Evaluation of mycotoxin production and phytopathogenicity of the entomopathogenic fungi fusarium caatingaense and F. pernambucanum from Brazil

Abstract

Fusarium incarnatum-equiseti species complex (FIESC) is considered as one of the richest insecticolous species. Fusarium species synthesize toxic secondary metabolites that are not fully understood. Mycotoxin production and pathogenicity on germinating seeds, seedlings, and leaves must be carefully studied for the use of Fusarium species in the biological control of insect pests. In this study, we evaluated the mycotoxin production and phytopathogenic potential of entomopathogenic strains of Fusarium sulawesiensis (1), F. pernambucanum (3), and F. caatingaense (23). The phytopathogenicity tests of F. caatingaense (URM 6776, URM 6777, URM 6778, URM 6779, and URM 6782) were performed during the development of bean (Phaseolus vulgaris, Vigna unguiculata, and Phaseolus lunatus), and corn (Zea mays) seedlings, using four treatments (soil infestation with the inoculum, spraying on leaves, root dip, and negative control). The mycotoxins, monoacetyl-deoxynivalenols (AcDON), deoxynivalenol (DON), beauvericin (BEA), fusarenone-X (FUS), T-2 toxin (T2), diacetoxyscirpenol (DAS), and zearalenone (ZEA), were detected in the study; BEA (detected in 25 strains) and FUS (detected in 21 strains) were found to be predominant. None of the strains showed any ability to cause disease or virulence in beans and corn. The FIESC strains showed a highly variable production of mycotoxins without the potential to be used as phytopathogenic agents for the cultures tested.