An external standard calibration was generated by analysing a tenfold
dilution series (100, 10, 1, 0.1, 0.01, 0.001 ng DNA ml21) of DNA
from each pure fungal culture. Quantified standard DNA of Fusarium
and Trichoderma was mixed with DNA extracted from uninoculated
rice and wheat haulms to simulate matrix effects. For each isolate, two
standard curves were set up (one for rice and one for wheat haulms).
Three replicates of the standard were used in each assay. The Ct value
and PCR efficiency were determined by using the CFX Manager
software (Bio-Rad). The Ct values were plotted against exponentially
transformed DNA of each tenfold dilution series of fungal DNA, and
linear regression equations were calculated.