芽孢杆菌与根瘤菌复合包衣对大豆结瘤固氮能力的影响

Effect on the nodulation and growth of soybean coated with Bradyrhizobium and Bacillus co-inoculants

为了探究不同芽孢杆菌与根瘤菌复合包衣对大豆结瘤固氮的影响,通过盆栽试验,设置不接菌对照(CK)、根瘤菌单独包衣(R)、阿氏芽孢杆菌(RB)和胶质类芽孢杆菌(RP)2种促生菌分别与根瘤菌双包衣以及3种菌混合包衣(RBP)共5个处理,测定大豆根瘤数量、干重、根瘤固氮酶活性及植株氮、磷、钾含量,筛选根瘤菌剂最佳组合。结果表明,接种菌剂的处理均能够促进大豆结瘤固氮,其中RB处理效果最好,能够获得最高的大豆植株干重、根瘤数量、根瘤干重、固氮酶活性、全氮含量,比CK分别提高51.80%、14.44%、53.33%、44.36%、25.61%,3种菌包衣并没有比双接种促生效果更好。相关性分析表明,根瘤干重与固氮酶活性、根瘤数量及植株干重都呈显著正相关关系,说明根瘤的质量可能比数量更能准确评价共生固氮效率。此结果为根瘤菌剂应用于机械化种植提供可能性,为进一步推广根瘤菌剂的规模化生产应用提供了科学依据。

To explore the effect on the nodulation and growth of soybean when coated with Bradyrhizobium and Bacillus coinoculants,pot experiment was carried out.Five treatments were set up,including CK(no inoculant),R(Bradyrhizobium inoculant coating),RB(co-inoculant coating of Bradyrhizobium and Bacillus aryabhattai),RP(co-inoculant coating of Bradyrhizobium and Paenibacillus mucilaginosus)and RBP(multi-inoculant coating of Bradyrhizobium,Bacillus aryabhattai and Paenibacillus mucilaginosus).Soybean nodule number,nodule dry weight and nodule nitrogenase activity,total nitrogen,phosphorus and potassium of soybean plant were analyzed.The result showed that all treatments with inoculation growth-promoting bacteria promoted soybean nodulation.The RB treatment obtained the highest soybean plant dry weight,nodule number,nodule dry weight,nitrogenase activity,and total nitrogen content,which were higher than that of CK by 51.80%,14.44%,53.33%,44.36%and 25.61%,respectively,and the three kinds of bacterial coating were not better than double inoculation in growth-promoting.Correlation analysis showed that nodule dry weight was significantly positively correlated with nitrogenase activity,nodule number and plant dry weight,indicating that the quality of nodule was more accurate than the quantity to evaluate the symbiotic nitrogen fixation efficiency.The study optimized a high-efficiency composite Bradyrhizobium and Bacillus coating agent for soybean,and provided a scientific support for the application of Bradyrhizobium in the future.