CN111793567B - Mucoraceae fungus and application thereof in promoting paphiopedilum brandisil seeds to germinate and form seedlings - Google Patents

Abstract

The invention relates to a Mucilariaceae fungus and application thereof in promoting paphiopedilum brandisii seeds to germinate and form seedlings, wherein the fungus is a Mucilariaceae strain which is Tulasnellaceae sp.GYBQ02, and the preservation number of the fungus in the China center for type culture Collection is as follows: CCTCC NO: m2020130. The invention provides the morphology and physiological and biochemical characteristics of the strain. According to morphological, physiological, biochemical and nucleotide sequence analysis results, Tulasnellaceae GYBQ02 belongs to a fungus of Musaceae, the strain can be used for promoting Paphioleracea seeds to germinate to form seedlings, has strong specificity, can be used for inoculating the Paphioleracea seeds to obtain high-quality symbiotic seedlings, realizes high-efficiency seedling cultivation of symbiotic germination, can be used for nursery seedling cultivation or field fungus seed dressing direct seeding, has the advantages of low cost, high field cultivation survival rate, no tissue degradation problem and the like compared with tissue cultivation, and lays a foundation for developing bionic cultivation, species regression and population reconstruction of the Paphioleracea.

Description

Mucoraceae fungus and application thereof in promoting paphiopedilum brandisil seeds to germinate and form seedlings

Technical Field

The invention relates to a Mucilomycetaceae fungus and application thereof in promoting paphiopedilum brandisianum seeds to germinate and form seedlings, and belongs to the field of applied microorganisms.

Background

Douglas, Baphicacanthus (Douglas, IeachPaphiopedilum spicerianum) Assam (Assam), first discovered in northern india, was later found at the junction with burma in northern eastern india. The sepals in the flower are large and white, like a white flag, the upper part of the flower is bent forwards into an arch shape, and the false stamen is in an ear inverted heart shape, so that the ornamental and breeding value is very high. The field distribution of paphiopedilum concordatum is found in Pu' er city in Yunnan province of China for the first time in 2006, and the field distribution point is only confirmed in China, and only 20 plants are stored in the original field population. The population grows on a steep bank of small river ditch of village of foreign immigration villageThe growth environment is soft, the river bank is easy to collapse due to the fact that rain washes or the river rises, a coffee plantation is arranged around the river, the river is seriously polluted by waste materials of coffee processing factories, the growth environment is very severe, and the national ministry of forestry brings national ministry of forestry into 'national tiny population wild plant rescue protection engineering planning' in 2011.

The seeds of orchids are very small, with only underdeveloped embryos, and under natural conditions seed germination requires the use of specific symbiotic fungi to obtain nutrients. At present, the germination of the seeds of orchids mostly adopts an artificial culture medium to carry out non-symbiotic germination under the aseptic condition, although the germination rate is high, when endangered species are subjected to field regression, the survival rate of seedlings transplanted to the natural environment is low, and the subsequent growth is seriously limited because the symbiotic relationship with fungi in the nature cannot be established. The problem can be well solved by symbiotic germination of the seeds and the effective germination fungi under natural conditions. The effective fungi are mostly obtained by separating from roots of wild orchids, but because a large amount of endophytic fungi with unknown functions exist in the orchids, the screening and separation of the seed germination effective fungi become complicated and tedious, and meanwhile, whether the fungi in different orchids are the same as the effective symbiotic fungi at the seed germination stage is still uncertain. Therefore, obtaining the effective symbiotic fungi for seed germination is a key link for developing the regression of rare or endangered orchids.

Disclosure of Invention

The invention overcomes the defects of the prior art and provides the Mucilomycetaceae fungus and the application thereof in promoting the germination of paphiopedilum brandisii seeds to form seedlings.

The invention is realized by adopting the following technical scheme.

The fungus is a Mucor strain, is Tulasnellaceae sp. GYBQ02, and has a preservation number in China center for type culture Collection of: CCTCC NO: m2020130, preservation time is 2020, 5, month and 18. Address: wuhan university in Wuhan city of Hubei province.

