68 results about "Nitrogen absorption" patented technology

The application discloses a protein separated from Pinus tabulaeformis Carr. Pinus tabuliformis ​ and an encoding gene PtAMT2.8 of the protein, which can significantly enhance nitrogen absorption and transportation of plants. 31019b The PtAMT2.8 gene is introduced into a yeast mutant strain with a deficiency in ammonium nitrogen absorption function, so that the growth phenotype of the yeast mutant is recovered, and the PtAMT2.8 gene is introduced into Pinus tabulaeformis and Arabidopsis thaliana, so that the nitrogen absorption and transportation capacity of the transgenic plants can be significantly enhanced. The application has important significance for accelerating genetic improvement of plants and cultivating new varieties with high yield, high quality and multi-resistance.

The invention discloses a protein which is separated from pinus tabuliformis and is capable of remarkably enhancing nitrogen absorption and transport of a plant, and a coding gene PtAMT2.8 of the protein. The PtAMT2.8 gene is introduced into a yeast ammonium nitrogen absorption function deficient mutant strain 31019b, so that the growth phenotype of a yeast mutant can be recovered, and the nitrogen absorption and transport capability of a transgenic plant can also be remarkably enhanced by introducing the PtAMT2.8 gene into pinus tabulaeformis and a model plant arabidopsis thaliana. The invention has important significance in accelerating plant genetic improvement and cultivating high-yield, high-quality and multi-resistant new varieties.

The utility model discloses a water and nitrogen absorption root system culture observation device for a leguminous green manure intercropping field. The water and nitrogen absorption root system culture observation device comprises an outer frame, an observation tank, a supporting frame and a climbing rod. The outer frame is of a cuboid structure, a plurality of containing grooves are formed in the outer frame and used for containing observation tanks, and labels are arranged on the front portions of the containing grooves. The observation tank is a transparent cylindrical tank with an open top and a closed bottom, and the outer wall of the observation tank is attached to the inner wall of the containing groove. The supporting frame is located in the observation tank and comprises a vertically-arranged supporting rod and a fixing ring. The climbing rods are rotatably arranged in the supporting frame, and threaded grooves with different curvatures are formed in the surfaces of rod bodies. Root growth is directly observed through the transparent observation tank, the device does not need to be opened, the natural growth environment of the root is prevented from being disturbed, and observation accuracy is improved. The threaded groove of the climbing rod guides the root system to grow orderly, so that the root system is uniformly distributed, the root systems at different positions are conveniently and comprehensively observed, and the growth condition of the root system is accurately evaluated.

The invention discloses application of CLE small peptide in promoting crop growth and development, and belongs to the technical field of bioengineering. Through water culture and soil culture tests, it is found that the growth and development of the tartary buckwheat can be remarkably promoted through exogenous application of the CLE7 small peptide, and the nitrogen absorption capacity of the tartary buckwheat is improved. A foundation is laid for analyzing the effect of the CLE small peptide in crop nitrogen absorption and utilization, and a basis is provided for developing the CLE7 small peptide into a novel polypeptide fertilizer for actual production in the future.

This invention discloses a selective CO2 capture device for industrial flue gas, relating to the field of industrial flue gas treatment and gas separation technology. The invention includes a distribution assembly, which comprises a distribution cylinder body. A rotating assembly is mounted on the inner wall of the distribution cylinder body. The rotating assembly includes a rotating support, and a gas storage assembly is mounted on the inner wall of the rotating support. A top cover is mounted on the top surface of the distribution cylinder body, and a driving arc block is mounted on the bottom surface of the top cover. A CO2 absorption assembly and a nitrogen absorption assembly are mounted on the outer wall of the distribution cylinder body. This invention uses the rotating assembly to drive the gas storage assembly to rotate, causing the driving arc block and the abutting arc block to periodically contact each other, thereby realizing a cyclic process of air intake to exhaust within the corrugated sleeve. The CO2 contained in the industrial flue gas is selectively absorbed by a solid amine adsorbent in the first reaction shell, and the nitrogen is selectively adsorbed by a carbon molecular sieve adsorbent in the second reaction shell, effectively achieving directional separation of gas components and improving gas purification efficiency and selective capture capability.

