Screening Research Of Antagonism Actinomyces Which Isolated From Saline-alkali Soil In Hexi Corridor On Four Plant Pathogenic Fungi

50strains of actinomycetes were isolated from the saline-alkali soils of HexiCorridor in Gansu Province which were used as experiment ones on resistanceresearch.The main results are as follows:1.Oxford cup method and Pair culture method were used to screen antagonisticbacteria. The results of antagonism activity showed that4strains have the antibaterialproperty to three different bacteria.?22-5-1has antagonism to E.coli, ?22-5-3hasantagonism to Bacillus subtitles, ?16-3-1,?8-5-2both have antagonism to S.aureus.In which ?22-5-3and ?16-3-1have higher antagonism diameters ofinhibiting bacteria circle were both beyond15mm.There are6strains have the antibaterial property to four different fungus.?18-5-2has antagonism to Rhizoctoniz solani and Botrytis cinerea, ?22-3-3hasantagonism to Botrytis cinerea, ?22-3-12has antagonism to Rhizoctoniz solani andAlternaria solani, ?23-4-3has antagonism to Botrytis cinerea, ?16-3-2,DC009-1-23both have antagonism to all four different fungus. In which ?22-3-12has a higherantagonism diameter to Alternaria solani, ?23-4-3has a higher antagonism diameterto Botrytis cinerea,?16-3-2has higher antagonism diameters to Rhizoctoniz solani,Alternaria solani and Botrytis cinerea, DC009-1-23has a higher antagonism diameterto Rhizoctoniz solani, Alternaria solani and Fusarium verticillioides. The inhibitingbacteria circle were all beyond15mm.2.Growth rate method was used to rescreen the strains which have higher antagonismdiameter(beyond15mm).The result showed:The mycelial growth of DC009-1-23toRhizoctoniz solani, Alternaria solani and Fusarium verticillioides, ?23-4-3toBotrytis cinerea, ?22-3-12to Alternaria solani, ?16-3-2to Rhizoctoniz solani,Botrytis cinerea are all beyond80%. the inhibition effect of DC009-1-23to Alternariasolani was up to88.88%.3.In order to increase the production of the fungicidal substance,the liquid mediacompositiom was optimized and the fermentation condition was primarily studied.Theoptimum fermentation medium of the ?16-3-2Strain was composed of millet10g, soluble starch10g,NaCl2g,peptone3g, CaCO32g.The optimum fermentation conditionwas the initial pH of medium6.5,fermentation temperature28?, shaking speed160r?min,liquide volume60mL(in250mL flask).4.Tissue culture method was used to determine the antagonistic efficacy of?16-3-2,DC009-1-23to Rhizoctoniz solani and ?22-3-12,?16-3-2,DC009-1-23toAlternaria solani.Biopsy tests showed,the control effects of ?16-3-2to Rhizoctoniasolani and ?22-3-12,?16-3-2,DC009-1-23to Alternaria solani reached beyond50%.5.Morphological characteristic and phylogenetic analysis based on16S rRNA genesequence supported the strain ?16-3-2to be Streptomyces variabilis,and the strainDC009-1-23to be Streptomyces lilaceus. Morphological characteristic supportedstrains ?18-5-2,?22-3-3??22-3-12to be Streptomyces,and strain ?23-4-3to beNocardiopsis.