从野大豆组织中分离筛选出1株内生真菌菌株YD02,通过形态学观察和分子生物学方法对该菌株进行鉴定;用单因素实验和正交试验确定菌株的最佳发酵条件;采用菌丝干重法和对峙培养法分别测定菌株的抗重金属镉胁迫的能力以及对植物病原菌的影响.结果表明:YD02菌落黑色或墨绿色,菌丝分支且产孢;为链格孢属(Alternaria Nees)菌株;其最佳发酵条件是以PDB培养基为基础,蔗糖4％,氯化铵0.6％,磷酸氢二钾0.4％,硫酸镁0.05％,pH5或pH9,培养温度28℃,装液量为60％,120 r/min发酵60h;当镉浓度为140 mg/L时,YD02正常生长几乎停止.YD02菌株对瓜果腐霉病和苹果霉心病的病原菌具明显拮抗作用,抑菌率分别达到64.15％和71.68％.%The endophytic fungus YD02 was isolated from a wild Glycine soja and identified using morphological feature and molecular biology methods.The single factor experiment and the orthogonal test were applied for determining the optimal fermentation conditions of the strain.Further,dry weight method was used to determine the resistance of the strain on heavy metal Cd stress,and the confrontation culture method was to value its effect on the pathogenic bacteria of plant.The results showed that YD02 colony was black or dark green,hyphae branched and spores produced,and it belonged to Alternaria Nees.The optimal fermentation condition was 4％ sucrose,0.6％ ammonium chloride,0.4％ potassium hydrogen phosphate,0.05％ magnesium sulfate,pH 5 or pH 9,culture temperature 28℃ with 60％ fluid amount,120 r/min and 60 h fermentation on the base of PDB culture medium.When cadmium concentration reached 140 mg/L,YD02's growth stopped.YD02 strain presented obvious antagonistic effects on the Pythium aphanidermatum and apple moldy core pathogens,and the bacteriostatic rate was 64.15％ and 71.68％,respectively.
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