Rossellomorea marisflavi and applications thereof

Abstract

The application provides a strain of Rossellomorea marisflavi and an application thereof, and belongs to the technical field of crop prevention and treatment. The Rossellomorea marisflavi is Rossellomorea marisflavi zju1, which has been preserved in the China Center for Type Culture Collection on August 14, 2023, and the preservation number is CCTCC NO: M 20231484. The Rossellomorea marisflavi can obviously promote the growth of crops, increase the resistance of crops to Spodoptera frugiperda, and reduce the growth rate and the feeding area of Spodoptera frugiperda on leaves. The application further prepares a biocontrol agent containing the Rossellomorea marisflavi, and the agent is harmless to the environment and has high safety, and cannot cause environmental pollution.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of crop prevention, and particularly relates to a strain of Rossellomorea marisflavi and application thereof. BACKGROUND

[0002] Spodoptera frugiperda belongs to Lepidoptera Noctuidae, mainly harms corn, and its larvae gather in corn fields and can harm corn at each growth and development stage of corn seedling stage, jointing stage, big trumpet stage, male stage, flowering and silk stage and mature stage, seriously affecting the growth and development of corn, and is a major migratory pest causing corn quality and yield reduction.

[0003] At present, the prevention and control method for Spodoptera frugiperda mainly is chemical prevention and control, that is, spraying chemical pesticides. Although chemical prevention and control can reduce the number of Spodoptera frugiperda to a certain extent, it is easy to cause environmental pollution and pesticide residues, and threatens human health, therefore, it is very important to use environmentally friendly biological means.

[0004] In addition, since the soil itself contains various microorganisms, including beneficial microorganisms and unfavorable microorganisms for plants, and plants and rhizosphere microorganisms form a complex interactive network. Therefore, if a microorganism capable of enhancing plant resistance can be isolated and screened from the soil, effective biological control can be carried out. SUMMARY

[0005] Therefore, the purpose of the application is to provide a strain of Rossellomorea marisflavi and application thereof. The Rossellomorea marisflavi provided by the application can obviously promote the growth of crops and reduce the growth performance and feeding performance of Spodoptera frugiperda on crops.

[0006] To achieve the above purpose, the application provides the following technical solutions.

[0007] The application provides a strain of Rossellomorea marisflavi, which is Rossellomorea marisflavi zju1, and has been preserved in China Center for Type Culture Collection (CCTCC) on August 14, 2023, with a preservation number of CCTCC NO: M 20231484.

[0008] The application also provides a biocontrol agent, which comprises the Rossellomorea marisflavi.

[0009] Preferably, the biocontrol agent is a liquid bacterial agent, wherein the viable cell count of Rossellomorea marisflavi in the liquid bacterial agent is 1.70-1.80 x 10 8 CFU / ml.

[0010] The application also provides a method for using the biocontrol agent, wherein the biocontrol agent is directly applied on the surface of soil in use, the use amount of the biocontrol agent is 8-12 ml / pot, the volume of the pot is 350-450 ml, the application frequency of the biocontrol agent is 1-2 times, and the application time of the biocontrol agent is 3-8 days after corn is sowed.

[0011] The application also provides an application of the biocontrol agent in preventing and treating Spodoptera frugiperda.

[0012] The application also provides an application of the biocontrol agent in improving the resistance of crops to Spodoptera frugiperda.

[0013] The application also provides an application of the biocontrol agent in promoting the growth of crops.

[0014] Preferably, the crop is corn.

[0015] The application also provides an application of the biocontrol agent in inhibiting the growth of Spodoptera frugiperda.

[0016] Compared with the prior art, the application has the following beneficial effects:

[0017] The application separates a strain of Rossellomorea marisflavi, which can obviously increase the resistance of corn to Spodoptera frugiperda, and specifically, the weight of the insect increases slowly and the loss area of the corn leaf is small in the same time. The strain provided by the application is harmless to the environment and has excellent potential in improving the resistance of corn to Spodoptera frugiperda and other lepidopteran pests and promoting the growth of corn. Meanwhile, the application also prepares a biocontrol agent containing Rossellomorea marisflavi, which is harmless to the environment and has high safety and will not cause environmental pollution. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a schematic diagram of a potting experiment device;

[0019] Figure 2 It is a result of the leaf feeding area of Spodoptera frugiperda;

[0020] Figure 3 It is a daily average weight gain multiple of Spodoptera frugiperda;

[0021] Figure 4 It is a result of the measured biomass of the above-ground part of corn plants.

