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CN-122012307-A - Rhodococcus strain and application thereof in degrading insecticide and enhancing resistance of parasitic wasps

CN122012307ACN 122012307 ACN122012307 ACN 122012307ACN-122012307-A

Abstract

The invention relates to biological control technology of agricultural pests, and aims to provide a rhodococcus strain and application thereof in degrading pesticides and enhancing parasitic wasp resistance. The strain is preserved in China Center for Type Culture Collection (CCTCC) with a preservation name of Fan Qingsheng rhodococcus IT-1, and Latin classification of Rhodococcus qingshengii with a preservation number of CCTCC NO: M20252461. The 16S rRNA gene sequence of the strain is shown as SEQ ID NO. 1. The strain has unique sources and broad functions, can strengthen biological control, has remarkable effect, can remarkably improve the tolerance of parasitic bees to imidacloprid and thiamethoxam by supplementing the strain back into the parasitic bees in a feeding mode, and has great significance for maintaining and enhancing the biological control function of an agricultural ecological system and reducing chemical pesticide dependence.

Inventors

  • CHEN JIANI
  • SHI WENQI
  • Fu Lidi
  • WANG YING
  • HUANG JIANHUA

Assignees

  • 浙江大学

Dates

Publication Date
20260512
Application Date
20260109

Claims (10)

  1. 1. The rhodococcus strain is characterized by being preserved in China Center for Type Culture Collection (CCTCC) with a preservation name of Fan Qingsheng rhodococcus IT-1, and Latin classification of Rhodococcus qingshengii with a preservation number of CCTCC NO: M20252461.
  2. 2. The rhodococcus strain according to claim 1, characterized in that it is isolated from the intestinal content of adult drosophila melanogaster gall bees.
  3. 3. The rhodococcus strain according to claim 1, wherein the 16S rRNA gene sequence of the rhodococcus strain is shown in SEQ ID No. 1.
  4. 4. A method for culturing a rhodococcus strain according to any one of claims 1 to 3, wherein the rhodococcus strain is transferred to a liquid medium, and cultured under shaking conditions at 28 to 32 ℃, wherein the liquid medium is LB medium or an inorganic salt medium using a neonicotinoid insecticide as a sole carbon source, and wherein the neonicotinoid insecticide is at least one of imidacloprid and thiamethoxam.
  5. 5. Use of a rhodococcus strain according to any one of claims 1 to 3 for degrading a neonicotinoid insecticide or for increasing the resistance of parasitic wasps to a neonicotinoid insecticide, said neonicotinoid insecticide being at least one of imidacloprid or thiamethoxam.
  6. 6. A microbial agent having an imidacloprid or thiamethoxam degrading function, characterized in that the microbial agent comprises the rhodococcus strain according to any one of claims 1 to 3 as an active ingredient, and an agriculturally acceptable carrier.
  7. 7. The use method of the microbial agent is characterized in that the microbial agent is added into water according to the dosage proportion of 1% -5%, the mixture is uniformly mixed, and then the mixture is applied in a spray mode to a field or a woodland polluted by imidacloprid or thiamethoxam, the application dosage is controlled within the range of 450-750L/hm 2 , the carrier in the microbial agent is sterile phosphate buffer, and the concentration of viable bacteria is 5 multiplied by 10 9 cfu/mL.
  8. 8. A microbial agent having a function of improving the resistance of parasitic wasps to imidacloprid or thiamethoxam, characterized in that the microbial agent comprises the rhodococcus strain of any one of claims 1 to 3 as an active ingredient, and an acceptable carrier in the parasitic wasp feed.
  9. 9. The method for using the microbial agent of claim 8, wherein the parasitic wasps are fed with a sucrose aqueous solution containing antibiotics for 1 day before use, the bacterial colony in the intestinal tracts of the parasitic wasps is removed, then the microbial agent is fed for 2 days, and the carrier in the microbial agent is sucrose water with the living bacterial concentration of 5 multiplied by 10 9 cfu/mL.
  10. 10. The method of claim 9, wherein the parasitic wasp is a parasitic wasp of genus goiter or genus goiter.

