Colonization In Plant And Promoting Plant Growth By Endophytic BS-2 (Bacillus Subtilis)

Mutanted by antagonism against the rifampicin (300μg/ml) and inoculated by dipping seeds, daubing leaves, and pouring roots, BS-2(Bacillus subtilis) strain was proved to be able to colonize inside of capsicum, cabbage and rice. If capsicum seeds were soaking for 24h in bacterial suspention with 5 × 10~2cfu/ml concentration before sowing, the target bacteria could be isolated from the capsicum seedlings late, but could not be isolated from both of cabbage and rice seedlings in the same treatment. When the seeds were soaking in bacterial suspention with 5×10 -10~6cfu/ml concentrations, the target bacteria could be isolated more from capsicum seedlings than cabbage and rice seedlings. The results also showed that the strain was able to get into the plants initiatively, and live and move in the plants. The inoculation by daubing leaves could get better result.The results of plant promoting growth by BS-2 showed that the bacteria could accelerate growth of cabbage and capsicum no matter which inoculation method was used. But the best one was daubing leaves.The fresh weights of the two plants were 151.20% and 168.70% increased respectively and the dry weights were 182.30% and 181.25% increased respectively.The bacterial cells and bacterial secretion could accelerate growth of cabbage and rice (Jiazao6hao & Shanyou63) separately. The fresh weights of the plants were 82.75% and 60.34% and 14.08% increased respectively inoculated by bacterial cells, and dry weights were 82.58% and 37.71% and 33.90% increased respectively. The fresh weights of the plants were 50.46% and 28.51% and 25.67% increased respectively inoculated by the bacterial secretion, and the dry weights were 70.24% and 13.63% and 32.94% increased respectively. The BS-2 strain could accelerate growth of cabbage and rice with different inoculation concertrations(5 × 10~4-10~8cfu/ml).The mechanisms of promoting plant growth by BS-2 were investigated. The results showed that (1) BS-2 strain could colonize in plant, and the quantity of colonizition was correlation with plant promoting.(2)The effect of plant promoting is gotten by both of the bacterial cells and their metabolites. (3) The bacteria could increase the content of chlorophyll of test plants. (4)The bacteria...