中文摘要：

通过改良蔗糖-天冬氨酸培养基筛选到一株产铁载体的内生细菌HS-4,测定了该菌在不同铁离子浓度下对棉花枯萎病致病菌尖孢镰刀菌（Fusarium oxysporum）的抑菌效果,并结合形态、生理生化、16S rDNA序列同源性和系统发育分析对菌株进行鉴定.结果表明：内生细菌HS-4在MSA培养基中产生荧光型铁载体,其铁载体相对含量为80%.该铁载体在低铁条件下对F.oxysporum具有抑制作用.内生细菌HS-4初步鉴定为萎缩芽孢杆菌（Ba-cillus atrophaeus）.

英文摘要：

In this study,a siderophore-producing endophytic strain was isolated using the improved sugar-aspartic acid（MSA） as selective medium,and then detected its antibacterial effect against fusarium wilt pathogens（Fusarium oxysporum） at different concentrations of FeCl3.This strain was identified by using morphological,biochemical and physiological characteristics,16S rDNA sequence homology and phylogenetics analysis.The results showed that strain HS-4 produced the fluorescent siderophores（pyoverdine） on MSA medium;whose content amounted to 80% of the total siderophores.The siderophore produced by strain HS-4 has the inhibitory action against Fusarium oxysporum under the low iron condition.Endophytic bacteria strain HS-4 was identified as Bacillus atrophaeus.