Application of nerolidol in prevention and treatment of soybean root rot

Abstract

The invention discloses application of nerolidol in prevention and treatment of soybean root rot, and relates to the technical field of crop protection. Nerolidol has an inhibition effect on the growth of hyphae of four pathogenic bacteria of soybean root rot, has a better inhibition effect on fusarium tripteroides and phytophthora sojae, has a slightly poor inhibition effect on phomopsis and fusarium oxysporum, and has a very poor effect on shared fusarium; pharmacodynamic tests of potted plants show that the treatment of spraying metabolites in advance promotes the growth of soybean seedlings along with the increase of the concentration, the plant height, root length and other physiological indexes of the soybean seedlings are all higher than those of the treatment of not inoculating pathogenic bacteria, the disease index of the soybean seedlings is obviously reduced, and the control effect of the treatment of 10 mu g / mL nerolidol at 20 days reaches 60% or above and is slightly higher than that of fludioxonin.

Description

Technical Field

[0001] The invention relates to the technical field of crop protection, and more particularly to the application of nerolidol in preventing and treating soybean root rot. Background Art

[0002] At present, soybean is an important economic and oil crop. Soybean root rot is mainly caused by fungal and oomycete infection. Generally, the yield of the field is reduced by 10%-30%, and the yield of the seriously diseased field is reduced by more than 60%. In severe cases, it may even cause a total loss of yield. Among them, pathogens such as Phytophthora sojae, Fusarium oxysporum, and Phomopsis oxysporum are the dominant species that cause soybean root rot in many places. Therefore, it is very necessary to develop control agents for Phytophthora trilineata, Phytophthora sojae, Phomopsis oxysporum, and Fusarium oxysporum.

[0003] However, the mainstream agents currently used to prevent and control this disease on the market are all chemical fungicides, which are prone to develop drug resistance and can also cause the soil microbial environment to deteriorate, which is not conducive to the healthy and sustainable development of the soybean planting industry.

[0004] Therefore, developing a new soybean root rot prevention and control formulation is a problem that those skilled in the art need to solve urgently. Summary of the invention

[0005] In view of this, the present invention provides the use of nerolidol in preventing and treating soybean root rot.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] Application of nerolidol in controlling soybean root rot.

[0008] Furthermore, the pathogenic bacteria of soybean root rot include: Fusarium trilineatum, Phytophthora sojae, Phomopsis spp., and Fusarium oxysporum.

[0009] A composition for preventing and treating soybean root rot. The composition uses nerolidol or at least one of its derivatives as an effective component and is prepared into a suitable prevention and treatment agent with auxiliary materials.

[0010] Furthermore, the composition is in the form of any one of emulsifiable concentrate, suspension concentrate, water dispersible granules, wettable powder and aqueous emulsion.

[0011] It can be seen from the above technical solution that, compared with the prior art, the beneficial effects of the present invention are:

[0012] Nerolidol has an inhibitory effect on the growth of mycelium of four pathogens of soybean root rot, among which the inhibitory effect on Fusarium trilineatum and Phytophthora sojae is better, the inhibitory effect on Phomopsis spp. and Fusarium oxysporum is slightly worse, and the effect on Fusarium spp. is extremely poor. Through potted efficacy tests, it can be seen that the treatment of pre-spraying metabolites promotes the growth of soybean seedlings as the concentration increases. Its physiological indicators such as plant height and root length are higher than those of the treatment without pathogen inoculation, and its disease index is significantly reduced. At 20 days, the prevention effect of 10μg / mL nerolidol treatment reached more than 60%, which is slightly higher than that of mechlorethamine. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0014] Figure 1 The effect of nerolidol on the mycelial growth of five soybean root rot pathogens; Figure 1 A is Phomopsis longicolla; Figure 1 B is Fusarium tricinctum; Figure 1 C is Fusarium oxysporium; Figure 1 D is Phytophthora sojae; Figure 1 E stands for shared Fusarium (F. commune);

[0015] Figure 2 This is a pot test of the control effect of nerolidol on four soybean root rot pathogens; Figure 2 A is Fusarium trilineatum; Figure 2 B is Phomopsis; Figure 2 C is Fusarium oxysporum; Figure 2 D is soybean phytophthora; fungicide: meclodiclofop-S-butyl. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0017] Example 1

[0018] Determination of the inhibitory effect of nerolidol on five soybean root rot pathogens

[0019] After dissolving nerolidol in methanol, a 1 mg / mL mother solution was prepared. After filtering and sterilizing with a 0.22 μm sterile organic filter membrane, a certain amount of the mother solution was added to the culture medium to make the concentration reach 0.5 μl / ml and 1 μl / ml, respectively. A water control was set, and each treatment concentration was repeated 3 times. After culturing three-line Fusarium, sharp Fusarium and Phomopsis on PDA plates, and soybean Phytophthora on carrot agar medium (CA medium) plates for 5 days, they were beaten into fungi (7 mm in diameter) and transferred to the target metabolite medium plate. After culturing for 5 days in a dark environment at 26°C, the colony diameter was measured, and each treatment was repeated 3 times. The mycelial growth inhibition rate was calculated.