The nrDNA ITS sequence in the nucleotide sequence of the strain is characterized in that: TATGCTTAAGTTCAGGGCGTAGTCCTACCCGAGTTGAGGTGTAAATGTCAAGTAATTTGTCCTAAGACGATTAGAAGCAGACTACAAAGGCTGACCTAACCAACGACGATCAAACTTATCACGCCAGAGGTAGACATCAAATAGTAAGTCCAGCTAATAATTTTAGGGTGAGTTGGAAACAAGTTCCAACAATAACACCCAAATCCAATATCACACAAGTTAATAAAAACTTGATGATTTGAGAATTTCAAGACACTCAACCGGGCATACCCTCCAGAATACTAGAGGGTGCAAGGTGCGTTCAAAGATTCGATGATTCACTGTGTTCTGCAAGTCACATTACTTATCGCAATTCGCTACGTTCTTCATCGAGTGGGATGCCAAGAGATCCGTTGCTGATGGTTGTATTAGGTTTATACAACTTGTCATTCTACAATACTTCAAATCATAGGGTATAGTAATAAAATACAGAGGCGTACACCAATTTCTTGGTAACCACCTCCATATTAGGGTGCACAGGTGTTTGGATTGAATAATGAAGGAGCGCACTTGCAAAGCCAGCGCATCCCCCAAAGTTATTCTTTAATGATCCTTC are provided.

The bacterial colony of the strain of the family Mucor of the invention is in a white blanket shape after being cultured on a PDA flat plate for 7 days, and has more aerial hyphae which grow in a regular circular way; culturing in a fungus incubator at 25 + -2 deg.C for 14 days, slicing the insert by conventional slicing method, observing under optical microscope to obtain mycelia with membrane and branch with nearly right angle, and separating branch mycelia with membrane in short distance; hyphae grow irregularly, and more chlamydospores grow on the hyphae; the cell wall of old hypha is thickened.

The fungus of the invention comprises Douglas fir (Douglas fir) promotingPaphiopedilum spicerianum) Seed germination forms a significant feature of application in seedlings.

The method for separating and obtaining the fungus strain and identifying the fungus strain in molecular biology comprises the following steps:

1-Induction of symbiotic germinating protocorms in Exit

(1) Collecting the original habitat matrix of Yunnan Pu' er tea and paphiopedilum concolor in 9 months of 2018, taking the matrix back to the laboratory, placing the matrix in a plastic lunch box (20.5 cm multiplied by 12.5cm multiplied by 6.0 cm), covering a nylon mesh with meshes of 45 mu m, and tightly connecting the mesh with the matrix.

(2) Taking out the seeds of paphiopedilum concordatum stored at-20 deg.C, and standing at room temperature for 10 hr to restore the temperature of the seeds to room temperature. Placing a small amount of seeds in a beaker, adding 1 g.L^-1The resulting suspension was thoroughly shaken to prepare a seed suspension.

(3) 5mL of suspension is sucked by a 5000mL pipette gun and is sown on the nylon mesh cloth, a disposable plastic lunch box cover is covered, and the temperature is 25 +/-2 ℃ in an artificial incubator. Dark culture is carried out for 60 days, light culture (the light cycle is 12/12 h L/D) is carried out after 60 days, the germination condition of the seeds is observed every two weeks, and the humidity of the matrix in the plastic box is kept.

(4) After 60, the paphiopedilum brandisii seeds were observed to germinate into white protocorms, and the protocorms were collected for subsequent strain separation experiments.

2-isolation of strain GYBQ02 of Musaceae

(1) Source of protocorms: and (3) carrying out ex-situ symbiotic germination experiments on paphiopedilum concordatum seeds to obtain paphiopedilum concordatum protocorms formed by symbiotic germination.

(2) Inducing, separating, purifying and storing protocorm endosymbiotic fungi: taking out the germinated protocorm, putting the protocorm into a sterilized beaker filled with a 1% sodium hypochlorite (NaClO) solution, slightly shaking the beaker, taking out the protocorm by using sterilized blunt-ended tweezers after 5 min, and washing the protocorm for 3-4 times by using sterile water. The protocorm is cut into two halves by a sterile blade on a clean bench and is placed in a PDA culture medium and cultured in an incubator at 25 ℃. And continuously cutting hypha tips to a new PDA culture medium for serial transfer after fungal hypha grows out from the original corm wound, and transferring for 3-5 times to obtain pure colonies.

