Abstract:

Bacillus megaterium strain R labeled by kanamycin was obtained after being marked with concentration 200μg?mL-1 kanamycin and the seeds of Hedysarum mongolicum, Caragana korshinskii and Artemisia ordosica were inoculated with the strain R solution by soaking it to evaluate the colonization density of R strain and rhizosphere effect of different root parts of these plants after the seeding root tip to 12 cm. The result showed that the density of R strain in sterilized soil was more than it in natural soil. The colonization density of strain R came from the root tip down gradually in different root parts, and the colonization density reached to maximum in the 0～3 cm part. The strain R could not be isolated in the 9～12 cm part. The rhizosphere effect of H. mongolicum was most prominent in these plants, and the colonization density of strain R reached to maximum in the rhizosphere of A. ordosica.