Moraxella rosellii and its application

Abstract

The present invention discloses Moraxella rosellii and use thereof as a bacterial agent in improving plant salt tolerance or alleviating plant salt stress. Rossellomorea sp. ) is numbered H136 and is deposited in China Center for Type Culture Collection with a deposit number of CCTCC NO: M 20241499. The Moraxella rosellii H136 provided by the present invention can survive in a highly saline-alkali environment and can produce indoleacetic acid, and has very good application prospects in biological microbial agents and saline-alkali land growth and yield promotion.

Description

Technical Field

[0001] The invention relates to the technical field of microorganisms, in particular to Moraxella rosellii and application thereof. Background Art

[0002] Salt-alkali stress is one of the major challenges facing global food security and agricultural production, and it seriously threatens the growth and development of crops. As one of the countries with the most widespread distribution of saline-alkali soils, my country urgently needs to make full use of saline-alkali land resources to address food security issues. Traditional saline-alkali soil improvement methods usually rely on physical, chemical and biological remediation strategies. Although physical and chemical remediation technologies have certain effects in improving soil quality, they often face problems such as high cost, large engineering workload and potential environmental pollution. Therefore, in recent years, microbial agents have received increasing attention due to their high efficiency and safety.

[0003] In the research and development of microbial agents, it is crucial to select the right strains. This can not only effectively improve saline-alkali soils, but also significantly promote plant growth. With the continuous deepening of scientific research, the relevant research on functional microbial strains has gradually increased. Many studies have confirmed that many strains have good salt tolerance and plant growth-promoting properties. For example, Ji Yan et al. (2024) found that Bacillus subtilis can enhance the growth and dry matter accumulation of corn in saline-alkali environments by optimizing the root morphology of corn and improving its stress resistance enzyme activity; Liu Li et al. (2020) pointed out that seawater salt monospores showed strong adaptability in high-salt and high-alkali environments, effectively reducing the soluble salt content in the soil, and increasing the biomass and yield of plants; in addition, Zhang Fenghua et al. (2021) showed that sea cocci can dissolve organic and inorganic phosphorus, increase the soluble phosphorus content in the soil, and thus promote the germination of crop seeds. These research results have given us a deeper understanding of the importance of microbial resources, especially microorganisms that survive in extreme environments. Their unique physiological structure, complex metabolic mechanism and rich genetic genes give them great application potential and can produce a variety of substances with unique biological activities. Therefore, exploring the potential of extreme environment microorganisms, especially their application in ecological restoration and bioengineering, has become a new research hotspot in the field of microbiology.

[0004] Among the many microorganisms, Moraxella rosellii ( Rossellomorea sp. ) is a new genus of bacteria within the genus Bacillus that exhibit Gram-positive or variant staining, form endospores, and move by monopolar flagella or periflagellum. The genus currently includes four species with published valid names ( Rossellomorea aquimaris , R. enclensis , R. marisflavi and R. vietnamensis). In recent years, more and more Moraxella rosellii have been discovered, and it has been confirmed that they have significant potential in improving saline-alkali land and promoting plant growth. However, there are still few studies on functional microorganisms in extreme environments in terms of salt-alkali tolerance, growth promotion, and soil improvement, especially a lack of reports on newly discovered microbial resources. In addition, most of the research on functional strains remains in laboratory or greenhouse conditions, and field application research is still insufficient. Therefore, the development of a functional strain that can effectively alleviate the effects of saline-alkali stress on plants is of great significance for promoting agricultural production. Summary of the invention

[0005] In view of the above technical problems, the present invention provides a Moraxella rosellii strain, aiming to solve the growth inhibition of plants in saline-alkali environments.

[0006] The present invention protects Rossellomorea sp. H136, which has been deposited in the China Center for Type Culture Collection on July 15, 2024, and its address is Wuhan University near Luonan 1st Road, Wuchang District, Wuhan City, Hubei Province, and its specific location is Room 211 opposite the First Affiliated Primary School of Wuhan University; the deposit number is CCTCC NO:M 20241499, and its 16SrDNA sequence is shown in SEQ ID NO.1, and its nbsp The sequence is shown in SEQ ID NO:2.

[0007] The present invention also protects a bacterial agent containing Moraxella rosellii H136.

