Isolation and identification of a T-2 toxin-producing Fusarium poae strain and studies on its culture conditions

Abstract:

[Objective] To select and identify an endophytic fungus isolated from wheat head collected from a Kashin-Beck disease area of Qinghai province, and study its influences of culture conditions on the production of T-2 toxin. [Methods] Primary selection of toxin-producing strain was using embryonic bud inhibition and yeast fungistatic tests on all isolated strains. Strain re-selection was carried out by TLC and HPLC assay to check the extract of the strain. Strain 5-5m-1 was identified based on its colonial and microscopic morphological characters and ITS sequencing. The optimization of culture condition for T-2 toxin production was investigated by single factor experiments and orthogonal design method. [Results] The morphological characters of the strain 5-5m-1 were similar to that of Fusarium poae. The ITS sequencing showed that the sequence of strain 5-5m-1 had high similarity to that of the strain F. poae. The optimal culture conditions of the strain to produce T-2 toxin were corn solid medium, alternative illumination with 25 °C during the day and 15 °C at night. [Conclusion] Strain 5-5m-1 was identified as Fusarium poae. Culture conditions have great influence on its ability to produce T-2 toxin. The results will provide important references for further studies on the mechanism of T-2 toxin production and the measure to prevent mycotoxin contamination.

Key words:Endophytic fungi, Fusarium poae, Strain identification, T-2 toxin, Culture conditions