To study the impact of yeast populations on wine flavour and to better understand yeast growth dynamics, wines were produced by the (i) indigenous microflora, (ii) vigorous yeast starter EC1118 and (iii) slowly fermenting yeast Assmannshausen. Sensory analysis revealed that wines differed depending on the fermentation type. However, these yeast‐related differences did not exceed the varietal character. Both added starter cultures clearly dominated the Saccharomyces population from the middle of fermentation onwards. The starter cultures differed in their repression of indigenous non‐Saccharomyces yeast. EC1118 limited growth of non‐Saccharomyces yeasts more strongly than Assmannshausen. Sulphite addition further repressed growth of non‐Saccharomyces yeasts. On completion, more than one Saccharomyces strain was present in each fermentation, with the largest variety in the non‐inoculated and the smallest in the EC1118‐inoculated fermentation. Results from the two genetic assays, karyotyping, and PCR using δ‐primers were not fully equivalent, limiting the usefulness of δ‐PCR in studies of native Saccharomyces yeasts.

A representative survey was made of maize ears of the 1988 and 1989 crop in Austria to establish the influence of corn borer injuries onFusarium species involved in ear fusariosis andFusarium toxin production.TheFusarium species most frequently isolated from rot-damaged ears wereFsacchari var. subglutinans (about 50 %) andF. graminearum (about 30 %). There was a striking difference between theFusarium species of the Liseola and the Discolor section concerning their occurrence on corn borer-damaged ears. More than 80 % of the ears infected withF. sacchari var. subglutinans andF. verticillioides, but less than 15 % of the ears infected withF. graminearum, F. crookwellense andF. culmorum showed corn borer injuries.Toxin analyses of the infected ears corresponded to the known toxigenicity of the respectiveFusarium species. Ears infected withF. sacchari var. subglutinans contained moniliformin (up to 20 mg/kg), those infected withF. verticillioides fumonisin B1 and B2 (up to 15 mg/kg). In ears infected withF. graminearum, F. culmorum andF. crookwellense zearalenone (up to 40 mg/kg) and deoxynivalenol (up to 500 mg/kg) or nivalenol (up to 10 mg/kg), respectively, could be detected. Hence measures to combat the European corn borer will mainly reduce moniliformin and fumonisin contamination, but will affect zearalenone, deoxynivalenol and nivalenol contents of the ears to a much lesser extent.

Fusarium subglutinans has been identified as a prevailing pathogen of maize ears in Poland in the seasons 1985-1991. About 95-100% of ears with Fusarium ear rot symptoms were infected by this species. Moniliformin was present in all 57 ears with pink ear rot symptoms examined. Fusarium-damaged kernels contained an average of 130.9 mg/kg of moniliformin, with large differences between individual samples each year--from 4.2 mg/kg to 530 mg/kg.

No abstract

Fusarium avanacoum infected wheat and triticale heads in Poland in each season between 1985 and 1989. The average number of heads infected byF avonacaum was 26 % for wheat and 46 % for triticale out of all examined heads withFusarium head blight symptoms.Fusarium-damaged wheat grain, naturally infected byF avenaceum, contained an average of 15.9±7.7 mg moniliformin/kg, healthy looking kernels from the same heads an average of 0.42±0.19 mg moniliformin/kg. Fusarfum-damaged kernels of triticale contained an average of 3.5 mg moniliformin/kg while healthy looking kernels from the same ears contained 0.25 mg/kg.