[0020] Table 1 Effects of nerolidol on the mycelial growth of five soybean root rot pathogens

[0021]

[0022] from Figure 1 As shown in Table 1, nerolidol has a certain inhibitory effect on the mycelial growth of the five soybean root rot pathogens, but there are significant differences in the inhibitory effect. For Phomopsis longicolla, Fusarium tricinctum, F.oxysporium and Phytophthora sojae, a single treatment reached more than 30%, while the inhibitory effect on F.commune was poor. In summary, with the increase in the mass concentration of the metabolite nerolidol, the inhibitory effect on the mycelial growth of some soybean root rot pathogens was significantly enhanced.

[0023] Example 2

[0024] Pot test of the efficacy of nerolidol against soybean root rot caused by four pathogens

[0025] On the 2nd and 7th day after the pathogens were inoculated in soil using infected sorghum kernels (Fusarium oxysporum, Fusarium trilineatum and Phomopsis spp.) and CA fungus discs (Phytophthora sojae), soybean seedlings were irrigated with fludioxonil and different concentrations (CK, 2, 5 and 10 μg / mL) of nerolidol. After 20 days, the plant height, fresh weight, root length and emergence rate of soybean seedlings were investigated. The effects of different concentration treatments were significantly different (P<0.05).

[0026] 1. Effects of nerolidol on Fusarium trilineatum

[0027] Different concentrations of nerolidol treatment had a significant growth-promoting effect on soybean seedlings inoculated with Fusarium trilineatum, and the emergence rate, plant height, root length and root fresh weight of soybean seedlings increased with the increase of treatment concentration, reaching the maximum value when the treatment concentration was 10 μg / mL, with a germination rate of 91.67%, a plant height of 17.17 cm, a stem diameter of 3.13 mm, a root length of 14.50 cm, and a root fresh weight of 1.56 g; at the same time, the control effect at this concentration reached 62.81% (Table 2, Figure 2 A).

[0028] Table 2 Potted plant test of the efficacy of nerolidol on soybean root rot caused by Fusarium trilineatum

[0029]

[0030] Note: The least significant difference (LSD) method was used to compare the treatment groups (P<0.05).

[0031] 2. Effects of nerolidol on Phomopsis

[0032] Different concentrations of nerolidol treatment had a certain inhibitory effect on Phomopsis spp. and also had a certain growth-promoting effect on soybean plants. The highest value was reached when the treatment concentration was 10 μg / mL, and the plant height and root length of the soybean plants were 19.57 cm and 9.67 cm, respectively. Under this concentration treatment, the germination rate and root fresh weight of the soybean plants were also the largest, which were 91.67% and 1.45 g, and the control effect at this concentration reached 65.28%, but the stem diameter reached a maximum of 3.03 mm at 5 μg / mL (Table 3, Figure 2 B).

[0033] Table 3 Potted test of the efficacy of nerolidol on soybean root rot caused by Phomopsis

[0034]

[0035] Note: The least significant difference (LSD) method was used to compare the treatment groups (P<0.05).

[0036] 3. Effect of nerolidol on Fusarium oxysporum

[0037] Different concentrations of nerolidol treatment had a growth-promoting effect on soybean seedlings inoculated with Fusarium oxysporum. The plant height, root length and underground fresh weight of soybean seedlings increased with the increase of treatment concentration. The highest values ​​were reached when the treatment concentration was 10 μg / mL, with a germination rate of 83.33%, a plant height of 25.50 cm, a stem diameter of 3.03 mm, a root length of 14.10 cm, and a root fresh weight of 1.25 g. The protective effect at this concentration reached 70.23% (Table 4, Figure 2 C).

[0038] Table 4 Potted plant test of the efficacy of nerolidol on soybean root rot caused by Fusarium oxysporum

[0039]

[0040]

[0041] Note: The least significant difference (LSD) method was used to compare the treatment groups (P<0.05).

[0042] 4. Effects of nerolidol on Phytophthora sojae

[0043] For soybean seedlings inoculated with soybean Phytophthora, the antagonistic growth-promoting effect of nerolidol solution treatment was basically consistent with the trend of Fusarium and Phomopsis. The emergence rate, plant height, root length and underground fresh weight of soybean seedlings increased with the increase of treatment concentration, and reached the highest value when the treatment concentration was 10 μg / mL, which were 87.50% for emergence rate, 21.67 cm for plant height, 3.17 mm for stem diameter and 15.33 cm for root length. The protection effect at this concentration reached 65.59%; the underground fresh weight was the largest at 5 μg / mL, which was 1.23 g (Table 5, Figure 2 D).

[0044] Table 5 Potted plant test of the efficacy of nerolidol on soybean root rot caused by Phytophthora sojae

[0045]

[0046]

[0047] Note: The least significant difference (LSD) method was used to compare the treatment groups (P<0.05).

[0048] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. Application of nerolidol in preventing and controlling soybean root rot.

2. The use according to claim 1, characterized in that: The pathogenic bacteria of soybean root rot include: Fusarium trilineatum, Phytophthora sojae, Phomopsis spp., and Fusarium oxysporum.

3. A composition for preventing and controlling soybean root rot, characterized in that: The composition uses at least one of nerolidol or its derivatives as an effective component and is prepared into a suitable control agent by combining with auxiliary materials.

4. The composition according to claim 3, characterized in that The composition is present in the form of any one of emulsifiable concentrate, suspension, water-dispersible granules, wettable powder and aqueous emulsion.

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