CN114651825A - Macadimia nut stem canker inhibitor based on molecular disease resistance approach - Google Patents

Abstract

The invention belongs to the technical field of pesticides, and particularly relates to a macadimia nut stem canker inhibitor based on a molecular disease-resistant approach. The effective components of the macadimia nut stem canker inhibitor are compounded by fluorothiazole pyrithylone, triadimenol, metrafoxanyl or fenhexamid. When two active ingredients in the macadimia nut stem canker inhibitor are compounded, the inhibitor has no cross resistance, shows good synergistic interaction effect, can improve the control effect of the macadimia nut stem canker, reduce the application dosage of pesticide, and simultaneously can reduce pesticide residue. In addition, the molecular action mechanisms and action sites of the fluorothiazole pyrithylone and other effective components in the macadimia nut stem canker inhibitor are different, when the inhibitor is used, pathogenic bacteria are killed under the combined action of multiple sites, the generation of drug resistance of the pathogenic bacteria can be delayed, and the life cycle of the inhibitor can be prolonged.

Description

An inhibitor of macadamia stem canker based on molecular disease resistance pathway

technical field

The invention belongs to the technical field of pesticides, and in particular relates to a macadamia nut stem canker inhibitor based on a molecular disease resistance approach.

Background technique

Macadamia is a nut plant native to Macadamia, which not only has high economic value, but also has good nutritional value and medicinal value. Macadamia has many diseases and insect pests, with more than 30 kinds of diseases and more than 300 kinds of pests, among which the more serious diseases are blight, root rot, flower blight, anthracnose, canker and gray mold. Among them, macadamia nut stem canker is a disease caused by Phytophthora cinnamomi Rands infecting the base, stem and main branches of macadamia nut stems. The stems or branches near the ground are infected first, and the bark becomes brown and hard at the affected part. , cambium necrosis. The demarcation between sick and healthy is obvious, and then the center of the lesion is depressed, exuding dark brown viscose, and the surface is severely shrunken, forming ulcerative plaques. The xylem under the bark turns brown, and the bark of the diseased part cracks in the later stage; after the disease spot expands and surrounds the stem or side branches for a week, the leaves of the diseased tree turn green, dull, have poor growth, and become dwarfed. withered or the whole plant died.

In the process of planting, the commonly used chemical control methods are: scraping the necrotic bark and xylem tissue at the ulcer spot, using copper oxychloride slurry (25g/L) or the equivalent Bordeaux mixture (1:1:25 ) Coat the wound and bandage it, spray the stem with 1% equivalent Bordeaux mixture or 80% dichlorfen wettable powder and other chemical agents. However, due to the long-term application of a single chemical agent, the macadamia nut stem canker has developed different degrees of resistance to the currently used agents, resulting in poor control effects of the current agents.

Fluthiazopyridone is a piperidinylthiazoleisoxazoline fungicide with both protective and therapeutic activity. It achieves bactericidal effect by inhibiting the oxidative sterol binding protein, has a novel action site, and is highly effective against plant diseases caused by Oomycetes pathogens. Due to its novel mechanism of action, fluthiazopyridone can be used for resistance control strategies, but its single site of action makes it a medium-to-high level of resistance risk. The life cycle.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a kind of macadamia nut stem canker inhibitor based on molecular disease resistance approach, to solve the problem that macadamia nut stem canker has produced different degrees of drug resistance to the currently used medicament, resulting in poor control effect of the current medicament on it The problem.

For achieving the above object, the present invention provides the following technical solutions:

An inhibitor of macadamia nut stem canker based on molecular disease resistance pathway, the active ingredients of which are compounded from fluthiazolyl, pyridoxine and triadimefon, strobilurin or cyclosporin.

Preferably, the mass ratio of the fluthiazopyridine and triadimefon is 1-50:40-1.

Preferably, the mass ratio of the fluthiazopyridine and triadimefon is 1:5.

Preferably, the mass ratio of the fluthiazopyridone and onystrobin is 1-8:20-1.

Preferably, the mass ratio of the fluthiazopyridone and cycloramid is 1-5:16-1.

Compared with the prior art, the present invention has the following beneficial effects:

(1) When the two active ingredients in the macadamia nut stem canker inhibitor of the present invention are compounded, they have no cross-resistance and show a good synergistic effect, which can improve the control effect of macadamia nut stem canker and reduce pesticides The application dose can also reduce pesticide residues.