(3) And (3) fungus preservation: the purified fungi were preserved using a conventional tube slant method. The prepared proper amount of PDA medium was poured into a glass test tube of 18X 20mm in size, and the amount of the medium was 1/3 which was about the volume of the test tube. After the silica gel plug, the mixture was placed in an autoclave for sterilization (20 min at 121 ℃). After sterilization, the test tube is placed in a superclean bench and is swung into an inclined plane for standby. On a clean bench, picking edge hyphae from the purified strain with a sterile inoculating needle, inoculating on PDA slant, and noting strain, number and date. And (3) placing the inoculated test tube in a climatic chamber for culture at 25 +/-2 ℃. When hyphae grow over the PDA slope, the test tube is taken out and stored in a refrigerator at 4 ℃.

The separated strain is subjected to biological preservation in China center for type culture Collection and survives.

Identification of 3-Musaceae GYBQ02 strain

(1) The nrDNA ITS sequence of the Mucor pulmonarius GYBQ02 strain is submitted to the national center database for biotechnology information (NCBI, http:// www.ncbi.nlm.nih.gov /) for storage, and the Genbank number is as follows: MN 793984; the strain is most similar to Tulasnellaceae JX545225.1 fungus by BLAST comparison, and the maximum similarity reaches 99.67 percent, and the Tulasnellaceae GYBQ02 fungus strain in the family of Musaceae mainly has the following microbiological characteristics:

(ii) morphological characteristics

The strain of Mucor family is cultured on PDA plate for 7 days, and its colony is white blanket-shaped, has more aerial hyphae, and grows in regular circular divergence.

② physiological and biochemical characteristics

Observing the microscopic morphological characteristics of the strains, culturing for 14 days in a fungus incubator at 25 +/-2 ℃ by using a cover glass insert culture method, and taking inserts to prepare slices according to a conventional slice preparation method. Observing under an optical microscope, wherein hyphae have diaphragms, branches are nearly right-angled, and the branched hyphae have diaphragms in short distance from the branches; hyphae grow irregularly, and more chlamydospores grow on the hyphae; the cell wall of old hypha is thickened.

The total DNA of the fungi related to the molecular biological identification is extracted by adopting a CTAB method; primers used for PCR amplification are fungus universal primers ITS4 and ITS 5; the PCR reaction system and conditions are carried out according to corresponding product instructions; and (3) sending the amplified product to Shanghai biological engineering Co., Ltd for sequencing.

Detecting whether the separated fungi have promotion effects on the seed germination stage and comparing the difference of the promotion effects of different fungi on the seed germination stage by utilizing a symbiotic germination experiment of the seeds and the fungi in a culture medium:

(1) preparing a symbiotic germination culture medium: the symbiotic germination culture medium is oat agar culture medium comprising 4 g.L^-1Oat and 8 g.L^-1Agar, wherein the pH value of a culture medium is 5.6-5.8;

(2) taking out Tulasnellaceae GYBQ02, inoculating on PDA culture medium, placing in artificial climate box, culturing and activating at 25 + -2 deg.C until fungus hyphae grow to fill the culture dish to obtain symbiotic germination strain;

(3) sterilizingThe treated seeds of Douglas fir are added to 1 g.L^-1The sterile agar suspension is uniformly mixed to obtain a seed suspension, and then the seed suspension is uniformly sowed in a culture dish of an oat agar culture medium;

(4) inoculating the symbiotic germination strain to a culture dish of an oat agar culture medium, then placing the culture dish in an artificial climate box, culturing at constant temperature under the condition of 25 +/-2 ℃, culturing under the dark condition in the first 60 days, and culturing under the conditions of illumination intensity of 2000-3000 Lx and light cycle of 12h/12h L/D in the last 60 days.

