Screening And Antagonism Of Culturable Growth-promoting Fungi In Rhizosphere Soil Of Cinnamomum Migao

Cinnamomum migao H.W.Li,a famous Miao medicine in Guizhou province,has high medicinal and economic value.However,the scarcity of wild resources,slow growth,low seed germination rate in natural conditions,the self-poisoning effect of rice haggis foliage on seedlings,the parasitism of the mulberry parasitic sheath flower and the damage caused by human logging have led to great difficulties in its natural renewal and artificial cultivation.With the pollution and deterioration of the environment,soil salinization,soil acidification and its calcium and iron deficiency stress,heavy metal pollution,and the excessive use of pesticides and fertilizers,the sustainable development of artificial cultivation has become an object of concern,with the application of chemical fertilizers becoming central to the soil problem.The fungus from the plant roots can be used to dissolve phosphorus and potassium,secrete the plant growth hormone IAA(Indole-3-acetic acid),and produce ferric acid,which can promote the growth and development of plants.Therefore,we screened and studied the antagonistic effects of the fungus on the roots of C.migao,in order to provide theoretical support for the subsequent production of micro-ecological preparations for it.To select C.migao inter-rhizosphere probiotic fungi,qualitative and quantitative studies were carried out on the phosphorus solubilization,potassium solubilization,IAA production,and ferredoxin production of inter-rhizosphere fungi using the transparent circle method.The final screening was carried out to obtain several hybrids of C.migao inter-rhizosphere probiotic fungi suitable for micro-ecological preparations..After the selection of growth-promoting fungi,the urease activities,β-glucosidase activities,acid phosphatase activities,and FDA hydrolase activities of the growth-promoting fungi were measured,and the same function of the growth-promoting fungi and the different functions of the growth-promoting fungi were tested.The urease activity,β-glucosidase activity,acid phosphatase activity,and FDA hydrolase activity were measured under the face-off condition.In the end,several mixtures of inter-rhizosphere fungal promoters of C.migao were screened for their suitability for micro-ecological preparations.The test results are as follows:(1)From 110 species of fungi of 57 genera isolated from the rhizosphere of C.migao,44 strains of rhizosphere fungi with clear circles were screened.BP41(Nectria pseudocinnabarina)、 BP44(Cordyceps javanica)、 BP47(Purpureocillium lilacinum)、 BP49(Thanatephorus cucumeris)、LD13(Gonytrichum macrocladum)and XL7(Metarhizium flavoviride)were found to have strong phosphorus-solubilizing capacity among the rhizosphere growth-enhancing fungi.There were BP19(Sordariomycetes sp.),LD4(Hypocrea lixii)and XL25(Penicillium coprophilum).Strains BP2(Clonostachys byssicola)and XL27(Coniothyrium platani)had strong IAA production capacity.And,strains that have a strong capacity to produce ferrophilia are LD11(Cordana terrestris),LD16(Kiflimonium curvulum),XL13(Fusarium solani),XL24(Metarhizium carneum).(2)BP33(Nectria polythalama)、 BP49(T.Poweris)、 LD19(Brunneochlamydosporium Poweris)and XL1(Scedosporium Poweris)and XL20(Gongronella butleri)in the selected growthpromoting strains had four growth promoting abilities of phosphorus solubilization,potassium solubilization,IAA production and ferrophilin production.In addition,the potassium solubilization capacity of BP33 was significantly higher than that of the other four strains,the phosphorus solubilization capacity of BP49 was significantly higher than that of the other four strains,and the IAA production capacity of XL20 was significantly higher than that of the other four strains.It was found that LD19 and XL1 could be used as microecological agents to test their ability of promoting C.migao growth.(3)In the face-off test of the same functional strains,it was found that BP47,which has strong phosphorus-solubilizing effect,produced obvious antagonistic band after face-off with BP41,and BP47 would reveal a few dendritic mycelia to BP41,in order to obtain some metabolites of BP41 to satisfy its growth and propagation.In addition,the inhibition effect of one strain was stronger than that of the other strain in the strain groups under the same functional confrontation,so that the two strains could coexist,thus satisfying the Lotka-Volterra competition model.(4)The face-off test of strains with different functions showed that BP19-BP47-LD16 possessed phosphorus solubilizing ability,potassium solubilizing ability,IAA production ability and ferriophilic production ability,while glucosidase activity,acid phosphatase activity and FDA hydrolase activity increased.In addition,it can be decided whether to add XL13 or not depending on the growth site of C.migao.In addition,the following mixed strains can be used as reference for microecological agents: XL25,LD16,XL29 and LD13;A mixture of XL25,XL13 and BP47;Mixture of LD16,BP44 and XL25;Mixture of LD16,BP44,XL25 and XL13;A mixture of XL25,BP44 and LD16.In this study,we screened C.migao inter-rhizosphere growth-promoting fungi and conducted a two-by-two confrontation test with the same functional strains and different functional strains to select a mixture of strains that can meet a variety of growth-promoting conditions and promote interdependence,providing theoretical support for the subsequent research and production of C.migao microecological formulations.