A composition for controlling fungal root rot in Panax notoginseng and its application

Abstract

This invention discloses a fungal composition for controlling root rot in Panax notoginseng. The fungal composition consists of Trichoderma harzianum SQ T8 and Mortierella alpina SQ T10, which can effectively control root rot in Panax notoginseng, providing a new selection of strains for the biological control of root rot in Panax notoginseng, reducing the input of chemical pesticides in the management of Panax notoginseng, enhancing the protection of the ecological environment, reducing the risk of pesticide residue and heavy metal pollution in Panax notoginseng, saving costs, and effectively increasing the content of monomeric saponins in Panax notoginseng, thus ensuring the quality of Panax notoginseng.

Description

Technical Field

[0001] This invention relates to the field of plant beneficial bacteria composition technology, specifically to a fungal composition for preventing and controlling root rot of Panax notoginseng and its application. Background Technology

[0002] Panax notoginseng is a perennial herb belonging to the genus Panax in the family Araliaceae. Its medicinal parts are the roots and rhizomes. It is a unique and precious medicinal material in my country, renowned as "priceless" and "the divine herb of the South." The chemical components of Panax notoginseng include non-saponins and saponins. Non-saponins mainly include notoginsenosides, proteins, polysaccharides, flavonoids, trace elements, and other components. Saponins are the main chemical components and active medicinal ingredients of Panax notoginseng, exhibiting good therapeutic effects on coronary artery disease and cardiovascular diseases, and also possessing a certain preventive effect against cancer. Therefore, saponin content is often used to evaluate the quality of Panax notoginseng.

[0003] Panax notoginseng is a perennial herbaceous plant that thrives in shady and moist conditions. Large-scale monoculture over many years makes it highly susceptible to infection and disease by soil-borne pathogens. Root rot is the most serious disease affecting Panax notoginseng, and its main pathogens include Fusarium oxysporum, Fusarium solani, and Cylindrocarpondestructans. Root rot can reduce Panax notoginseng yield by 5% to 20%, and in severe cases, by more than 70%. Losses caused by root rot account for 70% to 85% of all diseases affecting Panax notoginseng, making it a serious obstacle to the development of Panax notoginseng cultivation.

[0004] Currently, the main method for controlling root rot in Panax notoginseng is through the application of chemical agents. However, the long-term use of chemical pesticides can cause environmental pollution, damage to the ecosystem, the development of drug resistance in pathogens, and even pesticide residues and heavy metal pollution in Panax notoginseng. Therefore, it is of great significance to rationally reduce the use of pesticides and find green and environmentally friendly control methods to prevent and control root rot in Panax notoginseng. Summary of the Invention

[0005] The purpose of this invention is to provide a composition for preventing and controlling root rot of Panax notoginseng and its application, which addresses the current serious occurrence of root rot of Panax notoginseng and the unsatisfactory effects of pesticide, crop rotation and soil control measures, which also lead to reduced quality of medicinal materials and environmental pollution.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A type of Trichoderma harzianum, specifically Trichoderma harzianum SQ T8, is used to inhibit Fusarium oxysporum, Fusarium solani, and Trichoderma harzianum.

[0008] It is deposited at the China General Microbiological Culture Collection Center, with accession number CGMCC No. 41468; the deposit date of accession number CGMCC No. 41468 is July 19, 2024, and it is classified and named Trichodermaharzianum.

[0009] A type of Mortierella alpina, specifically Mortierella alpina SQ T10.

[0010] Used to inhibit Fusarium oxysporum, Fusarium solani, and Cyclospora rotundifolia;

[0011] It is deposited at the China General Microbiological Culture Collection Center, with accession number CGMCC No. 41410; the deposit date of accession number CGMCC No. 41410 is July 19, 2024, and it is classified and named Mortierella alpina.

[0012] A fungal composition for preventing root rot in Panax notoginseng, the fungal composition comprising: Trichoderma harzianum SQ T8 and Trichoderma harzianum SQ T8.

[0013] Application of a composition for preventing root rot of Panax notoginseng in promoting the growth of Panax notoginseng.