[0008] The present invention also protects the growth-promoting substances secreted and produced by Moraxella rosellii H136, and the growth-promoting substances include IAA (indoleacetic acid). Strain H136 can produce IAA under saline-alkali conditions and promote plant growth.

[0009] The present invention also protects the biological fertilizer or plant growth promoter prepared by Moraxella rosellii H136 or its bacterial agent, and the plants are corn and cotton.

[0010] The present invention also protects the use of Moraxella rosellii H136 in improving plant salt tolerance or alleviating plant salt stress, in promoting plant growth and development and increasing yield, and in reducing soil salt ion content. The plants are corn and cotton.

[0011] The Moraxella rosellii H136 disclosed in the present invention has been identified to have multiple functional characteristics, mainly including:

[0012] (1) Salt and alkali resistance: able to survive in an environment of 17% (w / v) NaCl, pH 10.0;

[0013] (2) IAA production capacity: the synthesis amount was 9.74 μg / mL;

[0014] (3) Promote plant growth: stimulate plant root growth, promote plant nutrient absorption and accumulation, and increase plant aboveground biomass (aboveground dry weight) and underground biomass (underground dry weight);

[0015] (4) Improve plant stress resistance: increase plant proline content and superoxide dismutase content;

[0016] (5) Reduce the salt ion content in soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The colony morphology of Moraxella rosellii H136 of the present invention;

[0018] Figure 2 A phylogenetic tree of Moraxella rosellii H136 and related strains based on 16S rRNA sequences of the present invention;

[0019] Figure 3 A phylogenetic tree of Moraxella rosellii H136 and related strains based on the whole genome sequence of the present invention;

[0020] Figure 4 This is a test result of the salt-alkali resistance of Moraxella rosellii H136 of the present invention;

[0021] Figure 5 The growth of Moraxella rosellii H136 of the present invention in a medium with pH=10.0 and different salt concentrations;

[0022] Figure 6 This is a diagram showing that Moraxella rosellii H136 in a preferred embodiment of the present invention is cultured on blood agar medium for 3 days without hemolysis zone;

[0023] Figure 7 This is a comparison of the growth-promoting and salt-reducing effects of Moraxella rosellii H136 on the aboveground part of corn and the rhizosphere soil in an artificial saline-alkali environment.

[0024] Figure 8 , Fig. 9 This is a comparison of the growth-promoting effects of Moraxella rosellii H136 on the aboveground and underground parts of corn in a natural saline-alkali environment.

[0025] Fig.10 , Fig.11 This is a comparison of the growth-promoting effects of Moraxella rosellii H136 on the aboveground and underground parts of cotton in the field. DETAILED DESCRIPTION

[0026] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art, and the raw materials used are all commercially available products.

[0027] Example 1 Isolation, purification and identification of strain H136

[0028] 1.1 Isolation and purification of strain H136

[0029] 2023 Soil was collected from a natural saline-alkali stress plot in Aksu, Xinjiang Uygur Autonomous Region. About 10 g of soil sample was weighed and added to a triangular flask containing glass beads and 90 mL of sterile saline. The soil suspension was fully shaken at 180 r / min for 30 min and allowed to stand for 10 min to obtain a soil suspension. 1 mL of the supernatant was taken and diluted with sterile saline for 10 min. -1 , 10 -2 , 10 -3 , 10 -4 and 10 -5 Five gradients, take 10 -2 , 10 -3 , 10 -4 , 10 -5 100 μL of each dilution was evenly spread on LB solid medium (yeast powder 5 g / L, peptone 10 g / L, NaCl 5 g / L, agar 15 g / L), and each gradient was repeated 3 times. After constant temperature culture at 28°C for 2 days, strain H136 ( Figure 1 ).

[0030] 1.2 PCR amplification of 16S rRNA Gene sequence

[0031] The strain H136 was inoculated into LB solid medium and cultured for 24 h. A 0.2 ml sterilized PCR tube was taken, 10 μL ddH2O was added, and a single colony was picked up with a sterile toothpick and placed in a PCR tube for mixing. The 16S rDNA sequence was amplified using primers 27F (5'-AGAGTTTGATCCTGGCTCAG-3') and 1492R (5'-GGTTACCTTGTTACGACTT-3'). The PCR reaction system and conditions were carried out according to Tables 1 and 2. After PCR amplification, the product was tested by 1% agarose gel electrophoresis, and there were obvious characteristic bands.

