Measurement method of inorganic nitrogen isotope fractionation value of ammonium salt assimilated by plant

Abstract

The invention discloses a measurement method of an inorganic nitrogen isotope fractionation value of an ammonium salt assimilated by a plant. Clonal tissue culture seedlings are cultured in culture media, in which two kinds of nitrate with different stable nitrogen isotope values serve as sole nitrogen sources, respectively; after the tissue culture seedlings are cultured for 5 weeks, the stable nitrogen isotope values of leaves of the tissue culture seedlings cultured under the two kinds of nitrate are measured; similarly, clonal tissue culture seedlings are additionally taken, and are cultured in culture media with mixed nitrogen sources formed by the ammonium salt and the two kinds of nitrate whose stable nitrogen isotope values are different respectively; the stable nitrogen isotope values of the leaves of the tissue culture seedlings cultured under the two mixed nitrogen sources are measured; shares, which are utilized by the tissue culture seedlings, of the nitrate are calculated, and accordingly, afterwards, the stable nitrogen isotope values after the ammonium salts assimilated by the tissue culture seedlings cultured under the mixed nitrogen sources generate nitrogen isotope fractionation are calculated; finally, the stable nitrogen isotope fractionation values generated by the ammonium salts assimilated by the tissue culture seedlings, namely, to-be-measured stable nitrogen isotope fractionation values generated by the ammonium salts assimilated by the plants, are obtained. The measurement method can measure the inorganic nitrogen isotope fractionation value of the ammonium salt assimilated by a plant which cannot grow due to monoammonium or a plant which grows under the mixed nitrogen source; as a culture experiment is developed by utilizing the clonal tissue culture seedlings of the same genotype, the measurement result is more reliable.

Description

technical field [0001] The invention relates to a method for measuring the fractionation value of inorganic nitrogen isotopes of ammonium salts assimilated by plants, and belongs to the technical field of crop production. technical background [0002] Nitrogen is an essential element in the process of plant growth and development, and is an important component of protein, nucleic acid, enzyme, chlorophyll, etc. Inorganic nitrogen absorbed by most plants is mainly nitrate and ammonium salts. Nitrate absorbed by plants needs to be reduced before it can be assimilated by plants, while ammonium salt can be directly assimilated by plants. Usually, it takes 15 molecules of ATP to reduce 1 molecule of nitrate, but only 5 molecules of ATP are needed to assimilate 1 molecule of ammonium salt. Therefore, from the perspective of energy consumption of plants, the absorption and utilization of ammonium salts by plants will save energy. However, most plants usually grow poorly and thei...

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Problems solved by technology

However, nitrogen assimilation of nitrate and ammonium in plants grown in the wild or in hydroponics occurs in both leaves and roots, so it is difficult to judge the ability of plants to assimilate ammonium by measuring the stable nitrogen isotope values ​​in leaves or roots

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