Differences Analysis In Purification Capability Of Nitrogen And Phosphorus In Different Geographical Populations Of Spirodela Polyrrhiza

The eutrophication is the most important water pollution problem in the world today.The excessive emission of nitrogen and phosphorus is the biggest source of water eutrophication.How to effectively purify nitrogen and phosphorus in water is the key to remediate water eutrophication.The use of aquatic bioremediation technology to treat water eutrophication is considered to be a green,inexpensive and easy to operateativee method that has been widely used.Duckweed(Spirodela polyrrhiza L.)has been reported to be applied to repair water body due to its competitive advantages in growth and high nutrient absorption rate.In this paper,the different geographical populations of S.polyrrhiza were collected from the southern region of China,then the growth and physiological responses and water purification ability of these populations S.polyrrhiza under different nitrogen and phosphorus concentrations was compared.The results mainly as follows:(1)There are differences in the growth of different geographical populations.The highest thallus number are from the populations of Tongren and Quanzhou,reach 412 and 388,respectively.The highest fresh weight of S.polyrrhiza are from the populations of Quanzhou and Tongren,reach 2.77 g and 2.65 g,respectively.The longest root lengths of S.polyrrhiza are from the populations of Yuxi and Dali,reach 3.32 cm and 3.27 cm respectively;the sources of Hengyang and Nanping of The chlorophyll content was the highest,reach 3.13 mg/g and 3.07 mg/g,respectively.The highest soluble sugar content are from the populations of Jingdezhen and Huzhou,reach 0.562 mg/g and 0.427 mg/g,respectively.The highest protein content are from the populations of Hunan and Huzhou,reach 25.90 mg/g and 24.94 mg/g,respectively.(2)Under different nitrogen concentrations,the growth and physiological index responses and nitrogen purification capacity of different geographical populations were significantly different.Under high nitrogen conditions,the populations of Guangzhou and Kunming had the highest biomass accumulation,both of which were 0.041 g,and the nitrogen contents of Anshun and Hengyang were the highest,reach 79.07 mg/g and 68.65 mg/g,respectively.The purification capacity of Kunming and JiaJiang was the highest,reach 2.77 mg and 2.71 mg,respectively.Under low nitrogen conditions,Shaoxing and Wuhan had the highest biomass accumulation,0.049 g and 0.044 g,respectively,and the highest nitrogen content are from the populations of JiaJiang and FuZhou,reach 74.52 mg/g and 69.52 mg/g,respectively,the highest nitrogen purification capacity are from the populations of Shaoxing and JiaJiang,reach 3.07 mg and 2.99 mg,respectively;nitrogen purification capacity of different geographical populations was significantly positively correlated with the number of fronds.(3)Under different phosphorus concentrations,the growth and physiological index responses and phosphorus purification ability of different geographical populations were significantly different.Under high phosphorus conditions,Guangzhou and Nanning had the highest biomass accumulation,reach 0.083 g and 0.077 g,respectively,and the highest phosphorus content are from the populations of Hengyang and ZhenJiang,reach 20.35mg/g and 20.27mg/g,respectively.The highest phosphorus purification capacity are from the populations of Dali and WuHan,reach 1.37 mg and 1.23 mg,respectively.Under low phosphorus conditions,Guangzhou and Dali had the highest biomass accumulation,reach 0.072 g and 0.071 g,respectively,and the highest phosphorus content are from the populations of Quanzhou and Anshun,reach 21.63 mg/g and 21.31,respectively.Mg/g,The highest phosphorus purification capacity are from the populations of Anshun and Dali,reach 1.16 mg and 1.12 mg,respectively;the purifying ability of the purple seed of different geographical populations was significantly positively correlated with the number of fronds and phosphorus content.This study demonstrates that there are significant differences in the growth and nitrogen and phosphorus purification capacities of different geographical populations of S.polyrrhiza under different nitrogen and phosphorus concentrations.It is clear that some varieties have ideal purification effect on water and nitrogen pollution,which provides a scientific basis for rational use of S.polyrrhiza resources for water purification.