Arbuscular mycorrhizal fungus bilayer cyst carbodiicola and application thereof

Abstract

The invention provides an arbuscular mycorrhizal fungus, the arbuscular mycorrhizal fungus is double-layer bursa caramei MQ01, the arbuscular mycorrhizal fungus is preserved in the China General Microbiological Culture Collection Center (CGMCC), and the preservation number is CGMCC No.40515. The arbuscular mycorrhizal fungus has the advantages that the arbuscular mycorrhizal fungus can be used for preparing the arbuscular mycorrhizal fungus; the double-layer bursal carbodiicola MQ01 can remarkably promote crop growth, improve biomass, optimize crop phosphorus absorption efficiency and relieve heavy metal stress in heavy metal contaminated soil; and the method is suitable for various crops and different types of soil, and has wide application prospects in the aspects of improving the agricultural production efficiency and solving the soil heavy metal pollution problem.

Description

Technical Field

[0001] The present invention relates to the field of microbial technology, and particularly to an arbuscular mycorrhizal fungus, Kamienskia bistrata, and its application. Background Art

[0002] With the continuous improvement of the requirements of agricultural production for food security and environmental protection, the problems of low utilization efficiency of soil phosphorus resources and heavy metal pollution have become the main challenges restricting the sustainable development of agriculture. Phosphorus in the soil mainly exists in a fixed state and is difficult to be directly absorbed by plants. In traditional agriculture, a large amount of chemical phosphorus fertilizer is applied to meet the needs of crops, but the utilization rate of phosphorus fertilizer is usually less than 30%, and most of it is fixed or lost by the soil, which not only wastes resources but also causes environmental problems such as water eutrophication. At the same time, the non-renewability of phosphate rock resources poses a threat to the long-term development of agriculture. In addition, the problem of heavy metals such as cadmium pollution is becoming increasingly serious, resulting in the inhibition of plant growth, an increase in food safety hazards, and damage to the stability of the ecosystem, and effective solutions are urgently needed. Summary of the Invention

[0003] In view of this, in order to at least partially solve at least one of the above-mentioned technical problems, the present invention provides an arbuscular mycorrhizal fungus, which is Kamienskia bistrata MQ01, and is deposited in the China General Microbiological Culture Collection Center, with the deposit number of CGMCC No. 40515.

[0004] According to an embodiment of one aspect of the present invention, an application of an arbuscular mycorrhizal fungus is provided, including:

[0005] Promoting plant growth;

[0006] Increasing the phosphorus absorption rate of plants;

[0007] Relieving the stress of soil heavy metal pollution; and / or

[0008] Improving the ecosystem.

[0009] According to the embodiment of the present invention, the plant is any one of the following:

[0010] (1) A plant of the phylum Angiospermae;

[0011] (2) A plant of the class Dicotyledoneae or Monocotyledoneae;

[0012] (3) A plant of the family Poaceae;

[0013] (4) A plant of the genus Zea or Triticum;

[0014] (5) Maize or wheat.

[0015] According to an embodiment of the present invention, promoting plant growth includes:

[0016] Increasing the shoot and / or root biomass of plants.

[0017] According to an embodiment of the present invention, increasing the phosphorus absorption rate of plants includes:

[0018] Increasing the phosphorus content in the shoot and / or root of plants.

[0019] According to an embodiment of the present invention, heavy metal pollution includes:

[0020] Cadmium pollution, mercury pollution, lead pollution, chromium pollution, and / or arsenic pollution.

[0021] According to an embodiment of the present invention, alleviating the stress of heavy metal pollution in soil includes:

[0022] Reducing the accumulation of heavy metals in the shoot and / or root during plant growth.

[0023] According to an embodiment of another aspect of the present invention, a composition, preferably a microbial agent, is provided, and the composition contains the above-mentioned arbuscular mycorrhizal fungi.

[0024] According to an embodiment of another aspect of the present invention, a method for preparing a composition is provided, including the step of using the above-mentioned arbuscular mycorrhizal fungi as a component of the composition.

[0025] According to an embodiment of still another aspect of the present invention, a method for planting plants is provided, including the step of bringing the above-mentioned arbuscular mycorrhizal fungi or the above-mentioned composition into contact with plants during the process of planting plants.

