CN113243391A

CN113243391A - Sterilization composition containing Taishan mycin

Info

Publication number: CN113243391A
Application number: CN202110559422.2A
Authority: CN
Inventors: 王红艳; 武玉国; 姜莉莉; 王开运; 于颀; 王开元
Original assignee: Shandong Huitaihua Biotechnology Co ltd; Shandong Agricultural University
Current assignee: Shandong Huitaihua Biotechnology Co ltd; Shandong Agricultural University
Priority date: 2021-05-21
Filing date: 2021-05-21
Publication date: 2021-08-13
Anticipated expiration: 2041-05-21
Also published as: CN113243391B

Abstract

The invention provides a teshan mycin-containing bactericidal composition, which can be used for preventing and treating various oomycete diseases such as tomato/potato late blight, cucumber downy mildew, pepper phytophthora blight and the like, and crop seedling diseases such as damping-off of cotton and eggplants, has high application value and very obvious economic and social benefits, and can be widely applied to the field of agricultural production.

Description

Sterilization composition containing Taishan mycin

Technical Field

The invention belongs to the field of plant protection, relates to a bactericidal composition containing Mount Taishan mycin, and particularly relates to a bactericidal composition containing Mount Taishan mycin and used for preventing and treating oomycete diseases.

Background

Diseases caused by oomycetes fungi are a worldwide problem, occurring on many important vegetables and fruits. Important diseases include late blight of tomato and potato, downy mildew of grape, cucumber, etc., phytophthora capsici, etc. Oomycete diseases such as downy mildew, epidemic diseases and the like are very important diseases, and the loss caused by the oomycete diseases is not negligible. The pesticide cost for downy mildew and epidemic diseases of vegetables and melons in 1997 in China is 7.96 hundred million yuan, and accounts for 32.5 percent of the total cost of sixteen crops. Tens of thousands of people die due to hunger caused by the occurrence of potato late blight in foreign history. Because of the lack of effective disease-resistant varieties, chemical control is still one of the most effective methods for controlling oomycete diseases at present, but with unreasonable and frequent use of some systemic bactericides, the resistance problem is increasingly prominent. Therefore, it is necessary to solve the resistance by compounding.

Bactericides such as zineb, mancozeb, trifloxystrobin, cyazofamid, pyraclostrobin, dimethomorph and the like are medicaments for preventing and treating oomycete diseases in traditional production. However, long-term use of chemical pesticides brings problems of generation of resistance of bactericides, serious environmental pollution, food safety and the like. It is necessary to screen green and safe novel medicaments for preventing and treating oomycete diseases for application in agricultural prevention and control. Fluopyram (fluopicolide) is a novel pyridine amide systemic fungicide developed by Bayer company, and is mainly used for preventing and treating diseases caused by oomycete pathogenic bacteria such as downy mildew, epidemic diseases and the like. Fluopyram has a unique action mode, mainly acts on specific proteins between cell membranes and cells to express bactericidal activity, has no cross resistance with other bactericides, has good inhibitory activity on each main form of pathogenic bacteria, simultaneously has protection and treatment effects, and has good lasting effect. The fluopicolide has good systemic property, can be absorbed by stem leaves, is conducted from the lower part of a plant to the upper part of the plant, and is distributed to the whole plant along the xylem of the plant.

Disclosure of Invention

Aiming at the problem that the resistance of an oomycete control agent in the prior art is fast to generate, the invention provides the texanil-containing sterilization composition which can be used for controlling oomycete diseases of various vegetables and fruits such as cucumbers, grapes, peppers, potatoes and the like and has a synergistic effect.

In order to achieve the purpose, the invention adopts the following technical scheme.

A strain of Alternaria tenuissima (Alternaria alternata) The SDTF016 and the application of the fermentation liquor or the extract thereof in preventing and treating plant diseases caused by oomycetes, wherein the preservation number of the Alternaria tenuissima SDTF016 is CCTCC M2021495.

Preferably, the fermentation broth may or may not contain biomass. The thallus can be mycelium or spore.

The extract is an ethyl acetate extract of fermentation liquor of Alternaria tenuissima SDTF 016. The main effective components in the extract are dibutyl phthalate, 4-methyl-5-thiazole ethanol, 2-methoxy resorcinol, p-hydroxyphenol, 4-coumaric acid and nicotinic acid.

