Pseudomonas reinhardtii Y8-2 strain and application thereof

Abstract

The invention discloses a pseudomonas reinhardtii Y8-2 strain and an application of the pseudomonas reinhardtii Y8-2 strain. The antagonistic strain which can effectively inhibit sexual coordination of sugarcane smut haploid spores and inhibit mycelial growth of the sugarcane smut haploid spores is separated from rhizosphere soil of sugarcane and is named as a Y8-2 strain. Through identification, the Y8-2 strain belongs to Pseudomonas reinhardtii, and can inhibit the growth of sugarcane smut, reduce the morbidity of sugarcane smut and relieve the influence of the sugarcane smut on the yield and the hammer sugar degree of sugarcane, so that the sugarcane infected with the sugarcane smut can still keep the yield and the hammer sugar degree which are equivalent to those of healthy sugarcane. In addition, the Y8-2 strain can also promote the growth of sugarcane seedlings, and obviously improve the plant height and sugarcane stems in the sugarcane seedling stage. The Y8-2 strain not only can be used for preventing and treating sugarcane smut, but also can be used for promoting the growth of sugarcane seedlings, and is beneficial to ensuring the yield and quality of sugarcane.

Description

Technical Field

[0001] The present invention belongs to the technical field of biological control of plant diseases, and more specifically, relates to a Pseudomonas rheinlandii Y8-2 strain and its application. Background Art

[0002] Sugarcane (Saccharum spp. hybrids) is an important sugar and energy crop that can be used to produce sucrose, ethanol, biofuels and fiber-related products. In addition to temperature and humidity, another key factor affecting sugarcane yield is the stress of pests and diseases during its growth. Among them, sugarcane smut (also known as sugarcane whip smut, smut) caused by Sporisorium scitamineum is a worldwide fungal disease that seriously affects sugarcane yield and quality.

[0003] The prevention and control of sugarcane smut mainly includes breeding new disease-resistant varieties, integrated agricultural prevention and control, and biological prevention and control. Biological prevention and control refers to the method of using biological organisms (animals, plants, microorganisms) or their metabolites for prevention and control. Compared with traditional chemical prevention and control, biological prevention and control can reduce dependence on chemical pesticides, is less likely to leave harmful substances in the environment, can reduce pollution to the environment and ecology, maintain biodiversity, and has the advantages of safety, high efficiency and environmental protection. It is a sustainable green prevention and control method. The antagonistic bacteria reported to be effective against sugarcane whip smut fungus include Pseudomonas guariconensis ST4 strain, Bacillus amyloliquefaciens ZHR0 strain, Bacillus subtilis HAS strain, Pseudomonas fluorescens HN58 strain, Burkholderia sp. CGB10 strain, Streptomyces sp. CGBa10X strain, Bacillus velezensis GH16-3 strain, Paenibacillus jamilae WAC199 strain and Pseudomonas aeruginosa B18 strain, etc.

[0004] Although there are reports of a variety of bacteria that can antagonize sugarcane whip smut, most of the antagonistic bacteria have only been tested for their inhibitory effects on sugarcane whip smut, and it is not clear how effective they are against sugarcane smut. Some other antagonistic bacteria are not very effective in preventing and controlling sugarcane smut as biocontrol bacteria, and their control efficiency cannot reach more than 80%. Therefore, it is still necessary to explore biocontrol bacteria that can effectively prevent and control sugarcane smut, so as to facilitate the efficient and green prevention and control of sugarcane smut. Summary of the invention

[0005] The present invention enriches the biocontrol bacteria library for sugarcane smut and improves the deficiency of the existing biocontrol bacteria that can effectively prevent and control sugarcane smut, and provides a Pseudomonas rheinlandii Y8-2 strain, which can effectively inhibit the sexual mating of haploid spores of sugarcane whip smut fungus and has a good control effect on sugarcane smut. In addition, the strain can also effectively promote the growth of sugarcane in the seedling stage, and increase the plant height and sugarcane stem.

[0006] The first object of the present invention is to provide a Pseudomonas reinekei Y8-2 strain, which was deposited in Guangdong Provincial Microbiological Culture Collection Center on July 31, 2024, with a deposit number of GDMCC NO: 64928.

[0007] The second object of the present invention is to provide a preparation containing live bacteria of the Y8-2 strain or its culture solution.

