Prussia adamsii T54, microbial inoculum and application of Prussia adamsii T54 and microbial inoculum

Abstract

The invention belongs to the technical field of microorganisms, and particularly relates to a Prussia adamsii T54 strain, a microbial agent and application of the Prussia adamsii T54 strain and the microbial agent. The Pichia aryabhattai T54 is preserved in the General Microbiological Culture Collection Center of the China Committee for Culture Collection of Microorganisms on February 21, 2025, and the preservation number of the Pichia aryabhattai T54 is CGMCC (China General Microbiological Culture Collection Center) No. 33613. According to the present invention, the Princisteria aryabhattai T54 and the bacterial agent have significant inhibition effects on a variety of plant pathogenic fungi, and further have plant growth promoting effects;

Description

Technical Field

[0001] The present invention relates to the technical field of microorganisms, and in particular to a Priesteria affluenti T54 strain, a bacterial agent and an application thereof. Background Art

[0002] cowpea( Unguiculata vine Walp (L.) is one of the world's most economically valuable legumes, with a long history of cultivation. In Hainan, my country, cowpea, a key vegetable crop shipped north for winter planting, is the primary winter vegetable grown in the southern region. Large quantities are harvested from November to the end of May each year, with over 90% exported. Cowpeas command a significant share of the national market and are crucial to the development of the local agricultural economy. However, the development of the cowpea industry is severely restricted by wilt disease. Cowpea wilt disease is one of the most serious diseases of Hainan cowpea, the most difficult to control, and causes the most significant economic losses. Its pathogen is the genus Fusarium (Deuteromycotina) of the subdivision Deuteromycotina. Fusarium ) of Fusarium oxysporum ( Fusarium oxysporum ), a typical soil-borne disease. This disease occurs in cowpea cultivation areas from tropical to subtropical regions around the world. In severe cases, it can reduce cowpea yields by over 70%, posing a significant threat to both yield and quality. Currently, the prevention and control of cowpea wilt disease still relies heavily on chemical agents. However, the long-term use of chemical agents can easily lead to environmental pollution, increased resistance of pathogens, and pesticide residues in agricultural products, which is contrary to the development needs of efficient and green agriculture. Therefore, finding environmentally friendly alternatives to chemical agents has become an important research direction in the current agricultural field. Among them, microbial agents, as an environmentally friendly and sustainable biological control method, have shown great potential in the prevention and control of cowpea wilt disease. However, existing related technologies still have problems such as insufficient targeting and unstable prevention effects. Further research and development of efficient microbial control technologies is urgently needed. Summary of the Invention

[0003] The present invention provides a strain of Priesteria affluenti and application thereof in preventing and controlling cowpea wilt disease, solving the problems that the current cowpea wilt disease is mainly prevented and controlled by chemical means, which easily causes residues and has a single prevention and control means.

[0004] On the one hand, a strain of Priesteria affluentii T54, classified as Priesteria affluentii Priestess aryabhattai The Priesteria affluenti T54 was deposited in the China General Microbiological Culture Collection Center on February 21, 2025, with the deposit number CGMCC No. 33613.

[0005] On the other hand, the invention relates to the use of Priesteria afroyi T54 in inhibiting plant pathogenic fungi.

[0006] Preferably, the plant pathogenic fungi include Fusarium oxysporum ( Fusarium oxysporum f. sp. tracheal ), wheat fusarium graminearum ( Fusarium gramineae ), banana wilt Fusarium oxysporum ( Fusarium oxysporum f.sp. from Cuba )、Coffee leaf blight Fusarium rubrum( Fusarium wilt )、Mango Anthracnose Colletotrichum gloeosporioides ( Colletotrichum gloeosporioides ), Rice blast fungus Pyricularia oryzae ( Magnaporthe grisea ), sisal leaf rot, Diplodia theobroma cacao ( Lasiodiplodia Theobroma cassava ), Coconut gray spot disease Pseudomonas aeruginosa ( Pestalotiopsis microspora )、Corn leaf spot Curvularia zeae ( Curvularia lunate )、Phytophthora capsici( Phytophthora capsicum ), the pathogen of Aspergillus genus ( Diaporthe biconispora )、New dark columnar spores of pitaya canker ( Neocytalidium halved ) or Colletotrichum kahawaiianum ( Colletotrichum kahawae ).

