A NEW NITROGEN FIXING ENDO-BACTERIUM STRAIN ISOLATED FROM SUGARCANE STEM

摘要

Aim: To isolate and identify nitrogen fixing endophyte bactaria from sugarcane. Materials and results: The upper portion of the stem of healthy sugarcane plants (variety RB867515) was used for isolation of N fixing bacteria. A bacterial strain B8S, with nitrogen fixation ability, was isolated from the stem of sugarcane variety RB867515 introduced from Brazil. This strain was identified based on morphological, physiological and biochemical characteristics and 16S rRNA gene sequence analysis. The 16S rRNA gene sequence analysis showed that the fragment sequence length was 1403bp. When compared with Agrobacterium tumefaciens (AY51349, AB116668.1 and AJ1307119) in GenBank, the homology of the nucleotides was 100%. Certain physiological and biochemical characteristics of the new bacterium strain B8S were almost the same as that of Agrobacterium tumefaciens. Based on its nitrogen fixation ability and similarity , the strain B8S was identifiied as a new nitrogen fixing endo-baterium strain in sugarcane, and it was named as Agrobacterium diazotrophicus. Significance of Study: The new nitrogen fixing endo-baterium strain may be valuable for further application in commercial sugarcane production.