Effects Of Different Exogenous Selenium On The Growth Of Morchella And Analysis Of Main Effective Components

The fruiting body of Morchella has delicate texture,crisp and delicious taste.It also contains a large amount of protein and a variety of amino acids necessary for human normal development.In addition,it is also rich in a variety of vitamins and iron,zinc and a variety of mineral elements higher than some other edible fungus.It has high medicinal value and economic value.Trace element selenium has a certain regulatory effect on many life activities of human body.As an important part of some enzymes in organisms,it directly participates in the metabolism of organisms,and the lack of selenium in human body will lead to a variety of diseases.Morchella has good selenium enrichment ability.Selenium enriched Morchella has great development potential and broad application prospects in the fields of food,health products and medical treatment.Therefore,this paper takes Morchella as the research object,takes sodium selenate and sodium selenite as exogenous selenium respectively,controls the selenium concentration in the medium by adding different quality of exogenous selenium to the water and carries on the mycelium culture.Compares and analyzes the growth of mycelium on the medium under different selenium concentration,and carries on the culture on different medium to screen out the appropriate exogenous selenium and the best concentration range.Then select different selenium concentrations from the best range for artificial cultivation of selenium enriched Morchella,compare the yield and quality of Morchella,and analyze the amino acids,inorganic elements and selenium forms in the fruiting body of Morchella.The main conclusions of this paper are as follows:（1）Using sodium selenate as selenium source,on the mother medium,the original medium and the cultivated medium,compared with the control,with the increase of selenium concentration,the growth rate was inhibited to different degrees,the mycelial density and morphology were affected,and the mycelial development became slower.Sodium selenate can inhibit the growth of mycelium and affect the morphology of mycelium at high concentration.It is not suitable for artificial cultivation of Morchella as exogenous selenium.（2）On the mother culture medium,when sodium selenite was used as selenium source and selenium concentration was 5 mg/L,10 mg/L and 20 mg/L,the growth of mycelium was not affected.On the original medium,when the selenium concentration is low,the density and morphology of mycelium are not affected.The growth rate of mycelium becomes faster,which can promote the growth of Morchella,and reaches the maximum at the concentration of 10mg/L.On the seed culture medium,when the concentration of selenium was 20mg/L,the morphology and density of mycelium were not affected,and the growth rate of mycelium increased rapidly.When the selenium concentration is 10 mg/L and 40mg/L,there is little difference compared with the blank control group.In the liquid fermentation medium,when the concentration of selenium was 10 mg/L and 20 mg/L,compared with the control,the growth of mycelium was promoted and the dry weight of mycelium increased.As exogenous selenium,low concentration sodium selenite can promote the growth of mycelium,and the mycelial morphology does not change.The effect is the best when the selenium concentration is 0～40 mg/L,which can be used as an ideal concentration for selenium-enrich cultivation of Morchella.（3）Through the selenium-enriched cultivation of Morchella,it is finally concluded that when the selenium concentration is 20 mg/L,the wet weight of harvested fruiting body is the largest,which is 221.329 g/m²,and the dry weight of fruiting body is the largest,which is31.659 g/m².The drying rate of selenium concentration of 0 mg/L is 15.150%.The average selenium concentration of Morchella is 40 mg/L,and the average length of Morchella is 20mg/L.Cap height was 0 mg/L>20 mg/L>40 mg/L>10mg/L.Stipe height was 10 mg/L>20mg/L>0 mg/L>40 mg/L.The ratios of cap to stipe length in the four groups were 131∶70,83∶55,22∶13 and 48∶25.The average perimeter of the cap was the longest when the selenium concentration was 10 mg/L.Comparing the perimeter of stipe,the selenium concentration of 0 mg/L is the longest and the selenium concentration of 40 mg/L is the shortest.PCA comprehensive evaluation was conducted on the effects of different selenium treatments on Morchella fruiting bodies.The results showed that the comprehensive evaluation score of various indexes of Morchella fruiting bodies cultivated under selenium concentration of 20 mg/L was the highest and the best concentration.（4）The amino acid content of Morchella was determined.The content of glutamate was the highest when the selenium concentration was 0 mg/L,10 mg/L,20 mg/L and 40 mg/L,which were 3.75%,3.56%,3.66%and 3.67%.Aspartic acid was the second.The contents of cystine,methionine,isoleucine and histidine were lower than 1%.Through comparison,it was found that when the selenium concentration was 10 mg/L,20 mg/L and 40 mg/L,the content of various amino acids was mostly lower than that in the control group.The addition of sodium selenite would affect the content of amino acids.Through the detection of inorganic elements in the fruiting body,it is found that the contents of Zn and Se increase with the increase of selenium concentration.The content of Fe decreased after adding sodium selenite.The principal component analysis showed that the addition of sodium selenite significantly affected the enrichment of most pollutants by Morchella fruiting body,and the enrichment effect was more obvious with the increase of selenium concentration.The morphological identification of selenium in the fruiting body of Morchella esculenta with selenium concentrations of 20 mg/L and 40 mg/L did not detect Secys₂,Selenite and Selenate.When the selenium concentration is 20 mg/L,the content of Se Met is 1.98 mg/kg,accounting for17.89%of the total selenium content.When the selenium concentration is 40 mg/L,the content of Se Met is 8.0 mg/kg,accounting for 24.94%of the total selenium content.