Preferably, the preparation method of the extract comprises the following steps:

(1) fermenting Alternaria tenuissima SDTF016 in a fungus fermentation broth to obtain a fermentation broth;

(2) filtering the fermentation liquor for sterilization and deproteinization to obtain filtrate;

(3) passing the filtrate through silica gel column with ethyl acetate as eluent to obtain effluent;

(4) and removing the eluent from the effluent to obtain a solid crude extract of the telithromycin.

More preferably, the above steps further comprise a process for further purifying the crude extract, comprising the steps of:

(i) dissolving the crude extract, separating by liquid chromatography, and collecting eluate with absorption peak at 214 nm wavelength;

(ii) removing solvent from the effluent to obtain the extract of telithromycin.

A bactericidal composition containing the extract comprises Mount Taishan mycin and bactericide A;

the bactericide A is selected from at least one of fluopicolide, fluoride ether bacteria amide, dimethomorph, fluthiazopyr, propamocarb hydrochloride, cyazofamid, metalaxyl-M, oxadixyl and cymoxanil.

Preferably, the mass ratio of the extract to the bactericide A is 1: 200-; preferably 1: 1000-.

Preferably, the content of the extract and the bactericide A in the composition is 1-100% (w/w); more preferably 20% to 55% (w/w).

Preferably, the composition also comprises other effective components, such as bactericides, insecticides or/and growth regulators, and is used for expanding the control spectrum, saving labor and facilitating application.

Preferably, the composition also comprises auxiliary materials, and the auxiliary materials can be fillers, solvents, disintegrants, thickeners, antifreezing agents, surfactants and the like, and are used for stably existing effective components and being easy to uniformly apply.

The invention has the following advantages:

the invention provides a teshan mycin-containing bactericidal composition, which can be used for preventing and treating various oomycete diseases such as tomato/potato late blight, cucumber downy mildew, pepper phytophthora blight and the like, and can also be used for preventing and treating crop seedling-stage diseases such as damping-off of crops such as cotton, eggplants and the like, has high application value and very obvious economic and social benefits, and can be widely applied to the field of agricultural production.

Biological preservation information

Alternaria tenuissima (A), (B), (C)Alternaria alternata) SDTF016, which is preserved in China center for type culture Collection (CGMCC) at 2021, 05 and 06 months, is preserved at the preservation number of CCTCC number M2021495 at the preservation center of Wuhan university in Wuhan, China.

Drawings

FIG. 1 is a transmission electron micrograph of hyphae of strain SDTF016 on a fungus culture medium;

FIG. 2 is a high performance liquid chromatogram of a crude extract of telithromycin.

Detailed Description

The present invention will be further described with reference to the following examples and drawings, but the present invention is not limited to the following examples.

Example 1 isolation and characterization of Alternaria tenuissima SDTF016

Soil of a farmland near Mount Taishan is collected in Taian City, and fungal strains are isolated therefrom. The specific separation and purification process comprises the following steps: weighing 10 g of sieved soil sample, placing the soil sample into a 250 mL sterilized triangular flask filled with 90 mL of sterile water and a small amount of glass beads, placing the triangular flask on a shaking table with the temperature of 37 ℃ and the speed of 180 rpm for 30 min to enable the triangular flask to be fully suspended, and diluting the suspension to 10 DEG with sterile water^-2-10^-5And 5 gradients are equal. Respectively sucking 1 mL of each gradient diluent into a 9cm culture dish, pouring 15 mL of improved Martin culture medium (containing 0.033 g/L of Bengal) cooled to about 45 ℃, horizontally shaking and uniformly mixing, repeating each gradient for 3 times, culturing in a constant-temperature incubator at 28 ℃ for 5-7 days, and then picking different single colonies and carrying out plate streaking purification. And screening the purified strains by taking various plant pathogenic bacteria as target bacteria to obtain a target strain with the best bacteriostatic effect, wherein the number of the target strain is SDTF 016. The bacteria are subjected to morphological identification and physiological and biochemical characteristic tests, and the hypha transmission electron microscope photos are shown in figure 1: the hyphae have smooth surface and bamboo-like growth, and are in discontinuous segmental stateThe top of the germinated hyphae grows outwards in a triangular shape, the strain does not produce spores under proper growth conditions, and the hyphae are exuberant and are distributed in clusters.

