土壤镉胁迫对田七体内镉分布及富集特性影响.

Panax notoginseng is a kind of traditional and precious herbaceous officinal plant in our country. Its heavy metal pollution problem has already caused wide public concern, and the related studies have shown that a certain concentration of cadmium can produce inhibition for the its growth, cadmium stress can reduce its accumulation of saponins, the main pharmacodynamic component, and influence the quality of its medicinal materials. The health risk assessment of cadmium in it showed that the hazard quotient(HQ)was greater than one, which indicates that cadmium in it has non-carcinogenic risk to users. In order to reveal the response of different parts of P. notoginseng to cadmium toxicity, to clarify the basic characteristics of cadmium distribution in it by cadmium pollution of its different concentrations and the enrichment characteristics of its different parts, and to reveal the mechanism of cadmium stress on enrichment and transfer characteristics of its different parts. The triennial P. notoginseng was used as the experimental material in P. notoginseng garden, Jingxi City, Guangxi, under the condition of soil culture, with no cadmium treatment as the blank control and six cadmium concentration gradients(5, 10, 20, 30, 40, 50 mg·kg-1), the characteristics of cadmium accumulation and transfer in its different parts were analyzed under the stress of different concentrations of cadmium. The results showed that cadmium accumulation in different organs(leaf, stem, scissor, fibrous root and taproot)increased significantly with the increase of cadmium concentration(P < 0.05), showing a positive correlation. The distribution characteristics of cadmium content in different parts of P. notoginseng were as follows: In the blank control group, the cumulative distribution of cadmium in each organ was fibrous root > cut root > tap root > stem > leaf; When the cadmium concentration was 5, 10, 20, 30, 40, 50 mg·kg-1, the distribution of cadmium was cut root > taproot > fibrous root > stem > leaf; The cadmium content in the underground part was significantly higher than that in the aboveground part, with the increase of cadmium concentration, the bioenrichment coefficient of both under-ground and above-ground parts decreased gradually. [ABSTRACT FROM AUTHOR]