[0014] According to the application of a composition for preventing root rot of Panax notoginseng in promoting the accumulation of saponins in Panax notoginseng roots.

[0015] Furthermore, the application method is as follows:

[0016] Seed cultures of fungi SQ T8 and SQ T10 were inoculated into PDA medium and cultured upside down in an incubator for activation. After activation, strains were picked and inoculated into PDA liquid culture medium for further culture.

[0017] Centrifuge the bacterial culture to remove the culture medium, resuspend the bacterial cells in sterile water, determine the dilution factor, and prepare adult bacterial strains at concentrations of 10... 8 A mixed bacterial culture with cfu / mL;

[0018] After the Panax notoginseng seedlings emerge, irrigate with a mixed bacterial solution.

[0019] Furthermore: the Panax notoginseng used to promote its growth is selected from two-year-old or three-year-old Panax notoginseng.

[0020] Furthermore: the method for determining the dilution factor is as follows:

[0021] According to the bacterial culture OD 600A standard curve was plotted using the bacterial concentration obtained from the plate count method and the OD value. The results were then compared with the measured OD values. 600 The value determines the dilution factor.

[0022] Furthermore: each Panax notoginseng plant is irrigated with 200ml of mixed bacterial solution.

[0023] Furthermore, in the aforementioned application, the determination of Panax notoginseng saponins involves selecting the main root of Panax notoginseng, which is dried at a constant temperature, ground into powder, sieved, and then measured.

[0024] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0025] (1) The beneficial bacteria provided by the present invention have an inhibitory effect on Fusarium oxysporum, Fusarium solani, and Cyclospora malathiformis.

[0026] (2) The beneficial bacteria combination provided by this invention can promote the growth of Panax notoginseng and increase the content and accumulation of various saponin monomers and total saponins in the main root of Panax notoginseng. It has a positive effect on the formation of Panax notoginseng quality.

[0027] (3) Based on the rhizosphere soil microorganisms of Panax notoginseng, this invention isolated and identified SQ T8 and SQ T10, screened the antibacterial activity of the pathogen causing root rot of Panax notoginseng, and prepared a mixed bacterial solution of SQ T8 and SQ T10 for field trials, resulting in a fungal combination that can prevent root rot of Panax notoginseng and improve its quality. It can effectively prevent root rot of Panax notoginseng, providing new strains for the biological control of root rot, reducing the input of chemical pesticides in the management of Panax notoginseng, enhancing ecological environmental protection, reducing the risk of pesticide residue and heavy metal pollution in Panax notoginseng, saving costs, and effectively increasing the content of monomeric saponins in Panax notoginseng, ensuring its quality, while also providing new materials for the development of medicinal microbial agents. Attached Figure Description

[0028] Figure 1 The above are colony diagrams of the strains SQ T8 and SQ T10 of this invention.

[0029] Figure 2 The diagram shows the results of plate confrontation experiments conducted on strain SQ T8 of the present invention with Fusarium oxysporum, Fusarium solani, and Cyclospora rotundifolia. In the diagram, A is a colony photograph of the Fusarium oxysporum control group; B is a colony photograph of the Fusarium oxysporum treatment group; C is a colony photograph of the Fusarium solani control group; D is a colony photograph of the Fusarium solani treatment group; E is a colony photograph of the Cyclospora rotundifolia control group; and F is a colony photograph of the Cyclospora rotundifolia treatment group.

[0030] Figure 3The diagram shows the results of plate confrontation experiments conducted on strain SQ T10 of the present invention with *Fusarium oxysporum*, *Fusarium solani*, and *Cyclophorus rotundus*, respectively; where A is a colony photograph of the *Fusarium oxysporum* control group; B is a colony photograph of the *Fusarium oxysporum* treatment group; C is a colony photograph of the *Fusarium solani* control group; D is a colony photograph of the *Fusarium solani* treatment group; E is a colony photograph of the *Cyclophorus rotundus* control group; and F is a colony photograph of the *Cyclophorus rotundus* treatment group.

[0031] Figure 4 This is a schematic diagram of the phylogenetic tree of the strain SQ T8 of this invention.

[0032] Figure 5 This is a schematic diagram of the phylogenetic tree of strain SQ T10 of the present invention.

