New application of tagatose

Abstract

The invention discloses a novel application of tagatose. The tagatose has an inhibition effect on any one or more than two of Alternaria panax, Cylindachton destruccs, Fusarium oxysporum and Fusarium solani, and the tagatose has an inhibition effect on any one or more than two of the Alternaria panax, the Cylindachton destruccs, the Fusarium oxysporum and the Fusarium solani, and also has an inhibition effect on any one or more than two of the Alternaria panax, the Cylindachton destruccs, the Fusarium oxysporum and the Fusarium solani. The tagatose disclosed by the invention has a relatively good inhibition effect on main pathogenic fungi of panax notoginseng root rot, and can inhibit alternaria alternata, destroy cylindrosporium, fusarium oxysporum and fusarium solani.

Description

Technical Field

[0001] The present invention relates to the inhibition of pathogenic bacteria by tagatose, and in particular to a new use of tagatose. Background Art

[0002] Panax notoginseng is a traditional precious Chinese medicinal material. It is a perennial herbaceous crop of the genus Panax in the Araliaceae family. It likes warm and humid weather. In agricultural production, the diseases of Panax notoginseng, especially root rot, are very prominent and have become a serious obstacle to the development of Panax notoginseng planting industry.

[0003] At present, the main method for treating Panax notoginseng root rot is chemical control. Chemical control not only brings about problems such as environmental pollution and drug resistance, but pesticide residues have also become an important factor affecting its drug efficacy, safety and product exports.

[0004] Rare sugars are a class of monosaccharides such as sorbitol, tagatose, xylose, and xylitol and their derivatives that occur in small quantities in the environment. Among rare sugars, tagatose is a ketohexose that is used as a low-calorie sweetener to replace sucrose. Tagatose can inhibit the growth of various plant pathogens, such as tomato and potato late blight (Phytophthora infestans) (The rare sugar tagatose differentially inhibits the growth of Phytophthora infestansand Phytophthora cinnamomi by interfering with mitochondrial processes. Front. Microbiol. 2020, 11, 128), cucumber downy mildew (Pseudoperonosporacubensis), wheat Fusarium wilt (Puccinia recondita) (Plant disease control agent comprising D-tagatose as active ingredient, and plant disease control method, EP patent, publication number: EP2329713A1; The rare sugar D-tagatose protects plants from downy mildews and is a safe fungicidal agrochemical. Commun. Biol. 2020, 3, 1-15; Ecological impact of agarose on grapevine phyllosphere microbialcommunities.Microbiol.Res.2020,232,126387). At present, there is no report on the inhibitory effect of tagatose on the pathogenic bacteria of Panax notoginseng root rot. Summary of the invention

[0005] The purpose of the present invention is to provide a new use of tagatose, which can have a good prevention and treatment effect on Panax notoginseng root rot.

[0006] In order to achieve the above object, the present invention provides a new use of tagatose, which has an inhibitory effect on any one or more of Alternaria panax, Cylindrocarpon destructans, Fusarium oxysporum and Fusarium solani.

[0007] Preferably, tagatose is used to prevent and treat Panax notoginseng root rot.

[0008] Preferably, the mass concentration of tagatose is 150-300 mg·L -1 .

[0009] Preferably, the administration amount of tagatose is 20 mL / plant.

[0010] Preferably, tagatose is poured onto the roots of Panax notoginseng.

[0011] Preferably, tagatose is poured from the base of the Panax notoginseng stem to the root by root irrigation.

[0012] The new use of tagatose of the present invention has the following advantages:

[0013] The tagatose of the present invention has a good inhibitory effect on the main pathogenic fungi of Panax notoginseng root rot, and can inhibit Alternaria, Columnar spores, Fusarium oxysporum, and Fusarium solani, and has an EC inhibitory effect on the growth of mycelium of Alternaria, Columnar spores, Fusarium oxysporum, and Fusarium solani. 50 The values ​​are 34.8260, 36.2312, 26.3171 and 33.8326 mg / L respectively.