[0007] On the other hand, the application of Priesteria affluent T54 in plant growth promotion.

[0008] Preferably, the plant comprises cowpea.

[0009] In another aspect, a bacterial agent comprises Priesteria affluenti T54.

[0010] On the other hand, the application of microbial agents in inhibiting plant pathogenic fungi.

[0011] Preferably, the plant pathogenic fungi include Fusarium oxysporum ( Fusarium oxysporum f. sp. tracheal ), wheat fusarium graminearum ( Fusarium gramineae ), banana wilt Fusarium oxysporum ( Fusarium oxysporum f.sp. from Cuba )、Coffee leaf blight Fusarium rubrum( Fusarium wilt )、Mango Anthracnose Colletotrichum gloeosporioides ( Colletotrichum gloeosporioides ), Rice blast fungus Pyricularia oryzae ( Magnaporthe grisea ), sisal leaf rot, Diplodia theobroma cacao ( Lasiodiplodia Theobroma cassava ), Coconut gray spot disease Pseudomonas aeruginosa ( Pestalotiopsis microspora )、Corn leaf spot Curvularia zeae ( Curvularia lunate )、Phytophthora capsici( Phytophthora capsicum ), the pathogen of Aspergillus genus ( Diaporthe biconispora )、New dark columnar spores of pitaya canker ( Neocytalidium halved ) or Colletotrichum kahawaiianum ( Colletotrichum kahawae ).

[0012] On the other hand, the application of microbial agents in plant growth promotion.

[0013] Preferably, the plant comprises cowpea.

[0014] Beneficial effects The present invention provides Priestia aryabhattai The T54 strain has a significant inhibitory effect on a variety of plant pathogenic fungi. In the plate confrontation test, it has a significant inhibitory effect on the cowpea wilt pathogen Fusarium oxysporum ( Fusarium oxysporum f.sp. tracheal ) had an inhibition rate of 71.11% against rice blast fungus ( Magnaporthe grisea ) reached an inhibition rate of 64.69%, and the inhibition rate of corn leaf spot disease Curvularia zeae ( Curvularia lunate ) reached an inhibition rate of 61.65%, and the inhibition rate of sisal leaf rot was 61.65%. Lasiodiplodia theobromae ) reached an inhibition rate of 59.50% against wheat fusarium graminearum ( Fusarium gramineae ) reached an inhibition rate of 57.85%, and the inhibition rate of Pseudomonas aeruginosa ( Pestalotiopsis microspora ) had an inhibition rate of 55.90%, and had an inhibition rate of 55.90% against the new dark columnar spores of pitaya canker ( Neocytalidium halimidium ) reached an inhibition rate of 55.67%, and the inhibition rate of banana wilt Fusarium oxysporum ( Fusarium oxysporum f.sp. from Cuba ) reached an inhibition rate of 51.17%, and the inhibition rate of mango anthracnose Colletotrichum gloeosporioides ( Colletotrichum gloeosporioides ) reached an inhibition rate of 50.91%, and the inhibition rate of pepper blight fungus ( Phytophthora capsicum ) has an inhibition rate of 50.97% against coffee leaf blight Fusarium rubrum ( Fusarium wilt ) reached an inhibition rate of 49.42%, and the inhibition rate of coffee anthracnose Colletotrichum kahawaii ( Colletotrichum kahawae ) had an inhibition rate of 43.82%, and the inhibition rate of Aspergillus genus pathogens ( Diaporthe biconispora ) has an inhibition rate of 35.03%, showing a broad-spectrum and highly effective antibacterial activity, and can effectively control plant diseases caused by various fungi.

