Effects Of Nitrogen And Phosphorus On AM Formation And Its Function In Wetland

With the rapid development of urbanization in our country,more and more hygrophyte have been used in city,but it also face with the problem of pollution stress,pests and diseases at the same time.Arbuscular mycorrhizal(AM)fungi is a kind of terrestrial microorganisms exist widely at aquatic and terrestrial environment that play an active role of terrestrial plant in the ability to resistance environmental stress,it may also have important significance to the ability of hygrophytes to resistance environmental stress.However,the formation and function of AM is easily affected by the concentration of nitrogen and phosphorus while the urban surface water nitrogen and phosphorus concentrations are generally higher,but we don't clear whether it will be affecting AM formation and function of hygrophytes at the same time.In this paper,we will studing the effects of the nitrogen and phosphorus on the formation and function of AM in several wetland plants.In addition,AM enhancement of plant resistance to heavy metals and the promotion of plant uptake of heavy metal elements,which are thought to be one of the imponant abilities for AM.So in this paper,under the premise of AM function influenced by nitrogen and phosphorus,we research the effect of AM mycorrhizal plants on Cd in wastewater.The main results are as follows:(1)In wetland,phosphorus concentration increase has inhibitory effect on the formation of AM,experiment found that the inhibitions of odium phytate has greater than phosphate ion.In the three kinds of AM structure,the proportion of hyphae in the different forms and concentrations of phosphorus were the largest,followed by bundles and vesicles.Although phosphorus could inhibit the formation of AM structure,but increase appropriately of phosphorus concentration was beneficial to the material exchange between AMF and host plants.In addition,it is beneficial to accumulated nitrogen but phosphorus of host plant in aquatic environment with AMF,and we found that AMF inoculation inhibite the growth of host plant.(2)It was inhibiting the formation of AM when increase the concentration of nitrogen in the environment,and in the tested three kinds of nitrogen form,the inhibition of order from strong to weak as follow:monosodium glutamate>ammonia>nitrate;Although nitrogen inhibits AM formation,but when the nitrogen concentration is beneficial to exchanging matter between AMF and the host plant.In addition,in aquatic environment it was conducive to the accumulation of nitrogen but phosphorus in plants with AMF.After inoculation with AMF,according to the difference of host plant species the plant growth was inhibited or promoted.(3)The cumulative quantity of Cd elements in inoculated AMF Canna are higher than non-inoculated AMF Canna,it showed that AM mycorrhizal plants accumulated Cd elements may be awesome strong.