Practical techniques for seed production of Edible Fungi

With the vigorous development of edible mushroom industry, the demand for strains increases, but the existing strain production units are obviously on the low side, so many mushroom farmers have to introduce. Long-distance purchase and transportation of bacteria is not only expensive and high cost, but also easy to cause miscellaneous bacteria pollution due to broken bottles, thus seriously affecting the economic benefits of cultivated edible fungi. If mushroom farmers can master the strain production procedures and seed production techniques, carry out their own seed production, and gradually develop into professional seed production households, it is also a good way to get rich. The procedure of strain production is usually divided into three levels: mother species, original species and cultivated species, that is, the so-called first, second and third class bacteria. Among them, the separation and breeding of mother species is highly technical and requires refinement, while the production of original species and cultivated species is relatively simple. The following describes the production techniques of all levels of bacteria.

Separation and breeding of mother species

The mother species are mainly obtained by means of artificial selection, mutation breeding, cross breeding and protoplast fusion. As a general professional household of seed production, the mother species can be separated and cultivated by manual selection, and the specific steps and operation methods are as follows.

The main results are as follows: 1. The representative excellent mushroom body was selected as the provenance from the wild to artificial cultivation population. The standard for growing mushrooms is medium well, which is round in shape, fleshy and free from diseases and insect pests. Two seed mushrooms which meet the above criteria were collected and numbered, which were used as the material for separating the mother species. The samples collected from the cultivation room should be marked with the code of the original strain.

2. Medium preparation Agar medium, also known as PDA medium, commonly used formula is: potato 200murmur250g, Agar 15murmur20g, glucose 20Mel 25g, clear water 1000 ml. You can also add 1.5 grams of magnesium sulfate, 1.5 grams of vitamin B1, 3 grams of potassium dihydrogen phosphate and 3 grams of potassium dihydrogen phosphate. First wash and peel the potatoes, cut them into thin slices, put them in an aluminum pot and boil them with water for 30 minutes, remove them and filter them with 4 layers of gauze to extract juice. Then add Agar to the juice, stir while heating, let the Agar fully dissolve; then add glucose, boil for a few minutes, and filter with 4 layers of gauze to get the juice. Put the juice into a glass test tube while it is hot. Pack to 1par 5 of the tube length, plug the pipe mouth with cotton, or put the juice into a glass triangle bottle with a capacity of 20 ml. Then put it in a pressure cooker and sterilize it at a pressure of 108 KPA / cm at 98muri for about 30 minutes. Take it out in time after sterilization, arrange the test tube obliquely on the table while it is hot, and cool it into a solid bevel culture medium.

3. There are three methods of mother-species separation: spore bullet firing, tissue separation and intrabasal separation. ① spore ejection method. After disinfecting the surface of the mushroom and absorbing the water, the mushroom body was suspended in a triangular flask with Agar medium, and the robe in the mushroom body was naturally scattered on the medium to germinate hyphae. The mother seed can also be obtained by cutting a small mushroom body, attaching it to the surface of the test tube inclined medium and letting the spores germinate hyphae on the culture medium. ③ tissue isolation method. The sterilized mushroom is dissected in half from the handle of the mushroom by hand in the inoculation box, or cut with a blade to form a split of the mushroom body. At the junction of the cap and stalk or the fold of the fungus, a small piece of mushroom body was cut with an inoculation knife, then a 5mm x 10mm slice was cut longitudinally, a thin slice was picked up with an inoculation needle and connected to the center of the inclined culture medium, and each test tube was inoculated with a small slice, and the mother seed could be obtained when the hyphae germinated. (3) Base separation method. Select the wood section of the mushroom, cut off the bark and surface xylem, disinfect it with 70% alcohol, saw it into thin slices 1 cm thick, put it into 0.1% mercury-liter water and disinfect it for 2 minutes, then wash off the residue with sterilized water. Then the thin slices were split into strips 1 cm wide and inserted into the center of the bevel culture medium, and the mother seed was obtained after the hyphae grew. The mycelium with pure color and vigorous growth in the bag can also be obtained after disinfection in the bag of Pleurotus ostreatus, and the mycelium can also be obtained after the mycelium germinated.

