中文摘要：

为了研究接种S.fredii WGF03及其exoD基因突变体对大豆结瘤及土壤的微生物群落影响,进一步了解exoD基因的功能,在大豆盛花期摘取每株大豆的根瘤并计数,利用PCR-DGGE电泳结合测序技术分析土壤的微生物群落。结果表明,大豆接种S.fredii WGF03后,根瘤数比不接种组增加191.67%。而大豆接种驻exoD突变体的根瘤数最少,比不接种组减少了16.67%。与空白相比,种植大豆后土壤细菌的种类和数量明显增加;接种不同根瘤菌后,细菌种类及细菌多样性也有变化;测序结果显示,土壤中细菌以Proteobacteria为主,占45.5%,土壤中土著根瘤菌为Bradyrhizobium。总之,S.fredii WGF03能够促进大豆结瘤,种植作物比接种根瘤菌对土壤细菌群落的影响更大。

英文摘要：

This paper aimed to study the impact of inoculating S. fredii WGF03 and its exoD mutant on soybean nodulation and soil microbial community, and to understand the function of exoD gene. We picked up soybean nodules and counted them during flower stage, and analyzed soil bacteria using PCR-DGGE and sequencing.Results showed that after soybean inoculating S. fredii WGF03, nodules number increased 191.67% than non-vaccinated group. However, the nodules with △exoD mutant decreased 16.67% than non-vaccinated group.Compared with the blank, after planting soybeans, the soil bacteria species and the numbers had a significant increase; After inoculation of different rhizobia, bacterial species and diversity also varied; Sequence analysis showed that in soil bacteria, Proteobacteria were the most, accounting for 45.5%. Bradyrhizobium was the indigenous rhizobia. In conclusion, S. fredii WGF03 can promote the soybean nodulation. Planting crops rather than inoculating with rhizobia has a larger effect on soil bacterial community.