[0015] In the pot control experiment of cowpea wilt, the application of 1×10 7 CFU / mL, 1×10 8 CFU / mL, 1×10 9 CFU / mL Priestia aryabhattai After being treated with T54 bacterial suspension, the disease index decreased by 27.08%, 31.25% and 33.33% respectively compared with the Fusarium oxysporum control group, reflecting a good disease prevention and control effect, which can significantly reduce the occurrence of cowpea wilt and reduce the yield loss caused by the disease. at the same time, Priestia aryabhattai The T54 strain has a significant growth-promoting effect on cowpea plants. 8 After treatment with CFU / mL bacterial suspension, the plant height, fresh weight and root length of cowpea plants increased by 47.57%, 54.37% and 65.05% respectively compared with the control group; 1×10 9 After treatment with CFU / mL bacterial suspension, the plant height, leaf area and root length increased by 89.00%, 563.75% and 69.33% respectively compared with the Fusarium oxysporum treatment group; compared with the clean water treatment group, the plant height, leaf area and root length increased by 77.90%, 114.03% and 25.17% respectively, which can effectively promote the growth and development of cowpea plants and improve the growth status and biomass of the plants. In addition, as a natural microbial strain, this strain has good environmental compatibility and will not cause environmental pollution, pathogen resistance, and agricultural product residues caused by the use of chemical pesticides. It meets the needs of green agricultural development, has a wide range of application scenarios and potential commercial application value, and can be used as a microbial preparation for the prevention and control of various plant fungal diseases and the promotion of crop growth, providing strong technical support for the sustainable development of agriculture. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 for Priestia aryabhattai Colony morphology of T54 strain on LB solid medium, where A is a single colony morphology and B is a line colony morphology on a flat plate; Figure 2 for Priestia aryabhattai Physiological and biochemical reactions of T54 strain, where A is Priestia aryabhattai The ability of the T54 strain to secrete siderophores, B is Priestia aryabhattai The nitrogen fixation ability of T54 strain, C is Priestia aryabhattai The potassium-dissolving ability of T54 strain, D is Priestia aryabhattai The phosphate solubilization ability of T54 strain, E is Priestia aryabhattai the ability of strain T54 to secrete auxin (IAA); Figure 3 for Priestia aryabhattai 16S rDNA phylogenetic tree of T54 strain; Figure 4 for Priestia aryabhattai T54 strain gyrB Gene phylogenetic tree; Figure 5 for Priestia aryabhattai The antibacterial ability of T54 strain against cowpea wilt pathogen was determined, where A was the control group of Fusarium oxysporum and B was Priestia aryabhattai The antibacterial ability comparison chart of T54 strain; Figure 6 for Priestia aryabhattai The antibacterial spectrum of T54 strain, in which A is the sisal leaf rot of Diplodia cocoa ( Lasiodiplodia theobromae ), B is the coconut gray spot disease Pseudomonas aeruginosa ( Pestalotiopsis microspora ), C is corn leaf spot corn curvature ( Curvularia lunata ), D is the new dark columnar spore of pitaya canker ( Neoscytalidium dimidiatum ), E is Colletotrichum kahawaensis ( Colletotrichum kahawae ), F is banana wilt Fusarium oxysporum ( Fusarium oxysporum f.sp. cubense ), G is mango anthracnose gum anthracnose fungus ( Colletotrichum gloeosporioides ), H is wheat head pathogen Fusarium graminearum ( Fusarium graminearum ), I is pepper blight fungus ( Phytophthora capsici ), J is the pathogen of Aspergillus genus ( Diaporthe biconispora ), K is coffee leaf blight Fusarium rubrum ( Fusarium lateritium ), L is the rice blast pathogen Pyricularia oryzae ( Magnaporthe grisea ); Figure 7 for Priestia aryabhattai The control effect and growth-promoting ability of T54 strain on cowpea wilt potted plants were analyzed, where H2O was the water control group, FO was the positive control group, and 1×10 7 T54 was inoculated with a spore suspension of Fusarium oxysporum and 1×10 7 CFU / mL of T54 bacterial suspension, 1×10 8 T54 was inoculated with a spore suspension of Fusarium oxysporum and 1×10 8 CFU / mL of T54 bacterial suspension, 1×10 9 T54 was inoculated with a spore suspension of Fusarium oxysporum and 1×10 9 CFU / mL of T54 bacterial suspension. DETAILED DESCRIPTION

[0017] 1. Experimental Materials PDA medium: Boil 200 g of potatoes for 15 min, retain the filtrate, add 18 g of glucose, 18 g of agar, add ddH2O to 1000 mL; sterilize at 121°C for 20 min.

[0018] LB medium (Luria-Bertani medium): 10.0 g tryptone, 5.0 g yeast extract, 8.0 g sodium chloride (NaCl), 20 g agar, add ddH2O to 1000 mL; sterilize at 121°C for 20 min.

