Int J Phytoremediation. 2014;16(5):469-81. doi: 10.1080/15226514.2013.798615.
Various planting densities (5, 10, or 20 plants per tank) of Pontederia cordata were water-cultivated in purifying tanks to treat polluted water. Seasonal effects of the planting densities on the water quality improvement and the morphology and physiology of the plant were analyzed. Results indicated that planting densities affected the nitrogen and phosphorus removal of water, and the morphology and physiology of plants, including activity of peroxidise and catalase, content of chlorophyll and soluble protein (SP), the length of root, stem and leaf, tiller number and root density. When planting density increased from 10 to 20 plants per tank, the morphology and physiology of plants, and the nitrogen and phosphorus removal by plants improved slowly, but caused a tiller number decline in individual plants. This variation was significant in autumn, and associated with seasonal variations of plant physiology. During autumn, there were 26 tillers in each plant with 10 plants per tank, compared to 14 tillers per plant with 20 plants per tank. Increase in the nitrogen and phosphorus contents of the plants for 5-10 plants per tank was 5.41 and 0.79 g kg(-1), compared to 1.17 and 0.12 g kg(-1) for 10-20 plants per tank, respectively.
采用水培的方式，在净化槽中种植不同密度（5、10 或 20 株/槽）的卵叶丁香蓼，以净化受污染的水。分析了种植密度对水质改善和植物形态及生理特性的季节性影响。结果表明，种植密度会影响水的氮磷去除率，以及植物的形态和生理特性，包括过氧化物酶和过氧化氢酶的活性、叶绿素和可溶性蛋白（SP）含量、根、茎和叶的长度、分蘖数和根密度。当种植密度从 10 株/槽增加到 20 株/槽时，植物的形态和生理特性以及植物对氮磷的去除作用提高缓慢，但会导致单株分蘖数下降。这种变化在秋季较为明显，与植物生理季节性变化有关。在秋季，每株植物有 26 个分蘖，而 20 株/槽的每株植物只有 14 个分蘖。每株植物氮磷含量增加，种植密度为 5-10 株/槽时，氮磷含量分别为 5.41 和 0.79 g/kg，而种植密度为 10-20 株/槽时，氮磷含量分别为 1.17 和 0.12 g/kg。