[0014] The tagatose of the present invention has a good control effect on Panax notoginseng root rot. Compared with the existing chemical agents (carbendazim and sclerotinol are used alternately), tagatose can significantly reduce the disease index of Panax notoginseng root rot. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] The experimental materials used in the following experimental examples are as follows:

[0017] (1) Panax notoginseng for testing: The experimental research was conducted at the Institute of Medicinal Plants, Yunnan Academy of Agricultural Sciences. Normal, undamaged, disease-free, and uniform-sized Panax notoginseng seeds that had been sown for 18 months were selected and cultivated in potted plants (33 cm in diameter × 20 cm in height) in a steel frame shed to avoid rain, with 3 plants per pot. The potting soil used was new soil that had not been used to grow Panax notoginseng.

[0018] (2) Test strains: Alternaria panax, Cylindrocarpondestructans, Fusarium oxysporum, and Fusarium solani.

[0019] Experimental Example 1 Determination of the biological activity of tagatose against pathogenic fungi

[0020] The pathogens of Panax notoginseng root rot are mainly fungi. This experiment intends to use the main pathogenic fungi of Panax notoginseng root rot, Alternaria panax, Cylindrocarpon destructans, Fusarium oxysporum, and Fusarium solani as representative strains to study the inhibitory activity of tagatose on the pathogens of Panax notoginseng root rot, in order to provide a theoretical basis for the prevention and control of the disease.

[0021] (1) Determination by mycelium growth rate method

[0022] First, tagatose was prepared into a mother solution with sterile water for standby use, and then diluted into a series of mass concentrations of the drug with sterile water. In the clean bench, potato dextrose agar medium (PDA) and the drug were evenly mixed at a volume ratio of 9:1, that is, 5 mL of the drug that had been prepared to the corresponding concentration was added to a conical flask containing 45 mL of PDA medium, and the mixed drug-containing medium was poured into a culture dish, ventilated and cooled to solidify, and a drug-containing plate was made, and each treatment was repeated 3 times. The mass concentration of tagatose in the drug-containing medium was 10, 20, 40, 80, and 100 mg / L, respectively.

[0023] According to the above method, 5 mL of sterile water was added to 45 mL of PDA medium to prepare the control group medium.

[0024] Use a sterile puncher to punch out a bacterial cake with a diameter of 5 mm on the pathogen plate, and then inoculate the bacterial cake into the culture dish containing the above-mentioned drug-containing culture medium or the control group culture medium. The culture dish is sealed with a sealing film and placed in a constant temperature culture at 28°C. After 7 days, the colony diameter is measured and recorded using the cross method, and the inhibition rate is calculated according to the following formula.

[0025] Inhibition rate (%) = [(control colony diameter - treated colony diameter) / control colony diameter] × 100

[0026] The pesticide indoor bioassay data processing system software was used to calculate the toxicity regression curve equation of each agent against different pathogens, and the correlation coefficient r, effective inhibition concentration EC 50 wait.

[0027] (2) Experimental results

[0028] The results of the biological activity of tagatose against four main pathogenic fungi of Panax notoginseng root rot are shown in Table 1. As the concentration of tagatose treatment increased, its inhibitory activity against the mycelial growth of the four pathogenic fungi was significantly enhanced. The logarithm of the tagatose mass concentration and its inhibition rate on the mycelial growth of pathogenic fungi showed a good linear relationship. The EC value of tagatose for inhibiting the mycelial growth of Alternaria alternata, Columnar spore of destructor, Fusarium oxysporum, and Fusarium solani calculated by the biological activity equation was 50 The values ​​are 34.8260, 36.2312, 26.3171 and 33.8326 mg / L respectively.

[0029] Table 1 Biological activity of tagatose against pathogenic fungi of Panax notoginseng

[0030]

[0031] Experimental Example 2: Test on the efficacy of tagatose in preventing Panax notoginseng root rot in potted plants

[0032] (1) Potted plant protection test

[0033] Two treatments were set for tagatose application concentration, namely T1 (150 mg / L) and T2 (300 mg / L); the positive control (CK) was the alternating application of chemical agents carbendazim (500 mg / L) and sclerotium net (400 mg / L); the negative control (CK0) was the application of clean water. Each treatment had 10 pots, 3 plants per pot, completely randomly arranged, and repeated 3 times.