(2) In the macadamia nut stem canker inhibitor of the present invention, the molecular action mechanism and action site of fluthiazopyridone and other active ingredients are different. When used, multiple sites work together to kill pathogenic bacteria, which can delay the drug resistance of pathogenic bacteria It can also prolong the life cycle of the medicine.

Detailed ways

The technical solutions of the patent of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

Example

Test reagents: 95% fluthiazopyridone (Corteva Agricultural Science and Technology Co., Ltd.), 97% triadimefon (Jiangsu Jianpai Agrochemical Co., Ltd.), 95% fortylostrobin (Shenyang Chemical Research Institute Co., Ltd. Company), 98% cycloamide (Shaanxi Hengrun Chemical Industry Co., Ltd.).

The pathogenic bacteria to be tested: collected from the site of macadamia nut stem canker, isolated, purified and identified in the laboratory, determined to be Phytophthora cinnamomi Rands, and stored on PDA medium.

PDA medium: peeled potatoes 200g, glucose 20g, agar 20g and water 1000mL, natural pH value.

Test method (refer to "NY/T 1156.2-2006 Pesticide Indoor Bioassay Guidelines for Fungicides Part 2: Inhibition of Pathogenic Fungal Mycelium Growth Test Plate Method")

1. The test agent is first dissolved in dimethyl sulfoxide, and then diluted with 0.1% Tween-80 to prepare a single-dose mother solution, and multiple groups of proportions are set. Set up 5 gradient mass concentrations.

2. Add the pre-melted PDA medium into a sterile conical flask, and quantitatively draw the medicinal liquid from low concentration to high concentration, respectively, add it to the above conical flask, and shake well. Then, equal amounts were poured into 4 petri dishes with a diameter of 9 cm to prepare a drug-containing plate. At the same time, a blank control treatment without active ingredients was set, and each treatment was set up with 3 repetitions.

3. Use a sterilization punch with a diameter of 5mm to make holes at the edge of the tested bacteria colony to make a bacterium cake with a diameter of 5mm. Inoculate the fungus cake in the center of the drug-containing plate with an inoculator, with the hyphae facing up, cover the dish, and place it in an incubator at 25°C for cultivation.

4. When the diameter of the blank control colony reaches more than 2/3 of the diameter of the petri dish, use a caliper to measure the diameter of the colony, and measure the diameter of each colony vertically once by the cross method, and take the average value to calculate the bacteria in each treatment. Mycelial growth inhibition rate, using DPS software to perform regression analysis on the logarithm value of the agent concentration and the probability value of the mycelial growth inhibition rate, calculate the EC ₅₀ of each treatment agent, and calculate the co-toxicity coefficient (CTC value) of the mixture according to the Sun Yunpei method.

D=D ₁ -D ₂

In the above formula: D - colony growth diameter; D ₁ - colony diameter; D ₂ - bacterial cake diameter.

In the above formula: I--mycelium inhibition rate; D ₀ --blank control colony growth diameter; D _t -medicine-treated colony growth diameter.

Measured virulence index (ATI) = (standard drug EC ₅₀ / test drug EC ₅₀ ) × 100;

Theoretical Toxicity Index (TTI) = Toxicity Index of Agent A × Percentage of A in the mixture + Toxicity Index of Agent B × Percentage of B in the mixture;

Co-toxicity coefficient (CTC)=[measured toxicity index (ATI) of mixture/theoretical toxicity index (TTI) of mixture]×100.

The drug compounding was evaluated according to the co-toxicity coefficient: CTC≤80 was antagonistic effect; 80<CTC<120 was additive effect; CTC≥120 was synergistic effect. The results are shown in Table 1-3.