[0033] Figure 6 This is a graph showing the relationship between the content and cumulative amount of each saponin monomer in the main root of Panax notoginseng and the fermentation broth of the mixed fermentation broth of strains SQ T8 and SQ T10 of the present invention; where A is the content of Panax notoginseng saponin R1; B is the content of ginsenoside Rg1; C is the content of ginsenoside Rb1; D is the content of ginsenoside Rd; E is the cumulative amount of Panax notoginseng saponin R1; F is the cumulative amount of ginsenoside Rg1; G is the cumulative amount of ginsenoside Rb1; and H is the cumulative amount of ginsenoside Rd.

[0034] Figure 7 This is a graph showing the relationship between the total saponin content and cumulative amount in the main root of Panax notoginseng and the mixed fermentation broth of strains SQ T8 and SQ T10 of the present invention; where A is the total saponin content and B is the cumulative amount of total saponins. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0036] Example 1

[0037] 1) Separation and purification

[0038] Rhizosphere soil from three-year-old Panax notoginseng plants was collected from Yunnan. After removing stones, 5g of the rhizosphere soil was weighed and placed in an Erlenmeyer flask containing 45mL of sterile water. The flask was then placed on a shaker at 25℃, 180r / min, and 30min to obtain a 10-fold diluted soil suspension. After standing for 1 hour, 1ml of the upper soil suspension was taken and diluted 1000, 10000, and 100000 times with sterile water to obtain a 1000-fold diluted soil suspension. Soil suspensions diluted 10,000 times and 100,000 times were prepared. Then, 100 μL each of the following soil suspensions (diluted with sterile water 1000 times, 10000 times, and 100,000 times) were evenly spread onto PDA medium. All PDA medium was placed in a 30°C incubator and inverted for 7–14 days. After bacterial growth, single colonies with different morphologies were picked out and inoculated into fresh PDA medium. These were then incubated in a 30°C inverted incubator for 2 days, followed by streak plating for purification. This streak plating purification process was repeated multiple times until purified single bacterial strains were obtained.

[0039] Dispense 10 mL of PDA culture medium into 18 mm × 180 mm test tubes, seal the tubes with gauze, and sterilize at 121 °C for 20 min. After sterilization, place the tubes on a slant about half the length of the test tube, allow them to cool and solidify, and set aside for later use.

[0040] The purified single strains were inoculated onto prepared PDA solid slant culture media, sealed with sterilized rubber stoppers, and stored at 4°C after full bacterial growth to serve as single-strain seed solutions. To ensure the purity of the single-strain seed solutions, inoculation was performed every 4 months. The single-strain seed solutions were used for inhibiting the antibacterial activity against the root rot pathogen of Panax notoginseng and for inoculation when preparing mixed bacterial solutions.

[0041] The PDA medium consists of 12 g / L potato extract powder, 20 g / L glucose, and 15 g / L agar powder, diluted to 1 L with water, and set to natural pH. After preparation, sterilize at 120°C for 20 minutes.

[0042] The PDA liquid culture medium consists of 12 g / L potato extract powder and 20 g / L glucose, diluted to 1 L with water, and set to natural pH. After preparation, it is sterilized at 120°C for 20 minutes.

[0043] 2) Screening of the antibacterial activity of the strains against the pathogen causing root rot of Panax notoginseng.

[0044] 2.1 Method:

[0045] Take a single-strain seed culture and inoculate it onto PDA medium. Incubate in a 30°C inverted incubator for 2 days to obtain activated single-strain colonies for later use.

[0046] Experimental group: Fusarium oxysporum, Fusarium solani, and Cyclospora demise, the pathogens of root rot of Panax notoginseng, were used as target bacteria. The target bacteria were inoculated in the center of PDA medium, and the above-mentioned activated single strains were inoculated at a point 2 cm away from the center of the plate. They were incubated in a 30℃ incubator for 5 days, and each single strain was repeated 5 times.

[0047] Control group: Fusarium oxysporum, Fusarium solani, and Cyclospora demise, the pathogens of root rot of Panax notoginseng, were used as target bacteria. The target bacteria were inoculated in the center of PDA medium and incubated in a 30°C incubator for 5 days, and the incubation was repeated 5 times.