[0026] According to an embodiment of the present invention, Claroideoglomus etunicatum MQ01 can significantly promote crop growth, increase biomass, optimize the phosphorus absorption efficiency of crops, and alleviate the heavy metal stress in heavy metal-polluted soil; and it is applicable to a variety of crops and different types of soil, and has broad application prospects in improving agricultural production efficiency and solving the problem of heavy metal pollution in soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Through the following description of the embodiments of the present invention with reference to the drawings, the above and other objects, features, and advantages of the present invention will become clearer. In the drawings:

[0028] Figure 1 It is a characteristic diagram of spores of different magnifications of Claroideoglomus etunicatum MQ01 in the embodiment of the present invention;

[0029] Figure 2 It is a phylogenetic relationship map of Claroideoglomus etunicatum MQ01 and related strains in the embodiment of the present invention;

[0030] Figure 3This is the result graph of the impact of inoculating double-layer Glomus caledonium MQ01 on wheat biomass in the embodiments of the present invention. (A) is the comparison graph of above-ground dry weight, and (B) is the comparison graph of root dry weight;

[0031] Figure 4 This is the result graph of the impact of inoculating double-layer Glomus caledonium MQ01 on the phosphorus concentration content of wheat in the embodiments of the present invention. (A) is the comparison graph of above-ground phosphorus concentration, and (B) is the comparison graph of root phosphorus concentration;

[0032] Figure 5 This is the result graph of the impact of inoculating double-layer Glomus caledonium MQ01 on maize biomass in the embodiments of the present invention. (A) is the comparison graph of above-ground biomass, and (B) is the comparison graph of root biomass;

[0033] Figure 6 This is the result graph of the impact of inoculating double-layer Glomus caledonium MQ01 on the phosphorus content of maize in the embodiments of the present invention. (A) is the comparison graph of above-ground phosphorus concentration, and (B) is the comparison graph of root phosphorus concentration;

[0034] Figure 7 This is the result graph of the impact of inoculating double-layer Glomus caledonium MQ01 on maize under cadmium pollution conditions in the embodiments of the present invention. (A) is the comparison graph of above-ground dry weight, and (B) is the comparison graph of above-ground cadmium concentration. Detailed implementation manners

[0035] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In the following detailed description, for the sake of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention. However, obviously, one or more embodiments can also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0036] The terms used herein are merely for describing specific embodiments and are not intended to limit the present invention. The term "including" used herein indicates the presence of features, steps, operations, but does not exclude the presence or addition of one or more other features.

[0037] In the case of using expressions such as "at least one of A, B, and C, etc.", generally, it should be interpreted according to the meaning that those skilled in the art usually understand this expression (for example, "a system having at least one of A, B, and C" should include but not be limited to a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). In the case of using expressions such as "at least one of A, B, or C, etc.", generally, it should be interpreted according to the meaning that those skilled in the art usually understand this expression (for example, "a system having at least one of A, B, or C" should include but not be limited to a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0038] In the process of implementing the inventive concept, it has been found that arbuscular mycorrhizal fungi (AMF), as important functional microorganisms in the soil, form a symbiotic relationship with plants, significantly improving the absorption efficiency of plants for phosphorus and other nutrient elements in the soil, while alleviating heavy metal stress and enhancing the stress resistance of plants. AMF expands the absorption range of plant roots through the hyphal network and dissolves fixed phosphorus by secreting organic acids and phosphatases, thereby improving the phosphorus absorption capacity of plants and reducing the dependence on chemical phosphate fertilizers. In addition, AMF can also alleviate heavy metal toxicity by adsorbing heavy metals, activating plant resistance mechanisms or improving the soil environment, and enhancing plant growth and biomass accumulation. However, there are significant differences in the functionality of different AMF strains, and the related technology for screening and applying excellent strains is still insufficient, restricting the wide promotion of mycorrhizal technology.

[0039] Specifically, according to an embodiment of one aspect of the present invention, an arbuscular mycorrhizal fungus is provided, and the arbuscular mycorrhizal fungus is Kamienskia bistrata MQ01.

