In vitro evaluation mycoparasitic capacity of Irpex lacteus P7B against fungi and oomycetes associated with plant diseases

Background/Objective. Diseases of agricultural crops affect the yields and quality of products. Synthetic chemical compounds are generally used to control them; these cause harmful impacts to the environment, as well as to human health. In this sense, beneficial microorganisms can be used in agriculture as biocontrol agents, and contribute to obtaining food in sufficient and safe quantities. The fungus Irpex lacteus has been reported as a potential biocontrol agent. The objective of this research work was to evaluate the in vitro mycoparasitic capacity of the endophytic fungus I. lacteus P7B against 22 fungi and one oomycete associated with plant diseases. Materials and Methods. The P7B isolate, previously detected as a mycoparasite, was used and molecularly identified by amplification and sequencing of the internal transcribed spacer (ITS) region of ribosomal DNA, using primers ITS1/ ITS4.The confrontations of the mycoparasite (P7B) against the phytopathogenic microorganisms were carried out in PDA culture medium. Three replicates were used for each microorganism, in addition to the controls, which consisted of placing the microorganisms individually. Results. Molecular analyses determined that isolate P7B corresponded to Irpex lacteus (GenBank: PP922180). The results of the in vitro assays indicated that I. lacteus P7B inhibited all the phytopathogenic agents with which it was confronted, 100% inhibition by I. lacteus occurred approximately in 14 days, except for Rhizopus spp., this was at 23 days after the confrontations. Conclusion. The present study demonstrates that the fungus I. lacteus presented 100% in vitro mycoparasitic capacity against the various fungi and an oomycete evaluated, so future work could focus on evaluating its mycoparasitic activity under field conditions.