Quality assesment and characterization of hybrid wheat in South Africa

English: The objectives of this study were to determine the quality characteristics of hybrid wheat in South Africa, the influence of the male and female parents on quality and to assess heterosis in hybrid wheat quality. The stability performance of the hybrids, their parental lines and conventional cultivars were also determined. A further objective was to assess sprouting tolerance in hybrid wheat. Twelve hard red genotypes were planted at six locations throughout the Free State in separate winter and facultative trials, during 2004 and 2005. A separate sprouting and falling number trial consisting of 25 genotypes was planted at Bethlehem during 2004 and 2005 to evaluate the sprouting and falling number problem in hybrid wheat and included males, females, hybrids and conventional cultivars. Heads were cut at physiological maturity and thereafter with seven day intervals, for evaluation in a rain simulation facility. Mean squares were highly significant for genotype, environment and year for test weight, SKCS kernel size, Hagberg falling number, ash, alveograph strength and mixograph mixing time in both trials. Highly significant differences were seen for hardness index, break flour yield, flour yield, consistograph water absorption in the IHBPT trial and wet gluten content in the WHBPT trial. The males mainly contributed to poor quality, with the females and conventional cultivars having acceptable quality. The hybrids made up from high quality parents, had better quality in general. Positive heterosis was expressed for test weight, SKCS kernel size and mixing time and negative heterosis for falling number, ash and alveograph strength for both the intermediate and winter trials. Negative heterosis was revealed for hardness index, flour yield and consistograph water absorption in the Intermediate trial and wet gluten content in the winter trial. AMMI stability values confirmed that hybrids had the best stability performance, even more stable than Elands. The males and females performed intermediate with the male genepool being more stable than the female one. The sprouting trial revealed that the male genepool mainly contributed to the poor sprouting tolerance of the hybrids. Combining males and females with good sprouting tolerance provided tolerant hybrids. This was also true for falling number. The method of evaluating sprouting was also revised and should be applied to ensure true tolerant types are selected and to exclude environmental affects.