[0008] The third object of the present invention is to provide the use of the Y8-2 strain or the preparation in inhibiting the growth of sugarcane whip smut fungus.

[0009] The fourth object of the present invention is to provide the use of the Y8-2 strain or the preparation in the preparation of a preparation for inhibiting the growth of sugarcane whip smut fungus.

[0010] The fifth object of the present invention is to provide the use of the Y8-2 strain or the preparation in resisting sugarcane smut.

[0011] A sixth object of the present invention is to provide use of the Y8-2 strain or the preparation in preparing a preparation for resisting sugarcane smut.

[0012] The seventh object of the present invention is to provide the use of the Y8-2 strain or the preparation in promoting the growth of sugarcane in the seedling stage.

[0013] The eighth object of the present invention is to provide the use of the Y8-2 strain or the preparation in the preparation of a preparation for promoting the growth of sugarcane in the seedling stage.

[0014] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0015] The present invention isolates an antagonistic strain that can effectively inhibit the sexual mating of haploid spores of sugarcane whip smut fungus and inhibit the growth of its hyphae from the rhizosphere soil of sugarcane susceptible to sugarcane smut fungus, namely the Pseudomonas reinekei Y8-2 strain of the present invention. The Y8-2 strain can inhibit the growth of sugarcane whip smut fungus, reduce the incidence of sugarcane smut fungus, and alleviate the effects of sugarcane smut fungus on sugarcane yield and hammer sugar content, so that sugarcane infected with sugarcane whip smut fungus can still maintain a yield and hammer sugar content equivalent to that of healthy sugarcane. In addition, the Y8-2 strain can also promote the growth of sugarcane seedlings. Therefore, the present invention requests protection for the Y8-2 strain and its related applications.

[0016] The present invention provides a Pseudomonas reinekei Y8-2 strain, which was deposited in Guangdong Provincial Microbiological Culture Collection Center on July 31, 2024, with a deposit number of GDMCC NO: 64928.

[0017] The present invention also provides a preparation, wherein the preparation contains live bacteria of the Y8-2 strain of the present invention or its culture solution.

[0018] Specifically, the culture solution includes a culture solution containing the Y8-2 strain or a supernatant culture solution from which the Y8-2 strain has been removed.

[0019] In view of the fact that the Y8-2 strain of the present invention can inhibit the sexual mating of haploid spores of Sugarcane Whip Ustilago farfara and inhibit the mycelial growth thereof, the present invention seeks to protect the use of the Y8-2 strain or the preparation in inhibiting the growth of Sugarcane Whip Ustilago farfara.

[0020] The present invention also claims to protect the use of the Y8-2 strain or the preparation in preparing a preparation for inhibiting the growth of sugarcane whip smut fungus.

[0021] The Y8-2 strain of the present invention can effectively prevent and treat sugarcane smut caused by sugarcane whip smut fungus. Therefore, the present invention also claims the use of the Y8-2 strain or the preparation in resisting sugarcane smut.

[0022] The present invention also claims to protect the use of the Y8-2 strain or the preparation in preparing a preparation for resisting sugarcane smut.

[0023] In addition, the Y8-2 strain of the present invention can also effectively promote the growth of sugarcane seedlings. Therefore, the present invention also claims the use of the Y8-2 strain or the preparation in promoting the growth of sugarcane seedlings.

[0024] The present invention also claims to protect the use of the Y8-2 strain or the preparation in preparing a preparation for promoting the growth of sugarcane in the seedling stage.

[0025] Specifically, the variety of sugarcane is New Taiwan Sugar 22 or Liucheng 05-136.

[0026] Specifically, the growth promotion is to increase the plant height and sugarcane stems of sugarcane in the seedling stage.

[0027] The present invention has the following beneficial effects:

[0028] The present invention isolates an antagonistic strain that can effectively inhibit the sexual mating of haploid spores of sugarcane whip smut fungus and inhibit the growth of its hyphae from the rhizosphere soil of sugarcane susceptible to sugarcane smut, and is named as the Y8-2 strain. It is identified that the strain belongs to Pseudomonas reinekei, which can inhibit the growth of sugarcane whip smut fungus, reduce the incidence of sugarcane smut, and alleviate the influence of sugarcane smut on sugarcane yield and hammer sugar content, so that sugarcane infected with sugarcane whip smut fungus can still maintain the yield and hammer sugar content equivalent to healthy sugarcane. In addition, the Y8-2 strain can also promote the growth of sugarcane seedlings, and significantly improve the plant height and sugarcane stems of sugarcane seedlings. That is, the Y8-2 strain of the present invention can not only be used to prevent and control sugarcane smut, but also can be used to promote the growth of sugarcane seedlings, which is beneficial to ensure the yield and quality of sugarcane. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a screening plate for the isolated Y8-2 strain that has an antagonistic effect on sugarcane whip smut fungus; A in the figure is a control plate for sugarcane whip smut fungus, and B in the figure is a screening plate for the Y8-2 strain.

