Arbuscular mycorrhizal fungus bio-fertilizer as well as preparation method and application thereof

Abstract

The invention relates to an application of an arbuscular mycorrhizal fungus bio-fertilizer, belongs to the technical field of agriculture, and particularly relates to an application of the arbuscular mycorrhizal fungus bio-fertilizer in tea garden cultivation management. According to the method, after spring tea is pruned, the microbial fertilizer containing arbuscular mycorrhizal fungi is applied to the tea trees for the first time, matched water and fertilizer management is combined, symbiotic arbuscular mycorrhiza is formed in the root systems of the tea trees after fertilization is conducted for 3 months, the morbidity of anthracnose pathogenic bacteria on leaves of the tea trees is effectively reduced, photosynthesis of the tea trees is improved, and growth of the tea trees is promoted.

Description

Technical Field

[0001] The invention belongs to the technical field of agriculture, and in particular relates to an arbuscular mycorrhizal fungus biological fertilizer and a preparation method and application thereof. Background Art

[0002] Tea trees are an important traditional cash crop in my country. Tea bud and leaf anthracnose is a worldwide fungal disease that occurs in all tea-growing areas in China. In recent years, the frequency and area of ​​occurrence have increased, and the severity of the disaster has worsened. Tea anthracnose mostly occurs in warm and humid areas and seasons, seriously affecting tea production and quality. Statistics show that the number of crown diseased leaves in tea gardens with severe disease can reach 3,000-4,000 / m 2 , resulting in an average reduction of 25%-30% in autumn tea production and 15%-23% in the following spring tea production, causing serious economic losses. Spraying chemical agents such as carbendazim, thiophanate-methyl or thiophanate-methyl is still the most effective means of preventing and controlling tea anthracnose in production, but the continuous application of chemical pesticides will lead to tea quality and safety problems, which is not conducive to the green and sustainable development of the tea industry. Therefore, the development of environmentally friendly and growth-promoting biological agents has an important role in promoting the green prevention and control of tea anthracnose.

[0003] Arbuscular mycorrhizal fungi (AMF, Glomomycetes) are a type of ancient fungi that have existed in the earth's soil for 400-450 million years and can form a mutually beneficial symbiotic relationship with 74% of vascular plants. Studies have shown that arbuscular mycorrhizal symbiosis is beneficial to the growth and stress resistance of host plants, such as promoting plant photosynthesis, promoting the absorption of elements such as phosphorus, nitrogen, potassium, and iron, and is beneficial to the quality formation of crop fruits and buds and leaves. For example, it improves tolerance to abiotic stresses such as drought, salt damage, and heavy metals, and improves resistance to biotic stresses such as powdery mildew, rust, and streptomyces. In addition, arbuscular mycorrhizal fungi are a "bridge" between host plants and soil flora, which helps to build a stable plant root microbial community, improve soil structure and properties, and promote the circulation of carbon, nitrogen, and phosphorus in the atmosphere-soil. At present, arbuscular mycorrhizal fungi have been used as environmentally friendly microbial fertilizers in the cultivation and management of crops such as vegetables, rice, and corn, but have not yet been used in tea garden cultivation and management. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention combines the research foundations such as the growth law of tea trees, the law of the occurrence of anthracnose, and the colonization principle of arbuscular mycorrhizal fungi to design and provide a technical solution of arbuscular mycorrhizal fungi biofertilizer and its preparation method and application, so as to reduce the incidence of anthracnose of tea trees and promote the growth of tea trees at the same time, which is specifically achieved through the following technical solutions:

[0005] The first aspect of the present invention provides a method for preparing arbuscular mycorrhizal fungal biofertilizer, which comprises the following steps:

[0006] Arbuscular mycorrhizal fungi are evenly spread on the substrate after high-temperature sterilization, the successfully germinated corn seeds are put into the substrate, and the corn is cultured in an environment with controlled light, temperature and humidity. After three months of cultivation, the corn plants are allowed to die of natural drought, the above-ground parts are cut off, the surface substrate is removed, and the corn roots are cut into pieces and mixed evenly with the substrate to obtain arbuscular mycorrhizal fungi biofertilizer.

