Based On The Effects Of Soil Amendments On Heavy Metal Enrich Ment Ability And Quality Of Dictyophora

Dictyophora is one of the rare edible and medicinal fungi in China,but the problem of exceeding the standard of heavy metals in Dictyophora is particularly prominent,which seriously affects the industrial development and the health of consumers.In this paper,the frame planting experiment of Dictyophora was carried out by adding a single and mixed modifier to the cultivated soil of Dictyophora,to explore the enrichment of heavy metals（Pb,Cd,Cu,Zn）in soil and Dictyophora cap,bacterial skirt + stalk and bacterial tray by calcium carbonate（T）,calcium dihydrogen phosphate（L）and calcium carbonate calcium dihydrogen phosphate（H）,and to analyze their effects on soil p H value,soil heavy metal content,soil heavy metal occurrence form The purpose is to study the differences of different modifiers on the absorption and accumulation of heavy metals in Dictyophora,and to screen the modifiers and their corresponding additions that can significantly reduce the bioavailability of heavy metals in soil;To study the effect of the application of modifier on the enrichment and accumulation of heavy metals in various parts of Dictyophora,and the effect of the application of modifier on the amino acid content of Dictyophora,in order to reduce the content of heavy metals in Dictyophora and improve the quality of Dictyophora.The results show that:（1）When the modifier was added to the soil,the order of influence on soil p H value was mixed modifier > calcium carbonate > calcium dihydrogen phosphate.The soil environment of T3,H3,H6 and H9 experimental groups was more suitable for planting Dictyophora.The content of Pb and Cu in the experimental soil exceeded the soil background value of Guizhou Province,and the content of Cd was higher than the national soil pollution risk control standard.After adding the modifier,the heavy metals in soil increased and decreased in varying degrees.The variation ranges of heavy metals Pb,Cd,Cu and Zn were46.27mg/kg～49.71mg/kg,0.30mg/kg～0.45mg/kg,38.06mg/kg～41.21mg/kg and 82.46mg/kg～98.85mg/kg respectively.The removal effects of H5,H6 and H8 treatment groups on the four heavy metals Pb,Cu,Cd and Zn were the most significant.（2）After adding the modifier,the contents of various forms of heavy metals（Pb,Cd,Cu,Zn）in soil changed to a certain extent,and the exchangeable content decreased significantly.The contents of exchangeable Pb,Cd,Cu and Zn decreased by 1.90%～42.42%,1.85%～52.59%,2.42%～35.49% and 12.50%～82.81% respectively.The correlation analysis between the forms of heavy metals in soil and p H shows that the increase of p H value can effectively reduce the effectiveness of heavy metals（Pb,Cd,Cu,Zn）.（3）Compared with all the modifier treatment groups in this experiment,among the single modifier,T2,T3,L2 and L3 treatment groups have better fixation effect on soil heavy metals,and the effect of calcium carbonate modifier is stronger than that of calcium dihydrogen phosphate modifier.In the mixed modifier treatment group,H3,H6 and H9 treatment groups had better fixation effect on soil heavy metals,and the inhibitory effect of mixed modifier on the bioavailability of soil heavy metals was better than that of single modifier.（4）Pb in the fungus tray of Dictyophora exceeded the standard,and Cd pollution existed in the fungus（cap,fungus skirt + stipe and fungus tray）,among which the enrichment of fungus skirt + stipe was the most serious.After adding the modifier,the content of heavy metals in various parts of Dictyophora can be effectively reduced.The contents of Pb,Cd,Cu and Zn in the cap were the lowest in H6,L3,L3 and H3 treatment groups,and the decline rates were-25.91%,-28.59%,-19.32% and-37.07% respectively;The contents of Pb,Cd,Cu and Zn in bacterial skirt+ stipe were the lowest in H3,L3,L1 and T3 treatment groups,and the decline rates were-58.01%,-45.11%,-23.32% and-20.97% respectively;The contents of Pb,Cd,Cu and Zn in bacterial tray decreased the most in H6,H8,T3 and L3 treatment groups,and the decline rates were-29.81%,-54.95%,-9.95% and-15.00% respectively.From the decrease of heavy metal content in Dictyophora by adding modifier,it can be seen that both mixed modifier and single modifier have achieved significant results.（5）After adding the modifier,the exchangeable contents of Pb and Cd in soil were significantly positively correlated with the contents of Pb and Cd in various parts of Dictyophora（P<0.05）,indicating that the addition of calcium carbonate and calcium dihydrogen phosphate could reduce the bioavailability of Pb and Cd in soil,and the exchangeable contents of Cu and Zn in soil were significantly positively or negatively correlated with the contents of Cu and Zn in various parts of Dictyophora（P<0.05）,indicating that the absorption of Cu and Zn by Dictyophora was not only related to the bioavailability of heavy metals,It is also affected by the absorption of Cu and Zn by Dictyophora itself.（6）The modifier had an effect on the enrichment ability of heavy metals in Dictyophora,and the decline rate of heavy metals was Cd >Pb > Cu > Zn.In Dictyophora cap,bacterial skirt + stipe and tray,the most significant effect of inhibiting Pb enrichment was L3,H3 and H6 treatment groups,with the decline rates of 24.96%,55.63% and 24.48%respectively;The most significant effect of inhibiting Cd enrichment was in H2,L3 and H8 treatment groups,with a decrease rate of 15.68%respectively 、 31.46% 、 46.46%;The most significant effect of inhibiting Cu enrichment was in L3,L1 and T3 treatment groups,with the decline rates of 22.82%,26.08% and 11.78% respectively;The enrichment rates of L1 and H3 were the most significant,and the enrichment rates of L1 and H3 were 12.3% and 62.3%,respectively.（7）The addition of modifier had a significant effect on the quality of Dictyophora.The total amount of amino acids increased by 83.81%,59.82%,77.10%,148.59% and 114.79% respectively compared with the blank control group.H6 treatment group was the most effective to improve the quality of Dictyophora.After adding the modifier,the contents of essential amino acids,non essential amino acids,sweet amino acids,delicious amino acids and pharmacodynamic amino acids of Dictyophora were higher than those of the blank control group,and the increase of essential amino acids was the most significant.The bamboo fungus treated with modifier meets the ideal protein requirements put forward by WHO/FAO and is a high-quality protein resource.