A greenhouse cultivation method for liquid spawn of Morchella

Abstract

The invention provides a greenhouse cultivation method for morels liquid spawn, which specifically comprises the following steps: step one, configuring a culture medium and an exogenous nutrient bag; step two, purifying the spawn; step three, preparing the purified spawn into a spawn liquid; step four, evenly spreading the spawn liquid on a bed surface; step five, managing during the growth period; step six, harvesting when the total length of the fruiting body is 12-14 cm and the length of the cap is 7-9 cm. The greenhouse cultivation method has the advantages of short cultivation cycle, convenient sowing, low production cost, etc., the yield reaches more than 200 kg / mu, and two-season cultivation in a plateau greenhouse is realized at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of Morchella cultivation, and in particular to a greenhouse cultivation method of Morchella liquid spawn. Background Art

[0002] The unique climate and ecosystem of the plateau breed rich biodiversity, including a large number of wild Morchella resources. Morchella has a unique flavor, delicious meat, rich in a variety of nutrients and bioactive substances, and has extremely high medicinal and edible value, and is deeply loved by people all over the world.

[0003] Morchella has been commercially produced for more than ten years. The industry scale has been expanding and developing rapidly. The cultivation area of ​​Morchella has been expanding, the output has been increasing, and the industry has begun to take shape. Except for a few cultivation modes such as factory three-dimensional cultivation and forest bionic cultivation, Morchella artificial cultivation is mainly based on greenhouse cultivation, and due to the unique cool climate of the plateau area, it can be cultivated twice a year.

[0004] At present, the production of cultivars in Morchella cultivation technology is mainly based on inoculating the original seed into solid culture bags. The solid culture bag matrix is ​​mainly made of wheat, sawdust and corn cobs, supplemented with other nutritional ingredients. The cost of culture bag seed production is high, and the wheat consumption is large. The research on Morchella cultivation grain-saving technology is becoming increasingly urgent. Liquid strains have the advantages of short culture cycle, convenient sowing and low production cost, but there are no reports on their direct application in production.

[0005] Therefore, providing a method for cultivating Morchella liquid spawn in greenhouse becomes an urgent problem to be solved. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a greenhouse cultivation method for Morchella liquid spawn, which specifically comprises the following steps:

[0007] Step 1: Prepare the culture medium

[0008] Potato, glucose, agar and water are mixed in a ratio of 20 g:2 g:2 g:100 ml, sterilized at 121° C. and 103 kPa for 20 min, and cooled to obtain PDA culture medium; preferably, a flat plate culture dish is prepared;

[0009] Peptone, yeast extract powder, MgSO4·7H2O, KH2PO4, K2HPO4, glucose and distilled water are mixed in a ratio of 2g:1g:0.5g:0.5g:1g:20g:1L, sterilized at 121°C and 103kPa for 20min, and cooled to obtain CYM liquid culture medium; or potatoes, glucose and water are mixed in a ratio of 200g:20g:1L, sterilized at 121°C and 103kPa for 20min, and cooled to obtain PDB culture medium;

[0010] Wheat, rape straw, humus, corn cobs and lime are mixed in a mass ratio of 50:30:10:9:1, sprayed with water to 60-65%, and packed in 12cm×24cm polypropylene bacteria bags at 121°C and 103kPa for sterilization for 3h to obtain exogenous nutrient bags; preferably, 3d before the preparation of the exogenous nutrient bags, the wheat is soaked in 25°C water for 16-20h, then mixed with rape straw and corn cobs and sprayed with water for pile fermentation, and then mixed with other materials after the fermentation is completed.

[0011] Step 2: Purify the strain

[0012] The mother strain of Morchella was inoculated into the PDA medium, sealed, and cultured at 20°C in a dark environment for 5 days. A non-polluted PDA medium was selected, and a 9 mm diameter bacterial cake was punched out with a hole puncher. The bacterial cake was inoculated into a new PDA medium, sealed, and cultured at 20°C in a dark environment again.