[0040] Depositing Instructions

[0041] Name of the strain: Kamienskia bistrata

[0042] Strain number: MQ01

[0043] Depositing date: March 3, 2023

[0044] Depositing center: China General Microbiological Culture Collection Center (CGMCC)

[0045] Depositing address: No. 1, Beichen West Road, Chaoyang District, Beijing

[0046] Accession number registered with the depositary: CGMCC NO. 40515

[0047] According to the embodiments of the present invention, the double-layered Glomus mosseae MQ01 can significantly promote crop growth, increase biomass, optimize the phosphorus uptake efficiency of crops, and alleviate heavy metal stress in heavy metal-contaminated soils; and it is applicable to a variety of crops and different types of soils, having broad application prospects in improving agricultural production efficiency and solving the problem of soil heavy metal pollution.

[0048] According to the embodiments of the present invention, it promotes plant growth; improves the phosphorus absorption rate of plants; alleviates soil heavy metal pollution stress; and / or improves the ecosystem.

[0049] According to the embodiments of the present invention, the double-layered Glomus mosseae MQ01 can significantly increase the biomass of crops by 35% - 80% through the secretion of plant growth hormones, and the dry weight of roots increases by more than 1 time; phosphorus is an important essential element for plant growth, but its availability in the soil is low and it is easily fixed and difficult to be directly absorbed by plants. However, MQ01 has high phosphorus-solubilizing ability and can convert insoluble phosphorus in the soil into a form that can be utilized by plants. The phosphorus concentration in the above-ground part increases by 45 - 85%, and the phosphorus concentration in the roots increases by 35 - 60%, showing a relatively excellent phosphorus absorption promotion effect; the double-layered Glomus mosseae MQ01 can also change the absorption and distribution pattern of heavy metals by plants, reduce the transport of heavy metals to the above-ground part of plants, and at the same time enhance the nutrient absorption of plants and improve the tolerance of plants to heavy metals, thereby reducing the toxicity of heavy metals to plants, providing an important and effective way for the ecological restoration of heavy metal-contaminated soils and the healthy growth of plants.

[0050] According to the embodiments of the present invention, the plant is any one of the following: (1) angiosperm plants; (2) dicotyledonous plants or monocotyledonous plants; (3) gramineous plants; (4) Zea plants or Triticum plants; (5) maize or wheat.

[0051] According to the embodiments of the present invention, angiosperm plants can include plants such as roses and bananas, dicotyledonous plants can include sunflowers, cotton, etc., monocotyledonous plants can include rice, palm, etc., gramineous plants can include wheat, sorghum, sugarcane, etc., Zea can include various corns such as sweet corn and waxy corn, and Triticum can include various wheats such as common wheat and durum wheat.

[0052] According to the embodiments of the present invention, promoting plant growth includes: increasing the biomass of the above-ground part and / or roots of plants.

[0053] According to an embodiment of the present invention, improving the phosphorus absorption rate of plants includes: increasing the phosphorus content in the above-ground parts and / or roots of plants.

[0054] According to an embodiment of the present invention, the double-layer Glomus caledonium MQ01 can significantly promote the accumulation of crop biomass by secreting phytohormone-like metabolites, while increasing the absorption of phosphorus in the soil, thereby reducing the use of phosphorus-containing chemical fertilizers, saving costs and reducing problems such as pollution caused by excessive application of chemical fertilizers.

[0055] According to an embodiment of the present invention, heavy metal pollution includes: cadmium pollution, mercury pollution, lead pollution, chromium pollution, and / or arsenic pollution.

[0056] According to an embodiment of the present invention, alleviating soil heavy metal pollution stress includes: reducing the accumulation amount of heavy metals in the above-ground parts and / or roots during plant growth.

[0057] According to an embodiment of the present invention, the double-layer Glomus caledonium MQ01 also has broad applicability in reducing metal accumulation in metal-polluted soils, including cadmium pollution, mercury pollution, lead pollution, chromium pollution, arsenic pollution, etc. These heavy metals are difficult to degrade in the soil and pose serious hazards to plant and human health. The double-layer Glomus caledonium MQ01 can reduce the bioavailability of these heavy metals in the soil through similar mechanisms, such as rhizosphere microenvironment regulation, metal fixation and transformation, and plant nutrition improvement, thereby reducing the toxicity to plants, such as pollution. Although these metal elements such as copper and zinc are beneficial to plant growth in appropriate amounts, they will be toxic to plants when excessive. The double-layer Glomus caledonium MQ01 may also reduce the accumulation of these metals in plants by regulating the absorption and distribution patterns of plants.

