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SESSION 3: PATHOGENESIS – EPIDEMIOLOGY AND POPULATION
GENETICS
P61 - Fusarium head blight of wheat in Algeria:
Preliminary investigations into the relationship with
some isolates and cultivars resistance
S. Hattab–Touati 1 , C. Barreau 2 , Z. Bouznad 3
1 Université Tlijène Laghouat, Algeria; 2 INRA UR MycSA, 71 avenue Edouard Bourlaux, 33883
Villenave d’Ornon, France; 3 Laboratoire de Phytopathologie et Biologie moléculaire, ENSA El Harrach,
Alger
E-mail: z.bouznad@ensa.dz
Fusarium head blight (FHB) is an important fungal disease of wheat, where it may
contribute to a significant reduction in crop and are therefore of great economic
importance. These Fusarium spp have also a potential to produce mycotoxins that
cause a potential health risk when contaminated grain. Also there are numerous
reports on how species differentially respond to different isolates and cultivars. In
Algeria there are two species which are frequently isolated from infected ear and
seeds: F. graminearum and F. culmorum, with a higher frequence for the later
species. During two last years, several experiments were carried out with four
isolates of F. culmorum inoculated in field on common cultivated varieties, to
determine their potential chemotype to produce toxins and to investigate into the
relationship with their aggressiveness and cultivars resistance.
The results obtained by PCR Taq Man using a specific probe both " chemotype "
known for F. culmorum suggest that isolates T52006 and T72007 have the
capacity to produce Nivalenol and Fusarenone X toxins (chemotype NIV / FX) and
isolate BD2011 and BT2011 produces Deoxynivalenol and deoxynivalenol 3-
Acetyl (chemotype DON / 3-ADON). The toxinogenic potential was also looked for
in vitro on sterile grains of rice; the analyses of the TCTB by HPLC / DAD allowed
to confirm the chemotypes of 4 isolates and to determine their toxinogenic
potential. It is shown that 2 isolates of chemotype DON/ 3-ADON produce levels
of toxin much superior to those NIV / FX isolates.
A quantification of Trichothecens B ( TCTB) by HPLC / DAD on 104 samples of
grains obtained from ears of 8 varieties inoculated in field, showed well and
confirmed that isolates T52006 and T72007 produces NIV and FX toxins, while
isolates BD2011 and BT2011 produce DON and 3-ADON toxins. The levels of
NIV / FX are clearly lower than the levels of DON / ADON. The 8 varieties of
wheat showed a significant variation in the level of accumulation, otherwise these
first results show that there is a correlation between the level of invasion of the
grain and the quantity of accumulated toxin.
Keywords: Wheat, Fusarium head blight, F. culmorum, Trichothecenes B (TCTB)
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