[0032] The PCR amplification products were sent to Beijing Qingke Biotechnology Co., Ltd. for sequencing. The obtained sequences were compared with the sequences in the gene library by Blast analysis. The results showed that the strain was Rossellomorea sp. strain W-5 has the highest similarity, with a homology of 99.93%. Rossellomorea oryzaecorticis strainALP-36 has a high similarity, with a homology of 99.72%. Based on the above identification results of strain H136 (SEQ ID NO: 1), it was determined that strain H136 belongs to Moraxella rosellii ( Rossellomorea sp.) and named this strain Moraxella rosellii H136 ( Rossellomorea sp. H136). Moraxella rosellii H136 and related strains based on 16S rRNA Phylogenetic tree of the sequence Figure 2 .

[0033] Table 1 16S rRNA PCR reaction system used

[0034]

[0035] Table 2 16S rRNA PCR reaction conditions used

[0036]

[0037] In this example, the 16s rRNA nucleotide sequence of strain H136 is shown in SEQ ID NO. 1:

[0038]

[0039] 1.3 Analysis of functional genes of strain H136

[0040] The H136 genome size is 4126368bp, with a G+C content of 41.3%. There are 4896 genes in total, with coding regions accounting for 83.3% of the genome, 33 ribosomal RNA operons, and 109 transfer RNAs (tRNAs) (Table 3). The functional genes in the H136 strain were analyzed through the annotation of the whole genome database.

[0041] The results showed that the H136 strain had Na + Excretion-related genes, intracellular small molecule compatible substance synthesis-related genes, glycine betaine synthesis, proline synthesis and betaine transport-related genes.

[0042] Table 3 Genome information of strain H136

[0043] project H136 Genome size (bp) 4, 126, 368 G+C content / % 41.3 Protein coding number 4896 Average CDS size (bp) 842 The percentage of coding region 83.3 Ribosomal RNA operon 33 Number of tRNAs 109

[0044] 1.4 Identification of strain H136

[0045] The average nucleotide similarity (ANI) between the H136 strain and other type strains of M. rosellii was calculated using JSpeciesWS (https: / / jspecies.ribohost.com / jspeciesws / #analyse), and the digital DNA-DNA hybridization (Dddh) between the H136 strain and other type strains of M. rosellii was calculated using GGDC Calculator 3.0 (http: / / ggdc.dsmz.de).

[0046] The evolutionary status of H136 strain was analyzed by ANI and species cluster analysis. The results of cluster analysis showed that H136 strain was closely related to Mangrovibacillus cuniculi The affinity of R1DC41 is 29.6%. Rossellomorea arthrocnemi The parentage of EAR8 is 25.8%, but it is lower than the threshold of 70%. The ANI calculation results also show that R. arthrocnemi EAR8 had the strongest parentage relationship with H136 strains (81.85%), but its value was lower than the species classification threshold of 95%. The standard scores of H136 and strains of the same genus were calculated by Tetra correlation analysis. The results in Table 4 showed that the annotation scores of H136 and all strains of the same genus were lower than the species classification threshold of 0.999.

[0047] In addition, the whole genome evolution tree also showed that H136 was related to Rossellomorea.sp Closely related species ( Figure 3 ), but the combination of ANI, cluster analysis, standard score and evolutionary tree suggests that the H136 strain is a new species in the genus. + Excretion of related genes (gene nbsp See SEQ ID NO:2 for the sequence), and this new strain was named Rossellomorea halotolerans .

[0048] Table 4 Calculation results of strain H136 and parent strains

[0049]

[0050] In this example, the gene of strain H136 nbsp The sequence is shown in SEQ ID NO. 2:

[0051]

[0052] Example 2 Determination of salt and alkali tolerance of strain H136

[0053] First, strain H136 was activated in LB liquid medium, and then the activated strain was inoculated into LB liquid medium containing 0, 5, 9, 13, 15, and 17% NaCl (w / v), pH 10.0 at a 1% inoculum, and cultured at 28°C, 150 rpm for 48 h. Finally, the OD 600 At the same time, LB medium without inoculation was used as control (CK), and each treatment was repeated 3 times.

[0054] The results showed that the growth of strain H136 was not significantly inhibited in the medium with pH 10.0 and salt concentration of 17% or below ( Figure 4 The results also showed that the strain NaCl could grow well in an environment with a pH of 10.0 and a salt content of 17% ( Figure 5 ).

