**In Vitro Fumonisin Biosynthesis and Genetic Structure of** *Fusarium verticillioides* **Strains from Five Mediterranean Countries**

**Giovanni Beccari 1, Łukasz St ˛epie ´n 2, Andrea Onofri 1, Veronica M. T. Lattanzio 3, Biancamaria Ciasca 3, Sally I. Abd-El Fatah 4, Francesco Valente 1, Monika Urbaniak 2 and Lorenzo Covarelli 1,\*,**†


Received: 24 January 2020; Accepted: 6 February 2020; Published: 11 February 2020

**Abstract:** Investigating the in vitro fumonisin biosynthesis and the genetic structure of *Fusarium verticillioides* populations can provide important insights into the relationships between strains originating from various world regions. In this study, 90 *F. verticillioides* strains isolated from maize in five Mediterranean countries (Italy, Spain, Tunisia, Egypt and Iran) were analyzed to investigate their ability to in vitro biosynthesize fumonisin B1, fumonisin B2 and fumonisin B3 and to characterize their genetic profile. In general, 80% of the analyzed strains were able to biosynthesize fumonisins (range 0.03–69.84 μg/g). Populations from Italy, Spain, Tunisia and Iran showed a similar percentage of fumonisin producing strains (>90%); conversely, the Egyptian population showed a lower level of producing strains (46%). Significant di fferences in fumonisin biosynthesis were detected among strains isolated in the same country and among strains isolated from di fferent countries. A portion of the divergent *FUM1* gene and of intergenic regions *FUM6*-*FUM7* and *FUM7*-*FUM8* were sequenced to evaluate strain diversity among populations. A high level of genetic uniformity inside the populations analyzed was detected. Apparently, neither geographical origin nor fumonisin production ability were correlated to the genetic diversity of the strain set. However, four strains from Egypt di ffered from the remaining strains.

**Keywords:** *Fusarium*; ear rot; maize; fumonisins; *FUM1*
