Effects Of Different N Concentrations On Growth And N And P Absorption Of Myriophyllume Latinoides Gaudich

The main reason for eutrophication is the increase of nitrogen and phosphorus in water.TheMyriophyllume latinoides Gaudichhas a strong ability to purify and decontaminate eutrophic water.However,the mechanism of nitrogen uptake,transport and accumulation in theMyriophyllume latinoides Gaudichis not clear about the different concentration of N and P and the ability of removing N and P by theMyriophyllume latinoides Gaudich.In this paper,the ability of N removal and P removal and the growth mechanism of roots,stems,leaves and whole plants,as well as the absorption of nitrogen and phosphorus by roots,stems,leaves and whole plants,were studied by culture medium absorption test with different N concentration and high and low P concentration.It provides theoretical basis and technical support for ecological restoration of eutrophic water body.The main results are as follows:1.The effects of N and P concentrations on the growth characteristics ofMyriophyllume latinoides Gaudich.Root length and biomass ofMyriophyllume latinoides Gaudichappeared stress phenomenon with the increase of N concentration,especially at high P concentration.Stem length,relative biomass and relative growth rate ofMyriophyllume latinoides Gaudichwere better at low P concentration(1mg/L),medium N concentration(20-50 mg/L)than high P concentration(5mg/L),and high N concentration(200 mg/L)was better at high P concentration(5mg/L).The results showed that the stem of S.viridis was N-like and tolerant to high N-N concentration.High N concentration promoted the growth of S.viridis stem,but high N concentration inhibited the growth of root system.2.The effect of N and P concentration on N and P uptake byMyriophyllume latinoides Gaudich.N uptake by the rhizome,leaf and whole plant ofMyriophyllume latinoides Gaudichincreased with the increase of N concentration,and the ability to absorb N was stronger at high P concentration.P uptake by stem,leaf and whole plant increased with the increase of N concentration at high P concentration,while P uptake capacity at low P concentration was low and independent of N concentration,while P uptake by root was inhibited at high P and N concentration.Considering that the biomass of P decreased with the increase of N concentration,the growth of P in low P and P was higher than that in low N or medium N concentration eutrophic water.Good and P,N absorption capacity is strong.3.Effects of N and P concentrations on nutrient uptake and distribution in the roots ofMyriophyllume latinoides Gaudich.Compared with the water treatment group(576.8 UG /(gFW h),the treatment group(1397.6 UG /(gFW h))in Hoagland solution had higher NH4 +-N absorption rate and better growth condition,and the treatment group(1480.4 UG /(gFW h))in Hoagland solution had slightly higher TN absorption rate than that in the water treatment group(1211.5 UG /(gFW h);and the treatment group(gFW h)in Hoagland solution had slightly higher TN absorption rate.The absorption rate of P in group A(67.04 ug/(gFW h))was also higher than that in group B(50.84 ug/(gFW h)).