Extracting strain genome DNA by using an Ezup pillar type fungus genome DNA extraction kit (Shanghai biological engineering Co., Ltd.), carrying out PCR amplification on fungus ITS sequences by using universal primers ITS1 and ITS4 as primers to obtain a target band with the size of about 500 bp, and sequencing a PCR product. The length of the target gene is 557bp, the sequence obtained by sequencing is compared with the known genome sequence in GenBank for homology analysis, and the genome sequence with similar homology is selected for complete phylogenetic analysis and the phylogenetic tree of the strain is constructed. According to phylogenetic trees, the sequence consistency of the test strain sequence and the sequence of the alternaria tenuissima is 100 percent; and the phylogenetic tree analysis result shows that the test strain and the alternaria tenuissima mode strain are in the same branch and have the closest genetic distance and affinity relationship. Therefore, according to the observation result of a scanning electron microscope, physiological and biochemical tests and the analysis of ITS sequences, SDTF016 is finally identified as Alternaria tenuissima (A) (B)Alternaria alternata) Abbreviated as Taishan variant. The strain is preserved in China center for type culture Collection (CGMCC) at 2021, 05 and 06 months, with the preservation number of CCTCC M2021495.

Example 2 obtaining of fermentation broth of Alternaria tenuissima SDTF016 and extraction of fermentation product

Adopting a multi-factor orthogonal test to optimize fermentation conditions of the Taishan mountain variety (the composition and content of a culture medium carbon source, a nitrogen source and inorganic salt, the fermentation time is 12-120h, the fermentation temperature is 20-37 ℃, the rotation speed is 90-150 rpm), and adopting the following optimized conditions to perform fermentation: a punch with the diameter of 7 mm is used for punching a bacterial cake on the edge of a PDA plate bacterial colony of the Alternaria tenuissima SDTF016 strain, and the bacterial cake is inoculated on 150 mL of liquid fungus culture medium (MgSO 4)₄·7H₂O 0.5 g，K₂HPO₄1.0g, 5.0 g of peptone, 20 g of glucose, 2.0 g of yeast powder and 1.0L of water, wherein the pH = 7.0), 3 fungus cakes are inoculated into each bottle, and the mixture is subjected to constant temperature of 25 ℃ and shaking culture at 120 rpm for 36h to obtain a fermentation liquid of the alternaria tenuissima SDTF016 strain, and 5 batches of the fermentation liquid are subjected to parallel fermentation.

And (2) carrying out suction filtration on the fermentation liquor by using a vacuum pump to obtain hypha and degerming fermentation liquor, further passing the degerming fermentation liquor through a 0.2-micron membrane to obtain dark yellow transparent sterile fermentation liquor from which proteins and impurities are removed, adding the dark yellow transparent sterile fermentation liquor into a chromatographic column filled with 200-mesh and 300-mesh chromatographic silica gel, carrying out column chromatography by using ethyl acetate as a solvent, collecting effluent, combining the effluent according to an activity monitoring result, and evaporating the ethyl acetate of the collected transparent liquor to dryness at 40 ℃ by using a rotary evaporator to obtain a light yellow solid, namely a crude extract of a metabolite of the SDTF016 strain of the Alternaria tenuissima. The crude extract was dissolved in acetonitrile and analyzed by Agilent 1200 LC HPLC, and the peak appearance at 214 nm was shown in FIG. 2.

Dissolving the crude extract of metabolite of the Alternaria tenuissima SDTF016 strain with acetonitrile, and performing liquid chromatography on Shimadzu LC-20AP to prepare a sample, wherein the chromatographic column is DALIETER C₁₈Column (packing: sino chrom ODS-BP 1 μm; size: 10.00 mm. times.250 mm), ultraviolet absorption wavelength of 214 nm, mobile phase acetonitrile: water =40:60 (v/v), flow rate 4.0 mL/min, effluent-80 deg.C freeze-drying to obtain pure product of main component of metabolite of Alternaria tenuissima SDTF016, abbreviated as Taishan mycin.

The main components of the thaumatin comprise 6 types of dibutyl phthalate, 4-methyl-5-thiazole ethanol, 2-methoxy resorcinol, p-hydroxyphenol, 4-coumaric acid and nicotinic acid, which can be known by adopting ultra-high resolution liquid chromatography-mass spectrometry (UPLC-MS) and nuclear magnetic resonance spectrum analysis. The weight percentage of the 6 main components in the fermentation liquor is 0.01-0.05 wt%, the average content is 0.02%, and the fermentation liquor is a mixed active substance with the ultraviolet absorption wavelength of 214 nm.