The invention relates to the technical field of microorganisms, and discloses a pseudobacillus strain FD-6, a microbial agent and application of the pseudobacillus strain FD-6 to promotion of growth of dendrobium chrysotoxum and nitrogen turnover efficiency. According to the present invention, the preservation number of the bacterial strain FD-6 of the bacillus sp. Is CCTCC (China Center for Type Culture Collection) NO: M 20252238, and the preservation number of the bacterial strain FD-6 is CCTCC NO: M 20252238; through bacterial liquid preparation and rhizosphere application, the growth of the dendrobium chrysotoxum root system can be obviously promoted, and the root number, the root system specific surface area and the root biomass are improved; meanwhile, rapid growth of the overground part is remarkably promoted, and the tiller number, the leaf number and the overground part biomass are increased. By comprehensively regulating and controlling the nitrogen accumulation amount, the nitrogen absorption efficiency and the nitrogen utilization efficiency of the root system and the overground part of the dendrobium chrysotoxum, the plant nitrogen turnover efficiency of the dendrobium chrysotoxum from the root system to the overground part of the dendrobium chrysotoxum is remarkably improved. The microbial inoculum prepared from the single strain of the pseudomonas strain FD-6 provided by the invention is simple in preparation process and extremely low in application cost, and has wide development and utilization prospects and popularization and application values.

The device comprises a supporting arm and a refractory cover installed at one end of the supporting arm, the refractory cover is provided with a downward opening, a plurality of side holes distributed in the circumferential direction are formed in the lower end of the side wall of the refractory cover, an argon outlet facing the lower end opening of the refractory cover is formed in the top of the refractory cover, and an argon outlet facing the lower end opening of the refractory cover is formed in the top of the refractory cover. And an argon pipeline communicated with the argon outlet is arranged in the supporting arm in a penetrating manner. Liquid slag on the liquid level is blown away through argon blown out of an argon outlet in the refractory cover, then the refractory cover is covered above a tapping hole area, molten steel enters the cover through a side hole in the lower end of the refractory cover and then flows into the tapping hole, and primary separation of the steel slag, secondary oxidation of the molten steel and nitrogen absorption are achieved. The slag is effectively prevented from entering the tapping hole area in the later tapping period, formation of vortex flow in a molten pool is slowed down, slag entrapment in the later tapping period is restrained, steel slag is prevented from being mixed out, the slag stopping quality and the molten steel quality are improved, and the metal yield is increased.

The invention discloses an application of an indica rice OsRNU2 gene. The registration number of the nucleotide sequence of the OsRNU2 gene in Genbank is LOC4324161, and the registration number of the nucleotide sequence of the OsRNU2 gene in Genbank is LOC4324161. The difference of the indica rice OsRNU2 gene promoter is the reason for the utilization efficiency and yield of indica rice and japonica rice nitrogen fertilizer, and the indica rice OsRNU2 gene promoter sequence is shown as SEQ ID NO.2. In the background of Huajing indica 74, 159 parts of materials carrying IRAT261 single fragment replacement lines are used for QTL (quantitative trait loci) analysis, and the site qRNU2 influencing the nitrate nitrogen absorption rate is positioned. The OsRNU2 haplotype expression level in indica rice is low, so that the indica rice can accumulate more auxin. The excellent allelic variation of the OsRNU2 in the indica rice is introduced into the japonica rice, so that the nitrogen fertilizer utilization efficiency and yield of the japonica rice can be improved.

