Pseudomonas chlororaphis subsp. Aurantii strain for preventing and treating wheat basal stem rot and application of pseudomonas chlororaphis subsp. Aurantii strain

Abstract

The invention relates to the technical field of agricultural biological prevention and control, in particular to a pseudomonas chlororaphis subsp. Aurantiaca strain for preventing and controlling wheat basal stem rot and application of the pseudomonas chlororaphis subsp. Aurantiaca strain. The pseudomonas chlororaphis subsp. Aurantiaca strain for preventing and treating wheat stem rot is P. chlororaphis subsp. Aurantiaca, has very good antagonistic activity to fusarium pseudograminearum and fusarium flavum, the inhibition rate to the fusarium pseudograminearum strain reaches 76.07%, the inhibition rate to the fusarium flavum strain reaches 73.26%, and the inhibition rate to the fusarium flavum strain reaches 76.07%, so that the pseudomonas chlororaphis subsp. Aurantiaca strain for preventing and treating wheat stem rot can be used for preventing and treating wheat stem rot. The P. chlororaphis subsp. Aurantiaca can induce wheat to generate resistance to Fusarium pseudograminearum and Fusarium fulvum, the prevention and treatment effect on the Fusarium pseudograminearum strain reaches 55.77%, the prevention and treatment effect on the Fusarium fulvum strain reaches 51.19%, therefore, the P. chlororaphis subsp. Aurantiaca can significantly reduce the severity of the wheat basal stem rot, and the P. chlororaphis subsp. Aurantiaca can be used for preventing and treating the wheat basal stem rot. Meanwhile, the plant height, fresh weight and root length of wheat can be increased, and a remarkable growth promoting effect on wheat plants is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural biological control, and in particular to a strain of Pseudomonas chlororaphis subspecies orange for controlling wheat stem rot and an application thereof. Background Art

[0002] In the past decade, wheat stem rot (Fusarium crown rot, FCR) has become one of the major diseases that endanger China's wheat production. The average annual occurrence area in the country exceeds 100 million mu, the diseased plant rate in the whole field is more than 1%, and the average annual damage loss is about 3.5 billion catties, causing significant economic losses to my country's agricultural production. Its main pathogenic fungi include: F. pseudograsses )、Yellow Fusarium( F. culms ) and Fusarium graminearum ( F. graminearum ), Fusarium asiatica ( F. asiaticum )、Fusarium spp. F. avenaceum ), Fusarium oxysporum ( F. oxysporum ) F. horsemen )、Fusarium spores( F. proliferatum ) and Fusarium trilineatum ( F. tricinct ) and more than 10 kinds.

[0003] In China, the prevention and control of wheat stem rot mainly adopts seed treatment and early spraying of fungicides. However, chemical control can lead to the development of resistance in pests, pollute the environment, damage beneficial microorganisms, and improper use of pesticides can also cause plant damage and pesticide residues.

[0004] Pseudomonas chlororaphis ( P. chlororaphis ) is a type of recognized environmentally friendly plant growth-promoting bacteria. This strain has a wide distribution range and has strong adaptability to the ecological environment.

[0005] At present, it is used to control tomato wilt, tobacco blight, pepper blight, cypress canker and bean anthracnose, and has a significant inhibitory effect on several important agricultural pathogenic bacteria, such as Burkholderia podifera ( Burkholderia glaucae )、Erwinia amylovora( Erwinia amylovora )、Corynebacterium michiganensis( Clavibacter michiganensis )、Carrot Pectin Bacillus( Pectobacterium carotovora ), Pseudomonas syringae ( Pseudomonas syringae ), Xanthomonas campestris ( Xanthomonas campestris) etc. After searching, the patent with publication number CN112899205B provides a kind of Pseudomonas chlororaphis MN225969 and its application. The content of the invention patent is that Pseudomonas chlororaphis MN225969 can achieve a control effect of 39.60% on Fusarium graminearum. The sequence homology between the strain YL-21 of the present invention and the strain MN225969 is 95.54%. Therefore, the strain of the present invention and the strain MN225969 are distantly related and do not belong to the same type of strain. At present, there is no report on the use of the orange subspecies of Pseudomonas chlororaphis of the present invention in controlling wheat stem base rot.