[0055] Example 3 Identification of IAA production and other functions

[0056] 2.1 IAA production capacity assessment

[0057] Prepare the reagents according to the following ratio:

[0058] 1) IAA detection medium: 5.0 g peptone, 1.5 g yeast extract, 1.5 g beef extract, 5.0 g NaCl, 0.5 g tryptophan, dissolved in deionized water and fixed to 1000 mL, pH 7.0, sterilized by high pressure steam at 121°C for 20 min.

[0059] 2) IAA detection reagent Solution Ⅰ (10 mM phosphoric acid): 1 mL phosphoric acid was dissolved in 13.48 ml deionized water to obtain 1 M phosphoric acid, which was then graded and diluted 100-fold to obtain 10 mM phosphoric acid.

[0060] 3) IAA detection reagent Solution II (Salkowkin colorimetric solution): 1 mL 0.5 M FeCl 3 and 50 mL 35% HClO 4 Mix well.

[0061] The H136 strain was inoculated in LB liquid medium and cultured on a shaker (28°C, 150 rpm) for 12 hours. It was inoculated in IAA detection medium at a 1% inoculum. After 7 days of culture under the same conditions, the bacterial solution was centrifuged at 12000 rpm for 5 minutes. 500 μL of the supernatant was taken into a 2 mL centrifuge tube, 25 μL of 10 mM phosphoric acid and 1 mL of Salkowki colorimetric solution were added, mixed, reacted at room temperature in the dark for 25 minutes, and the absorbance was measured at 530 nm. The IAA production was calculated by comparing with the standard curve. The results showed that the amount of IAA produced by H136 was 9.74 μg / mL.

[0062] 2.2 Safety Identification

[0063] Prepare the reagents according to the following ratio:

[0064] Blood agar medium: 18.0 g peptone, 1.0 g yeast powder, 5.0 g NaCl, 15.0 g agar, 1000 ml deionized water, pH 6.8-7.2; sterilize at 121°C for 20 min, add 5% defibrinated sheep blood when the medium cools to 50°C, mix well and pour onto a plate.

[0065] The activated H136 strain was inoculated into blood agar medium by puncture, cultured at 28℃ for 3 days, and observed for hemolysis circles. If there is a hemolysis circle, it means that the strain has hemolytic activity, which is a potential threat to humans and animals, and the strain should be prohibited from being used in microbial fertilizers; if there is no hemolysis circle, it means that the strain has no hemolytic activity and is a safe strain.

[0066] Rosellonia spp. H136 was cultured on blood agar for 3 days. Figure 6 As shown, the test results showed that no hemolytic zone appeared, indicating that the hemolytic activity of H136 was negative.

[0067] Example 4 Strain H136 promotes the growth of corn seedlings in an artificial saline-alkali environment

[0068] 3.1 Preparation of H136 inoculant

[0069] The activated Moraxella rosellii H136 was inoculated into LB medium for cultivation; the inoculation amount was 1.2%, the culture temperature was 28°C, the rotation speed was 200 rpm, and the culture time was 24 h to obtain H136 liquid bacterial agent, and the bacterial liquid OD was adjusted. 600 =1.0 (1×10 8 CFU mL -1 ).

[0070] 3.2 Application of H136 inoculant

[0071] The experiment was conducted in potted plants and divided into two groups, with 6 replicates in each group. The specific treatment methods are as follows:

[0072] CK: no bacterial treatment;

[0073] H136: Inoculated with H136 bacterial agent.

[0074] Select Zhengdan 958 corn seeds with full grains and soak them in sterile water for 1 hour. After washing, soak them in 3% sodium hypochlorite for 30 minutes. Gently rub the seed coating with your hands, wash and soak them in 70% ethanol for 10 minutes, then wash them 3 times with sterile water, and soak them in sterile water at room temperature for 10-12 hours. Spread 2 layers of sterile filter paper in a large culture dish, arrange the seeds on it, soak the filter paper with 20mL of sterilized distilled water, and cover it with a layer of sterile gauze. After covering the entire culture dish with a layer of plastic wrap, poke several small holes on its surface and culture at 28℃ until the seeds turn white. Use about 30mL of the prepared bacterial suspension in the culture dish, put corn and cotton seeds with consistent whitening, and soak the seeds for 5 hours. At the same time, soak the seeds in the fermentation medium without inoculation of bacterial liquid as a blank control.

