Abstract:
Background Bacillus subtilis is an emerging microbial material which potentially contribute to desertification combating. However, as a typical plant growth-promoting rhizobacteria, its effects on the plant colonization and growth in a desert environment still remain unclear. This study is aimed to investigate the effect of B.subtilis on the physiological characteristics of seed germination and seeding growth of psammophyte.
Methods The controlled experiments were conducted to determine the seed germination, seeding growth and physiological characteristics of Ammopiptanthus mongolicus and Caragana korshinskii using different bacterial application amount (0, 1, 3, 5, 7 and 10 g/kg). The changes of seed germination and the physiological characteristics of seeding growth were investigated, including contents of chlorophyll, malondialdehyde and proline.
Results 1) B. subtilis increased the seed germination rate of A. mongolicus and C. korshinskii, and the optimal dosage were 3 and 10 g/kg, respectively. Meanwhile, it had no significant effect on the seedling crown (P>0.05), only 10 g/kg dosage significantly impacted the height of C. korshinskii seedings (P < 0.05). 2) B. subtilis significantly affected the physiological and biochemical characteristics of A. mongolicus and C. korshinskii (P < 0.05). The chlorophyll content of A. mongolicus significantly increased (P < 0.05) and the malondialdehyde and proline of A. mongolicus and C. korshinskii significantly decreased (P < 0.05), and the optimal dosage was 5 g/kg.
Conclusions B. subtilis improves the plant physiological and biochemical characteristics therefore promotes the seeding growth, but this effect is limited with a lagging performance. Moreover, it varies with the bacterial application amount and plant species, the C. korshinskii is more impressionable than A. mongolicus. This improved information will provide theoretical basis and scientific support for desertification combating technology exploration using B. subtilis.
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