Laboratory of Legumes, Centre of Biotechnology of Borj-Cedria, Hammam-Lif, Tunisia.
FEMS Microbiol Ecol. 2011 Jul;77(1):211-22. doi: 10.1111/j.1574-6941.2011.01102.x. Epub 2011 Apr 26.
The aim of this study was to assess the impact of inoculation of Phaseolus vulgaris with two indigenous rhizobia strains on plant growth promotion, nitrogen turnover processes, richness and structure of the Rhizobiaceae and total bacterial communities in the bulk soil. Both strains used induced a significant increase in nodulation and grain yield. Analysis of bulk soil fertility showed positive, negative and strain-dependent effects of inoculation on nitrate, phosphorus and ammonium, respectively. Terminal-restriction fragment length polymorphism profiling demonstrated that inoculation significantly increased the phylotype richness of the bacterial communities. No significant difference in richness between the strains used and no additive effect of co-inoculation were observed. However, differences between both inoculants and a clear additive effect of co-inoculation on heterogeneity were found. This work gives original insights into the effect of rhizobial inoculation outside the restricted rhizospheric area. Effects on bacterial structure and diversity are clearly sensed in the neighbourhood of 25 cm and in a limited time course. Both Alpha- and Gammaproteobacteria, together with Firmicutes and Actinobacteria, were enhanced by inoculation, No evidence of terminal-restriction fragment inhibition was found. However, it remains to be answered how the impact on taxonomic groups can be related to effects on functional capabilities of soil microbial communities.
本研究旨在评估接种两种本土根瘤菌菌株对菜豆生长促进、氮转化过程、根瘤菌科和土壤总细菌群落丰富度和结构的影响。两种菌株都能显著增加结瘤和籽粒产量。对土壤肥力的分析表明，接种对硝酸盐、磷和铵分别有正、负和菌株依赖性的影响。末端限制性片段长度多态性分析表明，接种显著增加了细菌群落的基因型丰富度。未观察到使用的菌株之间的丰富度存在差异，也未观察到共同接种的加性效应。然而，在两种接种剂之间存在差异，并且共同接种对异质性有明显的加性效应。这项工作为根瘤菌接种在限制根际区以外的效果提供了新的见解。在 25 厘米的附近和有限的时间过程中，细菌结构和多样性的变化明显。接种后，α-和γ-变形菌、厚壁菌门和放线菌都得到了增强，没有发现末端限制性片段抑制的证据。然而，如何将对分类群的影响与对土壤微生物群落功能能力的影响联系起来，还有待回答。