(5) Seed germination condition detection and data statistical analysis: the amount of 4 stages, i.e. the non-germination of the seed, the germination of the seed (the enlargement of the seed embryo and the generation of roots), the formation and development of protocorms (the enlargement of the seed embryo breaks through the seed coat to the appearance of the protomeristem), the differentiation and development stages of the seedling (the first leaf outgrowth and the subsequent growth) is counted. Counting the number of seeds germinated (g), protocorm (p) and seedlings(s) treated differently in each group of experiment according to the above grading standard, and according to the total number of seeds sowed (t),SEis standard error. Calculating the seed germination rate G = mean (G + p + s)/t + -SEProtocorm formation rate P = mean (P + s)/t ± ]SEAnd the seedling formation rate S = mean S/t ±)SE。

Using nonparametric test methods Kruskal-Wallis test (KW) and Mann-WhitneyU – test (U) Significance tests were performed on seed germination rate, protocorm formation rate and seedling rate for different treatments, α = 0.05.

The disinfection and sterilization pretreatment method in the step (3) comprises the following steps: taking out the seeds stored in a-20 ℃ seed storage library, and placing the seeds at room temperature for 10 hours to restore the temperature of the seeds to the room temperature; placing the seeds in a paper seed bag, and sealing the paper bag by using a staple; soaking the paper bag filled with the seeds in distilled water for 5-10 min, and slightly extruding to form air bubbles; transferring the paper bag to a beaker containing sodium hypochlorite solution (the effective chloride ion concentration is 1%) and a drop of detergent by using tweezers, and slightly stirring or shaking the beaker; after 10min, the paper bag is moved to a clean bench, and is transferred to a beaker filled with sterile distilled water by using sterile tweezers, and the beaker is gently shaken; and repeatedly washing the seeds for 3-4 times, slightly extruding redundant water in the paper bag, and cutting the paper bag by using sterile scissors to obtain the sterilized seeds.

The fungus Tulasnellaceae GYBQ02 of the family hymenophoraceae has the following advantages:

(1) the Musaceae fungus Tulasnellaceae GYBQ02 is obtained by separating from the protocorm of paphiopedilum concordatum, and the separation method is simple and convenient;

(2) the Mucilariaceae fungus Tulasnellaceae GYBQ02 can be used for promoting Pacific Bighestan seeds to germinate and form seedlings, has strong specificity, and can obtain high-quality symbiotic seedlings by symbiosis of Mucilariaceae fungus strain Tulasnellaceae GYBQ02 and Pacific Bighestan seeds, so that the efficient cultivation of Pacific Bighestan seedlings is realized; compared with tissue culture, the method has the advantages of low cost, high field survival rate of transplanted seedlings, no tissue degradation problem and the like, and has application value of replacing tissue culture to obtain symbiotic seedlings;

(3) the method has the advantages of simple process, easy operation and low cost, is suitable for popularization and application, and has great popularization value in the aspects of regression of rare or endangered orchids, reconstruction of extremely small population, solving of the bottleneck problem of seedling source in the paphiopedilum concordatum cultivation industry and the like.

The present application is further explained below with reference to specific embodiments.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail by examples and experimental data below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and that the scope of the invention is not limited thereto.

Example I: inducing ex-situ symbiotic germination protocorm, separating and identifying Tulasnellaeceae GYBQ02 strain of Musaceae fungus

1-Induction of symbiotic germinating protocorms in Exit

(1) The yunnan Pu' er Baidoulan habitat matrix collected in 2018 and 9 months is taken back to a laboratory, the matrix is placed in a genetic plastic lunch box (20.5 cm multiplied by 12.5cm multiplied by 6.0 cm), and a nylon mesh with meshes of 45 mu m is covered, so that the mesh is tightly connected with the matrix.

(2) Taking out the seeds of paphiopedilum concordatum stored at-20 deg.C, and standing at room temperature for 10 hr to restore the temperature of the seeds to room temperature. Placing a small amount of seeds in a beaker, adding 1 g.L^-1The resulting suspension was thoroughly shaken to prepare a seed suspension.

