Growth-promoting effect of Bacillus strains on Eucalyptus seedling and their ACC deaminase activity

Abstract:

[Objective] aiming to screen out Bacillus strains which promoted growth of Eucalyptus seedlings, estimate relationship between ACC deaminase activity and seedling growth performances, and reveal preliminarily mechanism of growth promotion by Bacillus strains. [Methods] Pot experiment was conducted for Eucalyptus seedlings inoculated by 32 strains of Bacillus which were isolated from the soil under Eucalytus plantation in Yangjiang and Guangzhou City, Guangdong Province, and ACC deaminase activity of the strains as well as nitrogen and phosphorus contents of the seedlings were measured. [Results] The results showed that inoculations of strains 2306, 2301 and 2403 could increase significantly height and biomass growth of Eucalyptus seedlings, and strain 2306 was the best, relevant seedling height and biomass were 53.1% and 190.2% higher than control. [Conclusion] ACC deaminase activity of Bacillus strains was remarkably correlated with seedling height and biomass, and these three strains could also increase nitrogen and phosphorus contents of Eucalyptus seedlings. The findings will increase growth-promoting microorganism germplasm resources of Eucalyptus plantation and facilitate development of microbiological fertilizers for Eucalyptus.

Key words:Eucalyptus, Bacillus, plant growth promotion, ACC deaminase