Effects of genotype, environment and fungicide treatment on development of Fusarium head blight and accumulation of DON in winter wheat grain

Abstract

Abstract:Reactions to artificial infection with Fusarium culmorum and (metconazole-or tebuconazole-based) fungicides were studied in nine winter wheat cultivars that were evaluated in field experiments at the location Prague-Ruzyně for four years (2001)(2002)(2003)(2004) for deoxynivalenol (DON) content in grain, pathogen DNA content (Ct) by real-time quantitative PCR, percentage of Fusarium damaged grains (FDG), symptom scores and reductions in grain yield components. All examined traits were highly affected by conditions of experimental years and interactions with cultivars and treatments. Moderately resistant cultivars Arina and Petrus were included in the first homogeneous group in all traits, including the pathogen DNA content. To predict cultivar resistance to Fusarium head blight and accumulation of DON, the examination of the percentage of FDG in different environments appeared to be useful from practical aspects. The pathogen DNA content was significantly related to the content of DON under different conditions, however, the correlation coefficients ranged between 0.42 and 0.92. Different levels of DON could be detected at similar pathogen contents. The higher colonization of grain by the fungus was mostly connected with a strongly reduced amount of DON per pathogen unit (DON/Ct ratio). The fungicide treatment had a significant effect on a reduction in all traits except DON/Ct, but the effects on different traits were not often proportional and they were highly variable in the particular years (range 10-69%) and cultivars (range < 0-60%). While the application of fungicide caused a reduction in DON content in all cultivars, an increase in pathogen content after the application of fungicides was not exceptional. The low fungicide effect on a reduction in pathogen content was connected with higher temperatures (temperature extremes) in a 30-day period of disease development. The efficacy of fungicide treatment for DON was low at high pathogen content and late heading. The use of the collected data to improve control measures is discussed.

Resistance of winter wheat varieties registered in the Czech Republic to Fusarium head blight in relation to the presence of specific Rht Alleles

“…In the conditions of natural infection (in agricultural practice), the components of its passive resistance (such as greater plant height and loose spike) could be better expressed than in infection tests. A lower disease incidence and a high susceptibility to accumulation of DON were characteristic of the variety Ebi in the previous experiments Šíp et al 2007). On the other hand, Sultan and apparently also Federer (at a higher resistance level) can be classified according to these experiments as varieties producing less DON at a higher symptom expression and greater grain weight reduction.…”

Resistance of winter wheat varieties registered in the Czech Republic to mycotoxin accumulation in grain following inoculation with Fusarium culmorum

“…It was shown in different experiments (e.g. Arseniuk et al 1999;Ittu et al 2000;Lemmens et al 2003;Šíp et al 2007) that particularly the determination of the percentage of Fusarium damaged grains (FDG) appeared to be useful from these aspects. Close correlations between DON content and FDG were also revealed in the experiments of Mesterházy et al (2005), however, this research demonstrated the importance of measuring both FDG and DON in the breeding and selection of resistant germplasm and varieties.…”

Fusarium mycotoxins in spring barley and their transfer into malt.

“…Ošetření fungicidem je účinné v případě, že je použit bezprostředně před napadením patogeny a klasy jsou přípravkem zcela pokryty. Na účinnost má také významný vliv průběh povětrnosti během aplikace [23][24][25].…”