(3) Absorbing 5mL of suspension by using a 5000mL pipette, sowing the suspension on a nylon mesh cloth, covering a cover of a disposable plastic lunch box, culturing the suspension in the dark for 60 days at the temperature of 25 +/-2 ℃ in an artificial incubator, culturing the suspension in the light (the light cycle is 12/12 h L/D) after 60 days, observing the germination condition of seeds every two weeks, and keeping the humidity of a matrix in the plastic box.

(4) After 60 days, the paphiopedilum brandisii seeds were observed to germinate into white protocorms, and the protocorms were collected for subsequent strain separation experiments.

2-isolation of strain GYBQ02 of Musaceae

(1) Source of protocorms: and 6. inflixing and germinating paphiopedilum brandisil seeds in situ to obtain protocorms.

(2) Inducing, separating, purifying and storing protocorm endosymbiotic fungi: taking out the germinated protocorm, putting the protocorm into a sterilized beaker filled with a 1% sodium hypochlorite (NaClO) solution, slightly shaking the beaker, taking out the protocorm by using sterilized blunt-ended tweezers after 5 min, and washing the protocorm for 3-4 times by using sterile water. The protocorm is cut into two halves by a sterile blade on a clean bench and is placed in a PDA culture medium and cultured in an incubator at 25 ℃. And continuously cutting hypha tips to a new PDA culture medium for serial transfer after fungal hypha grows out from the original corm wound, and transferring for 3-5 times to obtain pure colonies.

(3) And (3) fungus preservation: the purified fungi were preserved using a conventional tube slant method. The prepared proper amount of PDA medium was poured into a glass test tube of 18X 20mm in size, and the amount of the medium was 1/3 which was about the volume of the test tube. After the silica gel plug, the mixture was placed in an autoclave for sterilization (20 min at 121 ℃). After sterilization, the test tube is placed in a superclean bench and is swung into an inclined plane for standby. On a clean bench, picking edge hyphae from the purified strain with a sterile inoculating needle, inoculating on PDA slant, and noting strain, number and date. And (3) placing the inoculated test tube in a climatic chamber for culture at 25 +/-2 ℃. When hyphae grow over the PDA slope, the test tube is taken out and stored in a refrigerator at 4 ℃.

The separated strain is subjected to biological preservation in China center for type culture Collection and survives.

Identification of 3-Musaceae GYBQ02 strain

(1) The nrDNA ITS sequence of the strain GYBQ02 in Mucoraceae is submitted to the national center database for biotechnology information (NCBI, http:// www.ncbi.nlm.nih.gov /) for storage, and the Genbank number is as follows: MN 793984; BLAST comparison is carried out on the strain, and the identification result shows that the strain is most similar to Tulasnellaceae JX545225.1 fungus, and the maximum similarity reaches 99.67 percent.

The fungus strain Tulasnellaceae GYBQ02 in the family of Cortinaceae mainly has the following microbiological characteristics:

(ii) morphological characteristics

The strain of Mucor family is cultured on PDA plate for 7 days, and its colony is white blanket-shaped, has more aerial hyphae, and grows in regular circular divergence.

② physiological and biochemical characteristics

Observing the microscopic morphological characteristics of the strains, culturing for 14 days in a fungus incubator at 25 +/-2 ℃ by using a cover glass insert culture method, and taking inserts to prepare slices according to a conventional slice preparation method. Observing under an optical microscope, wherein hyphae have diaphragms, branches are nearly right-angled, and the branched hyphae have diaphragms in short distance from the branches; hyphae grow irregularly, and more chlamydospores grow on the hyphae; the cell wall of old hypha is thickened.

The total DNA of the fungi related to the molecular biological identification is extracted by adopting a CTAB method; primers used for PCR amplification are fungus universal primers ITS4 and ITS 5; the PCR reaction system and conditions are carried out according to corresponding product instructions; and (3) sending the amplified product to Shanghai biological engineering Co., Ltd for sequencing.

