Fumonisin and Beauvericin Chemotypes and Genotypes of the Sister Species and .

and are common maize pathogens that produce mycotoxins and cause plant disease. The ability of these species to produce beauvericin and fumonisin mycotoxins is not settled, as reports of toxin production are not concordant. Our objective was to clarify this situation by determining both the chemotypes and genotypes for strains from both species. We analyzed 25 strains from Argentina, 13 and 12 strains, for toxin production by ultraperformance liquid chromatography mass spectrometry (UPLC-MS). We used new genome sequences from two strains of and one strain of , plus genomes of other species, to determine the presence of functional gene clusters for the synthesis of these toxins. None of the strains examined from either species produced fumonisins. These strains also lack biosynthetic genes but retain homologs of some genes that flank the cluster in None of the strains we examined produced beauvericin although 9 of 12 strains did. A complete beauvericin () gene cluster was present in all three new genome sequences. The gene was presumably functional in but was not functional in due to a large insertion and multiple mutations that resulted in premature stop codons. The accumulation of only a few mutations expected to disrupt suggests that the process of its inactivation is relatively recent. Thus, none of the strains of or we examined produce fumonisins, and the strains of examined also cannot produce beauvericin. Variation in the ability of strains of to produce beauvericin requires further study and could reflect the recent shared ancestry of these two species. and are sister species and maize pathogens commonly isolated worldwide that can produce several mycotoxins and cause seedling disease, stalk rot, and ear rot. The ability of these species to produce beauvericin and fumonisin mycotoxins is not settled, as reports of toxin production are not concordant at the species level. Our results are consistent with previous reports that strains of produce neither fumonisins nor beauvericin. The status of toxin production by needs further work. Our strains of did not produce fumonisins, while some strains produced beauvericin and others did not. These results enable more accurate risk assessments of potential mycotoxin contamination if strains of these species are present. The nature of the genetic inactivation of BEA1 is consistent with its relatively recent occurrence and the close phylogenetic relationship of the two sister species.