Table 1 The results of the indoor biological activity determination of Phytophthora camphorata by the combination of fluthiazolyl and triadimefon

Drug name and ratio EC₅₀(mg/L) ATI TTI CTC Fluthiazopyridone 1.07 100.00 -- -- Triadimenol 4.24 25.06 -- -- Fluthiazole Pyramidone 1: Triadimenol 40 2.46 43.50 26.89 161.78 Fluthiazole Pyramidone 1: Triadimenol 20 1.34 79.85 28.63 278.93 Fluthiazole Pyramidone 1: Triadimenol 10 0.75 142.67 31.87 447.63 Fluthiazole Pyramidone 1: Triadimenol 5 0.29 368.97 37.55 982.63 Fluthiazole Pyramidone 1: Triadimenol 1 1.12 95.54 62.53 152.79 Fluthiazopyridone 5: Triadimenol 1 0.90 118.89 87.51 135.86 Fluthiazole Pyramidone 10: Triazolol 1 0.64 167.19 93.19 179.41 Fluthiazole Pyramidone 30: Triazolol 1 0.42 254.76 97.58 261.07 Fluthiazole Pyramidone 50: Triadimenol 1 0.56 191.07 98.53 193.92

It can be seen from Table 1 that the co-toxicity coefficients of fluthiazopyridone and triadazole in the range of mass ratio of 1-50:40-1 are all greater than 120, indicating that after the combination of fluthiazopyridone and triadimefon It has a synergistic effect on Phytophthora cinnamomum. Especially when the mass ratio is 1:5, the co-toxicity coefficient reaches 982.63, and the synergistic effect is the most significant.

Table 2 The results of the indoor biological activity determination of Phytophthora camphorata by the combination of fluthiazole and pyraclostrobin

Drug name and ratio EC₅₀(mg/L) ATI TTI CTC Fluthiazopyridone 1.07 100.00 -- -- Onystrobin 6.19 17.29 -- -- Fluthiazopyridone 1: Styrax 20 3.54 30.23 21.22 142.41 Fluthiazole Pyramidone 1: Styrax 10 2.19 48.86 24.81 196.97 Fluthiazolyl Pyramidone 1: Styrax 5 1.59 67.30 31.07 216.58 Fluthiazole Pyramidone 1: Styrostrobin 1 1.07 100.00 58.64 170.52 Fluthiazole Pyramidone 2: Styrostrobin 1 0.57 187.72 72.43 259.18 Fluthiazole Pyramidone 4: Styrostrobin 1 0.24 445.83 83.46 534.21 Fluthiazole Pyramidone 8: Styrostrobin 1 0.82 130.49 90.81 143.69

It can be seen from Table 2 that the co-toxicity coefficients of fluthiazopyridone and onamostrobin in the range of mass ratio of 1-8:20-1 are all greater than 120, indicating that fluthiazopyridone and onamostrobin are complex. After matching, it showed a synergistic effect on Phytophthora cinnamomum.

Table 3 The results of the indoor biological activity determination of Phytophthora camphorata by the combination of fluthiazolyl and pyraclostrobin

It can be seen from Table 3 that the co-toxicity coefficients of fluthiazopyridone and cyclospiramide in the range of mass ratio of 1-5:16-1 are all greater than 120, indicating that fluthiazolyl and sulfasalazine are complex. After matching, it showed a synergistic effect on Phytophthora cinnamomum.

To sum up, when the fluthiazolyl-pyridone of the present invention is compounded with triadimefon, fenoxystrobin or cycloamide, it exhibits a synergistic effect within a certain mass ratio range, and can improve the resistance to Phytophthora cinnamomea. Prevention and control of macadamia nut stem canker caused by infection.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and illustration. These descriptions are not intended to limit the invention to the precise form disclosed, and obviously many changes and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described for the purpose of explaining certain principles of the invention and their practical applications, to thereby enable others skilled in the art to make and utilize various exemplary embodiments and various different aspects of the invention. Choose and change. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims (5)

1. The macadimia nut stem canker inhibitor based on a molecular disease-resistant approach is characterized in that the effective components of the inhibitor are compounded by fluorothiazole pyrithylone, triadimenol, and metrafoxanil or fenhexamid.

2. The macadimia nut stem canker disease inhibitor according to claim 1, wherein the mass ratio of the fluorothiazolopyrone to the triadimenol is 1-50: 40-1.

3. The macadimia nut stem canker disease inhibitor according to claim 2, wherein the mass ratio of the fluorothiazolopyrone to the triadimenol is 1: 5.

4. the macadimia nut stem canker disease inhibitor according to claim 1, wherein the mass ratio of the fluorothiazolepyrithylone to the mefenamate is 1-8: 20-1.

5. The macadimia nut stem canker inhibitor according to claim 1, wherein the mass ratio of the fluorothiazolopyrone to the fenhexamid is 1-5: 16-1.