Objective: To investigate the effects of cadmium (Cd) stress on the growth and physiological characteristics of Panax ginseng (ginseng). Methods: Two-year old ginseng was cultivated in barrels in phytotrone with different concentration of Cd (0, 0.3, 1.0, 2.0, and 4.0 mg/kg) soil for a whole growth period. In red fruit stage, the contents of biomass and SPAD, the activities of anti-oxidant enzymes, and contents of malondialdehyde (MDA) were determined and analyzed. Results: With Cd concentration increasing, the relative growth rate of ginseng expressed a slowly decreasing trend, and showed negative linear correlations with Cd stress level (P stem > root. Conclusion: Ginseng has an adaptability to the contaminated soil with Cd (≤1.0 mg/kg), and at this time ginseng can enhance the activity of anti-oxidant enzyme and other physiological and biochemical responses to eliminate reactive oxygen species, maintain stability of the cell membrane, alleviate the harm from the stress of Cd; Though with Cd (>1 mg/kg), the contents of MDA could increase significantly, and the oxidative damage of ginseng is very serious. The growth of plants is affected, resulting in a decline in ginseng biomass.