The application discloses application of a rice OsARF24 gene. The nucleotide sequence of the OsARF24 gene has an accession number of LOC4352211 in Genbank. The rice OsARF24 gene is a key element in an auxin signal pathway. Knocking out the OsARF1 can cause the expression amount of nitrogen metabolism related genes of the rice, the nitrate nitrogen absorption rate, the plant height and the yield of the rice to be reduced, and the nitrogen fertilizer utilization efficiency to be reduced in a comprehensive manner. The function of the OsARF24 gene in positively regulating the nitrogen fertilizer utilization efficiency of the rice is clarified, and a technical route for increasing the nitrogen fertilizer utilization efficiency of the rice by increasing the expression of the OsARF24 in the rice is provided.

The present invention relates to an alkali metal carbonate, more particularly to a natural alkali metal carbonate having lowered bulk density. The present inventors have found that a natural alkali metal carbonate having a bulk density less than 1000 Kg / m3 and an absorption pre size of more than 10 nanometers as measured using BET nitrogen absorption method provides the benefits of improved dispersibility, enhanced liquid carrying capacity.

The ultra-low carbon steel RH smelting system comprises a ladle furnace and a vacuum tank which are sequentially communicated, the vacuum tank is connected with a vacuum pipeline, the outlet end of the vacuum pipeline is connected with a pretreatment device, waste gas treated by the pretreatment device is discharged, the vacuum tank is located above the ladle furnace, and the vacuum tank is located above the ladle furnace. The vacuum tank is provided with an ascending pipe and a descending pipe, one end of the ascending pipe and one end of the descending pipe respectively extend into the ladle furnace, the other ends of the ascending pipe and the descending pipe are respectively communicated with a vacuum cavity of the vacuum tank, the position of the ascending pipe is fixedly connected with a three-way circulating pipe, and the position of the descending pipe is provided with a vacuum sealing cavity; the vacuum sealing cavity is arranged on the periphery of the descending pipe, the ascending pipe and the descending pipe are arranged in an asymmetric structure, and the length of the ascending pipe is larger than that of the descending pipe. The method is suitable for a pure steel production process for controlling gas inclusion ([N] and [O]) in steel and preventing recarburization and nitrogen absorption.

The invention provides application of an OsNER1 gene in regulation and control of nitrogen utilization efficiency and yield of rice, a nucleotide sequence of the OsNER1 gene is shown as SEQ ID NO.1, and the gene negatively regulates and controls nitrogen transport capacity of the rice under a low-nitrogen culture condition. Under the low-nitrogen culture condition, the overground part height and biomass of the Oser1 mutant plant are remarkably increased, and the inhibition of low-nitrogen stress on plant growth is effectively overcome. The 15N content ratio of the overground part to the underground part of the Oser1 mutant plant is obviously higher than that of a wild plant, which indicates that the nitrogen absorption or transport capability of the plant under a low-nitrogen condition is enhanced by the deletion of the OsNER1 gene.

This invention discloses a water and fertilizer integration decision-making method based on job window optimization and water-nitrogen synergy, relating to the field of intelligent irrigation and fertilization technology. The method uses the date on which the water or nitrogen gap first reaches the job trigger threshold during the future decision search period as the prediction benchmark date, and constructs multiple executable job windows around the prediction benchmark date. For each job window, the method evaluates the waiting loss before the job window, the risk of execution impact after the job window, and the loss of early execution. For each job window, the method calculates the target nitrogen application rate, basic irrigation amount, and main nitrogen absorption range, and predicts the main root zone distribution rate, main root zone water status, and leaching nitrogen below the root zone under candidate water and fertilizer combinations using a nitrogen transport response model. Furthermore, it employs water-nitrogen synergy hard constraints to construct a water and fertilizer synergy set, and jointly determines the final water and fertilizer implementation date, fertilizer application rate, and irrigation amount within the set.

