Morpho-Molecular Identification, Pathogenicity Variation, Mating Biology, and Fumonisin Production of Fusarium Species in Zea mays L.

Abstract

Fusarium verticillioides and Fusarium proliferatum cause a wide range of maize diseases.  These fungi produce dangerous mycotoxins, such as fumonisin B1, which are important threats to humans and animals. Given this predicament, the present study aimed to identify the fungi both molecular-morphologically and also investigate the pathogenicity variation and mating type of 41 Fusarium strains in maize (Zea mays L.) samples with sifting their fumonisin contents.  Furthermore, species-specific primers for the molecular identification of distinct strains amplified 2 fragments of 578 and 800 bp in Fusarium verticillioides, while a single 585 bp band was amplified in Fusarium proliferatum.  Accordingly, 24 isolates out of 41 were identified as F. verticillioides, and 13 isolates were identified as F. proliferatum.  The fumonisin-producing and non-producing Fusarium strains were identified using the VERTF-1/VERTF-2 primers.  A total of 24 isolates of F. verticillioides were positively scored based on the amplification of a single 400 bp fragment.  The highest and lowest fumonisin content, as measured using an enzyme-linked immunosorbent assay (ELISA), belonged to strains MS1 and MG3, respectively, and ranged from 960-12673 and 4.07-23 ppm, respectively.  Additionally, the mating type test showed that the sexual form of the studied Fusarium species could possibly belong to the A and D mating populations.  In vivo and in vitro pathogenicity tests revealed a high susceptibility.