[0006] Therefore, providing a strain of Pseudomonas chlororaphis orange subspecies for preventing and treating wheat stem rot and its application is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a strain of Pseudomonas chlororaphis subsp. orange for preventing and treating wheat stem rot and its application. P. chlororaphis subsp. aurantiaca has good antagonistic activity against both Fusarium graminearum and Fusarium solani, with an inhibition rate of 76.07% for Fusarium graminearum strains and 73.26% for Fusarium solani strains. It can also increase wheat plant height, fresh weight and root length, and has a significant growth-promoting effect on wheat plants.

[0008] The invention provides a Pseudomonas chlororaphis orange subspecies strain for preventing and treating wheat stem base rot. The Pseudomonas chlororaphis orange subspecies strain for preventing and treating wheat stem base rot is P. chlororaphis subsp. aurantiaca, the deposit number is CGMCC No. 32270, the depositor is the General Microbiology Center of China Microorganism Culture Collection Administration, and the deposit date is October 21, 2024.

[0009] According to the present invention, a Pseudomonas chlororaphis subspecies orange strain for controlling wheat stem rot is provided, and the 16s nucleotide sequence of the genomic DNA of the Pseudomonas chlororaphis subspecies orange strain is shown in SEQ ID NO: 1.

[0010] According to the Pseudomonas chlororaphis orange subspecies strain for preventing and controlling wheat stem rot provided by the present invention, the Pseudomonas chlororaphis orange subspecies strain is inoculated into LB culture medium for fermentation and culture to obtain a biocontrol agent of the Pseudomonas chlororaphis orange subspecies strain.

[0011] According to the present invention, a strain of Pseudomonas chlororaphis orange subspecies for preventing and controlling wheat stem rot is provided. The LB culture medium is composed of the following raw materials by mass fraction: 1% tryptone, 0.5% yeast extract powder, 1% sodium chloride, and the rest is distilled water. The pH is adjusted to 7.0±0.1, and then sterilized at a temperature of 121°C for 15 minutes.

[0012] According to the present invention, the Pseudomonas chlororaphis subspecies orange strain for preventing and controlling wheat stem rot has a fermentation time of 48 hours.

[0013] According to the present invention, a strain of Pseudomonas chlororaphis orange subspecies for preventing and controlling wheat stem base rot is provided. The concentration of the Pseudomonas chlororaphis orange subspecies strain in the biocontrol agent is OD 600 is 1.

[0014] The present invention also provides an application of the above-mentioned Pseudomonas chlororaphis orange subspecies strain for preventing and controlling wheat stem rot. The Pseudomonas chlororaphis orange subspecies strain for preventing and controlling wheat stem rot is applied to the rhizosphere of plants suffering from wheat stem rot, which can treat wheat stem rot caused by Fusarium fungi and promote wheat growth.

[0015] According to the application of the Pseudomonas chlororaphis orange subspecies strain for preventing and controlling wheat stem rot, the pathogenic bacteria of plants suffering from wheat stem rot are Fusarium fungi, including Fusarium graminearum and Fusarium pseudograminearum.

[0016] According to the application of the Pseudomonas chlororaphis orange subspecies strain for preventing and controlling wheat stem rot, the biocontrol agent of the Pseudomonas chlororaphis orange subspecies strain can also treat wheat stem rot caused by Fusarium fungi and promote wheat growth.

[0017] Compared with the prior art, the present invention has the following advantages: ① The biocontrol bacteria Pseudomonas chlororaphis subspecies orange provided by the present invention P. chlororaphis subsp. orange It has good antagonistic activity against both Fusarium graminearum and Fusarium solani, with the inhibition rate against Fusarium graminearum strains reaching 76.07% and the inhibition rate against Fusarium solani strains reaching 73.26%.

[0018] ② The biocontrol bacteria Pseudomonas chlororaphis subspecies orange provided by the present invention P. chlororaphis subsp. orange , can increase wheat plant height, fresh weight and root length, and has a significant growth-promoting effect on wheat plants.

[0019] ③ The biocontrol bacteria Pseudomonas chlororaphis subspecies orange provided by the present invention P. chlororaphis subsp. orangeIt can induce wheat to develop resistance to Fusarium graminearum and Fusarium solani. The control effect on Fusarium graminearum strains reaches 55.77%, and the control effect on Fusarium solani strains reaches 51.19%. Therefore, the orange subspecies of Pseudomonas chlororaphis can significantly reduce the severity of wheat stem rot.

