Abstract: We explored the effects of Bacillus (Bacillus amyloliquefaciens (Bam688) and Bacillus tequila (Bte724)) on the growth of maize seedlings under saline-alkali stress. The results showed that, under saline-alkali stress, the inoculation with Bam688 and Bte724 had the strongest effect at the concentration of 1×10⁷ cfu·mL^-1. Both Bam688 and Bte724 increased the activity of antioxidant enzymes in maize seedlings, with more increase in roots than that in leaves. The content of osmoregulation substances was increased significantly after maize seedlings were inoculated with Bam688 and Bte724. Compared with the control, the content of free proline in leaves of maize seedlings inoculated with Bam688 and Bte724 increased by 254.41% and 161.84%, respectively, with more increase of free proline in leaves than that in roots. ROS accumulation and lipid peroxidation content in maize seedlings were significantly decreased after inoculation with Bacillus. Results of the analysis of NBT and DBA infection showed that the oxidation of maize seedlings was significantly alleviated. The photosynthetic pigment content of maize seedling leaves increased after inoculation with Bacillus. Compared with the control, the carotenoid content of leaves increased by 45.99% and 60.07% after inoculation with Bam688 and Bte724, respectively. Our results indicated that both Bacillus strains can promote the growth of maize seedlings and alleviate the damage caused by saline-alkali stress.

Key words: corn seedling, Bacillus, salt-alkali stress, growth-promoting effect.