[0048] After 5 days of incubation, the treatment and control groups were removed, and the colony diameters of each pathogenic fungus in their PDA culture medium were measured, and the inhibition rate was calculated. Inhibition rate % = (target colony diameter in control group - target colony diameter in treatment group) / target colony diameter in control group × 100%.

[0049] 2.2 Measurement Results:

[0050] Among the purified single strains, only SQ T8 (single strain 8) and SQ T10 (single strain 10) showed inhibitory effects on the pathogen causing root rot of Panax notoginseng. Their specific antibacterial effects were as follows:

[0051] The control group of Panax notoginseng Fusarium colonies was as follows Figure 2 As shown in A and 3A, the colonies have irregular edges, a fuzzy surface, and are grayish-white. Treatment groups are as follows: Figure 2 As shown in B and 3B, after streaking single strains SQ T8 and SQ T10 next to the target pathogen, the growth of *Fusarium oxysporum* was inhibited, and a clear inhibition zone was formed on the side near the colonies of strains SQ T8 and SQ T10. The color of the pathogen colonies was lighter than that of the control group. According to Table 1, the diameter of single *Fusarium oxysporum* colonies in the control group was 30 mm, while the diameters of the inhibition zones of SQ T8 and SQ T10 against *Fusarium oxysporum* were 10.2 mm and 25.7 mm, respectively, with inhibition rates of 66.0% and 14.3%.

[0052] The colonies of Fusarium solani in the control group were as follows: Figure 2 As shown in C and 3C, the colonies have intact edges, are symmetrical, and are gray in color. Treatment groups are as follows: Figure 2 As shown in D and 3D, after streaking single strains SQ T8 and SQ T10 next to the target pathogen bacteria, the growth of *Fusarium solani* was inhibited. A distinct inhibition zone formed on the side near the colonies of strains SQ T8 and SQ T10, and the color of the pathogen colonies was lighter compared to the control group. According to Table 1, the single colony diameter of *Fusarium solani* in the control group was 63.3 mm. The inhibition zone diameters of SQ T8 and SQ T10 against *Fusarium oxysporum* were 12.3 mm and 20.8 mm, respectively, with inhibition rates of 80.6% and 67.1%, respectively.

[0053] Control group: destroyed columnar mold colonies such as Figure 2 As shown in E and 3E, the colony edges are intact, covering the central area of ​​the culture medium, and the colonies are generally symmetrical. The treatment groups are as follows... Figure 2 As shown in F and 3F, after streaking single strains SQ T8 and SQ T10 next to the target pathogens, the growth of *Cyclospora necrophora* was inhibited. A distinct inhibition zone formed on the side near the colonies of strains SQ T8 and SQ T10, with the colonies near SQ T8 being lighter in color than the control group. According to Table 1, the single colony diameter of *Fusarium solani* in the CK group was 23.8 mm. The inhibition zone diameters of SQ T8 and SQ T10 against *Fusarium oxysporum* were 11.5 mm and 17.7 mm, respectively, with inhibition rates of 51.7% and 25.6%, respectively.

[0054] The above results show that single strains SQ T8 and SQ T10 have inhibitory effects on the growth, development, and proliferation of *Fusarium oxysporum*, *Fusarium solani*, and *Cyclocarya necrophora*. Among these, SQ T8 shows stronger inhibitory effects on all three pathogens causing root rot of *Panax notoginseng* than SQ T10, thus its control effect on root rot of *Panax notoginseng* is stronger than that of SQ T10. SQ T10 shows stronger inhibitory effects on *Fusarium solani* than on *Fusarium oxysporum* and *Cyclocarya necrophora*.

[0055] Table 1. Antibacterial activity against pathogenic fungi of Panax notoginseng.

[0056]

[0057] 3) Identification

[0058] 3.1 Morphological observation: Single-strain SQ T8 and SQ T10 seed cultures were inoculated onto PDA plates and incubated upside down at 30℃ for 2 days to obtain single-strain colonies. The colonies formed by SQ T8 and SQ T10 are shown below. Figure 3 As shown, SQ T8 colonies appear green on PDA plates, with filamentous surfaces, neat edges, and a circular shape; SQ T10 colonies appear gray on PDA plates, with filamentous layers and irregular edges.