[0013] Step 3: Prepare bacterial culture solution

[0014] When the mycelium is full of PDA medium, select uncontaminated PDA medium, punch 20 bacterial cakes per PDA medium with a hole puncher, inoculate into CYM liquid medium, seal, and culture at 20°C and 160rpm constant temperature shaking. When the mycelium is full of CYM liquid medium, obtain the bacterial liquid;

[0015] Alternatively, when the mycelium is full of PDA medium, select uncontaminated PDA medium, punch 20 bacterial cakes per PDA medium with a hole puncher, inoculate into PDB medium, seal, and culture at 20°C and 160rpm constant temperature shaking. When the mycelium is full of PDB medium, obtain the bacterial liquid;

[0016] Preferably, when preparing the bacterial seed liquid, the prepared bacterial seed liquid can also be mixed with the liquid culture medium in a volume ratio of 1:10, sealed, and cultured at a constant temperature of 20°C and 160rpm with shaking. When the mycelium fills the liquid culture medium, a new bacterial seed liquid is obtained.

[0017] Step 4: Sowing seeds

[0018] Sowing time: Spring planting, when soil temperature is ≤15℃ and air temperature is ≤20℃. Generally, sowing can be done from early February to mid-March.

[0019] In autumn, the temperature in the greenhouse should be > 0℃. Generally, sowing can be done from mid-to-late October to mid-December.

[0020] 30 days before sowing, treat the soil, clean and organize the sundries in the greenhouse, remove the residual agricultural waste and impurities in the soil, keep the greenhouse clean and tidy, and after cleaning for 10-15 days, use a roller shutter machine to raise the outer cotton felt of the greenhouse to the roof, seal the inner plastic film, and use the method of sun exposure and high temperature to kill the surface bacteria and pests of the soil. Then apply 50-100kg / mu of quicklime to the soil, rotary till the surface 20-30cm of the soil, water until the soil moisture content is 22-28%, and after 7-15 days, the soil surface is slightly moist. At this time, turn over the surface 15-20cm of the soil and make ridges. The ridge width is 0.8-1.2m, the ridge height is 10-15cm, and a 30cm working path is set between the ridges;

[0021] Sowing is carried out when the soil pH in the greenhouse is 6.5-7.5. The bacterial liquid is diluted 5-10 times with water and evenly spread on the bed surface. The amount of bacterial liquid is 140-200L / mu. Then water is applied until the soil moisture content is 20-25%. 7-10 days after sowing, external nutrient bags are placed.

[0022] Unlike solid spawn cultivation, liquid spawn cultivation rarely or never produces "fungus frost".

[0023] Preferably, after sowing, the soil is raked to cover the fungus by 2-3 cm;

[0024] Preferably, the amount of exogenous nutrient bags is 1500 bags / mu, and each bag is placed on the bed surface with an interval of 20-30cm; most preferably, before placing, use a disinfectant to cut 2 lines on one side of the bag or punch 9-18 holes with a nail, with the cut or hole facing down, and put it on the bed surface, and compact it with a little force to make the morel hyphae closely contact the exogenous nutrient bag. After the nutrient bag is placed, the air and soil temperature and humidity control are the same as the management during the spawning period. If the nutrient bag is found to be contaminated by bacteria, the exogenous nutrient bag is quickly evacuated outside the shed to avoid the spread of bacteria and aggravation of the disease.

[0025] Step 5: Growth management

[0026] Management during the spawning period: air temperature ≤ 20°C, relative humidity 80-95%, soil temperature ≤ 15°C, soil moisture content 15-25%;

[0027] Preferably, the greenhouse is managed with curtains closed most of the time during the spawning period. If the temperature and soil temperature in the greenhouse are high, you can choose to open the curtains for ventilation and cooling before the sun rises or after the sun sets in the morning and evening. The ventilation time should not be too long to avoid a sudden drop in relative humidity and difficulty in moisturizing. When the outside temperature is low, you can open the curtains at noon to increase the temperature. Note that the curtains can be opened to the sunshade net to avoid direct sunlight on the greenhouse. When the temperature and humidity are suitable, choose a suitable time every 2-3 days to ventilate the greenhouse.