[0019] NBRIP inorganic phosphate medium: 10.0 g glucose, 0.1 g ammonium sulfate, 0.25 g magnesium sulfate heptahydrate (MgSO4·7H2O), 0.2 g potassium chloride (KCl), 5.0 g magnesium chloride (MgCl2), 5.0 g calcium phosphate, add ddH2O to 1000 mL; sterilize at 121°C for 20 min.

[0020] Alexandrite medium: sucrose 5.0 g, disodium hydrogen phosphate (Na2HPO4) 2.0 g, magnesium sulfate heptahydrate (MgSO4·7H2O) 0.5 g, ferric chloride (FeCl3) 0.005 g, calcium carbonate (CaCO3) 0.1 g, potassium feldspar 2.0 g, add ddH2O to 1000 mL; sterilize at 115°C for 20 min.

[0021] Ashubei nitrogen-free medium: 0.2 g potassium hydrogen phosphate (K2HPO4), 0.2 g magnesium sulfate heptahydrate (MgSO4·7H2O), 0.2 g calcium sulfate dihydrate (CaSO4·2H2O), 0.2 g sodium chloride (NaCl), 5.0 g calcium carbonate (CaCO3), 10.0 g mannitol, add ddH2O to 1000 mL; sterilize at 121°C for 20 min.

[0022] Chrome azurol (CAS) medium: The basal medium includes glucose 100.0 g, magnesium sulfate heptahydrate (MgSO4·7H2O) 0.5 g, tryptone 20.0 g, calcium chloride (CaCl2) 0.5 g, and agar 10.0 g. The CAS detection solution includes chrome azurol sulphonate (CAS) 0.06 g, ferric chloride (FeCl3) 0.0027 g, and hexadecy- ltrimethyl-ammonium bromide (HDTMA) 0.073 g. 10× PIPES buffer 1 mol / L, pH 7.0. Weigh 141 g of the culture medium and add ddH2O to 800 mL. Sterilize at 115°C for 20 min. Cool the basal medium to 60°C and slowly add 60 100 mL of 10× buffer and 100 mL of 10× CAS detection solution preheated at 4°C.

[0023] YMB medium: yeast extract (Yeast Extract) 1.0 g, mannitol (Mannitol) 10.0 g, potassium dihydrogen phosphate (K2HPO4) 0.5 g, magnesium sulfate heptahydrate (MgSO4·7H2O) 0.2 g, sodium chloride (NaCl) 0.1 g, calcium carbonate (CaCO3) 1.0 g, L-tryptophan (L-Tryptophan) 2.0 g, add ddH2O to 1000 mL; sterilize at 151°C for 20 min.

[0024] Example 1 Priesteria affluent Priestia aryabhattai ) Acquisition of T54.

[0025] Rhizosphere soil and tissue samples were collected from healthy cowpea plants in the cowpea wilt disease-infected plots. The soil was separated by dilution and spreading method: 10 g of soil sample was placed in a 250 mL Erlenmeyer flask, 90 mL of ddH2O was added, and the sample was placed in a shaker at 28°C and 180 rpm for 30 min. The sample was placed in an 80°C water bath and allowed to stand for 10 min, and then diluted to 10 -2 , 10 -3 , 10 -4 , 10 -5 Add 10-15 mL of preheated LB medium to a Petri dish. After cooling, pipette 0.2 mL of the above solution onto a plate. Use a glass spreader to spread evenly until dry. Repeat three times. Seal the plate and incubate at 28°C under 14 hours of light and 10 hours of darkness. After two days, observe for colonies. Select suspected colonies and streak them onto LB plates for purification. Number the strains and store them.

[0026] The above preserved strains were initially screened using the plate confrontation method, with V. wilt pathogen as the control strain. A 0.5 cm V. wilt fungus cake was inoculated in the center of the PDA solid medium plate, and four points 2.5 cm away from the center were selected in a cross symmetric manner. The same strain was inoculated on the four points using a toothpick. The strains with antagonistic effect were rescreened and preserved using the same method. The cross intersection method was used to measure the colony diameter. Inhibition rate / %=(control group colony diameter-treatment group colony diameter) / control group colony diameter x 100. The test was repeated three times, and three replicates were set for each treatment. The related data were arranged by Excel, and the data difference significance was analyzed by SPSS (25) software, and multiple comparisons were performed by Tukey's method.