[0075] The soil used in the potted plant experiment came from the Shangzhuang Experimental Station of China Agricultural University. The basic physical and chemical properties of the soil are shown in Table 5. During the potted plant experiment, an artificial saline-alkali environment was created by adding NaCl. 1.5 kg of soil was weighed for each potted plant, and the amount of bacterial solution added was 100 mL. At the same time, in order to maintain soil moisture, 100 mL of sterile water was added to the bacterial solution, and 2 g / kg NaCl was added to the sterile water. The sample soil was spread on kraft paper that was not easily stained with water and sprayed evenly. After each layer was evenly sprinkled with the bacterial solution, it was gently mixed. During this period, soil disturbance was avoided as much as possible until all the bacterial solution was added. At the same time, the fermentation medium without inoculation of bacterial solution was sprayed and mixed as a blank control.

[0076] After the bacterial solution was added, the soil was weighed 1.5 kg and placed in a plastic flower pot with a diameter of 18 cm. Three corn seeds with uniform germination were sown in each pot, with a sowing depth of about 1 cm. After sowing, 100 mL of water was applied every two days. Thinning began 3 days after germination, and only two corn plants of uniform size were retained in each pot. After 10 days of thinning, MS nutrient solution was supplemented (purchased from Qingdao Haibo Biotechnology Co., Ltd., 4.74 g was weighed, dissolved in 1000 ml of distilled water, and sterilized at 116°C for 30 minutes).

[0077] Samples were collected starting from the 40th day after sowing to test the growth-promoting ability of H136 inoculant on corn seedlings, and the plant height and fresh weight of corn seedlings were measured. The calcium, magnesium, sodium and potassium ion contents in the rhizosphere soil were determined using inductively coupled plasma-mass spectrometry.

[0078] Table 5 Basic physical and chemical properties of soil used in Shangzhuang experiment

[0079]

[0080] 3.3 Experimental Results

[0081] The results showed that strain H136 had a good growth-promoting and salt-reducing effect on the aboveground part and rhizosphere soil of corn in artificial saline-alkali environment ( Figure 7 , Table 6), can significantly increase the height of corn seedlings by 19.9%, fresh weight by 26.3%, Na + Decreased by 23.4%, Ca 2+ Reduced by 3.9%, Mg 2+ Reduced by 12.9%, K + A decrease of 7.8%.

[0082] The above pot test results show that the M. rosellii H136 strain has the ability to promote plant growth and reduce soil salt ions.

[0083] Table 6 Growth-promoting and salt-reducing effects of strain H136 in artificial saline-alkali environment

[0084]

[0085] Note: In the same column, * indicates significant difference (p<0.05), ** indicates extremely significant difference (p<0.01), and *** indicates extremely significant difference (p<0.001).

[0086] Example 5 Strain H136 promotes the growth of corn seedlings in a natural saline-alkali environment

[0087] 4.1 Preparation of H136 inoculant

[0088] 1) Preparation of seed solution: The activated Moraxella rosellii H136 was inoculated into the seed culture medium for cultivation; the inoculation amount was 1.2%, the culture temperature was 28°C, the rotation speed was 200 rpm, and the culture time was 12 h; wherein the composition of the seed culture medium was: peptone 12 g / L, yeast extract 5 g / L, glucose 10 g / L, NaCl 10 g / L, pH 7.2.

[0089] 2) Fermentation culture: The cultured seed liquid was inoculated into a 2L volumetric flask at a ratio of 5% v / v, with a liquid volume of 60%, a fermentation temperature of 32°C, a rotation speed of 180 rpm, and a fermentation time of 64 h to obtain H136 liquid inoculum. The bacterial liquid concentration was adjusted to 5×10 9 CFU ml -1 The fermentation medium consisted of 5 g / L yeast powder, 10 g / L peptone, 12 g / L glucose, 5 g / L NaCl, and K 2 HPO 4 3H 2 O 0.1 g / L, corn starch 20 g / L, soybean meal 5 g / L, KH2 PO 4 0.7 g / L, MgSO 4 7H 2 O 0.2g / L, pH7.2.

[0090] 4.2 Application of H136 inoculant

[0091] The experiment was conducted in potted plants and divided into two groups, with 6 replicates in each group. The specific treatment methods are as follows:

[0092] CK: no bacterial treatment;

[0093] H136: Inoculated with H136 bacterial agent.