[0030] Figure 2 This is the phylogenetic tree of the Y8-2 strain.

[0031] Figure 3 The hyphae growth of ROC22 sugarcane buds infected by Sugarcane Whip Ustilago in the treatments of water soaking, winter spore soaking and Y8-2 strain on the 6th day; A to C in the figure respectively represent the hyphae growth corresponding to the treatments of water soaking, winter spore soaking and Y8-2 strain.

[0032] Figure 4 The hyphae growth of sugarcane whip smut fungus infecting Liucheng 05-136 sugarcane buds on the 6th day during the water soaking, winter spore soaking and Y8-2 strain treatments; A to C in the figure respectively represent the hyphae growth corresponding to the water soaking, winter spore soaking and Y8-2 strain treatments. DETAILED DESCRIPTION

[0033] The present invention is further described below in conjunction with the accompanying drawings and specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0034] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0035] The Pseudomonas reinekei Y8-2 strain described in the present invention is isolated from the rhizosphere soil of a smut-resistant sugarcane variety, and is currently deposited in the Guangdong Microbial Culture Collection Center with a deposit number of GDMCC NO: 64928, a deposit date of July 31, 2024, and a deposit address of 5th Floor, Compound Experimental Building, No. 100 Xianlie Middle Road, Yuexiu District, Guangzhou City, Guangdong Province.

[0036] The present invention uses Microsoft Excel 2010 software to process the raw data, uses IBM SPSS Statistics 27 software to perform statistical analysis, performs one-way analysis of variance on samples of different groups, uses LSD-t test (p<0.05) for multiple comparisons between sample means, and uses Graphpadprism 8.3 software to make graphs.

[0037] Example 1 Isolation, screening and identification of strains

[0038] 1. Preparation of culture medium

[0039] LB liquid medium: 5 g yeast extract, 10 g peptone, 10 g sodium chloride, add ultrapure water to make up to 1000 mL; LB solid medium plus 16 g agar powder on the basis of liquid medium.

[0040] YePS liquid culture medium: 1.2 g sucrose, 0.6 g yeast extract, 1.2 g peptone, add ultrapure water to make up to 60 mL; YePS solid culture medium is based on the liquid culture medium and 1.2 g agar powder is added.

[0041] 2. Isolation of strains

[0042] The rhizosphere soil of 0-10 cm smut-resistant sugarcane varieties (CP89-2143, Yin 8) was dug out by the 5-point sampling method, and the excess soil was shaken off to collect a small amount of soil attached to the surface of the sugarcane root system; 45 mL of sterile water and 5 g of rhizosphere soil sample were placed in a shaker at 28 ° C and 280 rpm / min, and shaken for 2 min to prepare a soil suspension, and a certain amount of sterile water was added in proportion for gradient dilution to obtain a concentration of 10 -1 , 10 -2 , 10 -3 , 10 -4 of soil suspension; take a concentration of 10 -4100 μL of soil suspension was added to the prepared LB solid medium, and the plate was fully and evenly coated with a glass applicator. The coated plate was sealed and placed in a 28°C constant temperature incubator for 24 h; a single colony was picked and inoculated into LB liquid medium, and placed in a constant temperature shaker at 28°C and 280 rpm / min to culture until OD 600 =1.0 for standby use.