[0027] The morphology of the strain T54 obtained by screening on the LB solid medium is shown in Figure 1 The colony on the plate is light yellow to yellow brown, the colony edge is relatively smooth, and the colony is opaque, and the interval between the colonies is obvious.

[0028] Example 2 Physiological and biochemical characteristics of P. alliicida T54. Priestia aryabhattai

[0029] Phosphorus solubilizing ability determination: after activation, the strain T54 was inoculated into NBRIP inorganic phosphorus medium, and placed in a 28°C constant temperature incubator for 7 days. Whether there was a transparent oil droplet halo around the colony was observed. If yes, it indicated that the strain had phosphorus solubilizing ability, and the halo size was measured.

[0030] Potassium solubilizing ability determination: after activation, the strain T54 was inoculated into Alexander silicate medium, and placed in a 28°C constant temperature incubator for 7 days. Whether there was a transparent oil droplet halo around the colony was observed. If yes, it indicated that the strain had potassium solubilizing ability, and the halo size was measured.

[0031] Nitrogen fixation function determination: after activation, the strain T54 was inoculated into Ashby nitrogen-free medium, and placed in a 28°C constant temperature incubator for 7 days. The growth of the colony was observed. If it could grow on the Ashby nitrogen-free medium, it was considered to have nitrogen fixation function, and the nitrogen fixation ability was judged according to the colony growth diameter.

[0032] Iron carrier production ability determination: after activation, the strain T54 was inoculated into chrome azurol (CAS) medium, and placed in a 28°C constant temperature incubator for 7 days. Whether there was a yellow halo around the colony was observed, and the halo size was measured.

[0033] ​IAA secretion capacity: Strain T54 was inoculated into YMB medium and cultured at 28°C for 2 days. Centrifuge at 12,000 rpm for 2 minutes. Pipette 2 mL of the supernatant into a test tube and add an equal amount of Salkowski's reagent. Gently shake to mix thoroughly. Incubate in the dark for 30 minutes until the color turns red, indicating IAA production. YMB medium supplemented with Salkowski's reagent served as the blank control (CK control).

[0034] The results are as follows Figure 2 As shown, strain T54 has a certain degree of nitrogen fixation, phosphate solubilization, potassium solubilization, and siderophore secretion. On CAS medium, T54 was observed to have a clear yellow halo with a diameter of 12.32 mm, indicating that the strain can secrete siderophores. On Axubei nitrogen-free medium, the T54 secretion halo was smaller, indicating weak nitrogen fixation. On Alexander silicate medium, the T54 colony had a diameter of 7.22 × 7.86 mm, indicating that the strain has a certain ability to solubilize potassium. On NBRIP inorganic phosphate bacterial medium, the T54 secretion halo had a diameter of 24.21 mm, indicating that the strain can decompose organic phosphate. On YMB medium, the medium inoculated with T54 showed no significant color change, indicating weak IAA secretion.

[0035] Example 3 Priesteria affluent Priestia aryabhattai ) Molecular identification of T54.

[0036] The T54 strain was inoculated into LB liquid medium and shaken at 180 rpm for 16 hours. Biocontrol bacterial DNA was extracted using a bacterial DNA extraction kit from Tiangen Biochemical Technology (Beijing) Co., Ltd. according to the manufacturer's instructions. The resulting bacterial DNA was used as a template for PCR amplification. The target gene was selected using universal primers for the conserved region of the ribosomal 16S rDNA gene and bacterial-specific primers for the gyrase B subunit gene ( gyrB ), the amplification primers were 16S rDNA universal primers SEQ NO.1-27f (5′-AGAGTTTGATCCTGGCTCAG-3′) and SEQ NO.2-1492r (5′-TACGGCTACCTTGTTACGACTT-3′), SEQ NO.3-primer gyrB F (5′-GAAGTCATCATGACCGTTCTGCAYGCNGGNGGNAARTTYGA-3′) and SEQ NO.4- gyrB R (5′-AGCAGGGTACGGATGTGCGAGCCRTCNACRTCNGCRTCNGTCAT-3′).

