Botryosphaeria dothidea attenuated strain ZMXX551-1 containing penicillium-producing virus BdCV2 and application thereof

Abstract

The invention belongs to the field of strains, and particularly relates to a botryosphaeria dothidea attenuated strain ZMXX551-1 containing a penicillium-producing virus BdCV2 and application of the botryosphaeria dothidea attenuated strain. The attenuated strain ZMXX551-1 is preserved in the China General Microbiological Culture Collection Center on June 25, 2025, the preservation number is CGMCC NO.42040, the genome of the penicillium virus BdCV2 is composed of four dsRNAs, the penicillium virus BdCV2 has a remarkable effect in the aspect of weakening the pathogenicity of botryosphaeria dothidea, the attenuated strain ZMXX551-1 is used for treating peach seedlings, the length of scabs is inhibited by 8.63%, and the length of the scabs is inhibited by 8.63%. After 3 months, the scab of the treatment group begins to heal, and the scab of the control group is continuously increased, which indicates that the peach seedling inoculated with the strain ZMXX551-1 grows well; therefore, the strain ZMXX551-1 can inhibit expansion of peach gummosis scabs and improve plant growth, and has biological control potential.

Description

Technical Field

[0001] This invention belongs to the field of bacterial strains, and specifically relates to a weakly virulent strain of Staphylococcus aureus. Background Technology

[0002] Peach gummosis is a very common and extremely difficult-to-control disease worldwide. It is currently widespread in peach orchards, and is most severe during hot and humid seasons. *Botrytis cinerea* (… Botryosphaeria dothidea (This is a common pathogen causing peach gummosis; peach trees infected with this pathogen...) B. dothidea After infection, the affected area swells and oozes a translucent yellow resin, which worsens after rain. The resin turns reddish-brown upon contact with air, making the infected area more susceptible to saprophytic fungi, leading to rot of the bark and xylem. This weakens the peach tree, causing leaves to yellow and shrink, and in severe cases, the entire tree to die. In recent years, influenced by factors such as climate, pathogens, and cultivation conditions, peach gummosis has become widespread and its damage has intensified, hindering the healthy development of my country's peach industry.

[0003] In the application of biocontrol using attenuated viral-associated viruses to inhibit the pathogenicity of plant pathogenic fungi, a classic example is the successful control of European chestnut blight pathogen (Cryphonectria parasitica) using the fungal virus Cryphonectria hypovirus 1 (CHV1). The fungal virus Sclerotinia sclerotiorum hypovir ulence-associated DNA virus 1 (SsHADV-1) can transform pathogenic fungi into beneficial endophytes and increase the yield of Brassica crops. SsHADV-1 can also grow endophytically in wheat, rice, and barley, improving the crops' resistance to Fusarium head blight, stripe rust, and rice blast. Spraying a suspension of mycelial fungi from the fungal virus Stemphylium lycopersici alternavirus 1 (SlAV1) on various plants such as lettuce, tomato, pepper, eggplant, and cucumber can enhance the plants' resistance to highly pathogenic *Stemphylium* fungi. Patent 202011153985.3 discloses a fungal virus SlMV1, an attenuated strain, and its applications. This virus possesses four double-stranded RNAs of 1.4-3.6 kb. It reduces the pathogenicity of plant pathogenic fungi by inhibiting the synthesis of fungal pathogenic toxins and can be used to control plant diseases caused by fungi such as Alternaria and Crescentella. Research on the interaction between attenuated viruses and fungi provides a new perspective for the development of attenuated strains. Currently, the viral regulatory mechanisms targeting important fruit tree pathogens such as *Botrytis cinerea* are rarely reported. Screening for attenuated strains of *Botrytis cinerea* can not only enrich the understanding of viral pathogens but also... B. dothidea The types of viruses found in the virus also provide new biological control resources for preventing and controlling diseases caused by it. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a potent strain of *Botrytis cinerea* containing the penicillin-producing virus BdCV2, ZMXX551-1, and its application, thereby resolving the technical issue of severe gummosis in peach trees caused by *Botrytis cinerea*, which leads to significant yield reductions in peach orchards.

[0005] The technical solution of this invention is implemented as follows: The novel virus Botryosphaeria dothidea chrysovirus 2 (BdCV2 / ZMXX551-1) with attenuated virulence in this invention has a significant inhibitory effect on the colony morphology, growth rate and pathogenicity of the host fungus, and has great application potential in biological control.