[0043] 3. Screening of strains

[0044] On the left side of the YePS solid medium, 1 μL of haploid positive and negative mating types of wild-type sugarcane whip smut fungus (isolated, identified, and preserved in the Sugarcane Research Laboratory of South China Agricultural University) was inoculated every 1 cm, for a total of 4 inoculations. At the same time, 10 μL of isolated bacterial solution of sugarcane rhizosphere soil bacteria was inoculated around it (OD 600 =1.0), and the colonies of the inoculated positive and negative mating type haploids of Sugarcane Whip Ustilago fargesii were surrounded; on the right side of the same YePS solid culture medium, 1 μL of the positive and negative mating type haploids of the wild type of Sugarcane Whip Ustilago fargesii were inoculated every 1 cm in the same way, and a total of 3 colonies were inoculated, and the bacterial solution of the isolated sugarcane rhizosphere soil bacteria was not inoculated around it, which served as the in-plate control; in addition, the same positive and negative mating type haploids of the wild type of Sugarcane Whip Ustilago fargesii (without the bacterial solution of the isolated sugarcane rhizosphere soil bacteria) were inoculated on the left and right sides of the new YePS solid culture medium according to the above method, respectively, as the off-plate blank control (CK); each Three replicates (3 culture dishes) were set up for each isolated sugarcane rhizosphere soil bacteria according to the above method, and the plates were sealed and placed in a constant temperature incubator at 28°C for 2-3 days; it was observed whether the sugarcane whip smut fungus on the left and right sides of the plate grew white hyphae to determine whether the accessed sugarcane rhizosphere soil bacteria had an antagonistic effect on the sugarcane whip smut fungus (the wild-type control grew white velvety hyphae, and the sugarcane whip smut fungus surrounded by the test bacteria failed to grow white velvety hyphae or the grown white velvety hyphae was significantly weakened, then the test bacteria were antagonistic bacteria to the sugarcane whip smut fungus), and the antagonistic bacteria screened were preserved.

[0045] The screening plate of the sugarcane rhizosphere soil bacteria (named as strain Y8-2) isolated by the present invention that has an antagonistic effect on sugarcane whip smut fungus is as follows: Figure 1 As shown; Figure 1 A in the figure is a plate of sugarcane whip smut fungus (control), Figure 1 B in the figure is the screening plate for the Y8-2 strain. Figure 1It can be seen that after 36 hours of cultivation, the wild-type positive and negative gametes on the off-plate control plate cooperated normally, and a large number of white mycelium appeared at each inoculation point; while on the plate inoculated with Y8-2 bacterial solution, no white mycelium appeared on the wild-type positive and negative gametes on the left and right sides, indicating that the positive and negative gametes did not cooperate normally, that is, the Y8-2 strain can antagonize the sugarcane whip smut, and can effectively inhibit the sexual cooperation of the haploid spores of the sugarcane whip smut, and inhibit the growth of the mycelium of the sugarcane whip smut, and will be further identified and tested for its efficacy.

[0046] 4. Biological characteristics and molecular identification of strains

[0047] Testing of the growth characteristics of the Y8-2 strain revealed that its optimal growth temperature is 25-30°C, and it can grow in the pH range of 5-9. It can degrade protein and produce the long protein IAA.

[0048] The gene DNA of the screened Y8-2 strain was extracted by the CTAB method, and the extracted genomic DNA was used as a template to perform PCR amplification using the PCR primers shown in Table 1. The PCR amplification products were sent to the Guangzhou Synthesis Department of Shanghai Biotechnology Co., Ltd. for sequencing after electrophoresis detection. The antagonistic bacteria were sequenced according to the sequencing results, and the sequences were aligned at NCBI. A phylogenetic tree was constructed using MEGA-X software based on the alignment results.

[0049] Table 1 PCR primers used for molecular identification

[0050]

[0051] The amplification program was as follows: pre-denaturation: 95°C for 3 min; denaturation: 95°C for 15 s, annealing: 55°C for 15 s, extension: 72°C for 30 s, 35 cycles; and re-extension: 72°C for 5 min.

[0052] The size of the PCR amplification product was consistent with the expected size. The sequence was sequenced and compared using NCBI BLAST. The phylogenetic tree of the Y8-2 strain was constructed using MEGA-X software. Figure 2 As shown. Figure 2 It can be seen that the 16S rRNA sequence of the Y8-2 strain is highly similar to that of Pseudomonas reinekei. That is, the Y8-2 strain described in the present invention is Pseudomonas reinekei, which is deposited in the Guangdong Microbiological Culture Collection Center with a deposit number of GDMCC NO: 64928, a deposit date of July 31, 2024, and a deposit address of 5th Floor, Experimental Building, No. 100, Xianlie Middle Road, Yuexiu District, Guangzhou City, Guangdong Province.

