Keywords: 
• heavy metal pollution /
• Rumex japonicus Houtt /
• growth indexes /
• resistance indexes /
• malondialdehyde /
• soluble sugar

Abstract: To investigate the effects of cadmium and lead pollution on plant growth and physiology, Rumex japonicus Houtt, the dominant native plant in the wetland of Le’an River, was selected and studied via pot culture experiment method with soil culture in the laboratory. Different pollution gradients of single-factor and double-factors of cadmium and lead were set up, and the growth indexes such as biomass and height and the physiological indexes including malondialdehyde (MDA) and soluble sugar contents of R. japonicus were measured. The results showed that, with the increased cadmium and lead concentration and stress time, the biomass and height of the plants were significantly inhibited (P<0.05). Moreover, the inhibition effects of the two-factor combined pollution stress of cadmium and lead were significantly (P<0.05) higher than single-factor pollution stress of either cadmium or lead. The contents of MDA and soluble sugar in the plant tissues of R. Japonicus were significantly (P<0.05) increased with the enhancement of the cadmium and lead pollution concentrations and stress time. Under the single-factor and high-concentration challenge conditions, it was found that the self-regulation capacities of the plants were significantly improved, while the content of MDA was decreased. Furthermore, the effects of single factor of either cadmium or lead was significantly (P<0.05) different from the combined factors of cadmium and lead stress on the soluble sugar contents of R. japonicus.