[0006] This application provides a potent strain of *Botrytis cinerea* containing the penicillin-producing virus BdCV2, namely *Botrytis cinerea* ZMXX551-1. The strain ZMXX551-1 is classified as *Botrytis cinerea*. Botryosphaeria dothidea It was deposited on June 25, 2025 at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC NO.42040, located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing.

[0007] The preferred Penicillium-producing virus BdCV2 is a virus containing four dsRNAs, namely dsRNA1, dsRNA2, dsRNA3 and dsRNA4.

[0008] Four full-length dsRNA viral genome sequences, dsRNA1-dsRNA4, were obtained through sequencing and assembly, with sizes of 3731 bp, 3333 bp, 2961 bp, and 2946 bp, respectively. Analysis showed that the GC contents of dsRNA1-dsRNA4 were 48.65%, 49.08%, 51.67%, and 49.86%, respectively. Each dsRNA independently encodes an open reading frame (ORF), with ORF1-ORF4 encoding 1116 aa, 980 aa, 832 aa, and 845 aa, respectively, all encoded on the positive strand.

[0009] The preferred sequences of dsRNA1 are shown in SEQ ID No. 1, dsRNA2 in SEQ ID No. 2, dsRNA3 in SEQ ID No. 3, and dsRNA4 in SEQ ID No. 4.

[0010] Secondly, the application of the aforementioned attenuated strain ZMXX551-1 of *Botrytis cinerea* containing Penicillium-producing virus BdCV2 in the preparation of products for controlling plant diseases caused by *Botrytis cinerea*.

[0011] Thirdly, a plant disease control product contains the aforementioned attenuated strain ZMXX551-1 of Staphylococcus aureus containing Penicillium virus BdCV2.

[0012] Fourthly, the above-mentioned plant disease control products are used in the prevention and control of plant diseases caused by *Botrytis cinerea*.

[0013] The preferred plant disease mentioned above is peach gummosis.

[0014] Fifthly, a method for controlling plant diseases involves spraying the aforementioned attenuated strain ZMXX551-1 of *Botrytis cinerea* containing Penicillium virus BdCV2 or the aforementioned plant disease control product onto the lesions of peach trees affected by gummosis.

[0015] Preferably, the mycelial suspension of the above-mentioned attenuated strain ZMXX551-1 of Staphylococcus aureus contains 9% glycerol, and the mycelial fragment content is 1×10⁻⁶. 6 -1×10 7 per mL.

[0016] Preferably, the plant disease mentioned above is peach gummosis, and the plant is a peach tree.

[0017] The present invention has the following beneficial effects: 1. This invention isolated and identified a weakened viral strain ZMXX551-1, which contains a dsRNA virus. The genome of this dsRNA virus consists of four dsRNAs, with lengths of 3731 bp (dsRNA1), 3333 bp (dsRNA2), 2961 bp (dsRNA3), and 2946 bp (dsRNA4), respectively. Genome sequencing and analysis results indicate that this virus belongs to the Penicillinoviruses family ( ). Chrysoviridae ), Alphachrysovirus A new virus in the genus Botryosphaeria dothidea chrysovirus 2, abbreviated as BdCV2.

[0018] 2. The BdCV2 penicillin-producing virus from *Botrytis cinerea* provided in this invention has a significant effect in reducing the pathogenicity of *Botrytis cinerea*. When peach seedlings were treated with the attenuated strain ZMXX551-1, the lesion length in the ZMXX551-1 treatment group was inhibited by 8.63% compared to the control group. After 3 months, the lesions in the treatment group began to heal, while the lesions in the control group continued to enlarge, indicating that the peach seedlings inoculated with strain ZMXX551-1 grew better. Therefore, strain ZMXX551-1 can not only inhibit the expansion of lesions but also improve plant growth, demonstrating potential for biological control. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a colony morphology diagram of Staphylococcus aureus strain ZMXX551-1.

[0021] Figure 2 The image shows the PCR amplification results of the specific primers Bd-F / Bd-R, where M is the DNA ladder maker; lanes 1-6 are the strains isolated from different peach gummosis samples; lane 7 is strain ZMXX551-1; lane 8 is the positive control strain 180088; and lane 9 is the water control.

[0022] Figure 3 Images show the symptoms of *Vitis vinifera* strains 180088 and ZMXX551-1 inoculated on detached and living peach branches. A shows the symptoms and lesion length of strains 180088 and ZMXX551-1 detached on peach branches 3 days after inoculation; B shows the field symptoms and lesion length of strains 180088 and ZMXX551-1 in living peach branches 24 days after inoculation; C shows the field symptoms and lesion length of strains 180088 and ZMXX551-1 in living peach branches 3 months after inoculation.