[0022] Biological preservation instructions

[0023] Rossellomorea marisflavi zju1, which was preserved in China Center for Type Culture Collection (CCTCC) on August 14, 2023, and the preservation number is CCTCC NO: M20231484. DETAILED DESCRIPTION

[0024] The application provides a strain of Rossellomorea marisflavi, which is Rossellomorea marisflavi zju1, which was preserved in China Center for Type Culture Collection (CCTCC) on August 14, 2023, and the preservation number is CCTCC NO: M20231484.

[0025] The application further provides a biocontrol agent, which comprises the Rossellomorea marisflavi.

[0026] In the application, the biocontrol agent is preferably a liquid bacterial agent, and the viable bacterial count of the Rossellomorea marisflavi in the liquid bacterial agent is preferably 1.70-1.80 x 10 8 CFU / ml.

[0027] The application further provides a use method of the biocontrol agent, wherein the biocontrol agent is directly applied to the surface of soil.

[0028] In the application, the use amount of the biocontrol agent is preferably 8-12 ml / pot, further preferably 9-11 ml / pot, and more preferably 10 ml / pot; the volume of the pot is preferably 350-450 ml, further preferably 380-420 ml, and more preferably 400 ml; the application frequency of the biocontrol agent is preferably 1-2 times; and the application time of the biocontrol agent is preferably 3-8 days after corn sowing, further preferably 4-6 days, and more preferably 5 days.

[0029] The application further provides application of the biocontrol agent in prevention and treatment of Spodoptera frugiperda pest.

[0030] The application further provides application of the biocontrol agent in improving the resistance of crops to Spodoptera frugiperda.

[0031] The application further provides application of the biocontrol agent in promoting the growth of crops.

[0032] In the application, the crop is preferably corn.

[0033] The application also provides application of the biocontrol agent in inhibiting growth of Spodoptera frugiperda.

[0034] The technical solutions provided by the application are described in detail below in combination with examples, but they should not be understood as limiting the protection scope of the application.

[0035] Example 1

[0036] Rossellomorea marisflavi zju1 was inoculated into LB solid culture medium, activated at 30°C for 20h, and inoculated into LB liquid culture medium by picking single colonies, cultured at 30°C and 180r / min for 20h, centrifuged at 8°C and 5000r / min for 5min, the bacterial bodies were collected, washed twice with sterile water, and then adjusted to OD 600 value of 1.0, and obtained biocontrol agent with viable bacterial count of 1.73x10 8 CFU / ml.

[0037] Example 2

[0038] The resistance of corn to Spodoptera frugiperda after applying biocontrol agent containing Rossellomorea marisflavi zju1 was evaluated by calculating the leaf loss area after Spodoptera frugiperda feeding and the growth rate of larvae. The specific method is as follows:

[0039] The soil collected from the agricultural experimental field of Huajiachi campus of Zhejiang University was aired for 1d, then mixed with sterilized sand according to a weight ratio of 3:1 to obtain planting soil, and the planting soil was loaded into black plastic pots with a volume of 400ml, and wild type B73 corn seeds were planted. After 5d, when the corn grew 1 leaf, 10mL of biocontrol agent with OD 600 =1.0 was inoculated on the surface of the soil once (experimental group), and the same volume of sterile water was added to the control group, with 15 replicates in each group.

[0040] The corn was placed in a 25°C artificial climate chamber with 14h / d light, and after growing for 15d (i.e., after the third leaf fully expanded), the second instar Spodoptera frugiperda larvae with initial weight of 1.8-2.5mg (purchased from Henan Jiyuan Baiyun Industry Co., Ltd.) were selected, pre-starved for 2h, and then attached to the third leaf according to the device as shown in Figure 1 . Within 3d after the attachment, the leaf parts eaten by Spodoptera frugiperda were collected every 24h, attached to A4 paper, color scanned, and then the leaf loss area was calculated by software Digimizer (Version 5.6.0). After 72h of attachment, the Spodoptera frugiperda larvae were collected and weighed, the final weight was recorded, and the growth rate of the larvae was calculated. The results are shown in Table 1.