[0020] ④ The biocontrol bacteria of the present invention, Pseudomonas chlororaphis subspecies orange P. chlororaphis subsp. orange It can enhance wheat's drought resistance and salinity tolerance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 The strain obtained according to the 16S rDNA sequence of the present invention P. chlororaphis subsp. orange Phylogenetic tree diagram; Figure 2 Pseudomonas chlororaphis subsp. aurantiaca in Example 2 P. chlororaphis subsp. orange The effect of inhibiting the mycelial growth of Fusarium graminearum (AB) and Fusarium graminearum (CD) on the plate; Figure 3 Pseudomonas chlororaphis subsp. aurantiaca in Example 3 P. chlororaphis subsp. orange Effects on wheat plant growth; Figure 4 Pseudomonas chlororaphis subsp. aurantiaca in Example 4 P. chlororaphis subsp. orange Results of inhibiting Fusarium graminearum infection of wheat; Figure 5 Pseudomonas chlororaphis subsp. aurantiaca in Example 4 P. chlororaphis subsp. orange Results of inhibiting Fusarium oxysporum infection of wheat; Figure 6 Pseudomonas aurantium subsp. P. chlororaphis subsp. orange Results of enhancing the drought resistance coefficient of wheat; Figure 7 Pseudomonas chlororaphis subsp. aurantiaca in Example 6 P. chlororaphis subsp. orange Effects of salt stress on wheat root growth; Figure 8 Pseudomonas chlororaphis subsp. aurantiaca in Example 6 P. chlororaphis subsp. orange Effects of salt stress on wheat plant height; Figure 9 Pseudomonas chlororaphis subsp. aurantiaca in Example 6 P. chlororaphis subsp. orange Effects of salt stress on fresh weight of wheat.

[0023] Pseudomonas chlororaphis subsp. aurantiacum Pseudomonas chlororaphis subsp. aurantiaca The deposit number is CGMCC No. 32270, the depository is the General Microbiology Center of China Microbiological Culture Collection Administration, and the deposit date is October 21, 2024. DETAILED DESCRIPTION

[0025] Example 1 This embodiment provides a kind of Pseudomonas chlororaphis orange subsp. P. chlororaphis subsp. orange The separation and screening method of (denoted as YL-21) is as follows: S1. Isolation of strain YL-21 Pseudomonas chlororaphis subsp. aurantiaca strain YL-21 was isolated from the soil of wheat fields in Yili by the Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences.

[0026] Soil samples from wheat fields in Yili were collected and brought back to the laboratory for separation and purification using the soil dilution method. The biocontrol bacteria were screened using the plate confrontation method and pot test method with wheat stem rot as the target, and a strain with obvious control effect on wheat stem rot was screened out. P. chlororaphis subsp. orange , named as YL-21, with a deposit number of CGMCC No. 32270, deposited at the General Microbiology Center of China National Microbiological Culture Collection Administration, and deposited on October 21, 2024. The 16s nucleotide sequence of the genomic DNA of Pseudomonas chlororaphis subsp. aurantium is shown in SEQ ID NO: 1; S2. Classification and identification of strain YL-21 The genomic DNA of strain YL-21 was used as a template and PCR amplification was performed with bacterial universal primers 27F and 1492R to obtain the PCR amplification product; The sequence of primer 27F is shown in SEQ ID NO.2, and the sequence of primer 1492R is shown in SEQ ID NO.3. In the sequence, M represents A / C; Y represents C / T; The reaction system was 25 μL of 2× Taq Master Mix, 1 μL each of 27F (10 ppm) and 1492R (10 ppm), 1 μL of DNA template, and supplemented with 22 μL of ddH2O; PCR amplification conditions were as follows: pre-denaturation at 94°C for 5 min; denaturation at 94°C for 30 s, annealing at 54°C for 30 s, extension at 72°C for 1.5 min, 35 cycles; extension at 72°C for 10 min; The obtained PCR product was sequenced by Hangzhou Youkang Biotechnology Co., Ltd., and the 16Sr DNA gene sequence of strain YL-21 was obtained as shown in SEQ ID NO.1; The measured sequences were compared with NCBI by BLAST online homology comparison, and the standard strain with higher homology was selected as the reference object. The results showed that the 16S rDNA homology of strain YL-21 and Pseudomonas chlororaphis orange subspecies reached 99%; the phylogenetic tree was constructed, and the results are shown in Figure 1 ; YL-21 is clustered together with Pseudomonas chlororaphis orange subspecies, indicating that YL-21 belongs to Pseudomonas chlororaphis orange subspecies.