[0028] Management during mushroom accelerator period: air humidity 85-95%, soil moisture 25-30%; water stimulation is carried out 40-80 days after sowing morels and when the ground temperature is maintained at 8-15℃, primordium can be seen after 5-10 days of closed greenhouse management;

[0029] Preferably, the water stimulation is watering by sprinkler irrigation, watering until the soil moisture content is 22-28%.

[0030] Management from primordium differentiation to young mushroom stage: temperature 4-18℃, relative humidity>85%;

[0031] Management during the fruiting body growth period: After the 1.5-3cm mushrooms are formed, the temperature should be 10-18℃, the relative humidity should be 80-90%, and the soil moisture content should be 20-25%;

[0032] During the fruiting body maturity stage, the relative humidity of the air is 70-85%, and the soil moisture content is reduced to 18-22%;

[0033] Step 6: When the total length of the fruiting body is 12-14cm and the cap length is 7-9cm, it can be harvested.

[0034] The present invention also includes pest control, less or no application of chemical pesticides and killing agents. For fungal diseases, strengthen the early soil sterilization treatment, remove the contaminated nutrient bags from the greenhouse in time if found, and spread quicklime near the contaminated bags; for mold-contaminated fruiting bodies, remove them in time; for disk fungus diseases, reduce the continuous cropping years of greenhouse morels, and rotate other crops after two years of cultivation. Mouse traps, sticky mouse boards and rat poison should be placed in the greenhouse. Sprinkle quicklime in places where slugs often appear. If a large number of slug activity traces are seen, spread tetraacetaldehyde to lure and kill them. Flying insects such as mushrooms, mosquitoes, mushroom flies, etc. can be lured and killed by hanging sticky insect boards and insect-attracting lamps.

[0035] The present invention has the following advantages:

[0036] (1) Cost saving: At present, the cultivation of Morchella is mainly based on solid material bag strains, of which wheat is the main raw material of the cultivation. The general strain dosage is 125-150kg / mu; the liquid strain dosage is 140-200L / mu. The cost of solid wheat grain strains is about 3 yuan / kg, plus other auxiliary materials 1 yuan / kg, the cost of solid cultivation strains per mu is at least 500 yuan; while the cost of liquid strains is only 1 yuan / L, and the lowest cost per mu is only 140 yuan, which is more than 70% less than the cost of solid strains, greatly saving production costs and improving economic benefits.

[0037] (2) Save time: Solid culture of Morchella generally requires more than 20 days, while liquid culture generally only requires 7 days, which saves 65% of the time compared with solid culture, greatly shortening the seed production time and improving production efficiency. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the invention, not all of the embodiments. Based on the embodiments of the invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the invention.

[0039] From 2021 to 2023, the experimental cultivation of liquid spawn of Morchella was carried out continuously in the greenhouse facilities of the Academy of Agriculture and Forestry Sciences of Qinghai University and the National Plateau Modern Agricultural Science and Technology Demonstration Park in Huzhu County (Examples 1-2).

[0040] Example 1

[0041] Step 1: Prepare the culture medium

[0042] Prepare PDA culture medium: 20 g glucose, 200 g potato, 20 g agar, distilled water to 1 L, sterilize at 121°C for 20 min, cool to obtain PDA culture medium, and prepare a flat plate culture dish;

[0043] CYM liquid medium: 2 g of peptone, 1 g of yeast extract powder, 0.5 g of MgSO4·7H2O, 0.5 g of KH2PO4, 1 g of K2HPO4, 20 g of glucose, 1 L of distilled water, sterilize at 121°C for 20 min, and obtain CYM liquid medium after cooling;

[0044] Exogenous nutrient bag: Mix wheat, rape straw, humus, corn cob, and lime in a mass ratio of 50:30:10:9:1, adjust the moisture to 60-65%, bag them in 12cm×24cm polypropylene bags, and sterilize them at 100℃ and normal pressure for 10-36h or at 121℃ and 103kPa for 3h to obtain exogenous nutrient bags.

