Head blight and biosynthesis of Fusarium toxins in barley kernels field inoculated withFusarium culmorum

Abstract

Heads of 12 spring barley genotypes (eight cultivars, four lines) were inoculated with conidial suspensions of two Fusarium culmorum isolates (I1 and 12). Both isolates caused the following significant reductions (%) when compared with the control: number of kernels head-l 12 and 16, weight of 1000 kernels 47 and 24, yield 49 and 37, for Iland I2 respectively. Both isolates were able to produce average levels (mg kg-1) of deoxynivalenol of 67.1 and 13.9, 3-acetyldeoxynivalenol of 9.4 and 1.4 and zearalenone of 0.3 and 0.4 for 11 and I2 respectively. In kernels of three genotypes inoculated with the same isolates, 15-acetyldeoxynivalenol at an average level (rag kg-1) of 1.3 and 1.5 was detected, while in kernels of six genotypes inoculated with I2, 0.2 of nivalenol was found. A significant correlation for yield and toxin level was found for less pathogenic F. culmorum isolate I2.

Distribution of deoxynivalenol and 3-acetyldeoxynivalenol in naturally contaminated and Fusarium culmorum infected triticale samples

“…1), while 3-AcDON accumulation was higher after inoculation with I 2 (Fig. 2), what confirms the observations of variation between producing abilities of Fusarium culmorum strains [11][12][13].…”

“…: 23282-20-4) may be produced by the same species, but are also formed by Fusarium crookwellense Burges, Nelson et Toussoun and Fusarium poae (Peck) Wollenw [6][7][8][9][10]. Variation in producing ability is observed between strains the same species [11][12][13].…”

Distribution of deoxynivalenol in barley kernels infected by Fusarium

“…1). The above indicates that inoculation with F. culmorum or F. graminearum caused the significant increase of the small kernels number, what confirms reduction of yield traits observed earlier in barley cultivars inoculated with Fusarium [6,21]. As a conclusion higher DON content is correlated with increasing number of small kernels.…”

“…The same cultivars sprayed with distilled water were used as a control group. After inoculation or water spraying, the heads were protected with plastic bags for 24 h to avoid water evaporation and spread of inoculum [6,21] After DON analysis (total sample of kernels) all (48) samples were divided into 5 groups according range of DON concentration [mg/kg]: a2 (12 samples); F 2 -a10 (15 samples); F 10 -a50 (12 samples); F 50 -a 100 (5 samples) and F 100 (4 samples). For each range of DON concentration average distribution of kernels in fraction, average DON concentration in the fraction, average completely distribution of DON in grain and average distribution of DON in fraction was calculated on dry matter basis.…”

“…Four days after ahtesis (stage 10.5 on the Feekes scale) eighty heads of barley were inoculated separately with 2 different isolates of F. culmorum or 2 different isolates of F. graminearum. Inoculum, prepared as described earlier [21], was applied with a laboratory sprayer (1 ml/head). The same cultivars sprayed with distilled water were used as a control group.…”