【摘要】 【目的】从小麦内生菌中鉴定得到小麦赤霉病菌(Fusarium graminerum)拮抗菌,并对其生长条件进行优化.【方法】试验采用平板对峙法筛选小麦根、茎、叶中对小麦赤霉菌具有高效抗性的内生菌株.【结果】得到7株小麦赤霉菌拮抗菌株,其中拮抗能力最优的是菌株XG-7,抑菌圈宽度达32.5 mm.通过16S rDNA序列分析,并结合生物学特性,初步鉴定为枯草芽孢杆菌(Bacillus subtilis).XG-7对炭疽病菌(Colletotrichum gloeosporioides)、立枯病菌(Rhizoctonia solani)、白绢病菌(Sclerotium rolfsii)、梨黑斑病菌(Alternaria kikuchiana) 4种常见病原菌,表现为广谱拮抗活性;XG-7对氯霉素和氨苄西林钠表现出强的耐药性;该菌的最适生长温度为28℃,最适生长pH为8,在接种到NA培养液后的24 h内为对数期,24～60 h为稳定期,60 h后进入衰退期.【结论】小麦内生细菌XG-7对赤霉菌表现出良好的抑菌作用,且抑菌谱广,易培养,具有良好的应用前景.更多还原

【Abstract】 【Objective】 To isolate and identify the antagonistic bacteria from wheat endophyte against Fusarium graminerum,and to optimize the growth conditions.【Method】 The antagonistic bacteria against Fusarium graminearum in wheat root,stem and leaf were screened by plate confrontation method.【Result】 The results showed that the best strain was XG-7 from 7 isolated antagonistic strains.And its inhibition zone diameter was 32.5 mm.XG-7 was preliminarily identified as Bacillus subtilis by analysis of 16 S rDNA sequence and biological characteristics.It showed broad antagonistic activity to four common pathogens(Colletotrichum gloeosporioides,Rhizoctonia solani,Sclerotium rolfsii and Alternaria kikuchiana).XG-7 showed strong resistant to chloramphenicol and ampicillin sodium.The optimum temperature and pH for growth were 28 ℃ and 8.It was at logarithmic phase 24 hours after inoculation to NA culture,stable phase during 24 to 60 hours and recession phase after 60 hours.【Conclusion】 The application prospect of XG-7 for inhibiting Fusarium graminearum was promising.更多还原