4. After the bacteria were isolated and inoculated in the test tube by the above different methods, the test tube should be moved into the sterilized incubator or indoor culture in time, and the temperature should be controlled at about 25 ℃, so that the isolated spores or hyphae could develop at the appropriate temperature. In general, the spores germinated into colonies 4 days after the spore bullet was shot, and the hyphae grew full after 10 days. 3 days after tissue isolation and inoculation, the hyphae germinated and spread on the culture medium. 7 days after mushroom wood isolation and inoculation, the mycelium returned to growth.

5. The hyphae obtained by the above methods are not necessarily of high quality, but also need to be selected and purified. Therefore, after the mycelium germination, we should carefully observe, select the pure color, robust, normal growth, uninterrupted hyphae, take the hyphae together with the culture medium hook in the inoculation box, and insert them into the separate test tube culture medium. Under the constant temperature of 23 ℃ and 25 min, 7 Murray was cultured for 10 days, and after the mycelium was full of tube, it was observed and selected from it, which was the mother seed.

6. The mother species of rotating tube expansion can be expanded into offspring. Using the same slant culture medium, each branch can be expanded into 30 murmur50 offspring. Most of the offspring and mothers are supplied in production. It can turn the tube to expand again. Generally, each branch can be expanded into 25 offspring, but the tube can be transferred no more than 5 times.

7. In the experiment of mushroom emergence, the mother species separated and selected must also carry out the experiment of mushroom emergence. The method is as follows: the mother seed is inoculated on the sawdust medium in bottle or bag, and the suitable temperature culture is carried out according to the temperature requirements of all kinds of mushroom ear, and it is not proved that it can be used in production until the mushroom is produced.

Original seed propagation and culture

The mother seed is connected to the sawdust medium of the bottle or bag, and through culture, the original seed is formed. Its technical requirements are as follows.

1. The original sawdust medium formula is mixed sawdust 77.5%, wheat bran 20%, sucrose 1%, gypsum powder 1.2%, magnesium sulfate 0.3%. The pH value (before sterilization) is 6.5, and the water content is adjusted to 60%. Mix the above raw and auxiliary materials well and put them into a 750 ml glass strain bottle. The loading requirements are loose and tight. Tighten the cotton at the mouth of the bottle, then wrap the bottleneck and stopper with Kraft paper. Then put it in a high pressure sterilizer and sterilize it under the pressure of 147 KPA / square centimeter for 2.5 hours. It can also be sterilized under atmospheric pressure and kept at 100 ℃ for 11 hours. After reaching the standard, it can be taken out while it is hot and let it cool.

2. When the temperature of the inoculated strain is below 25 ℃, the test tube seed is divided into several decisions under the sterilization condition, and then quickly connected to the original culture medium through the alcohol lamp flame. Each mother seed can be divided into 6 bottles of the original seed.

3. After inoculation, the glass bacteria bottle was moved into the 25 ℃ culture room in time for culture. The space relative humidity is controlled above 70 ℃ to avoid strong light. The culture time of the original species of mushrooms generally takes 40 murmur50 days, while that of volvariella volvacea and Tremella fuciformis only takes 20 days.

4. In the process of removing and selecting excellent original species, observation should be carried out every day. If miscellaneous bacteria are found to be contaminated, they should be eliminated immediately.

Expanded cultivation of cultivated species

The original seed was expanded again on the same sawdust medium and cultured for 35 days under suitable temperature to be a cultivated species (also called production species), which can be used for production and cultivation. The cultivated species can use 750 ml special bottle of bacteria, because of the large amount of use, polypropylene seed bags are usually used. The size of the bag is 12cm x 24cm, 15cm x 28cm, 17cm x 33cm and so on. It can be used according to various mushroom ear characteristics and local customs. The culture medium is sterilized by atmospheric pressure sterilization stove, which requires that the sterilization temperature is up to 100℃ and the temperature is kept at 8m / m for 10 hours. after reaching the standard, unload the bag while it is hot and cool. When the feed temperature dropped below 25 ℃, the original seed of the selected variety was inserted under aseptic condition. Each bottle of original species can be expanded into 50 Murray and 60 bottles of cultivated species. The strain culture room is required to be clean and resistant to strong light, and the room temperature should be kept at 23 ℃ 25 min. Regular inspection shows that miscellaneous bacteria pollution should be eliminated in time, and the best should be selected to eliminate the bad. When the mycelium is full of bags and the tip mycelium is reversed and climbs up to 1m / m / m, it is a suitable age cultivated species.