[0058] In some specific embodiments of the present invention, for the target soil of reducing metal-polluted soil, the risk values and regulatory values of agricultural land soil with pH > 7.5 in the National Soil Environmental Quality Standard for Agricultural Land Soil Pollution Risk Control (Trial) of GB15618-2018 are 0.6 and 5 mg / kg respectively, and it can be slightly higher than the regulatory value. However, under severe pollution conditions such as mines, the range of AMF affecting plant metal content needs to be determined according to actual experimental data and soil environmental conditions, and there may be certain differences from farmland conditions.

[0059] As an embodiment of another aspect of the present invention, a composition is provided, preferably a microbial agent, and the composition contains the arbuscular mycorrhizal fungus Glomus caledonium MQ01.

[0060] According to an embodiment of the present invention, the active ingredient of the composition can be Glomus caledonium MQ01 and / or the metabolite of Glomus caledonium MQ01 and / or the culture of Glomus caledonium MQ01.

[0061] According to an embodiment of the present invention, the composition can be a microbial agent, a solid composition, a liquid composition, a compound bio-fertilizer, etc.

[0062] The dosage form of the above microbial agent can be various dosage forms, including but not limited to liquid, emulsion, suspension, powder, granule, wettable powder or water dispersible granule, etc. It can also include other auxiliary components such as the carrier for preparing the microbial agent. For example, it can include a mixture of soil, mycorrhizal root segments, spores and mycelia.

[0063] As an embodiment of another aspect of the present invention, a method for preparing a composition is provided, including the step of using the arbuscular mycorrhizal fungus of claim 1 as a composition component.

[0064] According to an embodiment of the present invention, the active ingredient containing Glomus bilayer MQ01 can be prepared into a composition by a conventional method, and the present invention does not make specific limitations on the preparation method.

[0065] As an embodiment of another aspect of the present invention, a method for planting plants is provided, including the step of bringing Glomus bilayer MQ01 and / or a composition with the active ingredient of Glomus bilayer MQ01 into contact with plants during the plant planting process.

[0066] In some specific embodiments of the present invention, the application amount of Glomus bilayer MQ01 is ~(6 - 10)% of the soil weight, and 5000 - 8000 spores per pot.

[0067] According to an embodiment of the present invention, the step of plant contact during the plant planting process can be divided into direct contact and / or indirect contact. For example, direct contact can be achieved by directly applying to the surface of the plant body such as seeds, roots, leaves, etc. For example, by applying Glomus bilayer MQ01 and / or a composition with the active ingredient of Glomus bilayer MQ01 to the growth medium such as the soil, nutrient solution, substrate, etc. where the plant grows, the functional conduction is realized through the medium-plant interaction.

[0068] To make the purpose, technical solution and advantages of the present invention clearer, the following further elaborates the present invention in detail with reference to specific embodiments and the accompanying drawings. Unless otherwise specified, the reagents used are conventional commercially available reagents in the art.

[0069] Example 1 Isolation and Identification of Strains

[0070] An arbuscular mycorrhizal fungus strain was isolated from the soil in Gansu, China, named MQ01, and its spore characteristics are as Figure 1 shown.

[0071] Figure 1 It is a spore characteristic diagram of different magnifications of Glomus bilayer MQ01 in the embodiment of the present invention.

[0072] Spores are loosely or densely tufted in the soil, borne at the apex of hyphae, containing several to dozens of spores, as shown in Figure 1 Figure (A).

[0073] Spores are transparent, spherical to subspherical, occasionally irregular in shape, 21-40 μm in diameter, with a connecting hypha as shown in Figure 1 Figure (B). The spore wall consists of two layers of permanent transparent walls. The outer layer SWL1 is a single wall, smooth, 0.9-1.8 μm thick. The second layer SWL2 is laminated, 0.6-1.2 μm thick as shown in Figure 1 Figure (C).

