Geographic distribution of phylogenetic species of the Fusarium graminearum species complex and their 8-ketotrichothecene chemotypes on wheat spikes in Iran

AbstractIsolates of theFusarium graminearum species complex (FGSC,n = 446) were collected from wheat spikes from northern and western regions of Iran with a history ofFusarium head blight (FHB) occurrences. The trichothecene mycotoxin genotypes/chemotypes, the associated phylogenetic species, and geographical distribution of these isolates were analyzed. Two phylogenetic species,Fusarium asiaticum andF. graminearum, were identified and were found to belong to sequence characterized amplified region (SCAR) groups V and I. Isolates fromF. asiaticum species lineage 6 were within SCAR group V, whereasF. graminearum species lineage 7 were of SCAR group I. Of the 446 isolates assayed, 274 wereF. asiaticum species predominantly of the nivalenol (NIV) genotype, while other isolates were either deoxynivalenol (DON) plus 3-acetyldeoxynivalenol (3-AcDON) or DON plus 15-acetyldeoxynivalenol (15-AcDON) genotype. Based onTri7 gene sequences, a new subpopulation of 15-AcDON producers was observed amongF. asiaticum strains in which 11-bp repeats were absent in theTri7 sequences. The trichothecene chemotype was confirmed and quantified by high-performance liquid chromatography (HPLC) in 46 FGSC isolates. Isolates produced NIV (33.4 –108.2 μg/g) and DON (64.7–473.6 μg/g) plus either 3-AcDON (51.4–142.4 μg/g) or 15-AcDON (24.1–99.3 μg/g). Among FGSC isolates,F. asiaticum produced the highest levels of trichothecenes. Using BIOCLIM based on the climate data of 20-year during 19...
Source: Mycotoxin Research - Category: Toxicology Source Type: research