[0045] Three days before preparing the exogenous nutrient bag, the wheat was soaked in 25°C water for 16-20 hours, then mixed with rape straw and corn cobs and sprayed with water for pile fermentation. After fermentation, it was mixed with other materials.

[0046] Step 2: Purify the strain

[0047] On the clean bench, transfer the mother strain of Morchella to the PDA plate culture dish, seal it and culture it in the dark at 20℃ in a constant temperature incubator for 5 days. Observe the growth and contamination of mycelium every day, select the culture plate with good growth, no pigment and no contamination, use a hole puncher to punch a cake (9mm in diameter) and place it in the center of a new PDA plate culture dish, seal it, and culture it in the dark at 20℃ again.

[0048] Step 3: Prepare bacterial culture solution

[0049] When the mycelium fills the PDA plate culture dish, select the uncontaminated PDA plate culture dish, punch 20 bacterial cakes in each PDA plate culture dish with a hole puncher, inoculate into CYM liquid culture medium, fill 1L CYM liquid culture medium in a 2L conical flask, seal it, and culture it at 20℃ and 160rpm constant temperature shaking for 5-7 days. When a large number of spherical or flocculent mycelium fill the culture liquid, obtain the bacterial liquid;

[0050] Step 4: Sowing seeds

[0051] Choose a greenhouse with good thermal insulation performance, complete facilities such as roller blinds, film rolls, irrigation, ventilation, and water and electricity. Keep the temperature above 0℃. Hang a 6-pin shade net along the greenhouse frame, 1.6m above the ground on the direct sunlight side of the greenhouse. The soil in the greenhouse should be free of obvious soil-borne diseases, and the previous crop should grow well and without continuous cropping diseases. The soil should be sandy loam, loam or chestnut soil with good air permeability and water retention, and free of pollution sources such as pesticides, fungicides and herbicides. The soil pH is 6.5-7.5.

[0052] 30 days before sowing morels, treat the soil, clean and tidy up the debris in the greenhouse, remove the residual agricultural waste and impurities in the soil, keep the greenhouse clean and tidy, and 10 days after cleaning, raise the outer cotton felt of the greenhouse to the roof with a roller shutter machine, seal the inner plastic film, and use the method of sun exposure and high temperature to kill the bacteria and pests on the soil surface. Then apply 100 kg / mu of quicklime, rotary till the surface of the soil to 30 cm, flood and irrigate the bottom with water. After 7 days, when the soil surface is slightly moist and can be worked, shallowly turn over the surface 20 cm to make ridges. The ridge width is 1m, the ridge height is 15cm, and a 30cm working path is set between the ridges.

[0053] When sowing, dilute the bacterial liquid 10 times with water and evenly spread it on the bed surface. The amount of bacterial liquid is 150L / mu. Harrow the soil to cover the bacterial liquid by 2cm, then water it until the soil moisture content is 20-25%. After 7 days of sowing, place the exogenous nutrient bag.

