Specific SCAR markers and multiplex real-time PCR for quantification of two Trichoderma biocontrol strains in environmental samples

Several strains from the genus Trichoderma (Ascomycetes, Hypocreales) are commercially used as biocontrol agents, e.g. in formulations containing the two Trichoderma strains IMI206039 (Hypocrea parapilulifera B.S. Lu, Druzhinina & Samuels) and IMI206040 (T. atroviride P. Karst). To quantify the presence of the two isolates after application, we developed primers for SCAR markers (Sequence-Characterised Amplified Region). In order to quantify both fungal strains simultaneously, we also designed fluorophore-labelled probes distinguishing the two strains, to be used in combination with the SCAR primers. In incubations of two different soils, artificially inoculated and maintained under controlled conditions, the quantification through amplification with the SCAR markers in qPCR and through colony-forming units from plate counting correlated well. Further tests of the markers on samples taken from a golf green treated with a product containing both strains indicated that the two biocontrol strains did not establish, either on the golf green or in the surrounding area.