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

湿地植物是人工湿地的核心部分，其根系分泌物是人工湿地的主要内部碳源.本研究分析了美人蕉、茭白、水柳等3种湿地植物在水培条件下的生长状况和根系分泌物特性.本实验条件下美人蕉、茭白、水柳在120 d的平均生物量/初始生物量分别为9.1、 3.7和4.7.植物根系分泌物的量与生物量正相关，分泌能力随生物量的增加而降低，生长期内，水柳的平均分泌能力为0.92 mg·(g·d)^-1，美人蕉为0.47 mg·(g·d)^-1，茭白为0.43 mg·(g·d)^-1.通过三维荧光光谱分析，3种植物的根系分泌物均以小分子有机酸和芳香族蛋白质为主.本研究表明，美人蕉、水柳为适宜的湿地植物.

Study on the Growth Characteristics and Root Exudates of Three Wetlands Plants at Different Culture Conditions

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.