[0037] PCR reaction system: 2xTap PCR MasterMix 12.5 μL, ddH2O 9.5 μL, forward primer and reverse primer 1 μL respectively, DNA 1 μL. 16S rDNA amplification procedure: pre-denaturation 95 ℃ 5 min, denaturation 95 ℃ 30 s, annealing 55 ℃ 45 s, extension 72 ℃ 1 min, re-extension 72 ℃ 10 min, a total of 35 cycles. Gyr B Amplification procedure: pre-denaturation 94 ℃ 4 min, denaturation 94 ℃ 1 min, annealing 57 ℃ 1 min, extension 72 ℃ 80 s, re-extension 72 ℃ 10 min, a total of 30 cycles.

[0038] The PCR amplification product was detected by 1% agarose electrophoresis, and the target band was observed and photographed in a gel imaging instrument. The PCR amplification product was sent to Shenguo Bioengineering (Shanghai) Co., Ltd. for sequencing. The sequencing results were compared and homology analyzed in the NCBI database, and the similar gene sequences and model strain sequences were downloaded.

[0039] The 16S rDNA and gyrB gene fragments of T54 were amplified by PCR, and the target fragments of about 1400 bp and gyrB 1200 bp of 16S rDNA and Priestia aryabhattai were obtained respectively. The PCR amplification product was sent to Shenguo Bioengineering (Shanghai) Co., Ltd. for sequencing, and the sequence was compared in the NCBI website. The 16S rDNA comparison result showed that the similarity of T54 and gyrB P. algi (NR_118442.1) was 99.79%, P. aryabhattai The comparison result showed that the similarity of T54 and gyrB P. algi (HJ.T3 (NZ_CP146499.1)) was 99.81%. The similar gene sequences and model strain sequences were downloaded, and the MEGA11 software was used to construct the 16S rDNA and Figure 3 phylogenetic tree of T54 by maximum likelihood method, and the results were shown in Figure 4 and Priestia aryabhattai Therefore, T54 was identified as P. algi Priestia aryabhattai Priestia aryabhattai ​T54 was deposited in the General Microbiology Center of the China Culture Collection Administration (address: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing), with the deposit date of February 21, 2025, and the deposit number is CGMCC No. 33613.

[0040] Example 4. Priesteria afroyi ( Priestia aryabhattai ) T54 antibacterial ability determination.

[0041] The plant pathogenic fungi tested included Fusarium oxysporum, the pathogen of cowpea wilt disease Fusarium oxysporum f.sp. tracheiphilum ), wheat fusarium graminearum ( Fusarium graminearum ), banana wilt Fusarium oxysporum ( Fusarium oxysporum f.sp. cubense )、Coffee leaf blight Fusarium rubrum( Fusarium lateritium )、Mango Anthracnose Colletotrichum gloeosporioides ( Colletotrichum gloeosporioides ), Rice blast fungus Pyricularia oryzae ( Magnaporthe grisea ), sisal leaf rot, Diplodia theobroma cacao ( Lasiodiplodia theobromae ), Coconut gray spot disease Pseudomonas aeruginosa ( Pestalotiopsis microspora )、Corn leaf spot Curvularia zeae ( Curvularia lunata )、Phytophthora capsici( Phytophthora capsici ), the pathogen of Aspergillus genus ( Diaporthe biconispora )、New dark columnar spores of pitaya canker ( Neoscytalidium dimidiatum )、Coffee Anthracnose Colletotrichum kahawaii( Colletotrichum kahawae ).

[0042] Use the flat plate stand-off method Priestia aryabhattai Determination of the antibacterial ability of T54 strain. Priestia aryabhattai The T54 strain was cultured in LB liquid medium on a shaker at 180 rpm and 28°C for 16 hours to obtain a bacterial fermentation broth. Using the "cross-cross method," sterile 5 mm filter paper was affixed to four points 2.5 cm apart from the center of a PDA culture plate. Using a sterile 5 mm punch, the target pathogen was punched from the edge of the activated strain colony to obtain a bacterial cake of uniform age. This was then inoculated in the center of the PDA plate. 1 μL of the bacterial fermentation broth was dripped onto the center of each of the four filter paper pieces. Three replicates were performed for each treatment. The treated PDA plates were placed in a 28°C incubator for 4–5 days. During this time, the colony growth was observed. When the colonies approximately covered three-quarters of the plate, the antibacterial activity was measured, recorded, and photographed. The antibacterial rate was calculated as follows: Inhibition rate / % = [(pathogen growth diameter of control group - pathogen block diameter) - (pathogen growth diameter of treatment group - pathogen block diameter)] / (pathogen growth diameter of control group - pathogen block diameter) × 100.