The invention provides a fertilizer synergist. The fertilizer synergist comprises a urease inhibitor, glutamic acid, organic silicon and a load carrier, the invention further provides a preparation method of the fertilizer and application of the fertilizer in improving the fertilizer utilization rate in the dry-farming potato planting process. According to the invention, the space-time synergistic effect of NBPT and L-glutamic acid discovered for the first time is taken as a basic mechanism; nBPT delays urea hydrolysis, and creates a time window for L-glutamic acid to activate root nitrogen transporter; l-glutamic acid is combined with soil particles through carboxyl of L-glutamic acid to form a slow-release microenvironment, meanwhile, root systems are promoted to secrete organic acid, and nitrogen absorption is enhanced; the organic silicon can change the soil agglomeration structure, increase the water holding capacity of the soil and reduce water infiltration and evaporation; through the synergistic effect of the three, the effective retention time of the nitrogen fertilizer in a root zone is remarkably prolonged, and the nitrogen utilization rate and the water utilization efficiency are improved.

The invention belongs to the technical field of forest tree genetic engineering breeding, and particularly relates to a CbuLBD19 gene for regulating and controlling root system development and nitrogen absorption and utilization of catalpa bungei and application of the CbuLBD19 gene. The nucleotide sequence of the CbuLBD19 gene is as shown in SEQ ID No.7, and the amino acid sequence coded by the CbuLBD19 gene is as shown in SEQ ID No.8. It is found that overexpression of the CbuLBD19 gene can cause reduction of the total root length and the root biomass of catalpa bungei. Meanwhile, the net absorption rate of nitrate ions in the root system, the activity of nitrate reductase (NR) and the content of amino acid are reduced, and the comprehensive expression is that nitrogen metabolism is reduced. The negative regulation and control function of the CbuLBD19 gene on the nitrogen absorption and utilization of the catalpa bungei is defined, and a technical route for improving the nitrogen absorption and utilization of the catalpa bungei by reducing the expression of the CbuLBD19 gene is provided.

The embodiment of the invention provides a method and a device for measuring parameters of a high-enthalpy unbalanced flow field of an atomic oxygen and atomic nitrogen absorption spectrum, and the method comprises the steps: generating a high-enthalpy flow field at an outlet of a high-enthalpy wind tunnel nozzle, a laser absorption spectrum measurement system arranged in a high-enthalpy wind tunnel experiment section is used for carrying out synchronous measurement on the same to-be-measured flow field area of a high-enthalpy flow field, and the Gaussian half width and the integral absorption rate of an atomic nitrogen characteristic spectral line and the Gaussian half width and the integral absorption rate of an atomic oxygen characteristic spectral line are obtained; the effective absorption optical path of the laser penetrating through the high-enthalpy flow field and the pressure of the high-enthalpy flow field are obtained at the same time; setting an initial iteration value of the electron population temperature of the flow field, and based on the initial iteration value, adopting the constructed iteration algorithm to carry out iteration calculation until the temperature parameter converges to obtain a final electron population temperature; and according to the Gaussian half-width of the atomic nitrogen characteristic spectral line and the Gaussian half-width of the atomic oxygen characteristic spectral line, respectively obtaining the translational temperatures of the atomic nitrogen and the atomic oxygen.

The invention discloses a method for accurately and efficiently evaluating nitrogen absorption and soil nitrogen supply conditions by measuring the nitrate content of bleeding sap of corn stalks. The method comprises the following steps: 1) culturing corn seedlings to grow to V8-V10 periods; 2) collecting stem bleeding sap in the morning of the second day after the plant is fully irrigated: transversely cutting the vertical stem in the second internode by using a blade until the stem is completely cut off; after standing for 5-60 minutes, bleeding sap seeps from the xylem from the cross section of the stalk, and after 5 minutes, the bleeding sap is condensed into liquid drops; using a sterile syringe to suck bleeding sap and transfer the bleeding sap into a centrifugal tube; after the bleeding sap is collected once and 3-10 minutes later, the bleeding sap is condensed into liquid drops again; collecting for multiple times to obtain bleeding sap meeting NO3 <-> determination requirements; 3, the NO3 <-> content of the stem bleeding sap is determined.According to the method, used consumables are simple and easy to obtain, the operation process is simplified, the method is easy to master, time is saved, and the method is especially suitable for obtaining nitrogen absorption phenotypes of large groups of corn in the field.

