通过平板对峙试验以分离筛选自青海托格若格半荒漠沙地、托素湖盐碱地、海北爆轰试验场3个极端生境植被根围的菌株为供试菌株,进行拮抗活性检测;采用16S rDNA及gyrB基因序列分析鉴定菌株;采用CMC法及Gram染色法测定菌株降解纤维素活性;对具降解纤维素活性的拮抗菌株进行促生活性测定.结果表明,菌株TGRG3、TGRG7、TSH5分别对油菜菌核菌(Sclerotinia sclerotiorum)、小麦赤霉菌(Fusarium graminearum)、小麦长孢蠕菌(Helminthosporium tritici-vulgaris)具有拮抗活性,抑菌圈平均直径均>20 mm.3株菌株均被鉴定为枯草芽孢杆菌(Bacillus subtilis),均具降解纤维素及促植物生长活性.%The strains were isolated from three representative extreme sample area including Tuogeruoge semi-desert sand,Tu-osu Lake salt and alkali land,detonation test site of Haibei in Qinghai province. Antagonistic activity detection was used to check antagonistic activity of these strains. Polyphasic molecular taxonomy methods including gyrB and 16S rDNA partial se-quence analysis were used to identify these strains. The CMC plate test and Gram staining method were used to analysis cel-lulose degradation of the bio-control strains. The results showed that three strains including TGRG3,TGRG7 and TSH5 could present distinct antagonistic activity to Sclerotinia sclerotiorum,Fusarium graminearum and Helminthotporium tritici-vulgaris,and diameters of the inhibition zone were all longer than 20 mm. The strains of TGRG3,TGRG7 and TSH5 were identified as Bacillus subtilis. All of three biocontrol B. subtilis strains had cellulose-degradation activity and promotion function on growth of plant.
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