[0094] Select Zhengdan 958 corn seeds with full grains and soak them in sterile water for 1 hour. After washing, soak them in 3% sodium hypochlorite for 30 minutes. Gently rub the seed coating with your hands, wash and soak them in 70% ethanol for 10 minutes, then wash them 3 times with sterile water, and soak them in sterile water at room temperature for 10-12 hours. Spread 2 layers of sterile filter paper in a large culture dish, arrange the seeds on it, soak the filter paper with 20mL of sterilized distilled water, and cover it with a layer of sterile gauze. After covering the entire culture dish with a layer of plastic wrap, poke several small holes on its surface and culture at 28℃ until the seeds turn white. Use about 30mL of the prepared bacterial suspension in the culture dish, put corn and cotton seeds with consistent whitening, and soak the seeds for 5 hours. At the same time, soak the seeds in the fermentation medium without inoculation of bacterial liquid as a blank control.

[0095] The soil used in the potted test was coastal undisturbed saline-alkali soil, and the basic physical and chemical properties of the soil are shown in Table 7. The soil was 1.5 kg per pot, and the amount of bacterial solution added was 100 mL. At the same time, in order to maintain soil moisture, 100 mL of sterile water was added to the bacterial solution. The sample soil was spread on kraft paper that was not easily stained with water, and sprayed evenly. After each layer was evenly sprinkled with the bacterial solution, it was gently mixed. During this period, soil disturbance was avoided as much as possible until all the bacterial solution was added. At the same time, the fermentation medium without bacterial solution was sprayed and mixed as a blank control.

[0096] After the bacterial solution was added, the soil was weighed 1.5 kg and placed in a plastic flower pot with a diameter of 18 cm. Three corn seeds with uniform germination were sown in each pot, with a sowing depth of about 1 cm. After sowing, 100 mL of water was applied every two days. Thinning began 3 days after germination, and only two corn plants of uniform size were retained in each pot. After 10 days of thinning, MS nutrient solution was supplemented (purchased from Qingdao Haibo Biotechnology Co., Ltd., 4.74 g was weighed, dissolved in 1000 ml of distilled water, and sterilized at 116°C for 30 minutes).

[0097] Samples were collected starting from the 40th day after sowing to test the growth-promoting ability of H136 fermentation liquid on corn seedlings. A handheld chlorophyll meter (SPAD-502PIU) was used to measure the largest leaf from top to bottom three times, and then the SPAD average value was used as the SPAD value of the corn plant. The plant height, fresh weight, dry weight, maximum leaf area, root length, root surface area, root volume, average root diameter, proline content, and superoxide dismutase content of corn seedlings were measured.

[0098] Table 7 Basic physical and chemical properties of coastal undisturbed saline-alkali soil

[0099]

[0100] 4.3 Experimental Results

[0101] The results showed that strain H136 had a good growth-promoting effect on the aboveground and underground parts of corn in a natural saline-alkali environment ( Figure 8 , Fig. 9 , Table 8, Table 9, Table 10), can increase corn plant height by 36.9%, fresh weight by 154.9%, dry weight by 109.7%, maximum leaf area by 259.1%, SPAD by 15.9%; root length by 378.9%, root surface area by 293.8%, average root diameter by 19.1%, root volume by 203.0%, root tip number by 485.7%; promote corn proline content by 94.7%, superoxide dismutase content by 196.8%.

[0102] The above pot test results show that the Moraxella rosellii H136 strain has the ability to promote plant growth and improve plant stress resistance, and can be used to develop stable and efficient microbial fertilizers.

[0103] Table 8 Growth-promoting effect of strain H136 on corn in natural saline-alkali environment

[0104]

[0105] Note: In the same column, * indicates significant difference (p<0.05), ** indicates extremely significant difference (p<0.01), and *** indicates extremely significant difference (p<0.001).

[0106] Table 9 The growth-promoting effect of strain H136 on corn roots in natural saline-alkali environment

[0107]

[0108] Note: In the same column, * indicates significant difference (p<0.05), ** indicates extremely significant difference (p<0.01), and *** indicates extremely significant difference (p<0.001).

[0109] Table 10 Effect of strain H136 on corn stress resistance in natural saline-alkali environment

[0110]

[0111] Note: In the same column, * indicates significant difference (p<0.05), ** indicates extremely significant difference (p<0.01), and *** indicates extremely significant difference (p<0.001).