[0074] Spores DNA was extracted using the FastDNA TM SPIN Kit for Soil (MP Biomedicals, CA, USA). The 18S rDNA, 5.8S rDNA and 28S rDNA regions were amplified by PCR using the primers SSUmAf and LSUmAr (Krüger et al., New Phytologist (2009) 183: 212–223). The PCR products were sent to the company for sequencing analysis, and the sequence is shown as SEQ ID No.1 below:

[0075]

[0076] Figure 2 This is the phylogenetic relationship map of the double-layered Claroideoglomus MQ01 and related strains in the embodiments of the present invention.

[0077] According to the sequencing results, using the type strain Rhizophagus irregularis DAOM197198 and the reference species for morphological identification (genus Dominikia) as the outgroup, a phylogenetic tree was constructed by the neighbor-joining method as Figure 2 shown, and it was identified as Claroideoglomus bistrata.

[0078] Example 2 Promoting effect of Claroideoglomus MQ01 on wheat growth and phosphorus uptake

[0079] Wheat (Triticum aestivum), as an important global food crop, its efficient phosphorus uptake is crucial for improving yield and quality. Based on this, this example aims to evaluate the effects of Claroideoglomus MQ01 on wheat growth and phosphorus uptake through pot experiments, in order to provide a scientific basis for the application of this strain in agriculture.

[0080] In this example, an inoculation treatment of AM fungi (MQ01) and a control (CK) treatment were set up, with 4 replicates for each treatment, and the experiments were arranged in a completely random manner.

[0081] The Claroideoglomus MQ01 inoculant (hereinafter referred to as the MQ01 inoculant) contains a mixture of soil, mycorrhizal root segments, spores and mycelium. After being co-cultured with sorghum and clover for large-scale propagation, it is used. Each gram of the inoculant contains 142 spores. The total phosphorus concentration of the tested soil is 3.07 g kg -1 , and the available phosphorus concentration is 5.24 mg kg -1 . After natural air drying and passing through a 5 mm sieve, it is sterilized by 25 kGy radiation.

[0082] The culture device selects plastic pots (21 cm in diameter, 14 cm in bottom diameter, 20 cm in height), and each pot is filled with 600 g of soil.

[0083] For the AM fungi inoculant treatment, the inoculant is applied by the layer method. 50 g of the inoculant (~8% of the soil weight, ~7000 spores per pot) is mixed with the soil at a height of 1 / 2 to 3 / 4 from the bottom of the container; for the treatment without adding the inoculant, 50 g of autoclaved inoculant and 10 mL of the inoculant filtrate are added. Wheat seeds are surface sterilized before sowing, and the seeds are soaked in 10% H 2 O 2For 20 minutes in the solution and then rinsed thoroughly with deionized water. Place the seeds in a sterilized petri dish lined with double-layer filter paper and germinate them in the dark at 25 °C for 2 - 3 days until germination. Select seeds with consistent growth status for the pot experiment. Sow 5 seeds in each pot, and thin out the seedlings two weeks after emergence, leaving 2 seedlings in each pot. The experiment is carried out in an intelligent greenhouse. During the experiment, keep the indoor temperature at 18 - 25 °C, the air humidity at 50 - 60%, and the daily light duration at 16 h.

[0084] Harvest after 90 days of plant growth. Remove the two plants from the pots, wash them clean with deionized water, and weigh the fresh weights of the above-ground parts and roots separately. The results are as Figure 3 shown.

[0085] The above-ground and root samples are dried at 75 °C for 72 h until constant weight, and the dry weights are weighed and used for the determination of element contents. Another about 100 mg of the sample is placed in a digestion tube and digested in a microwave digestion system (Mars5, CEM, USA). After diluting to 50 ml with ultrapure water and filtering the eluate, the phosphorus content is determined by ICP - OES (Prodigy, Teledyne Leeman, USA). The results are as Figure 4 shown.

[0086] Figure 3 This is the result graph of the effect of inoculating double - layer Glomus caledonium MQ01 on wheat biomass in the embodiment of the present invention. (A) is the comparison graph of the above - ground dry weight, and (B) is the comparison graph of the root dry weight.

[0087] According to Figure 3 it can be seen that inoculating double - layer Glomus caledonium MQ01 significantly increased the biomass of wheat. Compared with the control treatment (CK), the above - ground dry weight of wheat treated with double - layer Glomus caledonium MQ01 increased by 61.4%, and the root dry weight increased by about 1.1 times. This indicates that double - layer Glomus caledonium MQ01 can effectively promote the growth of the above - ground parts and roots of wheat.

