巨大芽孢杆菌在油菜根部定殖和促生作用的研究

BACILLUS MEGATERIUM A6 (gusA) COLONIZATION IN ROOTS AND ITS GROWTH PROMOTING EFFECT ON RAPESEED

采用基因标记技术和常规方法跟踪巨大芽孢杆菌A6 (gusA)在缩影系统油菜根际的定殖情况。A6 (gusA)菌在油菜不同根段部位的定殖密度表现从上到下逐渐递减的现象。随着接种后时间的延长而逐渐下降。在根段 8cm以外的根区几乎检测不到接种菌。在油菜播种后 3d ,定殖密度可达最高水平 (8 7×10 5cfug-1根 ) ,然后急速下降 ,30d后保持相对稳定的较低水平 (2 2× 10 2 cfug-1根 )。在促生试验中 ,表现在不同程度上增加植株干重、全氮。

Bacillus megaterium A6(gusA) colonization in roots of rapeseed in rhizosphere microcosms was investigated by means of gene labeling technique and traditional technique. Rape seeds were inoculated with A6(gusA), an effective strain of bacteria in promoting growth of rape seedlings. Results indicated that A6(gusA) population decreased with the roots going downwards and with the time after inoculation. Populations of A6(gusA) were not detectable on roots more than 8 cm apart from the hypocotyl base. The population density of A6(gusA) on roots reached the maximum of 8.7×10 5 cfu g -1 root 3 days after sowing, and then declined rapidly till 30 days when it leveled off at 2.2×10 2 cfu g -1 root in rhizosphere microcosms. The result showed A6(gusA) could increased dry weight of the plant and content of total N, total P and total K in the plant.