Example 3 Effect of Alternaria tenuissima SDTF016 fermentation broth and extract on oomycete disease

The Alternaria tenuissima SDTF016 was fermented according to the fermentation method in example 2 to obtain a sterilized fermentation broth and to extract the Mount Taishan mycin. Preparing the Taishan mycin into solutions with different concentrations by 0.1% TX-100 aqueous solution, measuring the toxicity and EC of respectively inoculating cucumber downy mildew, grape downy mildew, tomato late blight, pepper phytophthora capsici and melon and fruit pythium after spraying the Taishan mycin with different concentrations₅₀Respectively 0.823 mg/L, 0.570 mg/L, 0.665 mg/L, 0.228 mg/L and 4.019 mg/L, which are obviously superior to 6.161 mg/L, 0.803 mg/L, 1.947 mg/L, 0.351 mg/L and 10.671 mg/L of the reference medicaments fluopicolide. The data show that the fermentation liquor and the extract of the Alternaria tenuissima SDTF016 have good control effect on plant diseases caused by oomycetes.

Example 4 fermentation broth of Alternaria tenuissima SDTF 016/Combined virulence of Taishan mycin and Fluopyram against cucumber downy mildew

Fermenting Alternaria tenuissima SDTF016 according to the fermentation method in example 2 to obtain sterile fermentation broth (with the content of Taishan mycin being about 0.022%) and extracting Taishan mycin, and preparing a 0.02% aqueous solution of Taishan mycin; then respectively diluting the fermentation liquor or the aqueous solution of the Taishan mycin by 500 times, diluting 50% fluopicolide Wettable Powder (WP) by 500 times with clear water, and then respectively mixing the fermentation liquor or the diluent of the Taishan mycin and the fluopicolide diluent in equal volume. Spraying cucumber seedlings to inoculate cucumber downy mildew bacteriaPseudoperonospora cubensis(Berk. et Curt.) Rotov.) is inoculated for 5 days, cucumber seedling spray fermentation liquor, telithromycin, fluopicolide + fermentation liquor and fluopicolide + telithromycin which have symptoms are selected, clear water is used as a reference, the disease index is counted, and the control effect of potted plants is calculated after 7 days.

TABLE 1 prevention and control of cucumber downy mildew by fermentation broth and combination of Taishan mycin and fluopicolide

The data in the table are counted by a new repeated polarization method, and the data containing the same letters are not obvious in difference.

The results are shown in table 1: the fermentation liquor and the 0.02 percent aqueous solution of the Taishan mycin are respectively diluted by 500 times and sprayed, and the control effect on the cucumber downy mildew reaches 55.0 to 60.5 percent 7 days after the treatment. 50 percent of fluopicolide WP is diluted by 500 times for spraying, and the control effect 7 days after the spraying is 71.3 percent. The fermentation liquor and the 0.02 percent aqueous solution of the Taishan mycin are respectively mixed with the fluopicolide for use, the dosage of the effective components is reduced by 1/2 compared with the single use, the two mixtures are respectively diluted by 500 times for spraying, the control effect after 7 days of treatment is 93.0 percent and 90.7 percent respectively, and the synergy is very obvious. This shows that, in the early stage of cucumber downy mildew, the sterilization of the mixture of fluopicolide and fermentation liquor or Taishan mycin shows good synergistic effect.

The Alternaria tenuissima SDTF016 is fermented according to the fermentation method in the embodiment 2 to obtain a degerming fermentation broth, the telithromycin is extracted, then the fluopicolide is prepared into a mother solution by using 1% of tween-80, then the telithromycin is added into the fluopicolide mother solution according to the conditions that the telithromycin and the fluopicolide are =1:1000-1:5000, and then the protection effect toxicity is measured by diluting the concentration of 5-7, and the co-toxicity coefficient (CTC) is calculated.

TABLE 2 Combined virulence of the protective action of Mount Tai mycin and Fluopyram on cucumber downy mildew

The results are shown in table 2: the Taishan mycin and fluopicolide are respectively mixed according to the ratio of 1:1000, 1:2000 and 1:4000 for protecting cucumber downy mildew EC₅₀1.3793mg/L, 1.4068mg/L and 1.4094 mg/L respectively, the co-toxicity coefficients respectively reach 167.5, 170.9 and 171.3, all exceed 150, and the synergy is very obvious.