[0054] Step 5: Growth management

[0055] Management during the spawning period: air temperature ≤ 20°C, relative humidity 80-95%, soil temperature ≤ 15°C, soil moisture content 15-25%;

[0056] Management during mushroom accelerator period: air humidity 85-95%, soil moisture 25-30%; 50 days after sowing morels, when the ground temperature is maintained at 8-15℃, water stimulation is carried out, watering is carried out until the soil moisture content is 22-28%, and primordium is seen after 5 days of closed greenhouse management;

[0057] Management from primordium differentiation to young mushroom stage: temperature 4-18℃, relative humidity>85%;

[0058] Management during the fruiting body growth period: After the 1.5cm mushroom is formed, the temperature is 10-18℃, the relative humidity is 80-90%, and the soil moisture content is 20-25%;

[0059] During the fruiting body maturity stage, the relative humidity of the air is 70-85%, and the soil moisture content is reduced to 18-22%;

[0060] Step 6: When the total length of the fruiting body is 12-14cm and the length of the cap is 7-9cm, it can be harvested. When harvesting, hold the stem with one hand and a non-metallic blade with the other hand, cut horizontally from the base of the stem near the ground, gently put it into the harvesting container, and classify it according to grade. Fresh products are sold in time, or dried and stored. The yield of Morchella reaches more than 200kg / mu, and at the same time, high-altitude greenhouses can be cultivated twice a year.

[0061] Example 2

[0062] Step 1: Prepare the culture medium

[0063] Prepare PDA culture medium: 20 g glucose, 200 g potato, 20 g agar, distilled water to 1 L, sterilize at 121°C for 20 min, cool to obtain PDA culture medium, and prepare a flat plate culture dish;

[0064] PDB medium: 200 g potato, 20 g glucose, distilled water to 1 L, autoclave at 121°C for 20 min, and cool to obtain PDB medium;

[0065] Exogenous nutrient bag: Mix wheat, rape straw, humus, corn cob, and lime in a mass ratio of 50:30:10:9:1, adjust the moisture content to 60-65%, bag them in 12cm×24cm polypropylene bags, and sterilize them at 100℃ and normal pressure for 10-36h or at 121℃ and 103kPa for 3h to obtain exogenous nutrient bags.

[0066] Three days before preparing the exogenous nutrient bag, the wheat was soaked in 25°C water for 16-20 hours, then mixed with rape straw and corn cobs and sprayed with water for pile fermentation. After fermentation, it was mixed with other materials.

[0067] Step 2: Purify the strain

[0068] On the clean bench, transfer the mother strain of Morchella to the PDA plate culture dish, seal it and culture it in a constant temperature incubator at 20℃ for 5 days in the dark, observe the growth of mycelium and contamination every day, select the culture plate with good growth, no pigment and no contamination, use a hole puncher to punch a bacterial cake (9mm diameter) and place it in the center of a new PDA plate culture dish, seal it, and culture it in a dark environment at 20℃ again;

[0069] Step 3: Prepare bacterial culture solution

[0070] When the hyphae fill the PDA plate culture dish, select a non-contaminated PDA plate culture dish, punch 20 bacterial cakes on each PDA plate culture dish with a hole puncher, inoculate into PDB medium, fill 1L PDB medium in a 2L conical flask, seal it, and culture it at 20℃ and 160rpm constant temperature shaking for 5-7 days. When a large number of spherical or flocculent hyphae fill the culture solution, obtain the bacterial seed solution;

[0071] Step 4: Sowing seeds

[0072] Choose a greenhouse with good thermal insulation performance, complete facilities such as roller blinds, film rolls, irrigation, ventilation, and water and electricity. Keep the temperature above 0℃. Hang a 6-pin shade net along the greenhouse frame, 1.6m above the ground on the direct sunlight side of the greenhouse. The soil in the greenhouse should be free of obvious soil-borne diseases, and the previous crop should grow well and without continuous cropping diseases. The soil should be sandy loam, loam or chestnut soil with good air permeability and water retention, and free of pollution sources such as pesticides, fungicides and herbicides. The soil pH is 6.5-7.5.