[0059] 3.2 Identification of antagonistic functional bacteria: using Total fungal DNA was extracted from single strains SQ T8 and SQ T10 using the Spint Kit for Soil (MPBIO), and PCR amplification was performed using the universal fungal primers ITS1 / ITS2. After gel electrophoresis, the sequences were sent to a bioengineering company for sequencing, yielding full-length sequences of 594 bp and 650 bp, respectively. The obtained sequences were submitted to the GenBank database for BLAST analysis and comparison. The strains with high homology to SQ T8 and SQ T10 were identified as *Trichodermaharzianum* strain MR19 and *Mortierella alpina* isolate OVR6, respectively. A phylogenetic tree was constructed using MEG 7.0 software. Figure 4 As shown, single strains SQ T8 and SQ T10 belong to the same branch as Trichoderma harzianum strain MR19 and Mortierella alpina isolate OVR6, respectively.

[0060] Based on the above morphological characteristics analysis, ITS analysis and phylogenetic tree analysis, the single strains SQ T8 and SQ T10 were identified as Harzinium and Alpine Monascus, respectively.

[0061] 4) Field application of SQ T8 and SQ T10 strains for the control of root rot in Panax notoginseng

[0062] 4.1 Preparation method of bacterial suspension of mixed strains SQ T8 and SQ T10:

[0063] Seed cultures of fungi SQ T8 and SQ T10 were inoculated into PDA medium and incubated upside down at 30°C for 2 days to activate the strains. After activation, the strains were picked and inoculated into PDA liquid medium and incubated at 30°C and 180 rpm for 2 days. Then, the bacterial culture was centrifuged at 5000 rpm to remove the medium, and the cells were resuspended in an appropriate amount of sterile water. The OD values ​​of the bacterial culture were then determined. 600 A standard curve was plotted for the three strains using the values ​​and bacterial concentrations obtained from the plate count method. Then, the standard curves were compared with the measured OD values. 600 The dilution factor was determined, and the final concentration of the bacterial strain was 10. 8 Prepare a mixed bacterial culture of CFU / mL for later use.

[0064] 4.2 Field application:

[0065] 4.2.1 Field test sites and materials: The experiment was conducted in Qiubei County and Shilin County, and the test materials were two-year-old or three-year-old Panax notoginseng.

[0066] 4.2.2 Test Methods

[0067] The field trial consisted of two groups: an experimental group and a control group (CK). Each group had three replicates, with 100 Panax notoginseng plants per replicate.

[0068] In the experimental group, after three years and seven days of seedling emergence (mid-April), samples were taken at concentrations of 10... 8 For the CK treatment, irrigate the roots of each Panax notoginseng plant with 200 ml of a mixed bacterial solution of SQ T8 and SQ T10 at a concentration of cfu / mL. For the CK treatment, irrigate the roots of each Panax notoginseng plant with 200 ml of distilled water. Repeat the above treatment once after a one-month interval.

[0069] No chemical pesticides for preventing root rot were used during the growing season; other management practices were carried out as usual. Agricultural indicators were measured and the incidence of root rot was statistically analyzed upon harvesting the three-year-old Panax notoginseng. After agronomic trait testing, the main roots of each group were dried at a constant temperature of 45℃, powdered, and passed through a 60-mesh sieve for Panax notoginseng saponin determination.

[0070] Disease incidence rate = (Number of diseased plants / Number of plants surveyed) * 100%;

[0071] Disease control effect = (Disease incidence rate in control area - Disease incidence rate in control area) / Disease incidence rate in control area * 100%.

[0072] 4.2.3 Test Results:

[0073] (1) Results of the effect of SQ T8 and SQ T10 compositions on the incidence of root rot in Panax notoginseng:

[0074] The mixture of SQ T8 and SQ T10 can effectively prevent the occurrence of root rot in Panax notoginseng (see Table 2).

[0075] Table 2. Control of root rot in Panax notoginseng by mixed bacterial solutions of SQ T8 and SQ T10.

