Effect Of Exogenous Selenium On Quantity And Diversity Of Soil Microbes And The Quality Of Ganoderma Lucidum With Wild-Imitated Cultivation Under Woods

Selenium(Se)is one of indispensable microelements of human body.However,about 70%region of our country has a shortage of selenium that effects the health of human being severely.Supplement of Se prevents a lot of diseasas and improves immunity of human body.It was reported that edible fungus has a good Se-enriched ability.Ganoderma Lucidum is one of the most precious Chinese medicinal fungi.If we can enrich appropriate inorganic Se into Ganoderma Lucidum that can conver inorganic Se into organic Se,that can improve nutritional value and economic value.Spraying soil is an effective method to cultivate Se-enriched fungus.Four kinds of Ganoderma Lucidum(C is the abbreviation of Ganoderma Lucidum;R is the abbreviation of Red Ganoderma Lucidum;H is the abbreviation of Ganoderma Atrum;Z is the abbreviation of Ganoderma Sinenses.)were Se-entiched domestication on slant medium.The best fit's sodium selenite solution is 0.05 g/L on slant medium and two kinds of strains are Ganoderma Lucidum.and Red Ganoderma Lucidum in sawdust media with exogenous selenium.The wood covered with mycelium was planted in the soil under the woods with wild-imitated cultivation.Sodium selenite solution(0.05 g/L)was sprayed on the soil for eight times every seven days.Total Se and inorganic Se content of fruit body,total Se content of soil,quality of fruit body,soil enzyme activities,the cultured microbes of soil,bacterial community structure and so on are studied in paper.It should provide theoretical basis for the development and utilization of Se-enriched Ganoderma Lucidum The main researches content are given bellow1.The growth mycelium of five Se concentrations(0.01 g/L?0.05 g/L?0.1 g/L?0.5 g/L)were studied on slant medium.As the result,compared to non-treatment,when Na2SeO3 ? 0.05 g/L,the growth of mycelium for four kinds of Ganoderma Lucidum were improved;When Na2SeO3=0.1 g/L,the growth of mycelium that was?60%;When Na2SeO3=0.5 g/L,the inhibition was the strongest.The results showed that the concentration of Se was low could improve growth of the mycelium;Low Se concentration promotes the growth of mycelium,and high Se concentration inhibites the growth of mycelium.0.05 g/L was the best fit of Se concentration on slope.2.The two isolates were treated with serial doses of sodium selenite(0.01,0.05 gNa2SeO3/kg)in sawdust media(sawdust and rice bran as the main substrate).When the Se concentration was 0.01 gNa2SeO3/kg,grow rate of C and R fruit body was higher(?80%)than the control concentration;grow rate of H and Z fruit body was lower(?26%)when the Se concentration was 0.05 gNa2SeO3/kg,grow rate of four kinds fruit body was lower.But grow rate of C and R fruit body was? 80%,others was ?16%.In summary,the best Se concentration of sawdust media was 0.05 gNa2SeO3/kg and the screened strains were C and R.3.Spraying sodium selenate solution on soil under woods as Se-enriched treatment There are four treatments including CK C is the abbreviation of the control concentration grow C;CK R is the abbreviation of the control concentration grow R;SC is the abbreviation of the Se concentration(0.05 g/L)to grow C;SR is the abbreviation of the Se concentration(0.05 g/L)to grow R.Compared to non-treatment,the mode with soil spray(Na2SeO3=0.05 g/L)can raise total Se content in fruit body of screened stains significantly(P<0.05).The total Se contents are 1.38 and 1.61 mg/kg respectively for SC and SR.The total Se contents are>0.4 mg/kg that are Se-enriched soil in two soil types.The total Se contents are 16.5 mg/kg and 4.06 mg/kg respectively for SC and SR treatment.The organic Se contents are 13.9 mg/kg and 3.81 mg/kg respectively for Se-enriched treatment,they have more than 80%of total Se content in the fruit body.The total Se content is reached in the range from 0.5 mg/kg to 2 mg/kg that is the local standards of the Se content in agricultural produces in Guangxi province.That can be called Se-entiched Ganoderma Lucidum.The biological concentration factor of C was 4 times higher than R which indicated that C has a stronger Se-enriched ability4.Compared to CK C and CK R,polysaccharides contents,the crude proteins contents and triterpenoid contents were increased and the reducing sugar was decreased significantly for Se-enriched trearment(P<0.05).The increase of the crude proteins is 22.2%and 35.7%respectively for Se-enriched treatments.The increase of polysaccharides is 53.9%and 46.9%respectively.The increase of triterpenoid is 17.31%and 15.25%respectively.The decrease of the reducing sugar is 62.4%and 44.15%.The accumulation of crude proteins,polysaccharide and triterpenoid are promoted,but the production of reducing sugar is inhibited.The total Se and organic Se content had perfect positive relation to polysaccharides,the crude proteins and triterpenoid(P<0.01).5.Compared to CK C treatment and CK R treatment,total N and total P content were increased,but total K content was decreased significantly for Se-enriched treatment(P<0.05).The total Se and organic Se have perfect positive relation to total N and total P content,but have negative relation to total K content(P<0.01);Soil enzyme activities including invertase,phosphatase and urease were decreaced significantly in that soil sprayed sodium selenite solution(0.05 g/L)(P<0.05)6.Compared to non-treatment,the soil microbial quantity(the number of bacteria,fungi and actinomyces)were decreased significantly but the number of fungi of SR treatment and CK R treatment.(P<0.05)7.The bacterial community diversity was investigated by PCR-DGGE for the four treatments.Dominant bands disappeared and some new bands appeared with exogenous selenium.For instance,brightness of band 1 was weak and band 8 appeared on SC treatment;Band 2,4,5,6 were disappeared and band 3,7,9 were appeared after SR treatment;There is the phenomenon that some bacteria died and others adapted to the high Se environment.The index of richness(R),shannon-wiener index(H)and evenness(E)are lower than non-treatment for Se-entiched treatments.The trend of richness and shannon-wiener index were listed:CK C>CK R>SR>SC;For evenness,the trend was CKR>CKC>SC>SR.8.Compared to CK C treatment and CK R treatment,the dry matter accumulation and the cap thickness were increased significantly and the trend were listed:SR>SC>CK C>CK R.There were no significant difference between cap area and the height of SC compared to CK C;Compared to CK R treatment,cap area and the height were increased significantly for SRIn conclusion,there are three modes that 0.05g/L Se concentration were added to slant medium,0.05g/kg Se concentration were added to sawdust media and the mode with soil sprayed(Se=0.05 g/L).The three modes can boost total Se and organic Se content of fruit body,total Se content of soil,nutrients and medicinal ingredients of fruit body.The screened strains are C and R.The technique is practicable that the mode can increase Se content of Se-entiched treatment,which paves the way for future research on developing new Se-enriched theoretically.