Specifically, a CTAB method is adopted to extract fungus DNA, and primers used for PCR amplification are ITS1 and ITS 4; the PCR reaction system (25. mu.l) included: 2.5. mu.l of 10 XPCR buffer, 0.4. mu.l of dNTPs, 1.5. mu.l of Mg2+, 1.5. mu.l of ITS1, 1.5. mu.l of ITS4, 0.2. mu.l of Taq enzyme, 15.4. mu.l of ddH2O, 2. mu.l of DNA template; the amplification reaction was performed on a PCR instrument Perkin Elmer, with the following PCR cycles: pre-denaturation at 94 deg.C for 3 min, and circulating for 1 time; denaturation at 94 deg.C for 1 min, annealing at 51 deg.C for 1 min, extension at 72 deg.C for 1 min, and 30 times of circulation; finally, extending for 10min at 72 ℃; sequencing the PCR amplification product for Shanghai biological engineering company Limited; submitting the sequence to a national information center database of the biotechnology for comparison, and primarily determining the status under classification;

the identification result of the strain of the invention shows that the strain is most similar to Tulasnellaceae JX545225.1 fungus, and the maximum similarity reaches 99.67%. The fungus is identified as a Mucor fungus according to the colony, morphological characteristics and molecular biology means.

Example 2: mucilariaceae fungus GYBQ02 strain effectiveness test for promoting symbiotic germination of paphiopedilum concordatum seeds

Detecting whether the separated fungi have promotion effects on the seed germination stage and comparing the difference of the promotion effects of different fungi on the seed germination stage by utilizing a symbiotic germination experiment of the seeds and the fungi in a culture medium:

(1) preparing a symbiotic germination culture medium: the symbiotic germination culture medium is oat agar culture medium comprising 4 g.L^-1Oat flour and 8 g.L^-1Agar, wherein the pH value of a culture medium is 5.6-5.8; preparing 100 dishes of oat culture medium, sterilizing for later use, repeating 30 dishes of each experimental treatment, and performing 3 treatments in total;

(2) taking out a fungus strain Tulasnellaceae GYBQ02 of the family of the jelly fungi to be tested stored in a test tube inclined plane at the temperature of 4 ℃, inoculating the fungus strain on a PDA culture medium, then placing the culture medium in an artificial climate box, and culturing and activating the fungus strain at the temperature of 25 +/-2 ℃ until fungus hyphae grow to fill a culture dish to obtain symbiotic germination strains;

(3) adding the disinfected and sterilized paphiopedilum seeds into the mixture to 1 g.L^-1The sterile agar suspension is evenly mixed to obtain a seed suspension, the seed suspension is sucked by a liquid-transferring gun and evenly spread in a culture dish of an oat agar culture medium; the disinfection and sterilization pretreatment method comprises the following steps: taking out the seeds stored at the temperature of minus 20 ℃, and placing the seeds at room temperature for 10 hours to restore the temperature of the seeds to the room temperature; placing the seeds in a paper seed bag, and sealing the paper bag by using a staple; paper to be loaded with seedsSoaking the bag in distilled water for 5-10 min, and slightly extruding to form air bubbles; transferring the paper bag to a beaker containing sodium hypochlorite solution (the effective chloride ion concentration is 1%) and a drop of detergent by using tweezers, and slightly stirring or shaking the beaker; after 10min, the paper bag is moved to a clean bench, and is transferred to a beaker filled with sterile distilled water by using sterile tweezers, and the beaker is gently shaken; repeatedly washing the seeds for 3-4 times, slightly squeezing redundant water in the paper bags, and cutting the paper bags by using sterile scissors to obtain sterilized seeds;

(4) sowing and culturing: mixing sterile seeds with 1 g.L^-1Preparing sterile agar solution into sterile seed suspension; seeding approximately 0.5cm in the middle of OMA Medium³(1X 0.5cm) agar blocks containing pure cultures of a single fungus, 150. mu.l of seed suspension (150. mu.l of suspension containing about 35 seeds) are pipetted into a pipette and evenly seeded around the block, and the dish is sealed with a sealing film; wherein 3 groups of culture dishes of oat agar culture medium are respectively inoculated with a strain GYBQ02(Tulasnellaceae) separated from paphiopedilum bigelovii protocorm and a strain AgP-1 (A) separated from paphiopedilum bigelii protocormTulasnellasp.), setting OMA culture medium of another 1 groups of non-inoculated bacteria as nutrient-deficient culture medium as control treatment, and inoculating 0.5cm in the middle³Sterile pure PDA agar blocks; each group of the treatments is repeated for 30 times, and the cells are cultured in an artificial climate chamber at a constant temperature of 25 +/-2 ℃, dark for the first 60 days and under the conditions of illumination intensity of 2000-3000 Lx and light cycle of 12h/12h L/D after 60 days.