[0007] Furthermore, the matrix is ​​a mixture of soil, fine sand and vermiculite, and the mass ratio of soil:fine sand:vermiculite is 1:2:1.

[0008] Furthermore, the light, temperature and humidity controllable environment is specifically a light intensity of 600-1200 μmol / (m 2 ·s), photoperiod of 14h / 10h, temperature of 20-30 degrees Celsius, and humidity of 50%-75%.

[0009] The second aspect of the present invention provides an arbuscular mycorrhizal fungal biofertilizer obtained by any one of the above preparation methods.

[0010] The third aspect of the present invention provides the use of the above-mentioned arbuscular mycorrhizal fungi biological fertilizer in tea garden cultivation management.

[0011] Furthermore, the application has the effect of improving the resistance of tea trees to anthracnose and reducing the incidence of tea trees to anthracnose.

[0012] Furthermore, the application is to promote the growth of tea trees.

[0013] Furthermore, the specific application time of the arbuscular mycorrhizal fungi biological fertilizer is after spring tea pruning.

[0014] The present invention proposes for the first time to apply microbial fertilizers containing arbuscular mycorrhizal fungi to tea trees after spring tea pruning, combined with supporting water and fertilizer management, to form symbiotic arbuscular mycorrhizae in the root systems of the tea trees three months after fertilization, which effectively reduces the incidence of anthracnose pathogens on tea leaves, improves the photosynthesis of tea trees, and promotes the growth of tea trees. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram of the colonization of arbuscular mycorrhizal fungi in the root system of tea plants;

[0016] Figure 2 This is a picture showing the occurrence of anthracnose in tea leaves after infection with anthracnose bacteria;

[0017] Figure 3 This is a test chart of tea tree growth and development indicators. DETAILED DESCRIPTION

[0018] The present invention is described in detail below in conjunction with specific implementation modes.

[0019] Preparation of Arbuscular Mycorrhizal Fungal Biofertilizer:

[0020] The commercially available arbuscular mycorrhizal fungi Rhizophagus irregularis (R. irregularis) were evenly spread in the high temperature sterilized substrate (soil: fine sand: vermiculite = 1:2:1), 10-15 cm from the soil surface. The successfully germinated corn seeds were placed in the substrate. The corn was placed in an environment with controlled light, temperature and humidity, and the light intensity was 600-1200 μmol / (m 2 ·s), the photoperiod is 14h / 10h, the temperature is 20-30℃, the humidity is 50%-75%, and the low-phosphorus Hogland nutrient solution is watered regularly. During this period, use an insect-proof net with high light transmittance to protect the plants to avoid contamination by bacteria and pests. After three months of cultivation, gradually reduce the concentration of the nutrient solution and reduce the number of waterings. Finally, wait for the corn plants to die of natural drought, cut off the above-ground part, remove 2-5cm of the surface matrix, then cut the corn roots into pieces and mix them evenly with the matrix to obtain arbuscular mycorrhizal fungal biofertilizer.

[0021] The wet sieve pouring sucrose centrifugation method was used to determine the fungal spore density in the matrix. According to the inoculation scheme of 400-500 spores per tea seedling, arbuscular mycorrhizal fungal biofertilizer was added to the root soil of the tea tree, and the subsequent application of compound fertilizer could be reduced to 3 / 4.

[0022] Fertilization treatment of tea tree arbuscular mycorrhizal fungi biofertilizer: After spring tea pruning, microbial fertilizer containing arbuscular mycorrhizal fungi was applied to tea trees, combined with supporting water and fertilizer management. Three months after inoculation, clear arbuscular mycorrhizal fungi and root hyphae were seen in the root system of tea trees by trypan blue staining, indicating that the arbuscular mycorrhizal fungus R. irregularis can be successfully colonized in 'Longjing 43' ( Figure 1 A) According to statistics, the colonization rate of arbuscular mycorrhizal fungi in the roots of 'Longjing 43' tea trees reached 24.8% three months after inoculation, and 35.8% six months after inoculation ( Figure 1 B).

