Changes Of Elements And Metabolites In Morchella Sextelata Mycelium Stage

Morchella is one of the four most famous fungi in the world.At present,there are some problems in the large-scale cultivation of Morchella,In particular,there are frequent problems in nutrient supply,resulting in poor fruiting stability.Compared with other edible mushrooms,Morchella has extremely strict nutritional requirements.Insufficient supply will lead to low fruiting rate of Morchella and hindered fruit body development,but excessive nutrient supply will increase the probability of microbial contamination.Therefore,clarifying the nutritional changes during the growth of Morchella is the most important issue at present.In this experiment,Morchella 401 was used as the material to study the changes of elements（non-metal elements and metal elements）and intracellular metabolites during the growth of Morchella hyphae.The purpose of this paper is to study the nutrients suitable for the growth of Morchella in the mycelial stage.The main results are as follows:1.During the mycelial stage of Morchella sextelata,during early stage of Morels growth the hyphae began to germinate and secreted amylase and hemicellulase to hydrolyze starch and hemicellulose as the main carbon and energy sources;After placing nutrient wheat,the activities of the four enzymes all began to increase significantly,and the activities of the four enzymes increased significantly.And reached the peak at 25 d.At this time,the activities of amylase,hemicellulase,laccase and cellulase were 1601.11 U·L^-1,944 U·L^-1,810.19 U·L^-1and 789.53 U·L^-1;a large amount of nutrients have been enriched in the mycelium for fruiting.at the end of the mycelial stage,the activities of the four enzymes will increase,which indicates that there will be a peak period of enzyme activity before officially entering reproductive growth and stimulating fruiting,so as to accumulate nutrition and ensure the normal growth and development of Morchella.2.Morchella mycelium stage,the increase of carbon,nitrogen,phosphorus,potassium,magnesium,sodium,calcium,zinc,iron and manganese elements measured by the mycelium in the unit weight of the cultivation substrate.showed a clear upward trend.The main performance is（1）Among the non-metallic elements,The increase of carbon and nitrogen elements began to enrich when the nutrient wheat was placed;phosphorus began to enrich when the wheat was placed for 5 days;then the increase of the three non-metal elements continued to increase,and increased at the end of the mycelial stage to the highest;At this time,the increments of carbon,nitrogen,and phosphorus were 0.15 mg·g^-1,0.25 mg·g^-1and0.14 mg·g^-1.（2）Among metal elements,The increase of potassium,sodium and manganese began to enrich when the wheat was placed for 5 days;magnesium,calcium,iron and zinc began to enrich when the wheat was placed for 10 days,and then the increase of the seven metal elements continued to increase.and peaked at the end of the mycelial stage.At this time,the increments of potassium,magnesium,sodium,calcium,iron,zinc,and manganese were 2.51 mg·g^-1,2.1 mg·g^-1,0.24 mg·g^-1,0.2 mg·g^-1,0.15 mg·g^-1,0.1 mg·g^-1,0.15 mg·g^-1;The increase of potassium and magnesium elements in the mycelium is the highest,which can be applied as main elements,and other elements can be applied as secondary elements.3.In the mycelial stage of Morchella sextelata,a large number of small molecular metabolites were produced in the mycelium during the mycelial growth,and a total of21classes;It mainly includes carboxylic acids,fatty acyl groups,phenols,amines,alcohols and other substances..Among them,in the first 5 days,10 days and 15 days,the number of differential metabolites up-regulated were 7,7,and 13,there were 31,56,and 90 metabolic pathways,respectively.In the first 5 days,the accumulation ofα-linolenic acid,stearidonic acid and other metabolites increased most significantly;in the first 10 days,the accumulation of 2-ketoglutarate,sarcosine and other metabolites The increase was the most obvious;in the first 15 days,the accumulation of octadecanoic acid,methyl indole-3-acetate and other metabolites increased most obviously;These metabolites can play a role in the mycelial stage of Morchella to ensure the normal growth and development of the mycelium.Conclusion:This experiment clarified the requirements for nutrients in the mycelial stage of Morchella:the requirements for elements in the hyphal stage and the requirements for small molecule metabolites in the hyphal stage were clarified.