[0027] Example 2 1. Pseudomonas chlororaphis subspecies orange YL-21 against Pseudomonas graminearum ( F. pseudograminearum ) Using the PDA plate confrontation method, the biocontrol bacteria described in Example 1 were symmetrically inoculated 2.5 cm from the edge of a 9 cm diameter plate containing 15 mL of PDA culture medium, and the center of the plate was inoculated with the bacteria cultured for 2-3 days. F. pseudograsses The bacterial cake (5 mm in diameter) was inoculated with F. pseudograminearum The plate containing the bacterial cake was used as a control. The plate was incubated at 25°C in the dark and measured after 5 to 7 days. F. pseudograminearum The colony radius was calculated and the inhibition rate was calculated according to the following formula: Inhibition rate (%) = (control growth - treatment growth) / control growth × 100 The PDA medium is composed of the following raw materials by mass fraction: 0.6% potato extract powder, 2% glucose, 2% agar, and the rest is distilled water. The pH is adjusted to 5.6±0.2 and then sterilized at 115°C for 20 minutes.

[0028] The test results are shown in Table 1 and Figure 2, it can be seen that Pseudomonas chlororaphis subsp. F. pseudograminearum The inhibition rate of Pseudomonas chlororaphis subspecies orange YL-21 was over 76%. F. pseudograminearum It has a significant inhibitory effect.

[0029] Table 1 YL-21 pairs F. pseudograminearum The inhibition rate

[0030] 2. Pseudomonas chlororaphis orange subspecies YL-21 against Fusarium oxysporum ( F. culms ) Using the PDA plate confrontation method, the biocontrol bacteria described in Example 1 were symmetrically inoculated 2.5 cm from the edge of a 9 cm diameter plate containing 15 mL of PDA culture medium, and the center of the plate was inoculated with the bacteria cultured for 2-3 days. F. culms The bacterial cake (5 mm in diameter) was inoculated with F. culms The plate containing the bacterial cake was used as a control. The plate was incubated at 25°C in the dark and measured after 5 to 7 days. F. culms Colony radius, calculation of inhibition rate; The test results are shown in Table 2 and Figure 2 , it can be seen that Pseudomonas chlororaphis subsp. F. culms The inhibition rate of Pseudomonas chlororaphis subspecies orange YL-21 was over 73%. F. culms It has a significant inhibitory effect.

[0031] Table 2 YL-21 pairs F. culms The inhibition rate

[0032] Example 3 This example detects the effect of Pseudomonas chlororaphis subspecies orange YL-21 on wheat growth, and the detection method is as follows: S1. Inoculate the Pseudomonas chlororaphis subspecies orange YL-21 strain into LB liquid medium, culture it overnight at 28°C and 180 rpm / min, take part of the bacterial solution and inoculate it into NB medium, culture it at 28°C and 180 rpm / min for 48 h to obtain a bacterial suspension, centrifuge the obtained bacterial suspension at 4000 rpm for 10 min, resuspend it in sterile water, and dilute it to OD 600 =1, standby; The LB liquid culture medium is composed of the following raw materials in mass fractions: 1% tryptone, 0.5% yeast extract powder, 1% sodium chloride, and the rest is distilled water. The pH is adjusted to 7.0±0.1 and then sterilized at 121°C for 15 minutes.

[0033] The NB medium is composed of the following raw materials by mass fraction: 1% peptone, 0.3% beef extract powder, 0.5% sodium chloride, and the rest is distilled water. The pH is adjusted to 7.2±0.2, and then sterilized at 121°C for 15 minutes.

