qPCR datasets of the quantification of bacterial communities in the maize-reused cover crop root channels subjected to drought stress in three different soil types found in Germany

The copy number of the 16S rRNA gene per gram of soil was quantified by SYBR^® Green-based qPCR using a 7500 Fast Real-Time PCR System (Applied Biosystems™, Thermo Fisher Scientific, Waltham, MA, USA). Aliquots of the same DNA extract utilised in amplicon sequencing were used for qPCR. Dilutions of template DNA were used to compensate for the effect of PCR inhibitors in the samples. Each sample was analysed in triplicate. PCR amplicons of the Escherichia coli V3 region was used as standards. Each 20 µL reaction contained 1 µL of template DNA, the forward and reverse primers 341F and 518R for 16S rRNA without adapter nucleotides (Muyzer et al., 1993) and Luna^® Universal qPCR Master Mix (NEB). Reaction conditions were an initial denaturation for 1 min at 95°C, followed by 40 cycles of denaturation at 95°C for 15 s and extension at 60°C for 30 s. The melting curve was recorded in the temperature range of 60°C to 95°C. The gene copy numbers per gram of soil were determined in comparison against the standard essentially as before (Adelowo et al., 2018). The average efficiency value was 97.2 ± 5.4%.