[0053] Example 2 Visual Observation of Mycelium of Sugarcane Whip Ustilago infecting Sugarcane Buds

[0054] The sugarcane smut susceptible varieties ROC22 and Liucheng 05-136 were used as test varieties. Three treatments were set up in the experiment, namely CK1 (seed soaking in clean water), CK2 (seed soaking in winter spores) and T (CK2+Y8-2 strain). Twenty healthy fresh seed buds were taken per variety for each treatment. CK1 seed buds were soaked in clean water for 30 minutes, CK2 seed buds were soaked in 5×10 6 / mL sugarcane whip spores were soaked for 30min, and the T seed buds were treated with OD 600 = 0.8 Y8-2 bacterial solution for 6 h, and then in a concentration of 5 × 10 6 The samples were immersed in a suspension of 100 μg / mL of teliospores of Ustilago officinalis for 30 min; the samples of each treatment were cultured in a 28°C light incubator, and samples (seed buds) were taken on the 2nd, 4th, 6th, 9th and 12th days, respectively, and co-stained with WGA-AF488 and propidium iodide. The staining method was carried out according to the instructions of the reagents, and the hyphae growth of teliospores of Ustilago officinalis in sugarcane buds under different treatments was observed with an inverted fluorescence microscope (Leica DMi8) and photographed.

[0055] On the 6th day, the mycelial growth of sugarcane whip smut fungus infecting ROC22 sugarcane buds in the treatments of water soaking, winter spore soaking and Y8-2 strain was as follows: Figure 3 As shown; Figure 3 A to C in the figure are the mycelial growth of water soaking, winter spore soaking and Y8-2 strain treatment. For ROC22 variety, CK1 did not find green fluorescent mycelium within 12 days, CK2 found green fluorescent mycelium on the 4th day, and the number and length of mycelium increased with the passage of sampling time. No green fluorescent mycelium was found on the 6th day in the sugarcane buds inoculated with the antagonistic bacteria Y8-2 strain ( Figure 3 ), green fluorescent hyphae were not found until the 9th day, and the number and length of hyphae were significantly less than those of CK2.

[0056] On the 6th day, the mycelial growth of sugarcane whip smut fungus infecting Liucheng 05-136 sugarcane buds in the treatments of water soaking, winter spore soaking and Y8-2 strain was as follows Figure 4 As shown; Figure 4 A to C in the figure are the mycelial growth of the seed soaking in water, the seed soaking in winter spores and the Y8-2 strain treatment. For Liucheng 05-136 variety, CK1 did not find green fluorescent mycelium within 12 days, and CK2 found green fluorescent mycelium on the 4th day. No green fluorescent mycelium was found on the 6th day after the sugarcane buds were inoculated with the antagonistic bacteria Y8-2 strain ( Figure 4 ), green fluorescent hyphae were not found until the 9th day, and the number and length of hyphae were significantly less than those of CK2.

[0057] The above results showed that the Y8-2 strain could inhibit the germination of teliospores, mycelium formation and development of Ustilago officinalis.

[0058] Example 3: Potted Plant Experiment on Biocontrol of Sugarcane Smut

[0059] 1. Bucket Planting Experiment Design

[0060] Sugarcane smut susceptible varieties ROC22 and Liucheng 05-136 were used as test varieties. Three treatments were set up in the experiment, namely CK1 (water soaking), CK2 (winter spore soaking) and T (CK2+Y8-2 strain). The Y8-2 strain was activated and cultured in LB solid medium for 24 to 48 hours, and a single colony was inoculated in LB liquid medium and placed in a shaker at 28°C and 200 rpm to OD 600 =0.8. Take the plump, healthy and fresh single bud segments of sugarcane varieties ROC22 and Liucheng 05-136, soak them in the suspension of antagonistic bacteria for 6 hours, take them out and shade them to dry naturally, and then soak them in the suspension at a concentration of 5×10 6 The buds were immersed in a suspension of 100 g / mL of spores of sugarcane whip smut fungus for 30 min, taken out and germinated at 28 °C for 24 h, planted in barrels, 5 sugarcane buds were planted in each barrel, 3 barrels / replicate, 3 replicates were set for each treatment, planted in a greenhouse, and then the sugarcane growth management was carried out as usual.

