Study Of Identification And Mycelial Tissue In Vitro Culture Of A Wild Edible Lactarius

The wild Lactarius is a rare wild edible mushroom in the pine forest,which has a very high nutritional value.Chongqing is located in the south subtropical region of my country,due to the climatic characteristics of high temperature and high humidity in summer,the fruiting bodies of Lactarius often appear in the pine forests after the summer rains,becoming the rare wild edible fungi favored by farmers.Most of the wild edible Lactarius resources on the market are naturally produced in the pine forest,with low yield and strong seasonal output.Due to improper collection methods and excessive collection,the mycorrhiza habitat in the forest is further damaged,and the yield of wild edible Lactarius is low and in short supply.Therefore,people try to domesticate wild Lactarius and cultivate them artificially to meet market demands.However,wild Lactarius mushrooms are mostly mycorrhizal symbiotic bacteria,and the research progress of artificial domestication and cultivation is slow,the key technologies such as the separation of mycelial tissue and the large-scale production of strains have always been the focus and difficulty of the research on wild Lactarius edible fungi.Therefore,the biological characteristics of wild Lactarius strain identification,tissue isolation,and mycelium growth stages were studied,to explore and optimize its tissue isolation and mycelial growth culture conditions,that establishment of an in vitro culture system for wild Lactarius mushroom mycelium.It has important scientific significance and production value for the realization of artificial cultivation of wild milk mushrooms,and it is urgent to continue relevant work.In this study,the wild edible fungi collected from the pine forest in Fengjie County,Chongqing City were used as research materials,and their morphological and molecular identifications were carried out to determine their classification;Using the fruiting body as the tissue separation material,the mushroom flesh tissue is cut and cultured to obtain pure strains of wild edible fungi;The biological characteristics of the wild Lactarius mycelium were studied,and the suitable environmental factors and culture substrate ecological factors were explored in the culture process,and a set of solid culture system and liquid culture suitable for the in vitro culture system of the wild Lactarius primary mycelium were obtained.The cultivation conditions of the secondary strains were explored,in order to obtain the suitable culture material formula for the production of wild Lactarius.Through the above complete separation and cultivation process,the theoretical basis for the artificial cultivation of wild Lactarius is provided.The test results are as follows:1.Morphological characteristics of wild edible fungi in Fengjie County,ChongqingAccording to the literature,the morphological characteristics of wild edible fungi collected from Fengjie County,Chongqing City were compared and analyzed,The characteristic of bright color and spilling milk from wounds of this wild edible fungus are typical of the Lactarius fungus,so preliminary identification of the wild strain belongs to the wild Lactarius Pers.Ex Gray fungus.2.Isolation of wild edible fungiThe successful tissue isolation is closely related to the age and location of the fruiting bodies of milk mushrooms,the best separation efficiency is obtained by using the junction of the stipe and cap of young fruiting bodies as the material for explant tissue separation.3.Molecular identification of wild Lactarius fungiBy extracting genomic DNA from mycelium,PCR amplification,sequencing and comparison,combined with the above morphological characteristics,the wild Lactarius can be identified as Lactarius vividus X.H.Wang et al.4.Analysis of Biological Characteristics of Lactarius vividusDuring the in vitro culture of the mycelium of Lactobacillus vivax,different media(PDA,DPA,CM and YMA),different temperatures(22°C-30°C),different p H(p H4-9),different carbon sources(glucose maltose,etc.),different nitrogen sources(peptone,beef extract,etc.),different inorganic salts(potassium dihydrogen phosphate,magnesium sulfate,etc.)and added vitamin B1 for comparative experiments were designed.The result shows that in the process of in vitro culture,the growth rate and growth vigor of the mycelium of Lactarius vividus were the best when PDA was used as the basic medium.The suitable environmental factors for mycelial tissue culture are temperature 27℃,p H=6.The suitable carbon sources for the growth substrates of the mycelium of Lactarius vividus are glucose and fructose,and the suitable nitrogen sources are glycine,beef extract and peptone,The appropriate exogenous hormone VB1 concentration is.Addition of inorganic salts has inhibitory effect on the growth of Lactarius vividus mycelium.5.The Lactarius vividus mycelium grew best in the modified Martin’s medium,and the mycelial biomass and the number of spherules were significantly higher than those in the other two liquid mediums.The spheroids appeared on the 4th day in the modified Martin’s medium,on the 5th day in the PDB medium,and on the 6th day in the CM medium.6.The Lactarius vividus mycelium does not germinate in the solid medium,and cannot decompose the nutrients in the medium for the growth and development of the mycelium.