[0023] Figure 4 This is an electrophoretic pattern of dsRNA in strain ZMXX551-1.

[0024] Figure 5 This is a schematic diagram of the genome structure of the virus BdCV2.

[0025] Figure 6The images show the therapeutic effects of live inoculation of peach seedlings with strain ZMXX551-1. In the images, A shows the symptoms and lesion length of the control group (CK) and the treatment group with strain ZMXX551-1 8 days after inoculation with peach branches; B shows the symptoms and lesion length of the control group (CK) and the treatment group with strain ZMXX551-1 3 months after inoculation with peach branches. Detailed Implementation

[0026] The technical solution of the present invention will be clearly and completely described below with reference to embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Unless otherwise specified, the experimental methods used in the following experimental examples are conventional methods; the materials and reagents used are commercially available unless otherwise specified.

[0028] exist B. dothidea More than 20 fungal viruses have been officially reported in China, but only 4 of them can cause [the disease / illness]. B. dothidea The present invention describes four strains with weak pathogenicity: Botryosphaeria dothidea chrysovirus 1 (BdCV1), Botryosphaeria dothidea RNA virus 1 (BdRV1), Bipolaris maydis botybirnavirus 1 strain BdEW220 (BmBRV1-BdEW220), and Botryosphaeria dothidea botrexvirus 1 (BdBV1). The novel virus Botryosphaeria dothidea chrysovirus 2 (BdCV2 / ZMXX551-1), exhibiting weak virulence, significantly inhibits the colony morphology, growth rate, and pathogenicity of the host fungi, demonstrating great potential for application in biocontrol.

[0029] This invention investigated the pathogenicity of *Botrytis cinerea*, a fungus found in peach orchards in six regions of Henan Province, on one-year-old peach branches and detected fungal viruses. In July 2020, a weakened strain ZMXX551-1 was isolated and identified in Xinxiang, Henan Province. A dsRNA virus was found in the weakened strain ZMXX551-1; the genome of this dsRNA virus consists of four dsRNAs.

[0030] Example 1: Isolation, identification and preservation of Staphylococcus aureus strain ZMXX551-1 The morphology of colonies on both sides of the laboratory-preserved highly pathogenic Staphylococcus aureus strain 180088 and the Staphylococcus aureus strain ZMXX551-1 of this invention are as follows: Figure 1 As shown.

[0031] The results of PCR amplification of *Staphylococcus aureus* strain ZMXX551-1 using specific primers Bd-F / Bd-R are as follows: Figure 2 As shown. The specific primers for Staphylococcus aureus are: Bd-F: 5'-TTACCCTCAGTGTAGTGACCCTTG-3' Bd-R: 5'-GTCTGCATCATTCTCAGCGTGGG-3' The PCR amplification reaction system was as follows: In a 25 μL system, there were 12.5 μL of 2×Taq PCR Master Mix; 1 μL of Bd-F (10 μM); 1 μL of primer Bd-R (10 μM); and 50 ng / μL of template DNA. -1 The volume was 1 μL, and ddH2O was added to bring the total volume to 25 µL. The reaction program was as follows: 94℃ for 3 min, 94℃ for 30 s, 58℃ for 30 s, 72℃ for 30 s, for 40 cycles; final extension at 72℃ for 7 min; and storage at 16℃.

[0032] Preliminary identification of the attenuated strain ZMXX551-1 of *Botryosphaeria dothidea* indicates that it is *Botryosphaeria dothidea*, and it was deposited on June 25, 2025, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCCNO. 42040. The deposit address is No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing.

[0033] Example 2: Pathogenicity determination of Staphylococcus aureus strain ZMXX551-1 in vitro and in vivo inoculated on peach branches In vitro inoculation assay on peach branches: One-year-old peach and walnut branches of uniform thickness were selected, washed, and disinfected. Both ends of the branches were wrapped with sliced ​​paraffin wax to retain moisture. The branches were then placed in a sterilized inoculation tray, and wounds were made in the bark of the branches using a 5 mm sterilized punch to serve as inoculation sites for the fungal harvesting cake. Fungal harvesting cakes were collected from the edge of a 4-day-old pathogen colony using a 7 mm sterilized punch and inoculated onto the wounds on the branches. This process was repeated for four branches. The inoculation sites were then covered with moistened absorbent cotton to maintain a high-humidity environment. Finally, the inoculation tray was sealed with plastic wrap and placed in an artificial climate chamber at 30℃ and 80% humidity. Two days after inoculation, the fungal harvesting cakes and absorbent cotton were removed, and the expansion of lesions was observed and recorded. Moisture was replenished using a spray bottle.

