Isolation and characterization of Fusarium verticillioides from maize in eastern China

In 2012, we isolated mycotoxigenic fungi from maize kernels sourced in Jiangsu and Anhui provinces, China. Fusarium spp. accounted for most isolates detected, followed by Aspergillus and Penicillium spp. Of the Fusarium species, Fusarium verticillioides was the most prevalent, as revealed by direct PCR of DNA from kernel samples, followed by F. proliferatum and F. graminearum. Most F. verticillioides strains contained the FUM1 gene, the product of which plays a key role in fumonisin biosynthesis. In terms of mating type idiomorphs, about 80 % of all strains carried the MAT-1 allele, and 20 % carried MAT-2. The genetic structures of 192 representative F. verticillioides isolates were determined via an analysis of eight simple sequence repeat markers. This analysis revealed high-level gene diversity but low linkage disequilibrium in three populations grouped by the geographical areas in which they were collected. The three populations exhibited low-level genetic differentiation and high gene flow, indicating that geographical differences minimally influenced population differentiation; all three populations were potentially components of a larger, randomly mating population.