[0034] S2. Select pots with a diameter of 7 cm, plant 12 wheat seeds that are uniformly white after germination in each pot, and place them in a greenhouse at 25°C for cultivation; The experimental group (YL-21) consisted of: adding 10 ml of sterile water to resuspend the bacteria in each pot; The control group (CK) was as follows: 10 ml of sterile water was added to each pot; There were 6 replicates in each treatment of the experimental group and the control group; S3. Water each group of wheat with sterile water, and count the plant height, root length, fresh weight, and root weight of the wheat after 14 days; The statistical results are as follows Figure 3 As shown in Table 3: Table 3 Statistical results of wheat root length, plant height, fresh weight and root weight

[0035] In Table 3 above, the values ​​of root length, plant height, fresh weight and root weight are expressed as mean ± standard error, * indicates significant difference ( P <0.05); From the data in Table 3 above, it can be seen that the plant height and fresh weight of the experimental group were better than those of the control group, and the root weight was significantly increased. The above results show that Pseudomonas chlororaphis orange subspecies has a growth-promoting effect on wheat plants.

[0036] Example 4 This example is used to characterize the effect of Pseudomonas chlororaphis subspecies orange YL-21 on wheat stem rot.

[0037] Pseudomonas chlororaphis subsp. aurantium YL-21 F. pseudograminearum The impact of wheat stem rot caused by

[0038] (1) Pseudomonas chlororaphis subspecies orange YL-21 strain was inoculated into LB liquid medium, cultured overnight at 28°C and 180 rpm / min, and then a portion of the bacterial suspension was inoculated into NB medium and cultured at 28°C and 180 rpm / min for 48 h to obtain a bacterial suspension. The obtained bacterial suspension was centrifuged at 4000 rpm for 10 min, resuspended in sterile water, and diluted to OD 600 =1, standby; (2) F. pseudograminearumThe bacterial cake was inoculated into 2% mung bean powder medium and cultured at 28 °C and 180 rpm / min for 7 days. After filtering to remove the hyphae, the spore suspension was diluted to a concentration of 1 × 10 6 ,spare; (3) Select pots with a diameter of 7 cm, plant 12 wheat seeds that are uniformly white after germination in each pot, and place them in a greenhouse at 25°C; The experimental group was as follows: 10 mL of bacterial solution resuspended in sterile water was added to each pot, and 10 mL F. pseudograsses The spore solution was poured into the wheat pots; The control group was inoculated with 10 mL F. pseudograminearum Spore fluid; Four replicates were set for each treatment; (4) Sterile water was used to irrigate each group of wheat. After 28 days, the disease status of wheat plants was counted, and the disease index and control effect were calculated. The results are as follows: Figure 4 and as shown in Table 4; Table 4 YL-21 F. pseudograminearum Statistical results of the control effect of wheat stem rot caused by

[0039] The numerical expression of colony diameter in Table 4 above is: mean ± standard error, and a and b indicate significant differences at the 0.05 level.

[0040] The results in Table 4 show that when the disease index of the blank control wheat stem rot was 56.55, the disease index of the treatment with Pseudomonas chlororaphis orange subspecies YL-21 was 25.00, and its effect in preventing and controlling wheat stem rot could reach 55.77%.

[0041] Description Pseudomonas chlororaphis subspecies orange YL-21 F. pseudograminearum It has a good preventive and control effect on wheat stem rot caused by it.

[0042] 2. Pseudomonas chlororaphis subspecies orange YL-21 F. culms Effects of wheat stem rot caused by (1) Pseudomonas chlororaphis subsp. orange YL-21 was inoculated into LB medium and cultured overnight at 28°C and 180 rpm / min. A portion of the bacterial suspension was inoculated into NB medium and cultured at 28°C and 180 rpm / min for 48 h. The resulting bacterial suspension was centrifuged at 4000 rpm for 10 min, resuspended in sterile water, and diluted to OD 600 =1, standby; (2) F. culmsThe bacterial cake was inoculated into 2% mung bean powder medium and cultured at 28 °C and 180 rpm / min for 7 days. After filtering to remove the mycelium, the spore suspension was diluted to a concentration of 1 × 10 6 ,spare.

[0043] (3) Select pots with a diameter of 7 cm, plant 12 wheat seeds that are uniformly white after germination in each pot, and place them in a greenhouse at 25°C; The experimental group was: 10 mL of bacterial solution resuspended in sterile water was added to each pot, and 10 mL F. culms The spore solution was poured into the wheat pots; The control group was inoculated with 10 mL F. culms Spore fluid; Each treatment was set up with 4 replicates.