[0034] Live inoculation test on peach branches: Select one-year-old peach branches of uniform thickness from the peach tree. After washing and disinfecting, use a 5 mm sterile punch to make a wound on the bark of the branch as the inoculation site for the mycelium. Use a 7 mm sterile punch to collect mycelium from the edge of the pathogen colony, which has grown evenly for 4 days, and inoculate it at the wound on the branch. Repeat for 4 branches. Wrap the inoculation site with moist absorbent cotton, and then wrap it with two layers of plastic wrap for fixation. Remove the mycelium and absorbent cotton after 4 days, and observe the expansion of the lesions every three days and replenish moisture as needed.

[0035] The results showed that 3 days after inoculation of peach branches, the average lesion lengths of strains 180088 and ZMXX551-1 were 4.74 cm and 2.22 cm, respectively. 24 days after inoculation of peach branches, the average lesion lengths of strains 180088 and ZMXX551-1 were 2.85 cm and 1.05 cm, respectively. After 3 months, lesions produced by strain ZMXX551-1 had stopped expanding and were slowly healing, while lesions from strain 180088 continued to expand slowly, exhibited more severe gumming, and showed less wound healing. Figure 3 AC).

[0036] Example 3: Genomic dsRNA of fungal virus BdCV2 was found in attenuated Staphylococcus aureus strain ZMXX551-1. The dsRNA virus in the strain was extracted using a dsRNA fungal virus column isolation method (patent number: ZL201310072994.3). The specific steps are as follows: ① Collect the hyphae of the weakly pathogenic Staphylococcus aureus strain ZMXX551-1 cultured on PDA medium for 4 days. Grind the hyphae into powder in a grinding medium using liquid nitrogen and place the powder into a 2 mL sterile enzyme-free centrifuge tube. Then quickly add 800 μL of Buffer 1 and 10 μL of β-ME in sequence and shake vigorously for 15 s.

[0037] ②Incubate in a 65℃ water bath for 10 min, cool to room temperature, and centrifuge at 12000 r / min for 4℃ for 5 min.

[0038] ③ Pipette 700 μL of supernatant into a new 2 mL enzyme-free EP tube, add 1000 μL of Buffer2, mix by inverting, let stand for 5 min, and centrifuge at 12000 r / min for 4℃ for 15 min.

[0039] ④ Transfer 1000 μL of supernatant to a new 2 mL enzyme-free centrifuge tube, add 500 μL of anhydrous ethanol, mix by inverting, and let stand for 1 min. Add 750 μL of the mixed 1500 μL solution to the adsorption column in two portions, let stand for 1 min, centrifuge at 12000 r / min, 4℃ for 1 min, and discard the filtrate.

[0040] ⑤ Add 700 μL Wash buffer to the adsorption column, centrifuge at 12000 r / min, 4℃ for 1 min, and discard the filtrate.

[0041] ⑥ Add 750 μL of 80% ETOH to the adsorption column, centrifuge at 12000 r / min and 4℃ for 1 min, and discard the filtrate.

[0042] ⑦ Repeat the above steps.

[0043] ⑧ After discarding the filtrate, run the tube at 12000 r / min and 4℃ for 3 min to remove residual ETOH from the adsorption column. Then transfer the adsorption column to a new 1.5 mL enzyme-free EP tube, open the cap and let it dry for 10 min to remove residual ETOH.

[0044] ⑨ Add 40 μL of DEPC water preheated to 65℃ to the silica membrane in the center of the adsorption column, let stand for 1 min, and then centrifuge at 12000 r / min and 4℃ for 1 min.

[0045] ⑩ Reload the liquid from the 1.5 mL enzyme-free EP tube onto the column, centrifuge at 12000 r / min, 4℃ for 1 min to recover dsRNA. Add 2 μL DNase I, 4 μL 10×DNase I buffer and 1 μL RNase inhibitor, and bring the volume to 40 μL with DEPC H2O. Mix carefully and incubate at 37℃ for 30 min. Perform 1% agarose gel electrophoresis on 5 μL of the digested dsRNA.