[0088] Figure 4 This is the result graph of the effect of inoculating double - layer Glomus caledonium MQ01 on the phosphorus concentration content of wheat in the embodiment of the present invention. (A) is the comparison graph of the above - ground phosphorus concentration, and (B) is the comparison graph of the root phosphorus concentration.

[0089] According to Figure 4 it can be seen that the phosphorus concentrations in the above - ground parts and roots of wheat were significantly increased after inoculating double - layer Glomus caledonium MQ01. The above - ground phosphorus concentration increased from 517.8 mg / kg in the control to 906.38 mg / kg in the treatment with double - layer Glomus caledonium MQ01, an increase of 75%; the root phosphorus concentration increased by 36.9%. This shows that double - layer Glomus caledonium MQ01 can significantly enhance the phosphorus absorption ability of plants.

[0090] In summary, inoculation with the double-layer Glomus caledonium MQ01 can significantly increase the aboveground and root biomass of wheat, while enhancing its phosphorus uptake capacity. This provides strong support for the application of MQ01 in agricultural production. Especially in the context of the increasing environmental problems caused by phosphorus resource shortages and excessive application of phosphate fertilizers, it is of great significance to optimize phosphorus management using the double-layer Glomus caledonium MQ01.

[0091] Example 3: Promoting effect of double-layer Glomus caledonium MQ01 on maize growth and phosphorus uptake

[0092] As one of the major food crops globally, maize is widely cultivated in China. Due to its large biomass and rapid growth, it has a relatively high demand for phosphorus. Therefore, it is of great significance to conduct in-depth research and rationally apply mycorrhizal technology to fully exert its positive role in agricultural production. In this example, the isolated double-layer Glomus caledonium MQ01 was used as the research object, and through pot simulation experiments, the effects of inoculating AMF on maize growth and phosphorus nutritional status under different phosphorus application levels were investigated, aiming to verify the potential value of double-layer Glomus caledonium MQ01 in maize production, study the application scope and conditions of mycorrhizal technology, and provide support for the practical application and popularization of mycorrhizal technology.

[0093] In this example, treatments of inoculating double-layer Glomus caledonium (MQ01), non-inoculated control treatment (CK), and inoculating the commercial inoculant MycoUp from Symborg Corporate, Spain (sym) were set up. Among them, the main component of the commercial inoculant in the sym group is the arbuscular mycorrhizal fungus Glomus iranicum var. tenuihypharum. And two P addition levels (0, 40 mg kg -1 ) were set respectively, denoted as "control" and "P application" respectively, with a total of 6 treatments, and each treatment was repeated 4 times.

[0094] Tested soil: Total phosphorus 0.87 g kg –1 , Available phosphorus 15.01 mg kg –1 . The soil was sterilized by 25 kGy radiation.

[0095] The double-layer Glomus caledonium MQ01 was used after being multiplied in large quantities by co-culturing with sorghum and clover. Each gram of the inoculant contains 176 spores. According to the treatment numbers, phosphorus was fully mixed with the soil in advance. After filling 1.2 kg of soil into the pots, 50 g of AM fungal inoculant (~4% soil weight, ~8800 spores per pot) was added by the layer method, and the inoculant was fully mixed with the soil at 3 / 4 height from the bottom of the container; for the treatment without adding the inoculant, 50 g of autoclaved inoculant and 10 mL of the inoculant water filtrate were added.

[0096] The selected corn variety was Huaxingdan 88 (HXD88). After the seeds were surface-sterilized and germinated, plump and uniform-sized seeds were selected for sowing. Thinning was carried out one week after emergence, and one seedling of uniform size was retained in each pot. The experiment was conducted in an artificial climate chamber with a day / night temperature of 25°C / 18°C, a light cycle of 16 h / 8 h, and a light intensity of 1000 µmol·m - 2 s -1 , and a relative humidity of 70%. The plants were harvested after 65 days of growth, and the plant biomass and phosphorus content were measured. The results are as Figure 5 、 6 shown.

