水苏糖对地黄根际土壤微生物失衡的影响

目的通过水苏糖铵盐培养液对土壤细菌生长的影响,证明水苏糖对土壤细菌具有"筛选作用"。方法采用比浊法,在初始菌悬液浓度一致的前提下,每2h于600nm处测定菌悬液的吸光度值并绘制生长曲线,以定量分析水苏糖对土壤细菌生长的影响情况。结果大多数土壤细菌不能很好地利用水苏糖,仅少数土壤细菌在水苏糖培养液中生长良好。结论大多数土壤细菌不能很好地利用水苏糖作为其能源物质,因此可能造成根际细菌的种类和数量大幅下降,仅少数可较好利用水苏糖的土壤细菌活动旺盛,这些能够良好利用水苏糖的土壤细菌有可能作为"优势菌"大量繁殖,从而造成地黄根部土壤微生物失衡。

Effect of stachyose on microbiotic disequilibrium in rhizospheric soil of Rehmannia glutinosa

Objective To testify the screening function of stachyose on soil bacteria by investigating the bacterial culture in ammonium stachyose medium. Methods The turbidimetry was used to determine the absorbance of microbial suspension at 600 nm per 2 h under the same initial concentration of the microbial suspension and to draw their growth curves. Results Most of soil bacteria utilized stachyose ineffectively, while only a few of them grown well in ammonium stachyose medium. Conclusion Since the major soil bacteria can not take stachyose fully as their energy resources, the species and quantity of rhizobacteria may decrease largely and only a few that utilized stachyose better can develop vigorously. Those rhizobateria with better utilization of stachyose may multiply so rapidly as potential ones in the rhizosphere of Rehmannia glutinosa that the disequilibrium of soil microorganism appears.