The invention belongs to the technical field of rice planting, and relates to a method for improving the nitrogen absorption and utilization rate of first-season-regeneration-season rice, which comprises the following steps: deeply ploughing soil, applying a specific soil conditioner, optimizing the nitrogen fertilizer ratio and the fertilization time sequence, and matching with precise intermittent irrigation water management to form a systematic cultivation system. The method effectively solves the problems of low utilization rate, soil hardening, environmental pollution and the like caused by nitrogen volatilization, leaching and denitrification in the traditional double cropping rice cultivation, can obviously enhance the nitrogen conservation and fixation capability of the soil, ensures that nitrogen supply is accurately matched with the requirements of the rice in each growth critical period, and improves the yield of the rice. Meanwhile, nitrogen loss is inhibited through a dry-wet alternate irrigation mode, the nitrogen absorption and utilization efficiency of the rice is greatly improved on the premise that the nitrogen fertilizer consumption is not increased, balanced growth and yield increase of rice in the first season and the regeneration season are promoted, the ecological environment of soil is improved, and cost saving, efficiency increasing and sustainable development of rice production are achieved.

The invention discloses an application of a rice OsRNU9 gene. The registration number of the nucleotide sequence of the OsRNU9 gene in Genbank is LOC4325001, and the registration number of the nucleotide sequence of the OsRNU9 gene in Genbank is LOC4325001. RNA-seq is utilized to discover that the OsRNU9 shows response to the external nitrogen supply level, and fluorescent quantitative PCR (Polymerase Chain Reaction) proves that the OsRNU9 is induced by low nitrogen. Knockout of the OsRNU9 can cause reduction of the nitrogen absorption rate, tillering, plant height and yield of the rice, and the comprehensive performance is that the utilization efficiency of the nitrogen fertilizer is reduced. The function of the OsRNU9 gene for positively regulating the utilization efficiency of the rice nitrogen fertilizer is defined, and a technical route for improving the utilization efficiency of the rice nitrogen fertilizer by increasing expression of OsRNU9 in rice is provided.

The invention discloses a production method of cold forging steel with the nitrogen content lower than 40 ppm. The production method comprises the following steps of converter smelting, LF furnace refining, continuous casting and casting blank cutting. Through converter source nitrogen control, refining deep nitrogen removal and continuous casting secondary nitrogen absorption prevention, the nitrogen content of a cold heading steel finished product is controlled to be 30-40 ppm, so that the cracking rate of the cold heading steel is reduced, the quality problem that cracking is likely to occur during fastener production is solved, and the cold heading qualification rate is larger than or equal to 98%.

The invention provides application of an OsPLN1 gene in regulation and control of nitrogen utilization efficiency and yield of rice, a nucleotide sequence of the OsPLN1 gene is shown as SEQ ID NO.1, and the OsPLN1 gene can negatively regulate and control nitrogen absorption capacity of the rice under a low-nitrogen culture condition. The amino acid sequence of the protein coded by the OsPLN1 gene is as shown in SEQ ID NO. 2. A target spot of the OsPLN1 gene is knocked out, and an Ospln1 mutant plant is obtained. Experiments show that under a low-nitrogen culture condition, compared with a wild plant, the overground part height and biomass of the Ospln1 mutant plant are remarkably increased, and the inhibition of low-nitrogen stress on plant growth is effectively overcome. Under a low-nitrogen culture condition, the total nitrogen content of an Ospln1 mutant plant is obviously higher than that of a wild type plant, so that the nitrogen absorption capacity of the plant under the low-nitrogen culture condition is enhanced, and the inhibition effect of low-nitrogen stress on plant growth is relieved to a certain extent. The cooperative regulation capability of the OsPLN1 gene provides a core gene resource for cultivating a new variety of'fertilizer-saving and high-yield 'rice, and has great significance for agricultural sustainable development.

