Compost amendment and inoculations with specific microorganisms are fundamentally different soil treatment methods, commonly used in agriculture for the improvement of plant growth and health. Although distinct, both methods affect the rhizosphere and the plant roots. In the present study we used a 16S rRNA gene approach to achieve an overview of early consequences of these treatments on the assemblage of plant root bacterial communities. For this purpose, cucumber seedlings were grown, under controlled conditions, in perlite potting mix amended with biosolid compost or straw compost, or inoculated with Streptomyces spp. A uniform trend of response of root bacterial communities for all treatments was observed. Root bacterial density, measured as bacterial targets per plant tef gene by real-time PCR, was reduced in 31 to 67%. In addition, increased taxonomic diversity accompanied shifts in composition (α-diversity). The magnitude of change in these parameters relative to the perlite control varied between the different treatments but not in relation to the treatment method (compost amendments versus inoculations). Similarity between the compositions of root and of potting mix bacterial communities (β-diversity) was relatively unchanged. The abundance of Oxalobacteraceae was >50% of the total root bacterial community in the untreated perlite. Root domination by this group subsided >10-fold (straw compost) to >600-fold (Streptomyces sp. strain S1) after treatment. Thus, loss of dominance appears to be the major phenomenon underlining the response trend of the root bacterial communities.
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机译:叶绿素/壳聚糖/小球藻/铁/钙/ DHA / EPA /含绿豆/黑豆/红豆/白豆室温暴露,绿豆芽/绿色寄主豆芽/大白菜/新鲜/羽衣甘蓝/马铃薯/大蒜/姜/生姜/黄瓜/南瓜/菠菜/人参/红鸭/迷你番茄/西瓜/瓜,嫩芽/马铃薯/甘薯/黄瓜/西瓜/瓜/大白菜/大蒜/生姜/普通大米,阿克巴里,大米/大米/大麦/荞麦/橡子塑料空气分配孔,把手,阳光遮蔽的盖子,水分配孔处理幼苗,处理水耕栽培容器,不良,岩石形成,固体培养基,水耕,稻田,田地,耕种