[0097] Figure 5 This is the result graph of the effect of inoculating the double-layer Glomus mosseae MQ01 on corn biomass in the embodiment of the present invention. (A) is the comparison graph of aboveground biomass, and (B) is the comparison graph of root biomass; Figure 6 This is the result graph of the effect of inoculating the double-layer Glomus mosseae MQ01 on the phosphorus content of corn in the embodiment of the present invention. (A) is the comparison graph of aboveground phosphorus concentration, and (B) is the comparison graph of root phosphorus concentration.

[0098] According to Figure 5 it can be seen that whether phosphorus was applied or not, inoculating the double-layer Glomus mosseae MQ01 significantly increased the aboveground and root biomass of corn. Under the condition of no phosphorus application, the aboveground biomass of the double-layer Glomus mosseae MQ01 treatment was 26.7% higher than that of the control group (CK); while under the condition of phosphorus application, the aboveground biomass of the double-layer Glomus mosseae MQ01 treatment was about 35.9% higher than that of the CK group. The change trend of root biomass was similar. Under the condition of no phosphorus application, the double-layer Glomus mosseae MQ01 treatment was significantly higher than the CK and Sym groups, and under the condition of phosphorus application, this difference was further enlarged, indicating that the double-layer Glomus mosseae plays a significant role in promoting the accumulation of corn biomass.

[0099] According to Figure 6 it can be seen that the phosphorus concentration in the roots was significantly affected by the inoculant treatment and phosphorus application level. Under the condition of no phosphorus application, the aboveground phosphorus concentration of the double-layer Glomus mosseae MQ01 treatment reached 691 mg / kg, which was significantly higher than that of the CK treatment and the Sym treatment; while under the condition of phosphorus application, the aboveground phosphorus concentration of the MQ01 treatment further increased to 1132 mg / kg, which was 45.3% higher than that of the CK group. The change trend of the aboveground phosphorus concentration was similar to that of the aboveground part. When no phosphorus was applied, the MQ01 treatment was significantly higher than the control group, and under the condition of phosphorus application, the phosphorus concentration of the MQ01 treatment still remained at the highest level.

[0100] In summary, inoculation with the dual-layer Glomus caledonium MQ01 was outstanding in promoting the biomass accumulation of the above-ground parts and roots of maize and improving the phosphorus absorption and utilization efficiency. Especially under phosphorus application conditions, the synergistic effect of MQ01 was more significant. This indicates that MQ01, as a potential high-efficiency mycorrhizal fungal resource, has practical application value in improving crop yield and phosphorus utilization efficiency under low-phosphorus conditions, providing support for the popularization of the dual-layer Glomus caledonium MQ01.

[0101] Example 4 Functional Effects of Dual-Layer Glomus caledonium MQ01 on Maize Growth and Cadmium Accumulation in Cadmium-Contaminated Soil

[0102] Research has shown that there are significant functional differences among different AMF strains in heavy metal-contaminated soils, mainly reflected in aspects such as the promotion of plant growth, heavy metal tolerance, and their accumulation in plants. Therefore, in-depth comparison of the functional effects of different AMF strains in cadmium (Cd)-contaminated soils not only helps to reveal their action mechanisms but also provides a theoretical basis for screening and applying excellent AMF strains.

[0103] In this example, treatments of inoculating with the dual-layer Glomus caledonium (MQ01), non-inoculated control treatment (CK), and inoculating with Rhizophagus irregularis AH01 (preservation number CGMCC 12157) were set up.

[0104] The tested soil was taken from the 0-30 cm surface layer of a Cd-contaminated farmland in Baoding, Hebei. The total Cd concentration in the soil was 6.07 mg / kg -1 , and the available Cd concentration was 0.09 mg / kg -1 . The soil was sterilized by 25 kGy radiation.

[0105] The dual-layer Glomus caledonium MQ01 and Rhizophagus irregularis AH01 were used after being multiplied in large quantities through co-cultivation with sorghum and clover. Each gram of the MQ01 inoculant contained 176 spores, and each gram of the AH01 inoculant contained 84 spores. The fungal inoculants were added using the layer method. For the treatment without adding inoculants, autoclaved inoculants and the aqueous filtrate of the inoculants were added. The selected maize variety was Huaxingdan 88 (HXD88). After the seeds were surface-sterilized and germinated, plump and uniformly sized seeds were selected for sowing. Thinning was carried out one week after emergence, and one uniformly sized seedling was retained in each pot. The experiment was arranged in an artificial climate chamber with a day / night temperature of 25°C / 18°C, a light cycle of 16 h / 8 h, a light intensity of 1000 µmol·m - 2 / s -1 , and a relative humidity of 70%.