This invention provides a method for regulating nitrogen absorption and utilization in catalpa trees. CbuLBD9 This invention relates to genes and their applications, belonging to the field of forest tree genetic engineering breeding technology. CbuLBD9 The nucleotide sequence of the gene is shown in SEQ ID No. 1, and the amino acid sequence it encodes is shown in SEQ ID No. 2. This invention utilizes silencing... CbuLBD9 This gene significantly promotes the elongation and growth of the Catalpa tree root system and enhances the absorption and utilization of nitrogen by the plant roots. This invention provides an important candidate gene for genetic improvement related to efficient nitrogen utilization in Catalpa trees, and has broad application prospects in forest tree genetic engineering breeding and the development of Catalpa tree clones.

The invention belongs to the technical field of agriculture, and particularly relates to a rice field emission reduction and yield increase double-inhibitor nitrogen fertilizer and a preparation method and application thereof. According to the invention, low-dose double inhibitors NBPT and DMPP are uniformly wrapped in large-granule urea by adopting a biological agent, large-scale production is easy to realize, and a yield-increasing and emission-reducing application technology is provided, so that nitrogen loss in various ways in a rice field is reduced, the nitrogen absorption capability of rice is enhanced, the tillering capability of rice is improved, tillering and panicle formation are ensured, the yield and the nitrogen fertilizer utilization efficiency are improved, and the application prospect is wide. The method is safe, efficient and convenient for large-scale use.

The invention belongs to the technical field of plant nitrogen fertilizer management, and particularly relates to a plant nitrogen fertilizer recommendation method and system based on unmanned aerial vehicle spectrum diagnosis. Comprising the following steps: determining the deviation between historical nitrogen content data and current nitrogen content data of a target plant, correcting an initial nitrogen absorption curve based on the deviation to generate a corrected nitrogen absorption curve, generating the total amount of nitrogen fertilizer recommended to be applied based on the corrected nitrogen absorption curve and nitrogen demand information of the target plant, and determining the nitrogen content of the target plant according to the total amount of nitrogen fertilizer recommended to be applied. And dividing the total amount of the recommended applied nitrogen fertilizer into at least one dosage to determine a corresponding adding time point. According to the method, the accuracy of demand prediction is improved by dynamically calibrating the nitrogen absorption model, the accuracy of the recommended total fertilization amount is ensured by utilizing a verification mechanism, and the self-adaptive optimization of the fertilization plan is realized by virtue of a feedback correction closed loop, so that the fertilization effect is quantitatively evaluated, and the nitrogen fertilizer utilization rate is improved.

The invention provides application of an OsTNR2 gene in regulation and control of nitrogen utilization efficiency and yield of rice, a nucleotide sequence of the OsTNR2 gene is shown as SEQ ID NO.1, and the OsTNR2 gene negatively regulates and controls the nitrogen utilization efficiency and yield of the rice under a low-nitrogen condition. Under a low-nitrogen (0.2 mM NH4NO3) culture condition, compared with a wild type (WT), the overground part height and biomass of the Ostnr2 mutant after the OsTNR2 gene is knocked out are remarkably increased, and the inhibition of low-nitrogen stress on plant growth is effectively overcome. Under a low-nitrogen culture condition, the content ratio of 15N in the overground part to the underground part of the Ostnr2 mutant is increased, which proves that the deletion of the OsTNR2 gene enhances the nitrogen absorption or transport capacity of the plant under the low-nitrogen condition, thereby relieving the inhibition effect of low-nitrogen stress on plant growth to a certain extent. The cooperative regulation capability of the OsTNR2 gene provides a core gene resource for cultivating a new variety of fertilizer-saving high-yield rice, and has great significance for agricultural sustainable development.