[0043] The results are shown in Table 1. Figure 5 and Figure 6 As shown in the figure, T54 has a good antibacterial effect on Fusarium oxysporum, the pathogen of cowpea wilt, with an inhibition rate of 71.11%. T54 also has a good antibacterial effect on other tested pathogenic fungi, with an inhibition rate of 57.85% on Fusarium graminearum, the pathogen of wheat fusarium wilt, 51.17% on Fusarium oxysporum, the pathogen of banana wilt, 49.42% on Fusarium rubrum, the pathogen of coffee leaf blight, 50.91% on Colletotrichum gloeosporioides, the pathogen of mango anthracnose, and 51.17% on Pyricularia oryzae. The rate of resistance against blast pathogen is 64.69%, against Lactodiplodia theobromina which causes sisal leaf rot is 59.50%, against Polytrichomonas aeruginosa which causes coconut gray spot is 55.90%, against Curvularia zeae which causes corn leaf spot is 61.65%, against Phytophthora blight of pepper is 50.97%, against Aspergillus genus which causes stamen leaf spot is 35.03%, against Neotenys stylosporium which causes pitaya canker is 55.67%, and against Colletotrichum kahawa which causes coffee anthracnose is 43.82%.

[0044] Table 1 Priestera aficiosa ( Priestia aryabhattai )T54 antibacterial ability

[0045] Example 5. Priesteria afroyi ( Priestia aryabhattai ) The potted plant protection efficacy and growth-promoting ability of T54 against cowpea wilt disease.

[0046] When indoor potted cowpea seedlings reached the stage of 2 leaves and 1 heart, the pathogen Fusarium oxysporum was prepared into a concentration of 1×10 7 CFU / mL spore suspension. The seedlings were removed and the soil on the root surface was rinsed clean. Five fibrous roots were cut to injure the roots. The roots were soaked in the pathogen spore suspension for 15 minutes before transplanting into flower pots. Five treatment groups were set up: H2O (clear water control group, no root injure treatment), FO (positive control group, inoculated with Fusarium oxysporum spore suspension), FO + 1×10 7 T54 (inoculated with a spore suspension of Fusarium oxysporum and 1 × 10 7 CFU / mL T54 bacterial suspension), FO+1×10 8 T54 (inoculated with a spore suspension of Fusarium oxysporum and 1 × 10 8 CFU / mL T54 bacterial suspension), FO+1×10 9 T54 (inoculated with a spore suspension of Fusarium oxysporum and 1 × 10 9T54 bacterial suspension). Different concentrations of T54 bacterial suspension were applied to each treatment group every 5 days. After 20 days, the disease index evaluation and control effect determination were carried out. At the same time, the morphological indexes (plant height, leaf area, fresh weight, root length) of cowpea plants were measured to evaluate the growth-promoting effect of biocontrol bacteria on cowpea plants.

[0047] The disease index evaluation of cowpea fusarium wilt was carried out according to the following standards: 0 level: no discoloration of root stem vascular bundle, no yellowing and wilting of leaves; 1 level: less than 1 / 4 of the whole root stem vascular bundle discoloration, partial leaf discoloration, and no obvious change in plant growth; 2 level: less than 1 / 2 of the whole root stem vascular bundle discoloration, leaf discoloration and wilting, and inhibited plant growth; 3 level: nearly 3 / 4 of the whole root stem vascular bundle discoloration, significantly inhibited plant growth, and yellowing and wilting of leaves from the lower part to the upper part; 4 level: complete root stem vascular bundle discoloration, and whole plant wilting and death. The disease index evaluation and control effect determination were calculated according to the following formula: Disease index = [Σ (number of plants with each disease level x disease level) / total number of pots x highest disease level] x 100.

[0048] Control effect / % = [(control group disease index - treatment group disease index) / control group disease index] x 100.

