【摘要】 【目的】为探究攀枝花钒钛磁铁尾矿土壤中苜蓿共生根瘤菌的多样性和促生效应。【方法】利用苜蓿盆栽试验捕获钒钛磁铁尾矿土壤中的苜蓿共生根瘤菌,通过16S rRNA和持家基因系统发育分析来明确苜蓿根瘤菌的进化地位和多样性,并通过根瘤菌回接盆栽苜蓿试验以筛选出高效固氮根瘤菌。【结果】从钒钛磁铁矿尾矿土壤中捕获分离到9株根瘤菌,将其鉴定为中华根瘤菌属(Sinorhizobium)、根瘤菌属(Rhizobium)、慢生根瘤菌属(Bradyrhizobium);并筛选出高效固氮根瘤菌S. meliloti MX1、B. japonicum MX7和R. leguminosarum MX8,其苜蓿的氮含量分别增加58.8%、205.9%和270.6%,并能促进苜蓿植株生长,显著提高苜蓿的株高、根长和生物量。【结论】攀枝花钒钛磁铁尾矿土壤中含有丰富多样的苜蓿共生根瘤菌,其可应用于钒钛磁铁矿尾矿土壤的苜蓿-根瘤菌联合生物修复。更多还原

【Abstract】 【Objective】The aim of this study was to explore the diversity and growth promoting of alfalfa rhizobia from the V-Ti magnetite mine tailing soil in Panzhihua.【Method】A pot experiment was conducted to capture the indigenous rhizobia in the V-Ti magnetite mine tailing soil. The phylogenetic status and diversity of rhizobium isolates was determined by phylogenetic analysis of 16 S rRNA and housekeeping genes. The pot experiment of re-inoculating rhizobium was performed to select the effective symbiotic nitrogen-fixing rhizobia by analyzing the effects of rhizobium symbiotic nitrogen-fixing on height,root length,dry weight,and nitrogen content of alfalfa.【Result】Nine rhizobia strains were obtained from the V-Ti magnetite mine tailing soil. The nine rhizobia were identified as Sinorhizobium,Rhizobium and Bradyrhizobium. Three rhizobia of S. meliloti MX1,B. japonicum MX7 and R. leguminosarum MX8 with high-efficiency nitrogen-fixing capacity were selected. The three rhizobia strains increased nitrogen content of alfalfa by 58.8%,205.9% and 270.6%,respectively. They also height,root length and biomass.【Conclusion】The alfalfa rhizobia is rich in the V-Ti magnetite mine tailings soils at Panzhihua,which may be used for bioremediation of V-Ti magnetite mine tailings soils.更多还原