选择性培养基对分离土壤中大丽轮枝菌Verticillium dahliae微菌核的影响

INFLUENCE OF SELECTIVE MEDIUM ON ISOLATION OF MICROSCLEROTIA OF Verticillium dahliae FROM SOIL

本文比较了六种培养基的分离效果,认为籍秀琴(1988)报道的棉选1号培养基(B)分离效果最好。棉选1号培养基(B)中各成分对大丽轮枝菌(V.dahliae)微菌核生长影响的研究表明增加杀菌剂克菌丹、五氯硝基苯浓度或降低培养基 pH 值都会强烈抑制 V.dahliae 的生长,而改变抗细菌抗生素种类和浓度对 V.dahliae 生长影响不大。我们对棉选1号培养基(B)作了改进,改进后的配方如下:蔗糖5克,K_2HPO_4 1克,NaNO_3 2克,KC10.5克,MgSO_40.5克,FeSO_4 0.01克,蒸馏水1000毫升,克菌丹0.5ppm,PCNB 350ppm,井岗霉素2.5ppm,氯霉素、链霉素、青霉素各250ppm。在这种培养基上细菌很少生长,V.dahliae 菌落呈黑色,稍凸起,杂菌主要为白色的镰刀菌,但对 V.dahliae 计数影响不大。

Six selective media for isolating V.dahliae from soil were compared,and medium mianxuan 1(B)was the most effective.Influence of components of medium Mianxuan 1(B)on growth of V.dahliae microsclerotia(MS)was studied.Increase of concentration of Captan or PCNB or decrease of PH value inhibited strongly growth of V.dahliae MS.Various kinds and concentrations of antibacterial compounds had no adverse effect on growth of V.dahliae MS.It is pointed out that the selective medium has great effect on isolation of V.dahliae in soil.The medium Mianxuan 1(B)was modified and the components were as follows:Sucrose 5g,Na No_3 2g,MgSO_4 0.5g,KCl 0.5g,K_2HPO_4 1g,FeSO_40.01g,distilled water 1000ml,Captan 0.5ppm,PCNB 350ppm, Jinggangmeisu 2.5 ppm,Chloramphenicol 250 ppm,Streptomycin 250 ppm,Penicillin 250 ppm.On this medium,the colonies of V.dahliae were dark and slightly raised, bacteria had hardly been seen and the other fungus was mainly Fusarium spp. which Hardly had adverse influence on count of V.danliae MS.