巨大芽胞杆菌在3种固沙植物根部的定殖

Bacillus megaterium Colonization in Roots on Three Sand-Fixing Plants

用200μg/mL的卡那霉素标记巨大芽胞杆菌菌株R,并获得抗药标记菌株,明确其在固沙植物杨柴、柠条和油蒿根上的定殖能力。将标记菌株制成菌液,浸种接种至杨柴、柠条和油蒿的种子,待种苗根系生长至约12cm后,测定R菌株在3种植物不同根段的定殖密度和根际效应。结果表明,标记菌株在灭菌土壤中定殖密度比在自然土中大,根系不同部位标记菌株定殖密度表现为从上到下逐渐减小,0～3cm根段标记菌株在根际的定殖密度达到最大,9～12cm根段几乎不能分离到标记菌株。3种植物中,杨柴的根际效应最显著,标记菌株在油蒿根际的定殖密度最大。

Bacillus megaterium strain R labeled by kanamycin was obtained after being marked with concentration 200 μg/mL 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.