Isolation and Identification of Growth-promoting Rhizosphere Strains Isolated from Extreme Environment and Its Biological Activity Analysis
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.