| 1. Screen of antagonistic bacterias and the optimum combinationFour antagonistic bacterias(B3, B4, B5, B6) were obtained by screening on plate,whose inhibition activity against several phytopathogenic fungi had difference. Among B1, B2 (screened in 2000) and other four strains,B, , B2, B4 against Fusarium oxysporumf.sp. pisi ,and B1, B3, B5 against F.solani f.sp.pisi and B3 against Sclerotium cepivorum had strong inhibition effect,whose pathogen inhibiting zone diameters were larger than 31mm. Furthermore,B3 and B5 had apparently inhibition effect against Botrytis cinerea.The toxicity of different mixtures,which were made by mixing up cell-free filtrates of four with Bl and B2 according to different proportions,had been tested on F.oxysporum f.sp. pisi. The results showed that B146 and B2346 whose CTC were 132.19 and 147.17 respectively had strong inhibition effect to the growth of mycelium and had notable synergistic effect,which were optimum combinations.2. Resistance marked and colonizing dynamics of Bl and B2Bl and B2 mutants(B1R and B2R) of resistant Rif 100ug/ml were acquired by continuously screening on series concentration of Rif mediums.Compared with orginal strains,whose inhibition to F.oxysporum f.sp. pisi and growth promoting and disease control effects weren't changed or increased,except colonial morphology were slightly changed.The pea seeds were soaked in Bl and B2 suspension,and then sowed in soil of inoculating or not inoculating F.oxysporum f.sp. pisi.The recycling experiment showed that B1R and B2R could colonize in the rhizosphere of pea.The highest colonizing level were reached on 10th day after seeds sown,and the population of B2R were the highest(1.44×1010cfu/g).The population of B1R and B2R slowly decreased after that,on25th day,whose amounts ranged from 106 to 107. 3. The biological characters of S.cepivorum and growth promoting effect of Bl and B2The results showed that S.cepivorum could grow at 10C~30C,with the optimum growth at 20C;the optimum pH value of mycelium growth were 4.0 and the growth speed got slowly with the increase of pH value;the condition of darkness was benefit to growing of mycelium.The optimum temperature and RH for sclerotial germination were 15℃ and 100%RH.Moreover,the pathogen could utilize many carbon sources and nitrogen sources. Glucose and mannite were benefit to the growth of pathogen among of carbon sources,L-cystin and pectinase were the optimum nitrogen sources,but D-galactose and L-cystaine and urea could inhibit it.In field experiments,BK B2 and B1+2 could not only promote germination of garlic seeds and growth of seedings,but also increase yield. Among of treatments,the growth promoting and the yield increasing effect of Bi+2(50X) were notable,whose increasing rate were 12.57%(height) and 11.16%(yield) respectively. 4. 16S rDNA sequence analysis of Bl and B2The sequence of the two strains'(Bl and B2)16S rDNA were found to be homogeneous at the rate of 99% to the members of Bacillus sp.(Accession number were ABO 17591 and AF411118 in GenBank), which conformed with the results of spore stain. Therefore, the position of two strains in bacterial phylogeny were established.They were identified as Bacillus sp.
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