[0061] 2. Determination of the incidence and incubation period of sugarcane smut

[0062] The incubation period of sugarcane smut is the number of days from inoculation to the first appearance of lesions. After that, the occurrence of sugarcane smut was investigated once a week, and the smut-infected plants found were bagged to prevent the spread of winter spores. The number of diseased plants was recorded, and the investigation was continued for 6 months to calculate the incidence of sugarcane smut and the prevention and control effect.

[0063] Incidence rate = (number of diseased plants / total number of plants) × 100%

[0064] Control effect (%) = (incidence of teliospores of sugarcane whip smut fungus inoculated only - incidence of treatment) / incidence of teliospores of sugarcane whip smut fungus inoculated only × 100%

[0065] The incubation period (d), plant incidence (%) and control effect (%) of water soaking, winter spore soaking and Y8-2 strain treatment are shown in Table 2. As shown in Table 2, for the two tested sugarcane varieties, no sugarcane smut was found in the CK1 (water soaking) treatment, and the sugarcane smut incidence in the CK2 (winter spore soaking) treatment was the highest, both reaching 66.67%, and the incubation period was the shortest (both 106 days). The incidence of sugarcane smut inoculated with Y8-2 strain was significantly lower than that of CK2, the incubation period was longer than 106 days, and the control effect was significantly higher than that of CK2. Among them, the control effect of Y8-2 strain in ROC22 reached 87.51%, and the control effect in Liucheng 05-136 was as high as 100%, and its incubation period in ROC22 was also the longest, 35 days later than CK2. The results shown in Table 2 show that the Y8-2 strain can significantly reduce the incidence of sugarcane smut and has the effect of preventing and controlling sugarcane smut.

[0066] Table 2 Incubation period, incidence rate and control effect of sugarcane smut

[0067]

[0068] Different letters in the table indicate significant differences, P < 0.05.

[0069] Example 4 Effect of Y8-2 strain on sugarcane growth

[0070] The planting and inoculation treatment of sugarcane were the same as those in Example 3. After treatment, the plant height (from the stem base to the position of the +1 leaf ring) and stem diameter of potted sugarcane were investigated at the seedling stage, tillering stage, and jointing stage, and the roots of sugarcane at the seedling stage were taken to measure the root traits, including root length, root surface area, root volume, number of root tips, and average root diameter.

[0071] 1. Effect of strain Y8-2 on sugarcane plant height

[0072] The results of the effect of strain Y8-2 on sugarcane plant height are shown in Table 3.

[0073] Table 3 Effect of strain Y8-2 on sugarcane plant height

[0074]

[0075]

[0076] Different letters in the table indicate significant differences, P < 0.05.

[0077] As shown in Table 3, for the ROC22 variety, in terms of plant height, the inoculation of the Y8-2 strain was significantly improved compared with CK1 and CK2 during the sugarcane seedling stage, and the Y8-2 strain treatment was 38.01% higher than CK1 and 73.41% higher than CK2. In the tillering stage of sugarcane growth, there was no significant difference in the inoculation of the Y8-2 strain compared with CK1, but it was 88.37% higher than CK2. In the jointing stage of sugarcane growth, there was no significant difference in the inoculation of the Y8-2 strain compared with CK1, but it was 62.25% higher than CK2. For the Guiliu 05-136 variety, in terms of plant height, in the seedling stage of sugarcane growth, the inoculation of the Y8-2 strain was significantly increased by 34.59% compared with CK1, and significantly increased by 51.52% compared with CK2. In the tillering stage of sugarcane growth, although there was no significant difference in the inoculation of the Y8-2 strain compared with CK1, it was 56.58% higher than CK2. During the jointing stage of sugarcane growth, although there was no significant difference compared with CK1, the inoculation of Y8-2 strain increased the growth rate by 42.94% compared with CK2.

[0078] 2. Effect of strain Y8-2 on sugarcane stem diameter

[0079] The results of the effect of strain Y8-2 on sugarcane stem diameter are shown in Table 4.

[0080] Table 4 Effect of strain Y8-2 on sugarcane stem diameter

[0081]

[0082] Different letters in the table indicate significant differences, P < 0.05.

