tigation were sensitive and showed fast, selective and consistent results with composite DNA samples. Our findings outline and demonstrate the development of a useful tool for studying fungi that grow on or inside plant tissues and in symptomless hosts.

The results of this study have established the guidelines of a standardized, sensitive, multiplex methodology for evaluating the action of *T. atroviride* BV1CR as an antagonist of *B. cinerea* on blackberry fruits. We have developed a specific probe that selectively detects *T. atroviride* and does not detect *B. cinerea.* To our knowledge, this is the first report of a qPCR probe based on a powerful barcode marker, the tef1-α DNA sequence, for the detection of *Trichoderma* \[[@bib0415]\]. We propose the use of the Tatrov oligo set for mycological studies, competition assays, biological control programs and field evaluations with *T. atroviride*. The oligo set can also be used to evaluate active formulations of biopesticides.

CRediT authorship contribution statement {#sec00005}
========================================

**Irena Hilje-Rodríguez:** Conceptualization, Methodology, Validation, Formal analysis, Investigation, Data curation, Writing - original draft, Writing - review & editing, Visualization. **Federico J. Albertazzi:** Conceptualization, Formal analysis, Data curation, Writing - original draft, Writing - review & editing, Visualization. **German Rivera-Coto:** Conceptualization, Funding acquisition. **Ramón Molina-Bravo:** Conceptualization, Formal analysis, Writing - original draft, Writing - review & editing, Visualization, Project administration.

Declaration of Competing Interest
=================================

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Appendix A. Supplementary data {#sec0090}
==============================

The following are Supplementary data to this article:

This work was supported by *Fondo