[0073] 30 days before sowing morels, treat the soil, clean and tidy up the debris in the greenhouse, remove the residual agricultural waste and impurities in the soil, keep the greenhouse clean and tidy, and 10 days after cleaning, raise the outer cotton felt of the greenhouse to the roof with a roller shutter machine, seal the inner plastic film, and use the method of sun exposure and high temperature to kill the bacteria and pests on the soil surface. Then apply 100 kg / mu of quicklime, rotary till the surface of the soil to 30 cm, flood and irrigate the bottom with water. After 7 days, when the soil surface is slightly moist and can be worked, shallowly turn over the surface 20 cm to make ridges. The ridge width is 1m, the ridge height is 15cm, and a 30cm working path is set between the ridges.

[0074] When sowing, dilute the bacterial liquid 10 times with water and evenly spread it on the bed surface. The amount of bacterial liquid is 200L / mu. Harrow the soil to cover the bacterial liquid by 2cm, then water it until the soil moisture content is 20-25%. After 7 days of sowing, place the exogenous nutrient bag.

[0075] Step 5: Growth management

[0076] Management during the spawning period: air temperature ≤ 20°C, relative humidity 80-95%, soil temperature ≤ 15°C, soil moisture content 15-25%;

[0077] Management during mushroom growth period: air humidity 85-95%, soil moisture 25-30%; 50 days after Morchella sowing, water stimulation is carried out when the ground temperature is maintained at 8-15℃, and the water stimulation is watering by sprinkler irrigation until water accumulates in the furrows between the furrows and is parallel to the furrow surface, and the soil moisture content is 22-28%. Primordia are seen after 5 days of closed greenhouse management;

[0078] Management from primordium differentiation to young mushroom stage: temperature 4-18℃, relative humidity>85%;

[0079] Management during the fruiting body growth period: After the 1.5cm mushroom is formed, the temperature is 10-18℃, the relative humidity is 80-90%, and the soil moisture content is 20-25%;

[0080] During the fruiting body maturity stage, the relative humidity of the air is 70-85%, and the soil moisture content is reduced to 18-22%;

[0081] Step 6: When the total length of the fruiting body is 12-14cm and the length of the cap is 7-9cm, it can be harvested. When harvesting, hold the stem with one hand and a non-metallic blade with the other hand, cut horizontally from the base of the stem near the ground, gently put it into the harvesting container, and classify it according to grade. Fresh products are sold in time, or dried and stored. The yield of Morchella reaches more than 200kg / mu, and at the same time, high-altitude greenhouses can be cultivated twice a year.

[0082] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A greenhouse cultivation method for liquid Morchella spp., characterized in that: The following steps are involved: Step 1: Prepare the culture medium Prepare PDA culture medium, liquid culture medium and exogenous nutrient bags; Step 2: Purify the strain Inoculate the mother strain of Morchella into the PDA culture medium, seal it, and culture it in a dark environment at a constant temperature of 18-22°C for 3-7 days. Select an uncontaminated PDA culture medium, inoculate the hyphae on it into a new PDA culture medium, seal it, and culture it in a dark environment at a constant temperature of 18-22°C again; Step 3: Prepare bacterial culture solution When the mycelium is full of PDA medium, select uncontaminated PDA medium, inoculate the mycelium on it into CYM liquid medium, seal it, and culture it at 18-20°C and 120-160rpm constant temperature shaking. When the mycelium is full of CYM liquid medium, obtain the seed liquid; Step 4: Sowing seeds 0℃<temperature in greenhouse≤20℃, soil pH in greenhouse6.5-7.5, till the soil and make ridges, dilute the bacterial liquid with water 5-10 times and evenly spread it on the ridge surface, the amount of bacterial liquid is 140-200L / mu, then water until the soil moisture content is 20-25%, 7-10 days after sowing, place exogenous nutrient bags to make the mycelium contact the exogenous nutrient bags; Step 5: Growth management Management during the spawning period: air temperature ≤ 20°C, relative humidity 80-95%, soil temperature ≤ 15°C, soil moisture content 15-25%; Management during mushroom stimulating period: air humidity 85-95%, soil moisture content 25-30%; water stimulation is carried out 40-80 days after sowing morels and when the ground temperature is maintained at 8-15℃; Management from primordium differentiation to young mushroom stage: temperature 4-18℃, relative humidity>85%; Management during the fruiting body growth period: After the 1.5-3cm mushrooms are formed, the temperature should be 10-18℃, the relative humidity should be 80-90%, and the soil moisture content should be 20-25%; During the fruiting body maturity stage, the relative humidity of the air is 70-85%, and the soil moisture content is reduced to 18-22%; Step 6: When the total length of the fruiting body is 12-14cm and the cap length is 7-9cm, it can be harvested.