[0083] As shown in Table 4, for the ROC22 variety, in terms of stem diameter, in the seedling stage of sugarcane growth, the inoculation of the Y8-2 strain was significantly improved compared with CK1 and CK2, with an increase of 25.13% compared with CK1 and 49.69% compared with CK2. In the tillering stage of sugarcane growth, the inoculation of the Y8-2 strain had no significant difference compared with CK1, but it was 33.38% higher than CK2, which was a significant difference. In the jointing stage of sugarcane growth, the inoculation of the Y8-2 strain had no significant difference compared with CK1, but it was still higher than CK2, with an increase of 9.26%. For the Guiliu 05-136 variety, in terms of stem diameter, in the seedling stage of sugarcane growth, the inoculation of the Y8-2 strain was significantly improved compared with CK1 and CK2, with an increase of 27.8% compared with CK1 and an increase of 54.68% compared with CK2. In the tillering stage of sugarcane growth, the inoculation of Y8-2 strain had no significant difference compared with CK1, but it was 26.81% higher than CK2, which was a significant difference. In the jointing stage of sugarcane growth, the inoculation of Y8-2 strain had no significant difference compared with CK1, but it was still higher than CK2, with an increase of 36.68%, which was a significant difference.

[0084] 3. Effects of Y8-2 strain on sugarcane root characteristics

[0085] For ROC22, inoculation with Y8-2 increased the root length of sugarcane by 107.07% compared with CK1 and by 195.48% compared with CK2, but had no significant effect on other root traits.

[0086] Example 5 Effect of strain Y8-2 on sugarcane sugar brix and sugarcane stalk yield

[0087] The planting and inoculation treatment of sugarcane were the same as those in Example 3. At the jointing stage of sugarcane growth, the sugar brix and sugarcane stalk yield of each treatment were measured.

[0088] The effects of strain Y8-2 on sugarcane brix and sugarcane stalk yield are shown in Table 5.

[0089] Table 5 Effect of strain Y8-2 on sugarcane sugar brix and sugarcane stalk yield

[0090]

[0091] Different letters in the table indicate significant differences, P < 0.05.

[0092] As shown in Table 5, for the sugar brix of the two sugarcane varieties, inoculation with the winter spores of sugarcane smut will significantly reduce the sugar brix of sugarcane, and CK2 is significantly lower than CK1, while inoculation with the Y8-2 strain can reduce the effect of sugarcane smut on the sugar brix of sugarcane, making it equivalent to that of normally grown sugarcane. In addition, inoculation with the winter spores of sugarcane smut seriously affects the yield of sugarcane stalks of the two sugarcane varieties, but inoculation with the Y8-2 strain increases its yield compared with CK2. For the ROC22 sugarcane variety, it significantly increased by 52.04% compared with CK2. For the Guiliu 05-136 sugarcane variety, it significantly increased by 63.40% compared with CK2. The above results show that inoculation with the Y8-2 strain can alleviate the effect of the winter spores of smut fungus on sugarcane yield to a certain extent, mainly by inhibiting the growth of smut fungus, reducing the occurrence of sugarcane smut, and increasing sugarcane yield in disguise.

[0093] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A Pseudomonas reinekei Y8-2 strain, characterized in that: The Y8-2 strain was deposited in the Guangdong Provincial Microbiological Culture Collection Center on July 31, 2024, with the collection number GDMCC NO: 64928.

2. A preparation, characterized in that Containing live bacteria or culture fluid of the Y8-2 strain according to claim 1.

3. Use of the Y8-2 strain according to claim 1 or the preparation according to claim 2 in inhibiting the growth of sugarcane whip smut fungus.

4. Use of the Y8-2 strain according to claim 1 or the preparation according to claim 2 in the preparation of a preparation for inhibiting the growth of sugarcane whip smut fungus.

5. Use of the Y8-2 strain according to claim 1 or the preparation according to claim 2 in resisting sugarcane smut.

6. Use of the Y8-2 strain according to claim 1 or the preparation according to claim 2 in the preparation of a preparation for resisting sugarcane smut.

7. Use of the Y8-2 strain according to claim 1 or the preparation according to claim 2 in promoting the growth of sugarcane at the seedling stage.

8. Use of the Y8-2 strain according to claim 1 or the preparation according to claim 2 in the preparation of a preparation for promoting the growth of sugarcane at the seedling stage.

9. The use according to claim 7 or 8, characterized in that: The variety of the sugarcane is New Taiwan Sugar 22 or Liucheng 05-136.

10. The use according to claim 7 or 8, characterized in that: The growth promotion is to increase the plant height and sugarcane stems of sugarcane in the seedling stage.

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