CN-122012334-A - Evolvulus slow rooting tumor ASHLJNJ-23-2 with functions of promoting growth and inhibiting aspergillus flavus and application thereof

Abstract

The invention discloses an Escherichia slow rooting tumor bacterium (Bradyrhizobium elkanii) ASHLJNJ-23-2 with high-efficiency growth promoting and aspergillus flavus inhibiting functions and application thereof, and the strain has a preservation number of CCTCC M2026227. The invention realizes the integration of the characteristic antibacterial volatile matter of producing 2-tridecanone and the high-efficiency symbiotic nitrogen fixation on a single strain in the slow rooting tumor of the Ehrlich for the first time. The 2-tridecanone volatile released by the strain can accurately down regulate the expression of toxin synthesis key genes and spore development core genes in the aspergillus flavus, thereby realizing efficient bacteriostasis on a molecular level. Through one-time inoculation, the growth promotion, nitrogen fixation and source bacteriostasis can be synchronously realized in the peanut rhizosphere ecological niche. Especially for the biological characteristics of peanut flowering on the ground and underground fruiting, can form a durable biological fumigation protective layer in the soil microenvironment in the critical period of pod development.

Inventors

• ZHOU YANG
• ZHANG QI
• LI PEIWU

Assignees

• 中国农业科学院油料作物研究所

Dates

Publication Date

20260512

Application Date

20260212

Claims (6)

1. 1. The slow rooting tumor strain ASHLJNJ-23-2 with the functions of promoting growth and inhibiting aspergillus flavus is characterized by being classified and named Bradyrhizobium elkanii, having a preservation number of CCTCC M2026227 and a preservation date of 2026 and 23, and being preserved in China center for type culture collection, wherein the preservation unit address is in eight-path 299-number Wuhan universities in Wuchang district of Wuhan, hubei province.
2. 2. A microbial agent or formulation comprising at least one of the rhizobia elsen claimed in claim 1 ASHLJNJ-23-2, a fermentation product thereof, or a culture thereof, the fermentation product comprising a fermentation broth, a sterile supernatant or an active substance extracted from the fermentation broth or sterile supernatant, the culture comprising a solid culture, a liquid culture or a dry formulation thereof.
3. 3. Use of a microbial agent or formulation of slow rhizobia elsen claimed in claim 1 ASHLJNJ-23-2 or claim 2 to promote peanut growth and nodulation and nitrogen fixation.
4. 4. Use of a microbial agent or formulation of slow rhizobia elsen claimed in claim 1 ASHLJNJ-23-2 or claim 2 for inhibiting aspergillus flavus growth, spore production and aflatoxin synthesis.
5. 5. The use according to claim 4, wherein said inhibition function is achieved in particular by a volatile organic compound released by said slow rhizobia of the genus ASHLJNJ-23-2.
6. 6. A method for inhibiting Aspergillus flavus, which is characterized by comprising the step of applying the Rhizobium elsdii ASHLJNJ-23-2 of claim 1 or the microbial agent or preparation of claim 2 to peanut planting environments or peanut plants.

Description

Evolvulus slow rooting tumor ASHLJNJ-23-2 with functions of promoting growth and inhibiting aspergillus flavus and application thereof Technical Field The invention belongs to the technical field of agricultural microorganisms, and particularly relates to an Escherichia slow rooting tumor bacterium (Bradyrhizobium elkanii) ASHLJNJ-23-2 with high-efficiency growth promotion and nitrogen fixation and strong aspergillus flavus inhibition functions and application thereof in green and safe production of peanuts. Background 1. Importance and core challenges of the peanut industry The peanuts are used as global important oil and economic crops, and the safe production of the peanuts has strategic significance for guaranteeing the supply of grain and oil and increasing the income of farmers. However, the production thereof continuously faces two major core challenges of yield improvement and aflatoxin pollution prevention and control. Aflatoxins (AFs) are strong carcinogens generated by aspergillus flavus (Aspergillus flavus) infection, which not only seriously harm food safety and consumer health, but also often trigger international trade technical barriers, and become a key bottleneck for restricting the high-quality development of the peanut industry. 2. Core mechanism for increasing yield of leguminous crops and effect of slow rooting tumor bacteria of Ehrlichia pastoris For leguminous crops such as peanuts, the most fundamental and most efficient yield-increasing way is to establish a specific symbiotic relation with rhizobia and carry out biological nitrogen fixation through forming the rhizobia. The slow-growing rhizobia (Bradyrhizobium elkanii) is a known rhizobia which can efficiently symbiotic with leguminous crops such as peanuts and has important application value in the aspects of promoting plant nodulation and nitrogen supply. However, the traditional rhizobia agent has the functions of nitrogen fixation and growth promotion, generally lacks direct antagonism capability to soil-borne pathogenic fungi such as aspergillus flavus, and cannot meet the dual requirements of yield increase and security in peanut production. 3. Limitations of the existing aflatoxin prevention and control technology The current prevention and control of aflatoxins mainly depend on three technologies, namely agricultural management measures (passive instability of effect), physicochemical methods (high cost and residual risk), and biological prevention and control mainly comprising Bacillus spp and Trichoderma spp. The existing biological control strain focuses on bacteriostasis, and lacks direct contribution to promoting the symbiotic nitrogen fixation process of the core of leguminous crops. Particularly, the unique growth habit of peanut 'flowering on the ground and underground fruiting' makes the traditional chemical or biological prevention and control means based on the overground part difficult to effectively act on fruits in soil in the key period of pod development and infection, and forms obvious physical prevention and control barriers. 4. Systematic defects of the prior art path "stimulation" and "gas defense" are in the state of fracture in the prior art system, resulting in the following systematic defects: (1) The functional singleness and biological synergetic deficiency is that the design target of the existing growth promoting microbial inoculum (comprising the traditional rhizobium inoculant) is mainly concentrated on the growth promoting mechanisms such as nitrogen fixation, phosphorus dissolution or secretion of plant hormones, and the like, and the direct and efficient inhibition capability on specific pathogenic fungi such as aspergillus flavus is generally lacking. The breeding standard of the existing biological control microbial inoculum is mainly focused on antagonizing the activity of pathogenic bacteria, and the most critical symbiotic nitrogen fixation process of leguminous crops is lack of direct contribution, and the metabolic products of the biological control microbial inoculum may even interfere the colonization and functional exertion of rhizobia. When these two different types of microorganisms are introduced into the complex ecological niche of the rhizosphere at the same time, it is difficult to form synergistic synergy, but the field effect is unstable, unpredictable and even weakened due to nutrition, space competition or the generation of mutually antagonistic metabolites. (2) The complex operation and the obvious increase of the comprehensive cost, and in the practical production application, farmers need to purchase, store, prepare and apply two different microorganism products respectively. The application mode not only directly increases the material cost of seed treatment or field operation, but also greatly improves the labor input, equipment use and time management cost. The complex operation flow reduces the operability and user acceptance of the technology, and becomes an imp