[0023] Three months after the fungal colonization treatment, the leaves of the tea tree Longjing 43 inoculated with arbuscular mycorrhizal fungi (+AMF) and not inoculated with arbuscular mycorrhizal fungi (-AMF) were infected with the anthracnose fungus Colletotrichum fructicola (C. fructicola) at a spore concentration of about 10 6 After 7 days of infection, large lesions appeared on the leaves of tea trees in the -AMF treatment group, with an area of ​​about 0.15 cm 2 However, the pathogen on the tea leaves in the +AMF treatment group had not yet spread, and the lesion area was less than 0.05 cm 2 ( Figure 2A, B). Through the quantitative detection of ITS / Cs18srDNA of C. fructicola in leaves, it was found that after infection with C. fructicola, C. fructicola multiplied in large numbers on the leaves of the tea tree in the -AMF treatment group, but its reproduction was effectively inhibited on the leaves treated with +AMF ( Figure 2 C). Malondialdehyde (MDA) is a commonly used indicator of plant cell membrane lipid peroxidation, which will increase when subjected to stress. Through the detection of MDA, it can be clearly seen that the tea trees in the +AMF treatment group can effectively alleviate the damage caused by C. fructicola infection to tea leaves ( Figure 2 D). The above data show that tea plant colonization with arbuscular mycorrhizal fungus R. irregularis biofertilizer can effectively alleviate the incidence of tea plant anthracnose.

[0024] In addition, by testing the growth and development indicators of tea trees, we found Figure 3 It is clear that arbuscular mycorrhizal fungi can increase the net photosynthetic rate of tea trees, increase the internode length and stem thickness of tea trees, and the biofertilizer colonized with arbuscular mycorrhizal fungi R. irregularis is beneficial to the growth of tea trees.

[0025] Tea tree growth and development index detection method: Select sunny days from 9:00 to 11:00, use a portable photosynthetic meter (LI-6400XT, LI-COR, USA) to detect the net photosynthetic rate of mature leaves (4th and 5th leaf positions) of tea trees. Use a vernier caliper to measure the length of the internodes of the 3rd and 4th leaf positions, and measure the stem diameter at the 4th leaf position.

Claims

1. A method for preparing arbuscular mycorrhizal fungal biofertilizer, characterized in that: The following steps are involved: Arbuscular mycorrhizal fungi are evenly spread on the substrate after high-temperature sterilization, the successfully germinated corn seeds are put into the substrate, and the corn is cultured in an environment with controlled light, temperature and humidity. After three months of cultivation, the corn plants are allowed to die of natural drought, the above-ground parts are cut off, the surface substrate is removed, and the corn roots are cut into pieces and mixed evenly with the substrate to obtain arbuscular mycorrhizal fungi biofertilizer.

2. The method for preparing an arbuscular mycorrhizal fungal biofertilizer according to claim 1, characterized in that: The matrix is ​​a mixture of soil, fine sand and vermiculite, and the mass ratio of soil:fine sand:vermiculite is 1:2:

1.

3. The method for preparing an arbuscular mycorrhizal fungal biofertilizer according to claim 1, characterized in that: The light, temperature and humidity controllable environment is specifically a light intensity of 600-1200 μmol / (m 2 ·s), photoperiod of 14h / 10h, temperature of 20-30 degrees Celsius, and humidity of 50%-75%.

4. The arbuscular mycorrhizal fungal biofertilizer obtained by the preparation method according to any one of claims 1 to 3.

5. Use of the arbuscular mycorrhizal fungi biofertilizer as claimed in claim 1 in tea garden cultivation management.

6. The use according to claim 5, characterized in that The application is to improve the resistance of tea trees to anthracnose and reduce the incidence of tea trees anthracnose.

7. The use according to claim 5, characterized in that The application is to promote the growth of tea trees.

8. The use according to claim 5, characterized in that The specific application time of the arbuscular mycorrhizal fungi biological fertilizer is after spring tea pruning.

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