[0034] The test agent was diluted according to the above concentration. After dilution, the root irrigation method was used to irrigate the roots along the stem base of Panax notoginseng, and the application amount was 20mL / plant. The pesticide was applied 6 times on May 10, June 8, July 3, August 10, September 4, and September 27, 2020.

[0035] The four pathogens were activated, inoculated into PDA culture medium and cultured in the dark at 25°C. 25g of mycelium was scraped from the culture medium plate, mixed into 100g, and diluted with water to 100g / L. 10mL was poured on the roots of Panax notoginseng. The first, second, and third pathogen inoculations were carried out on May 11, June 8 (inoculated with pathogens after the application of the agent), and July 4, 2020, respectively. The inoculation was stopped on July 23 when Panax notoginseng began to show obvious symptoms.

[0036] On July 23, the Panax notoginseng plants began to show obvious signs of disease, and the first disease survey was conducted. The second, third, fourth, and fifth disease surveys were conducted on August 10, September 4, September 27, and October 27, respectively. The field classification standards for Panax notoginseng root rot are as follows:

[0037] 1) Level 0, healthy, asymptomatic;

[0038] 2) Level 1: 1 to 2 leaves are affected, with less than 3 lesions, and the leaves do not fall off;

[0039] 3) Level 3: 3 to 5 leaves are infected, and 1 to 2 leaflets fall off;

[0040] 4) Level 5: one compound petiole is infected, only the inflorescence and rachis are infected, and half of the total number of leaves on the plant fall off;

[0041] 5) Level 7: The plant's flower moss is diseased, but the leaves are not diseased; 2 / 3 of the leaves are diseased, the lesions are large, or 2 / 3 of the petioles are diseased;

[0042] 6) Level 9: The above-ground parts are dead or only the stems are left.

[0043] The calculation methods of disease index and control effect are as follows.

[0044] Disease index = ∑ (number of plants at each disease level × number of disease levels) / highest disease level × total number of plants × 100

[0045] Control effect (%) = control disease index - treatment disease index / control disease index × 100

[0046] The experimental data were statistically analyzed using SAS 9.1 and Origin 9.1 software, and Duncan's new multiple range method was used to test the significance of differences among multiple samples (P<0.05).

[0047] (2) Test results

[0048] As shown in Table 2, tagatose of different mass concentrations has a good control effect on Panax notoginseng root rot. There is no significant difference in the control effect of tagatose mass concentrations of 150 and 300 mg / L on Panax notoginseng root rot, and both are better than the chemical control (carbendazim and sclerotinia net used alternately). Therefore, tagatose can significantly reduce the disease index of Panax notoginseng root rot.

[0049] Table 2 The potted plant protective effect of tagatose on Panax notoginseng root rot

[0050]

[0051] Note: The differences are not significant if there is one identical letter, and are significant if there are different letters. Different lowercase letters after the same value indicate that the difference between treatments is significant at the 5% level.

[0052] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A new use of tagatose, characterized in that: Tagatose has an inhibitory effect on any one or more of Alternaria panax, Cylindrocarpon destructans, Fusarium oxysporum, and Fusarium solani.

2. The new use according to claim 1, characterized in that: Tagatose can prevent and treat Panax notoginseng root rot.

3. The new use according to claim 2, characterized in that: The mass concentration of tagatose is 150~300mg·L -1 .

4. The new use according to claim 3, characterized in that: The application amount of tagatose was 20 mL / plant.

5. The new use according to claim 2, characterized in that: Pour tagatose onto the roots of Panax notoginseng.

6. The new use according to claim 5, characterized in that: Use the root irrigation method to sprinkle tagatose from the base of the Panax notoginseng stem to the roots.

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