Natural occurrence of trichothecene-producing Fusaria isolated from India with particular reference to sorghum uri icon

abstract

  • In this study a total of 167 isolates collectedfrom different food materials (68.8% from sorghum and theremaining from various other food materials) were assayedby PCR for amplification of the tri 5 gene present intrichothecene-producing Fusaria. Amplification of the tri 5fragment was observed in 45 isolates (39 isolates fromsorghum and 6 isolates from vegetables). Isolates foundpositive for presence of the tri 5 gene were classified intodifferent morphological groups based on their cultural andconidial characters; 11 of the tri 5 positive isolates frommoldy grains of sorghum, one from each morphologygroup were selected for further analyses. Five deoxynivalenolproducers and three deoxynivalenol and Fusarenon-X producers were detected by analysing culturefiltrates of the 11 isolates using GC-MS. One isolate eachwere identified as producers of NIV alone, or NIV alongwith DON or DAS toxins. Identification of these isolates tothe species level was carried out using spore morphologyand sequence comparison of the translation elongationfactor 1-alpha (EF-1a) gene against the database as well asusing phylogenetic analyses. The isolates were identified asFusarium proliferatum (6), F. nelsonii (2), F. equiseti (1),F. thapsinum (1) and F. sacchari (1). Amplified FragmentLength Polymorphism (AFLP) based grouping clusteredthe isolates of same species together. This is the first detailed study of trichothecene production by Fusariumspp. associated with sorghum grain mold in India and theidentification of F. nelsonii and F. thapsinum as producersof trichothecenes

publication date

  • 2011
  • 2011