Research On Biological Restoration Of Ectomycorrhizal Fungi To Soline-alkali Soil

The ectomycorrhizal fungi and soil fungi in saline and alkali land were as objects,the methods of mycology and molecular biology were used to research the effects of different pH value culture liquid and saline-alkali soil filtrate liquid on the growth of ectomycorrhizal fungi, the effects of ectomycorrhizal fungi growth on the pH value change of different pH value culture liquid and soil filtrate liquid,fungal populations in different pH value saline-alkali soil and their growth competition with ectomycorrhizal fungi.The results show as follow:(1) The tested fungal strains can grow below pH12.In the culture liquid with the pH value from 6.5 to 12,Agaricus silvaticus has the highest mycelial biomass,and then is strain 025;in saline-alkali soil filtrate medium with different pH value,Agaricus silvaticus also has the highest mycelial biomass,and then is strain 025.(2) The growth of tested fungal strains can reduce the pH value of culture substrate definitely,in which strain GT005 and strain LH004 were better.14 days growth of strain 010(Agaricus silvaticus) and strain 025 with better alkali tolerance in pH 8 culture liquid could descend the pH value of culture liquid to pH 7.31 and pH 7.45,made pH 10.0 culture liquid to pH 7.80 and pH 7.95,and pH 12.0 culture liquid to pill0.05 and pH 8.47 respectively;14 days culture of strain 010 and strain 025 in pH 13.0 culture liquid could made the pH value of culture liquid to 11.93 and 8.54 though the two strains showed no growth or extremely slow growth.All strains had similar effects on the pH value of saline-alkali soil filtrate medium.(3) Twenty-two fungal species were isolated from saline-alkali soil in Daqing.Thereinto,7 species from pH 7.0 soils,5 species from pH 8.0 soils,5 species from pH 9.0 soils,2 species from pH 10.0 soils,2 species from pH 11.0 soils and 1 species from pH 12.0 soils.The soil fungal species population decrease with the pH value of soil alkali rising.Among the obtained soil fungal species population,the species of Fusarium had wider suitable growing range in saline-alkali soil.(4) There were definite inhibiting effects or enhancing effects between the growth of ectomycorrhizal fungi(strain 010 and strain 025) and saline-alkali soil fungi.Strain 010 (Agaricus silvaticus) had stronger growth competition ability which had remarkable inhibiting effects on the growth of 10 species of saline-alkali soil fungi.The relative inhibition effect of strain 010 to Alternaria alternata was over 27,to Rhizopus oryzae over 8;Strain 010 also had remarkable inhibiting effect to the pathogens of seedling damping-off disease Fusarium oxysporum(relative inhibition effect over 6),Thanatephorus cucumeris(relative inhibition effect close to 4) and Fusariurn solani(relative inhibition effect over 2).The growth of strain 025 can markedly inhibit the growth of Paecilomyces variotii,Rhizopus oryzae,Fusarium solani,Thanatephorus cucumeris and Fusarium equiseti.The saline-alkali soil fungal strains which had remarkable inhibiting effect(relative inhibition effect over 1) were Fusarium oxysporum,Mucor circinelloides,Trichoderma longibrachiatum,Trichoderma hamatum and Mucor sp..Strain 010(Agaricus silvaticus) had more remarkable growth competition advantage than strain 025.In conclusion,,strain 010(Agaricus silvaticus) and strain 025 can be used for biological restoration of saline-alkali land for their higher saline-alkali tolerance,wider suitable growing range in saline-alkali soil,better effects on reducing the pH value of growth substrate,stronger growth competition advantage,and remarkable inhibitiing effects on pathogens of seedling damping-off disease.