[0106] Harvest after 65 days of plant growth. Remove the plants from the pots, wash them clean with deionized water, weigh the above-ground parts separately, dry them at 75 °C for 72 h until constant weight, and weigh the dry weight. After grinding the dried plant samples with a ball mill (Retsch, MM400), sieve them through a 100-mesh sieve, digest the samples using a microwave digestion instrument (Mars5, CEM, USA), and measure the Cd concentration using an inductively coupled plasma mass spectrometer (ICP-MS, NexION 300X, Perkin Elmer, USA). The results are as Figure 7 shown.

[0107] Figure 7 This is the result diagram of the influence of inoculating the double-layer Glomus caledonium MQ01 on maize under cadmium pollution conditions in the embodiment of the present invention. (A) is the comparison diagram of the above-ground dry weight, and (B) is the comparison diagram of the above-ground cadmium concentration.

[0108] According to Figure 7 It can be seen that under different treatment conditions, there are significant differences in the above-ground biomass and Cd concentration of maize plants. Compared with the control group (CK), the treatments of inoculating the double-layer Glomus caledonium MQ01 and Glomus heterogamum AH01 both significantly increased the above-ground dry weight of maize. Among them, the above-ground dry weight of the MQ01 treatment was the highest, which was 35.2% higher than that of the control group CK and 26.2% higher than that of the Glomus heterogamum AH01 treatment. In terms of the above-ground cadmium concentration, the treatment of inoculating the double-layer Glomus caledonium MQ01 significantly reduced the cadmium accumulation. The above-ground cadmium concentration of the CK treatment was the highest, while the cadmium concentration of the MQ01 treatment was the lowest, only 0.36 mg / kg, showing its significant cadmium stress alleviation ability under cadmium pollution conditions, and the cadmium concentration was 17.9% lower than that of the AH01 treatment.

[0109] In summary, the double-layer Glomus caledonium MQ01 shows more significant advantages in promoting maize growth and reducing cadmium accumulation, indicating its greater application potential in cadmium-polluted soils.

[0110] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An arbuscular mycorrhizal fungus, wherein the arbuscular mycorrhizal fungus is Kamienskia bistrata MQ01, which is deposited in the General Microbiological Center of China Microorganism Culture Collection Administration, with a deposit number of CGMCC No.40515.

2. The use of the arbuscular mycorrhizal fungi according to claim 1, comprising: Promote plant growth; Improve plant phosphorus absorption rate; Alleviate soil heavy metal pollution stress; and / or Improve the ecosystem.

3. The use according to claim 2, wherein: The plant is any one of the following: (1) Angiosperms; (2) Dicotyledonous plants or monocotyledonous plants; (3) Grass plants; (4) Plants of the genus Zea mays or wheat; (5) Corn or wheat.

4. The use according to claim 2 or 3, wherein: The promoting plant growth comprises: Increase plant aboveground and / or root biomass.

5. The use according to claim 2 or 3, wherein: The method of improving the phosphorus absorption rate of plants comprises: Increase the phosphorus content in the aboveground parts and / or roots of plants.

6. The use according to claim 2 or 3, wherein: The heavy metal pollution includes: Cadmium contamination, mercury contamination, lead contamination, chromium contamination and / or arsenic contamination.

7. The use according to claim 2 or 3, wherein: The mitigation of soil heavy metal pollution stress comprises: Reduce the accumulation of heavy metals in the aboveground parts and / or roots of plants during growth.

8. A composition, preferably a bacterial agent, comprising the arbuscular mycorrhizal fungus according to claim 1.

9. A method for preparing a composition, comprising the step of using the arbuscular mycorrhizal fungus according to claim 1 as a component of the composition.

10. A method for growing plants, comprising the step of contacting the arbuscular mycorrhizal fungi according to claim 1 or the composition according to claim 8 with plants during the process of growing plants.

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