[0112] Example 6 Strain H136 promotes cotton growth in the field

[0113] 5.1 Preparation of H136 inoculant

[0114] Preparation of liquid bacterial agent: same as 3.1 in Example 3.

[0115] Preparation of powdered bacterial agent: Liquid bacterial agent is prepared by centrifugation and spray drying to obtain packaged bacterial agent.

[0116] 5.2 Application of H136 microbial agent

[0117] The experiment was conducted in the experimental field of Xinjiang Ulanwusu Ecological and Agricultural Meteorological Experiment Station (44°17′N, 85°49′E, 468.2 m above sea level), with a temperate continental climate, an average annual temperature of 7.2-8.0 ℃, an average annual sunshine of about 2700-2900 h, a frost-free period of about 155-175 d, and an annual precipitation of 235-275 mm.

[0118] The soil type of the test site is gray desert soil, the soil texture is sandy loam, the pH value of the test soil is 8.72, the EC value is 1210µS / cm, the organic matter is 17.0 g / kg, the alkaline nitrogen is 5.4 mg / kg, the available phosphorus is 6.8 mg / kg, and the available potassium is 115.0 mg / kg. The cotton variety for the test is Xinlu Zao 78, which has good promotion in Xinjiang and has a growth period of 115 days, provided by Xinjiang Academy of Agricultural Sciences.

[0119] The experiment set up a conventional fertilization treatment (CK) and a conventional fertilization treatment with H136 microbial agent (H136). Each treatment was set up with 3 replicates, for a total of 6 plots. Each plot was 4 m wide, 8.5 m long, and 34 m in area. 2 , using random grouping.

[0120] Before sowing cotton, powdered microbial agents were spread along the sowing route of the seeder, and 500 g of microbial powder was evenly spread in each replicate plot. After spreading, sowing was carried out. 30 days after sowing, drip irrigation was carried out with liquid microbial agents, and 1 L of microbial solution was dripped in each replicate plot. The experiment adopted the sub-film drip irrigation mode to plant cotton, with 1 film, 3 tubes and 6 rows. The drip irrigation capillary was located between two rows of crops, with a row spacing of 66+10 cm and a plant spacing of 10 cm. Cotton was sown dry and wet, and the total nitrogen application rate during the whole growth period was 300 kg / hm 2 , phosphorus application rate 225 kg / hm 2 , potassium application rate 105 kg / hm 2 , other management measures are the same as field management.

[0121] Samples were collected starting from the 110th day after sowing to test the growth-promoting ability of H136 fermentation liquid on cotton; plant height, stem diameter, aboveground fresh weight, underground fresh weight, boll number, and boll weight of cotton were measured.

[0122] 5.3 Experimental Results

[0123] The results showed that strain H136 had a good growth-promoting effect on the aboveground and underground parts of cotton in the field ( Fig.10 , Fig.11 , Table 11), it can increase cotton plant height by 5.5%, stem diameter by 26.0%, boll number by 52.5%, boll weight by 18.0%, above-ground fresh weight by 14.9%, and underground fresh weight by 10.4%.

[0124] The above field test results show that the Moraxella rosellii H136 strain has the ability to promote plant growth and improve plant stress resistance, and can be used to develop stable and efficient microbial fertilizers.

[0125] Table 11 Effect of strain H136 on cotton growth under natural saline-alkali environment

[0126]

[0127] Note: In the same column, * indicates significant difference (p<0.05), ** indicates extremely significant difference (p<0.01), and *** indicates extremely significant difference (p<0.001).

[0128] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A species of Moraxella rosellii ( Rossellomorea sp. ) H136, characterized in that, It was deposited in the China Center for Type Culture Collection on July 15, 2024, with the deposit number being CCTCC NO:M 20241499.

2. A bacterial agent containing the Moraxella rosellii H136 according to claim 1.

3. A biological fertilizer or plant growth promoter prepared from the Moraxella rosellii H136 or its bacterial agent according to claim 1; The plants are corn and cotton.

4. Any of the following uses of the Moraxella rosellii H136 according to claim 1 or the bacterial agent according to claim 2: Application in improving plant salt tolerance or alleviating plant salt stress; Application in promoting plant growth and development and increasing yield; Application in reducing the content of soil salt ions; The plants are corn and cotton.

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