Plant residues are often used as soil amendments in laboratory experiments, but they can reportedly release compounds interfering with soil DNA extraction and subsequent molecular biological analyses. Theoretically, for accurate comparison of microbial community composition in soils with and without added plant residues after a period of incubation, no significant difference at the beginning of the experiment is required between the amended and unamended control soils. We mixed plant residue into soil and immediately (within 10 min) commenced DNA extraction, and then performed 16S rRNA gene sequencing and quantitative PCR (qPCR) to determine bacterial community composition and abundance. Soil without plant residue addition served as a control. Five commonly used DNA extraction kits, 16S rRNA gene primer pairs, and soils, and two types (rice straw and alfalfa shoots) and three addition rates (2%, 4%, and 6%; w/w) of plant residue, were tested. In all cases, we found no significant difference in measured bacterial community composition or abundance between the treatments with and without added plant residue.

中文翻译：

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植物残体不会对土壤细菌群落组成和丰度产生直接影响

植物残留物通常在实验室实验中用作土壤改良剂，但据报道它们会释放干扰土壤 DNA 提取和后续分子生物学分析的化合物。从理论上讲，为了准确比较经过一段时间的培养后添加和不添加植物残体的土壤中的微生物群落组成，需要在实验开始时修改和未修改的对照土壤之间没有显着差异。我们将植物残渣混合到土壤中并立即（在 10 分钟内）开始提取 DNA，然后进行 16S rRNA 基因测序和定量 PCR（qPCR）以确定细菌群落组成和丰度。没有添加植物残留物的土壤作为对照。五种常用的DNA提取试剂盒、16S rRNA基因引物对、土壤、并测试了两种类型（稻草和苜蓿芽）和三种添加率（2%、4% 和 6%；w/w）的植物残渣。在所有情况下，我们发现在添加和不添加植物残留物的处理之间，测量的细菌群落组成或丰度没有显着差异。