[0076]

[0077] As shown in Table 2, the field control efficacy of using a mixture of SQ T8 and SQ T10 bacterial solutions for controlling root rot of Panax notoginseng can reach over 70%.

[0078] (2) Effects of the SQ T8 and SQ T10 combined strains on the growth of Panax notoginseng:

[0079] The SQ T8 and SQ T10 combined bacterial solutions promote the growth of Panax notoginseng, as shown in Table 3.

[0080] Table 3. Effects of SQ T8 and SQ T10 mixed bacterial cultures on the growth of Panax notoginseng.

[0081]

[0082] Note: Different letters for the same place of origin in the same column of the table indicate significant differences (P<0.05).

[0083] Inoculation with a combination of SQ T8 and SQ T10 bacterial cultures significantly promoted the growth of Panax notoginseng plants by 9%-27%, the increase in aboveground fresh weight by 18%-22%, the increase in underground fresh weight by 8%-12%, and the increase in underground dry weight by 4%-5%.

[0084] (3) Effects of the SQ T8 and SQ T10 combined bacteria on the percentage content and cumulative amount of Panax notoginseng saponins:

[0085] The content of each monomeric saponin in the main root of Panax notoginseng treated with SQ T8 and SQ T10 combined bacterial inoculum was higher than that in the control group. Figure 6 (AD) Among them, in Qiubei area, the contents of notoginsenoside R1 and ginsenosides Rg1, Rb1, and Rd in the main root of Panax notoginseng increased by 37.80%, 5.26%, 39.28%, and 88.58% respectively after treatment with mixed bacterial solutions compared with the control group. In Shilin area, the contents of R1 and ginsenosides Rg1, Rb1, and Rd in the main root of Panax notoginseng treated with mixed bacterial solutions increased by 93.68%, 28.22%, 24.14%, and 27.07% respectively compared with the control group. SQ T8 and SQ T10 mixed bacterial solutions treatment had a significant effect on the accumulation of each monomeric saponin in the main root of Panax notoginseng. Figure 6 In the mixed bacterial culture treatment group (EH), compared with the control group, the cumulative amounts of notoginsenoside R1, ginsenoside Rg1, Rb1, and Rd in the main root of Panax notoginseng from Qiubei area increased by 42.05%, 10.00%, 44.45%, and 94.79%, respectively. In the Shilin area, the cumulative amounts of each monomeric saponin in the main root of Panax notoginseng from the treatment group were significantly higher than those in the control group. Among them, the cumulative amounts of notoginsenoside R1, ginsenoside Rg1, Rb1, and Rd increased by 129.21%, 35.27%, 30.87%, and 33.86%, respectively, compared with the control group. All the above results indicate that the mixed bacterial culture of strains SQ T8 and SQ T10 has a good effect on increasing the cumulative amount of each monomeric saponin in the main root of Panax notoginseng, especially notoginsenoside R1 and ginsenoside Rd.

[0086] (4) Effects of the SQ T8 and SQ T10 combined strains on the percentage content and cumulative amount of total saponins in Panax notoginseng:

[0087] The total saponin content in the main root of Panax notoginseng treated with SQ T8 and SQ T10 combined bacterial solutions was higher than that in the control group. Figure 7 A) Among them, the total saponin content in the main root of Panax notoginseng treated with mixed bacterial solution in the Shilin area reached 91.03-108.99 mg / g, which was significantly higher than that in the control group (69.69-98.99 mg / g). The cumulative amount of total saponins in the main root of Panax notoginseng treated with SQ T8 and SQ T10 mixed bacterial solutions was significantly higher than that in the control group. Figure 7(B) The cumulative total saponin content in the main root of *Panax notoginseng* in the Qiubei treatment group was 1501.51 mg / plant, significantly higher than the control group's 1152.06 mg / plant. In the Shilin treatment group, the cumulative total saponin content in the main root of *Panax notoginseng* was 1214.49 mg / plant, significantly higher than the control group's 868.85 mg / plant. These results indicate that the mixed bacterial solution of single strains SQ T8 and SQ T10 has a good effect on increasing the cumulative total saponin content in the main root of *Panax notoginseng*. (Saponin accumulation = dry weight of underground part * percentage of saponin content, expressed in mg / plant)