Example 5 Combined virulence of Mount Taishan mycin and Fluopyram against Phytophthora infestans

Fermenting Alternaria tenuissima SDTF016 according to the fermentation method in example 2 to obtain sterilized fermentation liquor and extract Mount Taishan mycin, then preparing fluopicolide with 1% Tween-80 into mother liquor, then adding Mount Taishan mycin into the fluopicolide mother liquor according to Mount Taishan mycin: fluopicolide =1:400-1:5000, and then diluting 5-7 concentrations of Phytophthora infestans (Phytophthora infestans) (A. RTM.) and B. RTM.) respectivelyPhytophthora infestans (Mont.) De Bary) and calculating the co-toxicity coefficient (CTC).

TABLE 3 Combined virulence of Mount Taishan mycin and Fluopyram against Phytophthora infestans

The results are shown in Table 3: the Taishan mycin and the fluopicolide are respectively mixed according to the mass ratio of 1:400, 1:1000, 1:2000, 1:3000, 1:4000 and 1:5000, and the mixture has EC for phytophthora infestans₅₀1.3360 mg/L, 0.9524 mg/L, 0.9862 mg/L, 0.9970 mg/L, 1.0035 mg/L and 1.0113 mg/L respectively, the co-toxicity coefficients respectively reach 145.0, 143.2, 148.3, 149.9, 150.9 and 152.1, and the synergy is very remarkable. The two medicines are mixed to prevent and treat the late blight of the tomato or the potato, and the dosage of the medicine can be reduced and the medicine effect can be improved.

Example 6 Combined virulence of Mount Taishan mycin and Fluoroetheramid, Dimethomorph, Fluothiazolopyridinone, propamocarb hydrochloride, cyazofamid, metalaxyl, oxadixyl, cymoxanil against Pseudoperonospora cubensis

Fermenting Alternaria tenuissima SDTF016 according to the fermentation method in example 2 to obtain a degerming fermentation broth and extract the telithromycin, then preparing the mother liquor from the fluxafen, dimethomorph, fluthiazopyr, propamocarb hydrochloride, cyazofamid, metalaxyl, oxadixyl and cymoxanil respectively by using 1% of tween-80, then adding the telithromycin into the mother liquor of each medicament respectively according to the weight ratio of the telithromycin to the bactericide =1:100-1:5000 (w/w), and then diluting 5-7 for cucumber downy mildew (Pseudoperonospora cubensis) with each concentrationPseudoperonospora cubensis(Berk. et Curt.) Rotov.) virulence was determined by the leaf floatation method and the co-virulence factor (CTC) was calculated. The result shows that the mass ratio of the telithromycin to the fluoroether bacteria amide is 1:400-1:5000, the CTC is higher than 120, the synergy can be realized, and particularly, the CTC is higher than 150 when the mass ratio is 1:2000-1:4000, and the synergy is remarkable. The mass ratio of the telithromycin to the dimethomorph is 1:200-1:5000, the CTC is higher than 120, the synergy can be realized, and particularly, the CTC is higher than 150 when the ratio is 1:2500-1:5000, and the synergy is remarkable. The mass ratio of the Tashan mycin to the fluorothiazole pyrithylon (CTC) is 1:200-1:2500, which is higher than 150, the synergy can be remarkable, especially the CTC reaches up to 180 at 1:500-1:1250, and the synergy effect is very remarkable. The mass ratio of the Tlsamycin to the propamocarb hydrochloride is 1:1000-1:5000, and the CTC is higher than 120, so that the synergy can be realized, and particularly, the CTC is higher than 150 when the ratio is 1:2000-1:3000, and the synergy is remarkable. The mass ratio of the telithromycin to the cyazofamid is 1:200-1:2000, the CTC is higher than 120, the synergy can be realized, and especially, the CTC is close to or higher than 150 when the ratio is 1:500-1:1000, and the synergy is remarkable. Taishan mycin-metalaxylCTCs in the amount ratio of 1:200-1:3500 are all higher than 120, and can realize synergism, and especially CTCs in the amount ratio of 1:500-1:1500 are higher than 150, so the synergism is remarkable. The mass ratio of the telithromycin to the oxadixyl is 1:200-1:2000, and the CTC is higher than 150, so that the effect can be remarkably enhanced. The mass ratio of the telithromycin to the cymoxanil is 1:400-1:4000, the CTC is higher than 120, the synergy can be realized, and particularly, the CTC is higher than 150 when the ratio is 1:800-1:2000, and the synergy is remarkable.

