Study on the Growth Characteristics and Root Exudates of Three Wetlands Plants at Different Culture Conditions
3种湿地植物在水培条件下的生长状况及根系分泌物研究

Wetland plants are the important component of constructed wetlands and their root exudates provide the interior hydrocarbon for denitrification. In this study, the growth characteristics and root exudates of Canna indica, Zizania caduciflora and Lythrum salicari in different culture conditions were researched. The results showed that the average biomass initial/biomass in 120 days growth of Canna indica, Zizania caduciflora and Lythrum salicari were 9.1, 3.7, and 4.7, respectively. There was a positive correlation between the root exudates and the biomass of plants, but the release rate of root exudates decreased with the biomass increase. The root exudates release rates of unit biomass were 0.92, 0.47, 0.43 mg·(g·d)-1 for Lythrum salicari, Canna indica and Zizania caduciflora, respectively. And the root exudates of those three plants are mainly organic acids and aryl protein based on the three-dimensional fluorescence spectrum analysis. The results of this study also indicate that Canna indica and Lythrum salicari are befitting wetlands plants.