[0088] 4.2.4 Conclusion: The mixture of SQ T8 and SQ T10 isolated from the rhizosphere soil of Panax notoginseng exhibits inhibitory effects against Fusarium oxysporum, Fusarium solani, and Cyclospora malathiformis, promoting the growth of Panax notoginseng and increasing the content and accumulation of saponins in the main root. Specifically, strain SQ T8 showed inhibition rates of 66.1%, 80.5%, and 51.7% against Fusarium oxysporum, Fusarium solani, and Cyclospora malathiformis, respectively, while strain SQ T10 showed inhibition rates of 14.4%, 67.1%, and 25.9%, respectively. Field trials showed that inoculation with the mixed inoculant SQ T8 and SQ T10 significantly improved the control of root rot in Panax notoginseng (Sanqi) by over 70%, and significantly promoted plant height growth by 27%, aboveground fresh weight gain by 18%-22%, underground fresh weight gain by 8%-12%, and underground dry weight gain by 4%-5%. Furthermore, it effectively increased the content and accumulation of various saponin monomers, as well as the total saponin content and accumulation, in the main root of Panax notoginseng, particularly notoginsenoside R1 and ginsenoside Rd. The strains SQ T8 and SQ T10 in this invention both inhibit root rot pathogens such as Fusarium oxysporum, Fusarium solani, and *Cyclocarya pallida*. Simultaneously, the mixed inoculant solution of the two strains also promoted the growth and improved the quality of Panax notoginseng. This invention provides new strains for the control of root rot in medicinal plants and also provides new materials for the development of medicinal microbial agents.

[0089] Although the invention has been described herein with reference to several illustrative embodiments, it should be understood that many other modifications and implementations can be devised by those skilled in the art, which will fall within the scope and spirit of the principles disclosed herein. More specifically, various variations and modifications can be made to the components and / or layout of the subject matter arrangement within the scope of the disclosure, drawings, and claims. Besides variations and modifications to the components and / or layout, other uses will be apparent to those skilled in the art.

Claims

1. A composition for controlling fungal root rot in Panax notoginseng, characterized in that: The fungal composition consists of Trichoderma harzianum SQ T8 and Mortierella alpina SQ T10; The accession number for Trichoderma harzianum SQ T8 is CGMCC No. 41468; The preservation number of *Morchella alpineensis* SQ T10 is CGMCC No. 41410.

2. The application of the composition for preventing and controlling root rot fungi in Panax notoginseng as described in claim 1 in promoting the growth of Panax notoginseng.

3. The application of the composition for preventing and treating root rot fungi in Panax notoginseng as described in claim 1 in promoting the accumulation of saponins in Panax notoginseng roots.

4. The application according to claim 2, characterized in that: The application method is as follows: Seed cultures of fungi SQ T8 and SQ T10 were inoculated into PDA medium and cultured upside down in an incubator for activation. After activation, strains were picked and inoculated into PDA liquid culture medium for further culture. Centrifuge the bacterial culture to remove the culture medium, resuspend the bacterial cells in sterile water, determine the dilution factor, and prepare strains with concentrations of 10-1. 8 A mixed bacterial culture with cfu / mL; After the Panax notoginseng seedlings emerge, irrigate with a mixed bacterial solution.

5. The application according to claim 4, characterized in that: The method for determining the dilution factor is as follows: A standard curve was plotted based on the OD600 value of the bacterial culture and the bacterial concentration obtained by plate counting. The dilution factor was then determined based on the standard curve and the measured OD600 value.

6. The application according to claim 4, characterized in that: Each Panax notoginseng plant was irrigated with 200ml of mixed bacterial solution.

7. The application according to claim 3, characterized in that: When determining saponins in Panax notoginseng roots, the main root of Panax notoginseng was selected, dried at a constant temperature, ground into powder, sieved, and then the determination was carried out.

8. The application according to claim 2 or 3, characterized in that: The Panax notoginseng mentioned refers to two-year-old or three-year-old Panax notoginseng.

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