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SESSION 3: PATHOGENESIS – EPIDEMIOLOGY AND POPULATION
GENETICS
P67 - Genetic and mycotoxigenic diversity of isolates
belonging to the Fusarium incarnatum-equiseti
species complex, and recovered from maize and
banana in China
F. Munaut 1 , J. Scauflaire 2 , M. Gourgue 2 , C. Bivort 2 , Y. Qi 3 , A. Wu 4 , S. de
Saeger 5 , D. Zhang 4 , F. Van Hove 1
1 Université catholique de Louvain, Earth and Life Institute (ELI), Applied Microbiology, Mycology,
Mycothèque de l’UCL (BCCM TM /MUCL), Louvain-la-Neuve, Belgium; 2 Université catholique de
Louvain, Earth and Life Institute (ELI), Applied Microbiology, Mycology, Louvain-la-Neuve, Belgium;
3 Academy of Tropical Agricultural Sciences (CATAS), Environment and Plant Protection Institute,
Haikou, Hainan Province, China; 4 College of Life Science and Biotechnology, Shanghai Jiao Tong
University (SJTU), Shangai, China; 5Universiteit Gent (UGent), Faculteit Farmaceutische
Wetenschappen, Laboratory of Food Analysis, Ghent, Belgium
E-mail: francoise.munaut@uclouvain.be
In the frame of a research project aiming to describe the Fusarium spp diversity on maize
and banana in four Chinese provinces, 80 out of the 201 isolates obtained were identified
as belonging to the Fusarium incarnatum-equiseti species complex. Isolates were identified
on basis of the Elongation Factor-1 a sequences (EF), which were then submitted to a
phylogenetic analysis together with four isolates representative of four phylogenetic
species inside the complex (F. incarnatum s.s., F. lacertarum, F. scirpi and F. equiseti). On
maize, five main phylogenetic groups were determined (I, II, III, IV and V), from which three
groups (I, II and V) were also recovered from banana. Surprisingly, groups I, II, III and V
can be correlated to phylogenetic species described in completely different ecosystems by
O’Donnell et al. (2009) (from human beings) and by Funnell-Harris et al. (2010) (from
sorghum). Furthermore, one possible new phylogenetic species (group IV) was detected.
Genetic diversity of the FIESC isolates was analyzed using the AFLP technique. A total of
200 polymorphic bands were generated for 28 FIESC isolates from maize and were used
to construct a phenetic tree. The EF phylogenetic groups were clearly clustered separately
by AFLP, with bootstrap values >70%. The groups II and V presented an approximate
similarity of only 50% and 40 % from the other cluster, respectively. This raises the
taxonomical status of the groups. Within each cluster, an important genetic diversity is
observed, although no strict correlation can be made with any parameters of collect such
as location, field, etc. Preliminary results on banana isolates showed similar results as well
as the occurrence of an important genetic diversity.
Molecular studies have demonstrated that the FIESC isolates do not possess the FUM
gene cluster. Nevertheless, it has been reported that FIESC isolates are able to produce
type A and B trichothecenes. Due to the fact that trichothecenes are also produced by
Fusarium graminearum, which was frequently isolated from Chinese maize, the origin of
trichothecene contaminations on that crop has to be reconsidered. Furthermore, the
occurrence of FIESC isolates on both maize and banana, which are often cultivated close
to each other, raises the question of possible cross-contaminations.
Keywords: Fusarium, FIESC, maize, banana, China, phylogeny, AFLP, mycotoxins
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