[0044] (4) Sterile water was used to irrigate each group of wheat. After 28 days, the disease status of wheat plants was counted and the disease index and control effect were calculated. Figure 5 And as shown in Table 5.

[0045] Table 5 Pseudomonas chlororaphis subsp. aurantiacus YL-21 F. culms Statistical results of the control effect of wheat stem rot caused by

[0046] The numerical expression of colony diameter in Table 5 above is: mean ± standard error, a and b represent significant differences at the 0.05 level.

[0047] The results in Table 5 show that when the disease index of the blank control wheat stem rot was 49.41, the disease index of the treatment with Pseudomonas chlororaphis orange subspecies YL-21 was 24.11, and its effect in preventing and controlling wheat stem rot could reach 51.19%.

[0048] The invention describes that the Pseudomonas chlororaphis orange subspecies YL-21 is effective against F. culms It has a good preventive and control effect on wheat stem rot caused by it.

[0049] Example 5 This example tests the ability of Pseudomonas chlororaphis subspecies orange YL-21 to enhance drought resistance in wheat, and the specific method is as follows: S1. Inoculate the Pseudomonas chlororaphis subspecies orange YL-21 strain into NB medium and culture at 28°C with shaking until OD 600 =1, standby; S2. Select clean seeds with full grains of uniform size, soak them in 75% ethanol for 1 min and disinfect them with 5% sodium hypochlorite for 1 min, rinse them with distilled water 5-6 times, sow the wheat seeds in pots, and place them in a greenhouse (about 25°C) for normal growth; S3, when the wheat grows to three leaves and one heart, the experimental treatment is carried out; Clean water was used as a control: each pot was irrigated with 10 mL of clean water; Treatment group: each pot was watered with 10 mL of resuspended bacterial solution; After the treatment, water deprivation (simulated drought) treatment was started, and no water was applied for 15 consecutive days; Each treatment was repeated 5 times; S4. Evaluate the drought resistance coefficient every day for 15 consecutive days; The drought resistance index refers to the observation of wheat growth status every day from the beginning of water cut-off for 15 consecutive days. According to the degree of wilting of wheat plants, each repeated ramet is investigated and counted according to the following grading standards: Level 0: normal plant growth, no wilting phenomenon; Level 1: basically normal plant growth, only one leaf is slightly wilted; Level 2: plant wilting is aggravated, and 2 leaves are wilted; Level 3: the plant is obviously wilted, and more than 3 leaves are wilted; the leaves wilt and droop, and it is difficult to recover; The statistical results are used to calculate the drought resistance coefficient according to the following formula: Drought resistance coefficient = [1−∑(number of plants at each level × corresponding level) / (total number of plants × 3)] × 100%; The results are as follows Figure 6 and as shown in Table 6; Table 6 Statistical results of wheat drought resistance coefficient

[0050] The numerical expression of drought resistance coefficient in Table 6 is: mean ± standard error, * indicates significant difference ( P <0.05).

[0051] From the data in Table 6, it can be seen that starting from the third day of water cutoff, the two groups of treated wheat showed differences. With the increase of water cutoff days, the drought resistance coefficient of each treatment showed a downward trend, and there were significant differences among different treatments. From the third to the seventh day of water cutoff, the drought resistance coefficient of wheat treated with YL-21 was significantly higher than that of the control, and the control group was the first to wilt and droop all the wheat leaves. After 15 days of water cutoff, the fresh weight of wheat in each group was measured. The fresh weight of the treated group increased by 25.83% on average compared with the control, which was significantly higher than that of the control group, indicating that the orange subspecies of Pseudomonas chlororaphis YL-21 of the present invention has a growth-promoting effect on wheat plants.

