Studies On Internation Of Nitrogen And Phosphorus Absorption And Medicinal Plant By Arbuscular Mycorrhizal Fungus

Arbuscular mycorrhizal (AM) fungus are the most important endogenous mycorrhizal fungus that can be make symbiotic relationship with more than80%of the land plant. AM fungus plays a key role on promoting plant growth, increasing plant yield and enhancing the plant resistance. When AM fungus infect in the host plants, the extraradical mycelium (ERM) extends to the soil farther than roots,it can absorb the nutritional from the soil that roots can’t reach, then it can improve the ability of plants to absorb soil nutrients.The nitrogen and phosphorus are two essential nutrients for plant growth, AM fungus can promote the absorption of the two nutrients, especially to the phosphorus absorption, and when it improves the absorption of phosphorus firstly, the ability of exogenous nitrogen assimilation will be promoted. By studying the absorption of nitrogen and phosphorus mutual effection by AM fungus, we can find the more suitable combination of nitrogen and phosphorus fertilizer to plant, then make the plant more efficiently use of soil nutrients. In addition, there are large amounts of organic nitrogen can’t be utilize by plant directly, if we find the AM fungus have the function of degradation and absorption to theorganic nitrogent, it will greatly significant to improve the absorbing ability of plant nutrient. In this experiment, AM fungus (Glomus intraradices) was inoculated to sorghum as the host plant, the sorghum was growth in the pot culture, by adding different forms and content nutrients of nitrogen and phosphorus to the mycelium room, the absorption capacity of AM fungus was researched. (1)、In this experiment, setting the different phosphorus concentration as0、30mg/L、60mg/L、120mg/L, with NH4NO3, Gln for the nitrogen souece, then to study the effect of AM growth and absorption on the different phosphorus concentrations. The results showed:high phosphorus concentrations significantly improved the spore number of AM fungus; the dry weight of ERM is the highest in the low phosphorus concentrations, and when Gln was used as the nitrogen source,it was higher than NH4NO3was used as the nitrogen source; low phosphorus concentration prompted the dry weight of sorghum shoots and mycorrhizal roots; the total nitrogen content of sorghum shoots is highest with NH4NO3for added nitrogen, in the different phosphorus concentration the sorghum total nitrogen content was P30>P120>PO>P60; the Arg content of mycorrhizal root was higher with Gln was used as the nitrogen sources,and the low phosphorus concentrations make the Arg content be the highest. In short, the absorption ability of extrogenous nitrogen by arbuscular mycorrizal fungus can be effected by the phosphorus content, low phosphorus content was more beneficial to AM fungus to abosob the extrogenous nitrogen, and the AM fungus is easiest for absorption the NH4+form nitrogen source.(2)、 The research was about the effect of arbuscular mycorrohizal on growth and nutrition absorption under different nitrogen and phosphorus fertilizer levels, The results showed that the arbuscular mycorrhizal colonization rate reached to70%; the innoculation increased the dry matter and chlorophyll content of sorghum, and significantly increased the sorghum total nitrogen and phosphorus content. In the innoculation of sorghum, the nitrogen content was increased significantly with the increasing of supplied N level, while decreased with the increasing of supplied P level. When in the4mmol·L-1nitrogen and0.01mmol·L-1phosphorus (N2P1) level the plant total nitrogen content was the highest. The phosphorus content was increased with the increasing of supplied N and P level, when in the4mmol·L-1nitrogen and0.1mmol/L phosphorus (N2P2) level the plant total phosphorus content was highest. Wherefore the nutrition absorption of AM fungi was effected by the interaction of nitrogen and phosphorus. (3)、AM fungus absorbing ability of corn steep liquor,soybean meal,amino fertilizer, and organic fertilizer is different, the result showed:The absorbing ability has significant different of AM fungus for different organic nitrogen.The AM fungus growed best when corn steep liquor was the nitrogen source, the sorghum growed strongest when amino fertilizer was the nitrogen source; the total nitrogen and phosphorus content of sorghum shoot were all the highest in the corn steep liquor, in the soybean meal they were lowest, and the organic nitrogen impede the AM fungus absorb phosphorus from the soil. The Arg content of mycorrhizal root was highest in the amino fertilizer, and under the organic fertilizer the Arg content of ERM was highest. To sum up, the AM fungus was most efficient for corn steep liquor.(4)、Atractylodes macrocephala Koidz and Bulbus Fritillariae Thunbergii are two plants with high medicinal value,in this experiment,the AM fungus was inoculated to the plants, then research the effect of different nitrogent level on the growth of two host plants by AM fungus. The results showed:AM fungus make a good symbiotic relationship with Atractylodes macrocephala Koidz; but the Bulbus Fritillariae Thunbergii was hard to be infected by AM fungus, the mycorrhizal infection rate was less than30%, the mycelium infection rate was increased as the applying nitrogen concent increasing. The AM fungus promote the Chlorophyll content、biomass and total nitrogent content of two host plants. In the Atractylodes macrocephala Koidz, The total nitrogen content of the Cauline leaf was increased as increasing in applying nitrogen content, but the underground part was the opposite trend. The total nitrogen content of the Cauline leaf part about Bulbus Fritillariae Thunbergii was highest in the4mmol/L(N2) level, the total nitrogen content of underground part was highest in2mmol/L(N1) level.