(5) Detecting the germination condition of the seeds 60 days after sowing, and recording the time of the germination of the seeds and the formation of protocorms; after 120 days of culture, when a large number of seedlings at the early stage of development are produced in the culture dish, all the culture dishes are taken out, and the germination of the seeds and the development of the protocorm are observed and recorded under a stereo microscope. This study simplified seed germination to 4 stages: non-germination of seeds, germination of seeds (enlargement of the seed embryo and generation of roots), protocorm formation and development (enlargement of the seed embryo breaks through the seed coat to the appearance of the primary meristem), seedling differentiation and development stages (emergence of the first leaf and subsequent growth). The number of seeds germinated (g), protocorm (p) and protocorm (p) treated differently in each group of experiment were counted according to the above classification criteriaThe number of seedlings(s), and according to the total number of seeds sown (t),SEis standard error. Calculating the seed germination rate G = mean (G + p + s)/t + -SEProtocorm formation rate P = mean (P + s)/t ± ]SEAnd the seedling formation rate S = mean S/t ±)SE。

(6) In the 120-day cutoff experiment of symbiotic culture, non-parameter detection methods Kruskal-Wallis test (KW) and Mann-Whitney are utilizedU – test (U) Carrying out significance test on the germination rate, protocorm formation rate and seedling rate of the seeds subjected to different treatments, wherein the alpha = 0.05; paphiopedilum armeniacum arbitrary inoculation treatment included seed germination for the placebo control (table 1).

TABLE 1 influence of different fungi on the germination of Douglas fir seeds (120 days statistics)

Treatment group	Bacterial strain	Germination Rate (%)	Protocorm rate (%)	Seedling percentage (%)
					GYBQ02	Tulasnellaceae	90.00±0.59%	56.19±3.47%	43.45±3.16%
AgP-1	Tulasnella sp.	65.71±0.79%	0	0
					OMA	Inoculating no bacteria	61.31±1.13%	0	0

As can be seen from Table 1, at the 120-day end of the symbiotic culture, the OMA control group without inoculation had seeds germinated but no protocorms and seedlings formed; inoculating AgP-1 strain separated from protocorm of arundina graminifolia, wherein the germination rate is (65.71 +/-0.79%), but no protocorm and seedling are formed; and the GYBQ02 strain separated from the protocorm inoculated with the paphiopedilum dolabrotanum can obviously promote the germination of paphiopedilum dolabrotanum seeds (90.00 +/-0.59 percent), the formation of the protocorm (56.19 +/-3.47 percent) and the subsequent development of the protocorm into seedlings (43.45 +/-3.16 percent) on the 120 th day. The Tulasnellaceae GYBQ02 is shown to effectively promote the seed germination and growth of the paphiopedilum davidii to the seedling stage.

Experiments prove that the paphiopedilum concordatum and different strains can germinate at the initial stage of symbiotic culture, but the seed germination only means that the seed embryo absorbs water and swells but does not break through the seed coat, so that the seed germination has no practical application value, and the more important index is the seedling formation rate. In the later symbiotic culture period, namely the seedling formation period, the fungus AgP-1 which is separated from the cymbidium arundinaceum and can effectively promote the germination of the cymbidium arundinaceum seeds and can not promote the germination of the cymbidium arundinaceum seeds to form protocorms and seedlings is inoculated, however, the GYBQ02 strain separated from the cymbidium arundinaceum seeds in-situ symbiotic germination protocorms can effectively promote the germination of the cymbidium arundinaceum seeds. The paphiopedilum brandisin seeds and the strain of the invention show stronger specificity, and can utilize GYBQ02 strain and paphiopedilum brandisin seeds to symbiotically germinate and produce seedlings.