[0046] The results showed four dsRNA fragments between approximately 3 kb and 5 kb, which were named dsRNA1-dsRNA4. Figure 4 ).

[0047] Example 4: Genomic dsRNA Sequencing and Analysis of BdCV2 Virus Using dsRNA extracted from strain ZMXX551-1 as a template, reverse transcription was performed using random primers (26-mer) (5'-GACGTCCAGATCGCGAATTCNNNNNN-3') and Promega's M-MLV reverse transcriptase. PCR amplification was then performed using primers (20-mer) (5'-GACGTCCAGATCGCGAATTC-3') and the enzyme used was 2×Taq PCR Master Mix from Shanghai Huiling Biotechnology Co., Ltd. (Shanghai). After PCR product electrophoresis on a 1% agarose gel, bands longer than 500 bp were recovered according to the instructions of the Takara DNA gel recovery kit.

[0048] The target fragment was ligated into the T-cloning vector pMD18-T (TaKaRa), and positive clones were selected and sent to Shanghai Sangon Biotech (Shanghai) Co., Ltd. for sequencing. Sequences between discontinuous fragments were obtained by designing primers (including forward and reverse complementary primers) using DNAMAN 6.0 software based on the obtained random fragment clone sequences, performing PCR amplification, electrophoresis detection, and sequencing assembly. 5' end sequence cloning employed the classic 5' RACE cloning method, using terminal deoxynucleotidyl transferase (TdT) to add a polyC tail to the 5' end of the reverse transcription product cDNA, followed by nested PCR amplification using adapter primers and sequence-specific primers. The PCR product was ligated into the T-vector, transformed into *E. coli*, and sequenced. 3' end sequence amplification used oligoRNA-ligation RACE (RLM-RACE), where a specially modified oligonucleotide chain (5' phosphorylation and 3' amino groups) was ligated to the 3' hydroxyl end of the RNA chain by T4 RNA ligase. Specific primers were designed based on the oligonucleotide chain sequence and, together with a 3' end sequence-specific primer, amplified the 3' end sequence. The PCR product was ligated into a T vector, transformed, and validated by sequencing. Then, the results of random cloning, end cloning, and PCR amplification were assembled using DNAMAN 6.0 software to obtain the full-length sequences of four dsRNA virus genomes. The obtained full-length sequences were aligned using the BLAST program in the NCBI (https: / / www.ncbi.nlm.nih.gov) database, and then ORF findersearches (ORFs) (https: / / www.ncbi.nlm.nih.gov / orffinder) were used to predict possible open reading frames and corresponding putative protein sequences.

[0049] Four full-length dsRNA viral genome sequences were obtained through sequencing and assembly, namely dsRNA1-dsRNA4, with sizes of 3731 bp (as shown in SEQ ID No. 1), 3333 bp (as shown in SEQ ID No. 2), 2961 bp (as shown in SEQ ID No. 3), and 2946 bp (as shown in SEQ ID No. 4), respectively. Analysis showed that the GC contents of dsRNA1-dsRNA4 were 48.65%, 49.08%, 51.67%, and 49.86%, respectively. Each dsRNA independently encodes an open reading frame (ORF), with ORF1-ORF4 encoding 1116 aa, 980 aa, 832 aa, and 845 aa, respectively, all encoded on the positive strand. Figure 5 BLASTp search revealed that the proteins encoded by dsRNA1-4 sequences showed high similarity to the virus MpCV1 (Macrophominaphaseolina chrysovirus 1). ORF1-ORF4 exhibited 73.12% (Cover 98%, E value=0), 51.54% (Cover 99%, E value=0), 45.26% (Cover 98%, E value=0), and 67.97% (Cover 99%, E value=0) similarity to MpCV1's RdRp, CP, P3, and P4, respectively. Based on gene sequence and phylogenetic analysis, these four dsRNAs were identified as belonging to the family Penicillium-Polypoviridae (Macrophominaphaseolina chrysovirus 1). Chrysovirdae The applicant named the genome of a new virus, Botryosphaeria dothidea chrysovirus 2 (BdCV2), after BdCV1 (Botryosphaeria dothidea chrysovirus 1) had already been reported in Botryosphaeria.

