Diversity of trichothecene genotypes of Fusarium graminearum sensu stricto from winter wheat in Serbia

Data related to genetic diversity of F. graminearum chemotypes in Serbia are limited, thus the main objective of this study was to analyze the divergence of genes associated with the trichothecene cluster. F. graminearum was shown to be the dominant Fusarium species in Serbia occurring with frequency of 65.6% in 2016/2017 growing season. Isolates of F. graminearum dominantly belonged to SCAR type 1 (104/105) producing PCR product of 420 bp, but one isolate was proven to be SCAR type 6 producing PCR product of 400 bp. This is the first report of the presence of SCAR type 6 in Southeastern Europe. Results from this study reveal that F. graminearum populations were shown to be DON-DON chemotype with respect to Tri7 and Tri13 genes. All but one of these isolates were 15-AcDON chemotypes based on Tri3 gene. One isolate carried a deletion of Tri7 and was found to be 3-AcDON by using Tri303F/R primer pair. This is the first record on the presence of a 3-AcDON isolate with the Tri7 deletion in Serbia. The Tri7F/Tri7DON primer pair was not effective if isolates carried more than four 11-bp repeats in the Tri7 gene. Primer pair GzTri7f1/r1 was proven to be more effective in comparison with Tri7F/Tri7DON. Genetic variation ranged from 57 to 80% with no significant association of Tri7 alleles with localities. Results of this study have brought new insights into the distribution and population structure of F. graminearum in Serbia.