Description

Rhodococcus strain and application thereof in degrading insecticide and enhancing resistance of parasitic wasps Technical Field The invention relates to a microbiological technology and an agricultural pest biological control technology, in particular to a rhodococcus strain (IT-1) and application thereof in degrading pesticides and enhancing parasitic wasp resistance. Background Neonicotinoid insecticides (such as imidacloprid and thiamethoxam) are widely used worldwide due to their highly effective, broad spectrum nature. However, research shows that the neonicotinoid insecticides have high bioaccumulation and environmental persistence, can exist in soil, water bodies and organisms for a long time, pose serious threat to non-target organisms (such as pollinating insects and natural enemy insects), and destroy ecological balance. Microbial degradation is an economical and environmentally friendly strategy for removing pesticide residues from the environment. In nature, the fruit flies are widely distributed, the number is huge, the variety is great, and in agricultural production, especially in berry fruit planting industry, huge harm is caused, so that huge economic loss is caused. It is counted that about 90% of fruit flies are parasitized by parasitic wasps in nature. It has now been found and reported that Drosophila parasitic wasps are of the genus 16 of the 4 families, wherein the number of three species of the genus Cyclopentablaceae FIGITIDAE key-chest gall wasps of the subfamily Eucoilinae, the genus Leptopilina, the genus Ganaspis and the genus Asobara of the genus Braconidae open arm cocoon of the family Apiaceae is in excess of 20%. The genus of the goiter and the genus of the Apis are dominant parasitic natural enemies of Drosophila pests, and the method has excellent biocontrol potential in an orchard ecosystem. The drosophila minor-ring gall bees (L. drosophilae) are particularly outstanding with Japanese open-arm anti-jaw cocoon bees (A.japonica), the drosophila minor-ring gall bees can accurately position and parasitize early larvae of drosophila, population base numbers of the drosophila minor-ring gall bees are effectively suppressed, and the drosophila minor-ring gall bees are good at parasitizing middle-late larvae, and a remarkable pest control effect is achieved through high parasitizing rate. However, the application of field pesticides severely affects the population survival and pest control efficacy of parasitic wasps. In recent years, research shows that insect intestinal symbiotic bacteria possibly participate in the detoxification metabolic process of a host on the insecticide, and a new thought is provided for enhancing the drug resistance of natural enemy insects. At present, few microorganisms for degrading anabasine pesticides are reported, for example, patent CN112779194B discloses a strain of Gordonia alcaligenes for degrading imidacloprid, and patent CN116376764A discloses a strain of Pseudomonas capable of degrading acetamiprid. However, most strains are single-function, and there are few studies directly correlating the improvement of resistance of degrading bacteria to natural enemy insects. The functional strain is screened from the special habitat of the parasitic wasp intestinal canal, and the functional strain is proved to be capable of directly degrading the pesticide and supplementing the pesticide into a host body to enhance the resistance, and has important innovation significance and application value. At present, reports about the fact that the rhodococcus strain has the function of degrading imidacloprid, thiamethoxam and enhancing the resistance of parasitic bees at the same time are not seen. Disclosure of Invention The invention aims to solve the technical problem of overcoming the defects in the prior art and providing a rhodococcus strain and application thereof in degrading pesticides and enhancing parasitic wasp resistance. In order to solve the technical problems, the invention adopts the following solutions: The rhodococcus strain is characterized by being preserved in China Center for Type Culture Collection (CCTCC) with the preservation name Fan Qingsheng being rhodococcus IT-1, the Latin classification being Rhodococcus qingshengii and the preservation number being CCTCC NO: M20252461. As a preferred embodiment of the present invention, the rhodococcus strain is isolated from the intestinal contents of fruit fly ringworm gall bees adults. As a preferable scheme of the invention, the 16S rRNA gene sequence of the rhodococcus strain is shown as SEQ ID NO. 1. The invention also provides a culture method of the rhodococcus strain, which comprises the steps of transferring the rhodococcus strain into a liquid phase culture medium, and culturing the rhodococcus strain under the conditions of 28-32 ℃ and shaking, wherein the liquid phase culture medium is an LB culture medium or an inorganic salt culture medium taking a neonicotinoid insecticide as a