The germination of the orchid seeds can be realized by two modes of non-symbiotic germination culture and symbiotic germination culture; although most of orchids can be cultured through non-symbiotic germination and have higher germination rate, seedlings obtained by the method are transplanted into the nature, grow slowly, have poor capability of resisting pathogenic microorganisms and lower survival rate, and meanwhile, the subsequent growth is seriously hindered because the symbiotic relationship is difficult to establish with fungi which come into contact later; the symbiotic germination culture technology is characterized in that plant seeds and symbiotic fungi are simultaneously sown in a specific medium (culture medium), and the method can improve the germination rate of the seeds, the growth speed of seedlings and the survival rate of the seedlings after being transplanted to a natural environment; because the symbiotic relationship between the seeds of the orchids and the fungi has specificity, the symbiotic fungi of different seeds of the orchids are different; determining effective fungi capable of forming symbiotic relationship with paphiopedilum concordatum seeds and promoting germination of paphiopedilum concordatum seeds is a key link for cultivating paphiopedilum concordatum seedlings. The acquisition of symbiotic seedlings is the basis for developing the work of returning paphiopedilum brandisii to the original habitat. The strain provided by the invention is characterized in that paphiopedilum concordatum seeds, different fungi and a blank control group are respectively cultured on an oat agar culture medium through a symbiotic germination experiment, and an effective strain for promoting paphiopedilum concordatum seeds to germinate is successfully obtained through comparison of seed germination rates, so that a new way is developed for efficiently culturing seedlings by utilizing paphiopedilum concordatum seeds and fungus symbiotic germination, returning the seedlings to an original habitat and reestablishing the population.

The above description is only a part of specific embodiments of the present invention (since the technical solution of the present invention relates to the numerical range, the embodiments are not exhaustive, the protection scope described in the present invention is subject to the numerical range and other technical essential ranges), and the specific contents or common general knowledge in the technical solution are not described too much here. It should be noted that the above-mentioned embodiments do not limit the present invention in any way, and all technical solutions obtained by means of equivalent substitution or equivalent transformation for those skilled in the art are within the protection scope of the present invention. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.

<110> university of Yunnan

<120> Mucor fungus and application thereof in promoting germination of paphiopedilum bigeminum seeds to form seedlings

<160> 1

<210> 1

<211> 595

<212> DNA

<213> Artificial sequence

<400> 1

TATGCTTAAGTTCAGGGCGTAGTCCTACCCGAGTTGAGGTGTAAATGTCAAGTAATTTGTCCTAAGACGATTAGAAGCAGACTACAAAGGCTGACCTAACCAACGACGATCAAACTTATCACGCCAGAGGTAGACATCAAATAGTAAGTCCAGCTAATAATTTTAGGGTGAGTTGGAAACAAGTTCCAACAATAACACCCAAATCCAATATCACACAAGTTAATAAAAACTTGATGATTTGAGAATTTCAAGACACTCAACCGGGCATACCCTCCAGAATACTAGAGGGTGCAAGGTGCGTTCAAAGATTCGATGATTCACTGTGTTCTGCAAGTCACATTACTTATCGCAATTCGCTACGTTCTTCATCGAGTGGGATGCCAAGAGATCCGTTGCTGATGGTTGTATTAGGTTTATACAACTTGTCATTCTACAATACTTCAAATCATAGGGTATAGTAATAAAATACAGAGGCGTACACCAATTTCTTGGTAACCACCTCCATATTAGGGTGCACAGGTGTTTGGATTGAATAATGAAGGAGCGCACTTGCAAAGCCAGCGCATCCCCCAAAGTTATTCTTTAATGATCCTTC

Claims (2)

1. A fungus, wherein the fungus is a strain GYBQ02 of family Musaceae (Tulasnellaceae), which has a deposit number of: CCTCC NO: m2020130.

2. Use of the fungus of claim 1 in promoting Douglas (Douglas fir) (Douglas) Laguerrea (Douglas) hook (Iuglas) hook (Ipomoea)Paphiopedilum spicerianum) Application of seeds in germinating and forming seedlings.