Novel toxigenic species on maize kernels in Southeastern Europe

Abstract

In recent years, global climate changes have caused the variability of agro-climatic conditions, which could contribute to the synthesis of higher concentrations of mycotoxins in cereal grains during the growing season and could result in economic losses in the production, as well as in increased risk to human and animal health. These reasons and the fact that new toxigenic species have been identified in Serbia and its neighbouring countries in a few past years, indicate the need for permanent monitoring of mycopopulations on cereals. In Serbia, 30 different species of the genus Aspergillus have been identified, isolated mainly from cereal grains. The uncommonly high frequency and incidence of Aspergillus infestation of maize grain in the last few years were caused by extremely stressful agrometeorological conditions, high temperatures and drought over the period from flowering to waxy maturation of maize. Molecular detection of Aspergillus species collected from different samples of cereal kernels was done by using PCR-RFLP analysis of aflR-aflJ intergenic spacer (IGS). Restriction digestion of PCR products with BglII enzyme gave profiles specific for A. parasiticus - two fragments of 363 and 311 bp, which confirmed the presence of this species in the samples subjected to analysis. Characterization of Fg comlex species was done by DNA sequence-based analysis using primer pairs ef1/ef2. Specific genome fragments were sequenced and analized. Sequences were compared to the data from GeneBank. Most of the tested isolates appeared to represent F. graminearum sensu stricto species, while only two of them were identified as Fusarium boothii and Fusarium vorosii.