Fig. 1. Comparisons of qPCR standard curves between
synthetic DNA and plasmid DNA standards. Standards were diluted by 10
times for each step from 108 to 101copies per μl. R2 is the coefficient of determination.
P < 0.001 indicates the significance of the linear regression.
Gene copy numbers (copies per dry gram soil) were log10-transformed. E =
(10−1/slope) – 1.