The fusarloses of barley with emphasis on the content of trichothecene

Abstract

The infestation of barley grains by fungi of the genus Fusarium was studied on malting barley from Kromei'iz (360 samples) and one sample from Kojet!n in Czech Republic. Most frequent species in the season 1997-1998 were: F. culmorum (over 70% of the isolates), F. poae (over 20% of the isolates), F. avenaceum (over 2%). Much less frequent were: F. stilboides v. stilboides, F. aqaeductum v. aqaeductum, F. merismoides v. merismoides and F. gigas. The isolates of F. culmorum were highly pathogenic when barley was artificially inoculated; those of F. poae had low pathogenity. Five varieties of spring barley at growth stage 1-5 on the Feekes scale reacted to F. culmorum as follows: I) Tolar (most resistant), 2) Akcent, Lumar and Rubfn (intermediate), 3) Krona (most susceptible). An application of fungicides on a plot inoculated with F. avenaceum and F. graminearum increased the yield of grain by 0.46 to 1.71 t/ha. Most effective fungicides against the pathogens were: metconazole, tebuconazole and prochloraz. The effect of the combination tebuconazole + triadimefon + prochloraz was found to be most effective. For determi­ nation of six trichothecene mycotoxins in fungal mycelium, macroconidia and spring barley, high resolution capillary gas chro­ matography with electron capture detection was used. Only toxin T-2 and nivalenol (NIV) were detected in fungal mycelium, and a low level of NIV was found in spring barley, variety Rubfn (lower than legislated limit- 2 mglkg of cereals).

Seed mycoflora of malting varieties and lines of spring barley in localities Kroměříž and Žabčice.

“…Fusariózy klasů byly zaznamenány ve všech oblastech pěstování obilnin, např. v Rusku [15], Indii [16], Mexiku [17], Polsku [18], České republice [10].…”

“…The species most often isolated in our experiments was F. culmorum (46 % and 30 %). Hýsek et al [10] reported on F. culmorum (70 %) and F. poae (20 %) as the Fusarium species most often isolated in the Czech Republic and Richardson [12] also recorded F. culmorum as the most frequent contaminant of barley seeds, and named F. graminearum, F. moniliforme, M. nivale and F. poae as other species. In our study, only 7 % of undisinfected seeds and 2 % of surface disinfected ones out of the total number of fusaria were infected by F. poae whereas F. graminearum and F. avenaceum were present in higher proportions.…”

“…Ear fusarioses have been noted in all regions where cereals are grown, e.g. in Russia [15], India [16], Mexico [17], Poland [18] and in Czech Republic [10].…”

“…V našich pokusech bylo nejčastěji izolovaným druhem F. culmorum (46 % a 30 %). Hýsek et al [10] uvá-typical symptoms of ear blight, they bring about a lowering of quality. Up to 17 fusaria species can take part in barley ear blight [3,4], in particular Fusarium graminearum, F. culmorum, F. avenaceum and F. poae [5,6].…”

Fungi of Fusarium sp. in naturally infected malting barley varieties/lines ( Hordeum vulgare L.) and their identification and quantification by the real-time PCR method.

“…Složení druhové spektra se může lišit v rámci roku a lokality. Hýsek [18] uvádí na ječmeni v České republice jako nejčastěji izolované druhy F. culmorum a F. poae. Schilling [19] uvádí jako nejčastější druh v Německu F. graminearum a v Holandsku F. avenaceum.…”