[0052] Example 6 This example tests the ability of Pseudomonas chlororaphis orange subspecies YL-21 to enhance the salt-alkali tolerance of wheat. The specific detection method is as follows: S1. Inoculate the Pseudomonas chlororaphis subspecies orange YL-21 strain into LB medium, and culture overnight at 28°C and 180 rpm / min to obtain seed solution; S2. Inoculate the seed solution into NB medium, culture at 28 °C and 180 rpm / min for 48 h, centrifuge the resulting bacterial suspension at 4000 rpm for 10 min, resuspend with an equal volume of sterile water, and dilute to OD 600 =1, standby; S3. Select clean seeds with full grains and uniform size, soak them in 75% ethanol for 1 min, disinfect them with 5% sodium hypochlorite for 1 min, rinse them with distilled water for 5-6 times, germinate them for 2 days, then select wheat seedlings with uniform growth, soak them in the bacterial solution for 10 min, and then place them in Hoagland nutrient solution (PH=8.5) with NaCl concentrations of 50 mmol / L, 100 mmol / L and 200 mmol / L, respectively. The treatment without salt stress and no inoculation was used as the blank control, and the treatment without inoculation under salt stress was used as the salt treatment control, and the process was repeated 5 times. After 4 and 7 days, the plant height, root length and fresh weight of wheat were counted. The results are as follows: Figure 7~9 And as shown in Table 7.

[0053] Table 7 Statistical results of wheat plant height, root length and fresh weight

[0054] In Table 7 above, the values ​​of colony diameters are expressed as mean ± standard error; From the data in Table 7, we can see that after the wheat seedlings were cultured in salt solution for 7 days and treated with YL-21 bacterial suspension, the plant height increased significantly under the conditions of 50 mmol / L NaCl and 100 mmol / L NaCl respectively; under the condition of 100 mmol / L NaCl, the fresh weight of the wheat seedlings treated with YL-21 bacterial suspension increased significantly.

[0055] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent change made to the above embodiment according to the technical essence of the invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A strain of Pseudomonas chlororaphis subspecies orange for preventing and treating wheat stem rot, characterized in that: The Pseudomonas chlororaphis subspecies orange strain for preventing and controlling wheat stem rot is P. chlororaphis subsp. aurantiaca, the deposit number is CGMCC No. 32270, the depositor is the General Microbiology Center of China Microorganism Culture Collection Administration, and the deposit date is October 21, 2024.

2. The Pseudomonas chlororaphis subsp. orange strain for preventing and treating wheat stem rot according to claim 1, characterized in that: The 16s nucleotide sequence of the genomic DNA of the Pseudomonas chlororaphis subsp. aurantiacus strain is shown in SEQ ID NO:

1.

3. The Pseudomonas chlororaphis subsp. orange strain for preventing and treating wheat stem rot according to claim 1, characterized in that: The orange subspecies of Pseudomonas chlororaphis strain is inoculated into LB culture medium for fermentation and culture to obtain a biocontrol agent of the orange subspecies of Pseudomonas chlororaphis strain.

4. The Pseudomonas chlororaphis subsp. orange strain for preventing and treating wheat stem rot according to claim 3, characterized in that: The LB medium is composed of the following raw materials by mass fraction: 2% glucose, 2% peptone and 1% yeast extract powder, and the rest is water, and then sterilized at a temperature of 121° C. for 20 minutes.

5. The Pseudomonas chlororaphis subsp. orange strain for preventing and treating wheat stem rot according to claim 3, characterized in that: The fermentation time is 48h.

6. The Pseudomonas chlororaphis subsp. orange strain for preventing and treating wheat stem rot according to claim 3, characterized in that: The concentration OD of the Pseudomonas chlororaphis subspecies orange strain in the biocontrol agent 600 is 1.

7. A use of the Pseudomonas chlororaphis subsp. aurantium strain for preventing and treating wheat stem rot according to any one of claims 1 to 6, characterized in that: The Pseudomonas chlororaphis orange subspecies strain for preventing and controlling wheat stem base rot is applied to the rhizosphere of plants suffering from wheat stem base rot, thereby treating the wheat stem base rot caused by Fusarium fungi and promoting wheat growth.

8. The use of a strain of Pseudomonas chlororaphis subsp. orange for preventing and treating wheat stem rot according to claim 7, characterized in that: The pathogens of the plants suffering from wheat stem rot are fungi of the genus Fusarium, including Fusarium graminearum and Fusarium pseudograminearum.

9. The use of a strain of Pseudomonas chlororaphis subsp. orange for preventing and treating wheat stem rot according to claim 7, characterized in that: The biocontrol agent of the Pseudomonas chlororaphis subspecies orange strain can also treat wheat stem base rot caused by Fusarium fungi and promote wheat growth.

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