Browsing by Subject "Inokulation"

Now showing 1 - 1 of 1

Genetische und physiologische Einflußfaktoren sowie deren Wechselwirkungen auf die Trichothecenbildung bei Roggen, Triticale und Weizen nach Inokulation mit Fusarium culmorum (W. G. Sm.) Sacc.
(2002) Reinbrecht, Carsten; Geiger, Hartwig H.
Fusarium culmorum causes specific hazards of cereal quality by the producion of trichothecenes. Prophylaxis by plant breeding can be highly effective. The aim of this study was to investigate the accumulation of trichothecenes in cereals with regard to host and fungal genotype, to physiological factors and the resulting interactions. To determine the effects of 6 environments (E), 2 inoculation dates (ID), 2 fungal isolates (I), and 5 conidia concentrations (C) and their interactions, field trials with up to 12 rye, 6 triticale, and 8 wheat genotypes (G) were conducted in 1995-1997. Kinetics of trichothecene in the heads were described with 6 harvest dates (H) in 2 host genotypes each. In a growth chamber, 2 levels of temperature (T) and 2 of relative humidity (R) were investigated by using 2 host genotypes each. Average deoxynivalenol (DON) accumulation of rye, triticale, and wheat was 41, 46, and 82 mg kg-1, respectively. Genotypes differed significantly in rye and wheat. In all cereal species, GxE interactions were important. In wheat, DON content was highly correlated to all resistance traits, whereas in rye only a tight correlation existed to the relative specific grain weight. In triticale and wheat, inoculation at full anthesis resulted in higher DON contents than inoculation at heading. In rye, no effect of inoculation date was found. In contrast, GxID interaction was significant in rye. The nivalenol (NIV) producing isolate led to lower trichothecene contents than the DON producing isolate. This effect was found to be significant only in rye and triticale. Significant GxI interactions occurred in wheat only. Even one week after inoculation, considerable DON concentrations could be obtained in harvested heads, especially in wheat. Maximum DON contents were observed between 3 and 6 weeks after inoculation (in wheat: partially above 300 mg kg-1). NIV contents were always lower than DON contents. Until full ripening, DON contents slightly decreased, whereas NIV contents increased continuously. HxE and HxI interactions were most important. Trichothecene content in chaff and spindles was 2-4 fold higher than in the respective kernels at 6 and 8 weeks after inoculation. With higher conidia concentrations, increasing contents of DON+3-Acetyl-DON were measured. GxC interactions were highly significant. Highest heritabilities were found in the upper concentration levels. When the relative humidity was high, trichothecene concentrations of kernels were superior. With the temperature, an inverse effect was obtained. It seems that GxT interaction contributed most to GxE in rye and wheat, in triticale also the GxR interaction. In conclusion, assisting resistance traits may replace an expensive quantification of trichothecenes in early generations. In advanced generations, tests should be conducted in several environments with high conidia concentrations, and a toxin analysis should be carried out directly.