[0049] The results of the pot experiment showed that the control group with water had no disease, the pathogenic fungus Fusarium oxysporum caused disease in the control group, and the disease index was 85.83 (Table 2, Figure 7 ). The T54 bacterial suspension treatment group showed no obvious disease on the outside, but part of the vascular bundle was still brownish red. The higher the concentration of the bacterial suspension, the lower the disease index and the better the control effect. The application of 1 x 10 7 CFU / mL, 1 x 10 8 CFU / mL, and 1 x 10 9 CFU / mL of T54 bacterial suspension, compared with the Fusarium oxysporum control group, the disease index decreased by 47.57%, 54.37%, and 65.05%, respectively. In addition, as shown in Table 3 and Figure 7 Table 4, the 1 x 10 7 CFU / mL, 1 x 10 8 CFU / mL, and 1 x 10 9 CFU / mL T54 bacterial suspensions all had a certain growth-promoting effect on cowpea plants. Among them, the plant height, leaf area, and root length of cowpea plants treated with 1 x 10 9 CFU / mL bacterial suspension increased by 89.00%, 563.75%, and 69.33% compared with the FO treatment group, and increased by 77.90%, 114.03%, and 25.17% compared with the H2O treatment group, respectively.

[0050] Table 2 Priestera aficiosa ( Priestia aryabhattai ) Potted test of T54 against cowpea wilt

[0051] Table 3 Morphological indexes of cowpea plants under different treatments

[0052] Note: Different lowercase letters in the same column indicate significant differences among treatments at the 0.05 level.

Claims

1. A strain of Priesteria africana ( Priestia aryabhattai ) T54, characterized in that, The Priesteria affluenti T54 is deposited in the General Microbiology Center of China Culture Collection Administration of Microorganisms with a deposit number of CGMCC No. 33613.

2. The use of Priesteria afroyi T54 according to claim 1 in inhibiting plant pathogenic fungi, characterized in that: The plant pathogenic fungi include cowpea wilt pathogen Fusarium oxysporum ( Fusarium oxysporum f. sp. tracheiphilum graminearum ( Fusarium graminearum ), banana wilt Fusarium oxysporum ( Fusarium oxysporum f.sp. cubense )、Coffee leaf blight Fusarium rubrum( Fusarium lateritium )、Mango Anthracnose Colletotrichum gloeosporioides ( Colletotrichum gloeosporioides ), Rice blast fungus Pyricularia oryzae ( Magnaporthe grisea ), sisal leaf rot, Diplodia theobroma cacao ( Lasiodiplodia theobromae ), Coconut gray spot disease Pseudomonas aeruginosa ( Pestalotiopsis microspora )、Corn leaf spot Curvularia zeae ( Curvularia lunata )、Phytophthora capsici( Phytophthora capsici ), the pathogen of Aspergillus genus ( Diaporthe biconispora )、New dark columnar spores of pitaya canker ( Neoscytalidium dimidiatum ) or Colletotrichum kahawaiianum ( Colletotrichum kahawae ).

3. The use of Priesteria affluenti T54 according to claim 1 in promoting plant growth, characterized in that: The plants include cowpea.

4. A bacterial agent, characterized in that The bacterial agent includes the Priesteria affluenti T54 according to claim 1.

5. Use of the microbial agent according to claim 4 in inhibiting plant pathogenic fungi, characterized in that: The plant pathogenic fungi include cowpea wilt pathogen Fusarium oxysporum ( Fusarium oxysporum f. sp. tracheiphilum graminearum ( Fusarium graminearum ), banana wilt Fusarium oxysporum ( Fusarium oxysporum f.sp. cubense )、Coffee leaf blight Fusarium rubrum( Fusarium lateritium )、Mango Anthracnose Colletotrichum gloeosporioides ( Colletotrichum gloeosporioides ), Rice blast fungus Pyricularia oryzae ( Magnaporthe grisea ), sisal leaf rot, Diplodia theobroma cacao ( Lasiodiplodia theobromae ), Coconut gray spot disease Pseudomonas aeruginosa ( Pestalotiopsis microspora )、Corn leaf spot Curvularia zeae ( Curvularia lunata )、Phytophthora capsici( Phytophthora capsici ), the pathogen of Aspergillus genus ( Diaporthe biconispora )、New dark columnar spores of pitaya canker ( Neoscytalidium dimidiatum ) or Colletotrichum kahawaiianum ( Colletotrichum kahawae ).

6. Use of the microbial agent according to claim 4 in promoting plant growth, characterized in that: The plants include cowpea.

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