大豆根瘤菌与促生菌复合系筛选及机理研究

Screening and Analysis for Efficient Co-inoculation System of Soybean Rhizobia and Plant Growth-promoting Rhizobacteria

通过溶磷和生长素分泌的定性测定,从大豆根际土壤及实验室保藏菌株中分离筛选植物根际促生细菌(PG-PR),采用大豆根瘤菌和促生菌双接种的蛭石盆栽试验,初筛获得能够促进大豆植株生长、提高大豆根瘤菌结瘤固氮作用的促生菌5株。进一步的土壤盆栽复筛实验表明,筛选得到的5株促生菌与大豆根瘤菌进行双接种,能够在阜阳、济宁和延安的3种土壤中明显提高大豆的根瘤数量、根瘤干重、植株干重和全氮含量,并且能够促进植株对磷素的吸收。溶磷能力定量测定表明,5株促生菌均具有溶解无机磷的能力,有的菌株具有较高的溶磷能力;高效液相色谱法测定促生菌发酵液的成分,结果显示5株促生菌具有产生植物激素和有机酸的能力。经过16S rRNA基因序列分析,所分离的根际促生菌1-3,P7和P13分别属于芽孢杆菌属(Bacillussp.)、叶杆菌属(Phyllobacteriumsp.)和中华根瘤菌属(Sinorhizobiumsp.)。

Plant growth promoting rhizobacteria（PGPR）were screened from soybean rhizosphere soil and collected strains through qualitative analysis of phosphate solubilization and IAA.Five PGPR strains were acquired,which improved nodulation on soybean when co-inoculated with soybean rhizobia in vermiculite pot experiment.Furthermore in the soil pot experiment with Fuyang,Jining and Yanan＇s soils,the co-inoculation of soybean rhizobia with five PGPR strains significantly increased the number of nodules,nodule dry weight,plant dry weight,total N and P contents.The result of quatitive determination of phosphate displayed that five PGPR strains dissolved inorganic phosphorus efficiently.Analysis of fermentation with HPLC showed that 5 isolated strains secreted plant hormones and organic acids.Through 16S rRNA gene sequence analysis,three PGPR 1-3,P7 and P13 strains isolated from soybean rhizosphere soil were belonged to Bacillus sp.,Phyllobacterium sp.and Sinorhizobium sp.,respectively.