2. A greenhouse cultivation method for liquid Morchella spp. according to claim 1, characterized in that: The preparation method of the PDA culture medium described in step 1 is to mix potatoes, glucose, agar and water in a ratio of 20g:2g:2g:100ml, sterilize at a temperature of 121°C and a pressure of 103kPa for 20min, and obtain the PDA culture medium after cooling.

3. A greenhouse cultivation method for liquid Morchella spp. according to claim 1, characterized in that: The liquid culture medium in step 1 is CYM liquid culture medium or PDB culture medium; The preparation method of the CYM liquid culture medium is as follows: peptone, yeast extract powder, MgSO4·7H2O, KH2PO4, K2HPO4, glucose and distilled water are mixed in a ratio of 2g:1g:0.5g:0.5g:1g:20g:1L, the temperature is 121°C, the pressure is 103kPa, sterilized for 20min, and cooled to obtain the CYM liquid culture medium; The preparation method of the PDB culture medium is as follows: potatoes, glucose and water are mixed in a ratio of 200 g:20 g:1 L, sterilized at a temperature of 121° C. and a pressure of 103 kPa for 20 min, and the PDB culture medium is obtained after cooling.

4. A greenhouse cultivation method for liquid Morchella spp. according to claim 1, characterized in that: The preparation method of the exogenous nutrient bag described in step 1 is to mix wheat, rape straw, humus, corn cob, and lime in a mass ratio of 50:30:10:9:1, spray water to a moisture content of 60-65%, and sterilize at a temperature of 121°C and a pressure of 103 kPa for 3 hours after bagging to obtain an exogenous nutrient bag.

5. A greenhouse cultivation method for liquid Morchella spp. according to claim 4, characterized in that: Three days before preparing the exogenous nutrient bag, the wheat was soaked in 25°C water for 16-20 hours, then mixed with rape straw and corn cobs and sprayed with water for pile fermentation. After fermentation, it was mixed with other materials.

6. A greenhouse cultivation method for liquid Morchella spp. according to claim 1, characterized in that: Step three also includes mixing the prepared bacterial seed liquid with the liquid culture medium at a volume ratio of 1:10, sealing, and culturing at a constant temperature of 20° C. and 160 rpm. When the mycelium fills the liquid culture medium, a new bacterial seed liquid is obtained.

7. The method for cultivating Morchella liquid spawn in a greenhouse according to claim 1, characterized in that: In step 4, 30 days before sowing, clean and organize the debris in the greenhouse, remove the residual agricultural waste and impurities in the soil, and apply quicklime to the soil 10-15 days later, with a dosage of 50-100 kg / mu, and till the soil surface 20-30 cm, water until the soil moisture content is 22-28%, and then seal the greenhouse. After 7-15 days, plow the soil surface 15-20 cm to make ridges, with a ridge width of 0.8-1.2 m and a ridge height of 10-15 cm. Set a 30 cm working path between ridges.

8. The method for cultivating Morchella liquid spawn in a greenhouse according to claim 1, characterized in that: In step 4, after sowing, rake the soil to cover the fungus by 2-3 cm.

9. The method for cultivating Morchella liquid spawn in a greenhouse according to claim 1, characterized in that: In step 4, the amount of exogenous nutrient bags used is 1500 bags / mu, and each bag is placed on the bed surface with an interval of 20-30cm.