[0041] Table 1 Effect of biocontrol agent on Spodoptera exigua

[0042] Group Leaf loss area (cm 2 )]]> Larval growth rate (average daily weight gain multiple) Control group 12.07 3.29 Experimental group 8.00 2.78

[0043] The results show that, compared with the control group, the corn inoculated with the biocontrol agent containing Rossellomorea marisflavi zju1 has a significantly reduced growth rate of Spodoptera exigua larvae and leaf loss area after 15 days. It can be known that Rossellomorea marisflavi zju1 can significantly increase the resistance of corn to Spodoptera exigua larvae.

[0044] Example 3

[0045] The corn plants are treated in the manner of Example 2, and after the corn is grown in a 25℃ artificial climate room with light for 14h / d for 18d (i.e., after the third cotyledon is fully expanded), the aboveground part of the plant is cut, dried in an envelope at 60℃ electric heating air drying oven for 3d, weighed, and the data is recorded. The results are shown in Table 2.

[0046] Table 2 Effect of biocontrol agent on corn growth

[0047] Group Aboveground biomass (g) Control group 0.30 Experimental group 0.45

[0048] The results show that, compared with the control group, the corn inoculated with the biocontrol agent containing Rossellomorea marisflavi zju1 has a significantly increased biomass of the aboveground part of the corn plant after 18d. It can be known that Rossellomorea marisflavi zju1 can significantly increase the biomass of the aboveground part of the corn plant, i.e., has the effect of promoting the growth of corn.

[0049] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. Application of a biocontrol agent in the control of Spodoptera frugiperda, characterized by, The biocontrol agent is a liquid agent, and the liquid agent contains... Rossellomorea marisflavi The viable bacterial count was 1.70~1.80×10⁻⁶. 8 CFU / ml; The Rossellomorea marisflavi To Rossellomorea marisflavi zju1, deposited on August 14, 2023, at the China Center for Type Culture Collection (CCTCC), with the accession number CCTCC NO: M 20231484; The use method of the biocontrol agent is directly applied on the soil surface at the time of use, the use amount of the biocontrol agent is 8-12 ml / pot, the volume of the pot is 350-450 ml, the application frequency of the biocontrol agent is 1-2 times, and the application time of the biocontrol agent is 3-8 days after corn is sowed.

2. Use of a biocontrol agent in increasing the resistance of a crop to Spodoptera frugiperda, characterized in that, The biocontrol agent is a liquid agent, and the liquid agent contains... Rossellomorea marisflavi The viable bacterial count was 1.70~1.80×10⁻⁶. 8 CFU / ml; The Rossellomorea marisflavi To Rossellomorea marisflavi zju1, deposited on August 14, 2023, at China Center for Type Culture Collection (CCTCC), with the accession number CCTCC NO: M 20231484; The use method of the biocontrol agent is directly applied on the soil surface at the time of use, the use amount of the biocontrol agent is 8-12 ml / pot, the volume of the pot is 350-450 ml, the application frequency of the biocontrol agent is 1-2 times, and the application time of the biocontrol agent is 3-8 days after corn is sowed.

3. Use of a biocontrol agent in inhibiting the growth of Spodoptera frugiperda, characterized in that, The biocontrol agent is a liquid agent, and the liquid agent contains... Rossellomorea marisflavi The viable bacterial count was 1.70~1.80×10⁻⁶. 8 CFU / ml; The Rossellomorea marisflavi To Rossellomorea marisflavi zju1, deposited on August 14, 2023, at China Center for Type Culture Collection (CCTCC), with the accession number CCTCC NO: M 20231484; The use method of the biocontrol agent is directly applied on the soil surface at the time of use, the use amount of the biocontrol agent is 8-12 ml / pot, the volume of the pot is 350-450 ml, the application frequency of the biocontrol agent is 1-2 times, and the application time of the biocontrol agent is 3-8 days after corn is sowed.

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