The invention relates to the technical field of biological engineering, in particular to application of a gene ZmNPF6.8 in regulation and control of corn nitrogen absorption and utilization efficiency and single-plant yield of corn. The gene ZmNPF6.8 has the following characteristics: 1) a coding region nucleotide sequence as shown in SEQ ID NO: 3; and 2) a nucleotide sequence which has more than 90% of homology with the nucleotide sequence as shown in SEQ ID NO: 3 and forms protein with the same function as the nucleotide sequence as the nucleotide sequence as shown in SEQ ID NO: 3. According to the invention, the expression quantity of the gene ZmNPF6.8 can be down-regulated by inserting a Mutuator transposon into an amino acid coding region of the gene, and meanwhile, the nitrogen absorption and utilization efficiency and the yield per plant of corn are remarkably reduced. Researches show that the nitrogen absorption and utilization efficiency of the corn and the change of the yield of a single plant of the corn can be regulated and controlled by changing the expression quantity of the gene ZmNPF6.8, and the gene is of great significance to the high-efficiency and high-yield breeding work of the corn in the future.

The present application belongs to the technical field of molecular marker assisted breeding, and is particularly suitable for rapid screening and molecular marker assisted breeding of watermelon nitrogen absorption efficiency. The present application discloses a KASP molecular marker for identifying different watermelon nitrogen utilization efficiencies based on BSA pool sequencing positioning watermelon nitrogen absorption efficiency related genes, wherein the KASP molecular marker is an SNP marker located at 27873651bp of the 7th chromosome of watermelon, and the present application further provides a primer combination for identifying the KASP molecular marker related to watermelon nitrogen absorption efficiency, i.e. a forward primer F-Fam and a forward primer F-Hex. The method of the present application can be used to select and separate single plants with high nitrogen absorption efficiency in a population for breeding improvement, realize efficient utilization of nitrogen in watermelon plants, and accelerate the molecular breeding process of "green" watermelon varieties.

The application provides a hydrolytic nitrogen absorption device and a method for determining the content of hydrolytic nitrogen, and belongs to the technical field of analysis and detection. The hydrolytic nitrogen absorption device comprises an automatic sampling tube, a sealed tube for containing the automatic sampling tube, an elastic buckle support for fixing the automatic sampling tube on the upper part inside the sealed tube, and a sealing cover for sealing the opening at the top of the sealed tube. The device is used for pretreating the sample to be measured, and has the advantages of simple operation, high processing efficiency, high-throughput detection by using a full-automatic equipment, liberation of manpower, time and labor saving, more than 200 samples can be tested in one day (24 hours of unattended operation), low error probability, and accurate determination of the content of hydrolytic nitrogen in soil.

A PagPB gene regulating nitrogen absorption and utilization in a root system of a woody plant is provided. The nucleotide sequence of the PagPB gene is shown in SEQ ID NO: 1. By silencing the PagPB gene, efficiency of the nitrogen absorption and utilization of a root system of poplar can be improved. In contrast, by overexpressing the PagPB gene, the efficiency of the nitrogen absorption and utilization of the root system of the poplar is reduced. This provides significant genetic resources for identification of key regulatory genes involved in the nitrogen absorption and utilization in the woody plant and holds important application value in the fields of forest genetic engineering and clonal forestry.

The invention provides application of an OsXYLPI9 gene in the aspects of the ammonia absorption rate and grain growth and development of rice, the nucleotide sequence of the OsXYLP19 gene is shown as SEQIDNO.1, under the condition of compound stress of salt stress and nitrogen deficiency, the ammonia absorption rate of a mutant osxylp19 plant of the OsXYLP19 gene is higher than that of a wild plant, and the OsXYLPI9 gene can be applied to the growth and development of grains. Namely, the nitrogen absorption capacity of the rice under the combined conditions of salt stress and nitrogen deficiency is negatively regulated by the OsXYLPI9. Field experiments show that the grain length of the osxyp19 mutant is significantly increased, which indicates that the OsXYLP19 gene has the function of regulating and controlling the rice grain length and is expected to be used for improving the rice yield.