The Studies On Characteristics Of Larix Gmelinii Seedlings Uptaking Amino Acid

Nitrogen is known as the“elements of life.”Plant growth requires a lot of nitrogen,therefore,nitrogen is one of the most important limiting factors for plant growth.In recent years,the study on nitrogen in soil and how plant use it has been gradually attracted more attention.Although the content of free amino acids is low,because of its short half-life in the soil,there is still a high content of free amino acids in the soil.Plus although the researches on amino acid in soil have been more and more common,they were mostly focus on field crops,doing a study on how forest seedlings uptake amino acid seems especially important.In this paper,we measured nitrogen content in soil that took from Larix gmelinii land in cold temperate zone-Da Hinggan Mountains,and select the Larix gmelinii seed in same area,simulated its growth environment,and selected three kinds of amino acid?Gly,Glu,Lys?to hydroponics cultivate the seedlings in different concentration gradient,we got conclusions by comprehensive analysis based on experimental result.The results showed that there were various forms of nitrogen in soil,and the content of amino acid is very large.And ectomycorrhizal could promote plant growth,and by adjusting the proportion of nutrients in different parts of the plant to improve the nitrogen uptake.The experimental results show that:1)The total soluble nitrogen,dissolved organic nitrogen and free amino acid content in cold temperate forest soil in Greater Khingan Range area were generally apeared the order of O layer>0-5cm>5-25cm,July>June>August.The organic nitrogen accounted for 90.97%-95.42%.2)The Larix gmelinii seedlings absorbed three kind of concentration series amino acid for 12h,the absorption of Gly was the largest,followed by Glu,the process of seedlings absorbed three kinds of amino acid was initiative.3)After adding NH₄⁺to series concentration amino acid solution,the order of three kinds of amino acid was still Gly>Glu>Lys.When the concentration of amino acid solution was more than 250?mol/L,The addition of NH₄⁺had a significant effect on absorbing three kinds of amino acid nitrogen sources by Larix gmelinii.However,the addition of NO₃^-did not promote the absorption of three kinds of amino acid.4)The seedlings infected by ectomycorrhizal fungi had a superior growth effect,they had a higher biomass and length than Larch seedlings grew in aseptic environment,although the increase amount of total nitrogen in all parts of seedlings were small,ectomycorrhizal improved the proportion of amino acid nitrogen in different which balanced the nitrogen nutrition in roots,stems and leaves.