[0050] Example of implementation effect: Therapeutic effect of live inoculation of peach seedlings with strain ZMXX551-1 Select peach seedlings of similar growth. Disinfect the branches of the seedlings with alcohol. Then, use a 5 mm sterile punch to make a wound on the bark as an inoculation site. Use a 5 mm sterile punch to collect fungal cakes of the highly pathogenic strain 180088, which has been growing for 3 days, at the edge of the colony where it is growing evenly. Inoculate the mycelial side of the fungal cake onto the wound on the branch. Cover the inoculation site with moist absorbent cotton to keep it moist, and wrap it with two layers of plastic wrap to fix it. After 4 days, remove the fungal cake and absorbent cotton. At this time, obvious lesions can be observed with the naked eye at the inoculation site. Next, use a weakly virulent strain to treat the infected branches.

[0051] On healthy tissue approximately 2 mm from the lesion on the branch surface, a 5 mm sterile punch was used to create a wound as the inoculation site for the attenuated viral strain. Three-day-old attenuated viral strain mycelial cakes were collected at the edge of the colony using a 7 mm sterile punch to prepare a mycelial suspension of attenuated viral strain ZMXX551-1 containing 9% glycerol. The mycelial fragment content in the mycelial suspension was 1×10⁻⁶. 6 -1×10 7 The mycelial suspension was sprayed onto the gummosis lesions of peach trees at a concentration of 10 mycelia per mL, with 20 branches treated in total. The control group (CK) was inoculated with blank PDA blocks. The inoculated sites were covered with moist absorbent cotton to retain moisture, and then secured with two wraps of plastic wrap. The mycelial cakes were removed after 7 days, and the length of the lesion expansion was observed and recorded weekly.

[0052] Treatment was performed on peach seedlings using a weakened strain of ZMXX551-1. Results were as follows: Figure 6 As shown, after 8 days of treatment with strain ZMXX551-1 and the control (CK), the average length of lesions was 1.80 cm and 1.97 cm, respectively. Compared with the control group, the lesion length in the treatment group was inhibited by 8.63%. After 3 months, the lesions in the treatment group began to heal, while the lesions in the control group (CK) continued to enlarge, indicating that the peach seedlings inoculated with strain ZMXX551-1 grew better than those in the control group (CK). Therefore, strain ZMXX551-1 can not only inhibit the expansion of lesions but also improve plant growth.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A Eutypa lata attenuated strain ZMXX551-1 containing BdCV2, characterized in that: The taxonomic name of the weakly virulent strain of G. cingulata ZMXX551-1 is Botryosphaeria dothidea , and was preserved in the China General Microbiological Culture Collection Center on June 25, 2025, with a preservation number of CGMCC NO. 42040 and a preservation address of No. 1, Xibaixili, Chaoyang District, Beijing.

2. The attenuated strain ZMXX551-1 of Eutypa lata containing BdCV2 according to claim 1, characterized in that: The BdCV2 is a virus containing four dsRNAs, i.e. dsRNA1, dsRNA2, dsRNA3 and dsRNA4.

3. The attenuated strain ZMXX551-1 of Eutypa lata containing BdCV2 according to claim 2, characterized in that: The sequence of the dsRNA1 is shown as SEQ ID No. 1, the sequence of the dsRNA2 is shown as SEQ ID No. 2, the sequence of the dsRNA3 is shown as SEQ ID No. 3, and the sequence of the dsRNA4 is shown as SEQ ID No.

4.

4. Use of the Botryosphaeria dothidea attenuated virus strain ZMXX551-1 containing BdCV2 in the preparation of a product for preventing and treating plant diseases caused by Botryosphaeria dothidea according to claim 3.

5. A plant disease control product, characterized by: Botryosphaeria dothidea attenuated virus strain ZMXX551-1 containing BdCV2 according to claim 3.

6. Use of the product for preventing and treating plant diseases according to claim 5 in preventing and treating plant diseases caused by Botryosphaeria dothidea.

7. Use according to claim 4 or 6, characterized in that: The plant disease is peach gummosis.

8. A method for controlling plant diseases, characterized by: Spraying the Botryosphaeria dothidea attenuated virus strain ZMXX551-1 containing BdCV2 according to claim 3 or the product for preventing and treating plant diseases according to claim 5 on the peach gummosis lesion of a peach tree.

9. The method for controlling plant diseases according to claim 8, characterized by: The hyphal fragment content of the mycelial suspension of the weakly virulent strain ZMXX551-1 of the grapevine pathogen Botryospaeria dothidea is 1 x 10 6 -1 x 10 7 mycelial fragments per mL.

10. The method for controlling plant diseases according to claim 9, characterized in that: The plant disease is peach gummosis, and the plant is a peach tree.

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