本研究以河北省沧州黄骅市紫花苜蓿(Medicago sativa)为研究对象,对采自黄骅地区常郭乡赵子札村、羊二庄镇张八寨村及旧城镇云庄村等10个地点的紫花苜蓿根际土壤进行细菌分离纯化和培养,获得134株根际细菌。进而将其接种到紫花苜蓿植物种苗,培养60d后,比较分析了接种不同根际促生菌对植物生长的促生影响,选择了30株促生细菌优良菌株,并且对30株细菌菌株进行了溶磷能力和分泌生长素能力的测定。结果表明,菌株EF2对植物干重增重影响最为显著(P<0.05),其溶解有机磷和无机磷能力也最强;菌株LF13分泌生长素的能力最强,其对株高的影响较为明显。研究最终初步筛选出9株溶磷能力和分泌生长素能力较强并能促进紫花苜蓿显著生长的根际细菌。 In this study, alfalfa (Medicago sativa) in Huanghua, Cangzhou, Hebei Province was selected as the research object. The purple flowers collected from 10 sites of Zhaozazhai Village, Changjiu Township, Zhangba Zhai Village, Yang Erzhuang Town and Yunzhuang Village, The rhizosphere soil of alfalfa was isolated and purified by bacteria, and 134 rhizobacteria were obtained. Then inoculated them into alfalfa plant seedlings. After 60 days of cultivation, comparatively analyzed the growth promoting effects of different growth promoting bacteria on inoculation with rhizosphere bacteria, selected 30 strains which are good for promoting bacteria, and 30 strains of bacteria Determination of ability to dissolve phosphorus and auxin secretion. The results showed that strain EF2 had the most significant effect on plant dry weight gain (P <0.05), and its ability to dissolve organic phosphorus and inorganic phosphorus was the strongest. The strain LF13 had the strongest ability to secrete auxin and its effect on plant height was obvious . Finally, nine rhizobacteria with better ability of dissolving phosphorus and auxotrophic hormone, which could promote the significant growth of alfalfa, were screened out.