论文部分内容阅读
目的研究标记菌株在水稻国丰1号幼根根表的吸附动态规律和不同类型土壤中存活情况,为禾本科植物凝集素介导作用、吸附的影响参数和联合固氮的研究及应用提供科学依据。方法采用三亲本杂交法将发光基因luxAB导入水稻根际促生菌黄单胞菌(Xanthom onassp)P5310菌株中,标记菌株P5310-luxAB能稳定遗传,luxAB基因的导入不影响标记菌株生长特性。结果 P5310-luxAB菌株存在稳定型和松散型两种吸附,随标记菌株浓度变化的吸附规律符合Langmu ir等温吸附方程,水稻根表最大吸附量qm=3.33×109CFU/g,吸附系数α=2.86×10-8。凝集素处理的水稻根表对标记菌株的亲和力增强,吸附量也随之增大。标记菌株在灭菌土壤和不灭菌土壤中都能很好的存活。在前25 d,不灭菌土壤中菌落数要低于灭菌土壤,随着营养的消耗,细菌明显减少;但补充营养后,在灭菌土壤和不灭菌土壤中标记菌株数量都快速增加,证明标记菌株与不灭菌土壤中的土著微生物的竞争占优势,很快与灭菌土壤中的菌数接近,证明菌株能在土壤中很好地存活与定植。结论以上研究结果为菌株P5310的开发应用提供了可靠的实验数据。
OBJECTIVE To study the dynamic of adsorption of labeled strain on the rhizome of rice rhizome 1 and the survival of different types of soil in order to provide a scientific basis for the study and application of the lectin mediation of the gramineous plant, the influence parameters of adsorption and the combined nitrogen fixation . Methods The luxAB gene was introduced into Pseudomonas aeruginosa Xanthomobacteria P5310 by the method of three parents, and the marker strain P5310-luxAB was stably inherited. The introduction of luxAB gene did not affect the growth characteristics of the marker strains. Results The adsorption of P5310-luxAB strain was stable and loose. The adsorption wasotherm equation with Langmuir, the maximum adsorption capacity of rice was q = 3.33 × 109CFU / g and the adsorption coefficient was 2.86 × 10-8. The affinity of the lectin-treated rice root surface to the labeled strain increased, and the amount of adsorption increased. The marker strain survived both sterilized and non-sterile soil. In the first 25 days, the number of colonies in the non-sterile soil was lower than that in the sterile soil, and the bacteria decreased significantly with the consumption of nutrients. However, the number of the labeled bacteria in the sterile soil and the non-sterile soil rapidly increased after nutrition supplementation It was demonstrated that the competition between the labeled strain and the indigenous microorganism in the non-sterile soil was predominant and quickly approached the number of bacteria in the sterilized soil, demonstrating that the strain survived well in the soil and colonized. Conclusion The above results provide reliable experimental data for the development and application of strain P5310.