Example 7 preparation of Mount Taishan mycin Fluopyram Suspension (SC)

Weighing the raw materials and the auxiliary agent according to the following formula by weight percent:

the filler in the formula can be white carbon black and diatomite; the wetting dispersant can be Morwet EFW, sodium dodecyl sulfate, EL80, agricultural milk No. 500; the thickener can be high-efficiency polysiloxane, xanthan gum, and magnesium aluminum silicate; the antifreezing agent is ethylene glycol; according to a conventional preparation method of the suspending agent, fluopicolide is subjected to gas flow pre-crushing, then is mixed with the telithromycin and part of the auxiliary agent, water is added to obtain slurry, then ball milling is carried out until the specified fineness is reached, and the rest auxiliary materials are added after discharging to prepare the suspending agent.

EXAMPLE 8 preparation of wettable powder of Thielaphm flutolanil (WP)

the filler in the formula can be white carbon black, diatomite, bentonite, kaolin, light calcium carbonate and attapulgite; the wetting agent can be Morwet EFW, sodium dodecyl sulfate, EL80, agricultural milk No. 500; the dispersant may be Morwet D-425, TERSPERSE 2700; according to the conventional preparation method of wettable powder, the original medicine and the auxiliary agent are prepared into the wettable powder after being pulverized by airflow.

Example 9 preparation of Mount Taishan mycin. metalaxyl suspension (WP)

the filler in the formula can be white carbon black, diatomite, bentonite, kaolin, light calcium carbonate and attapulgite; the wetting agent can be Morwet EFW, sodium dodecyl sulfate, EL80, agricultural milk No. 500; the dispersant may be Morwet D-425, TERSPERSE 2700; according to the conventional preparation method of wettable powder, metalaxyl is absorbed by partial filler, and then is subjected to airflow pulverization with the telithromycin and the auxiliary agent to prepare the wettable powder.

Example 10 preparation of Mount Tai mycin. cymoxanil wettable powder (SC)

the filler in the formula can be white carbon black and diatomite; the wetting dispersant can be Morwet EFW, sodium dodecyl sulfate, EL80, agricultural milk No. 500; the thickener can be high-efficiency polysiloxane, xanthan gum, and magnesium aluminum silicate; the antifreezing agent is ethylene glycol; according to a conventional preparation method of the suspending agent, cymoxanil, telithromycin and part of auxiliary agents are mixed and added with water to obtain slurry, then ball milling is carried out to specified fineness, and the rest auxiliary materials are added after discharging to prepare the suspending agent.

Example 11 preparation of aqueous Taishan mycin propamocarb hydrochloride (AS)

the emulsifier in the formula can be Morwet EFW, sodium dodecyl sulfate and Nongru No. 500; the antifreezing agent is ethylene glycol; according to the conventional preparation method of the aqueous solution, the Taishan mycin, the propamocarb hydrochloride, the emulsifier and the antifreeze are added with water, mixed uniformly and filtered, and then the mixture is discharged to obtain the aqueous solution of the Taishan mycin and the propamocarb hydrochloride.

Claims

1. A strain of Alternaria tenuissima (Alternaria alternata) The application of SDTF016 and fermentation liquor or extract thereof in preventing and treating plant diseases caused by oomycetes is characterized in that the preservation number of the Alternaria tenuissima SDTF016 is CCTCC M2021495.

2. The use according to claim 1, wherein the fermentation broth comprises or does not comprise bacteria; the extract is an ethyl acetate extract of fermentation liquor of Alternaria tenuissima SDTF 016.

3. The use according to claim 2, wherein the main active ingredients in the extract are dibutyl phthalate, 4-methyl-5-thiazoleethanol, 2-methoxyresorcinol, p-hydroxyphenylethanol, 4-coumaric acid and nicotinic acid.

4. A bactericidal composition containing an extract of Alternaria tenuissima SDTF016, which is characterized by comprising the extract and a bactericide A;

5. The composition as claimed in claim 4, wherein the mass ratio of the extract to the bactericide A is 1: 200-5000; preferably 1: 1000-.

6. The composition of claim 4, wherein the extract and the bactericide A are contained in the composition in an amount of 1% to 100% (w/w); more preferably 20% to 55% (w/w).

7. The composition according to claim 4, further comprising other active ingredients selected from bactericides, insecticides and/or growth regulators.

8. The composition of claim 4, further comprising an adjuvant.