Flour proteins linked to quality traits in an Australian doubled haploid wheat population

The Cranbrook/Halberd doubled haploid population has provided a unique opportunity to examine in detail the contributions made by a number of different high molecular weight (HMW) and low molecular weight (LMW) glutenin alleles to the dough properties in a set of homogeneous lines of wheat. A range of different instruments was employed, including Farinograph, Extensograph, Do-Corder, Resistograph, and GRL/EasyMix, to study the dough rheology of the lines from 3 sites over 2 years. Correlation studies showed that 2 basic parameters (dough strength and extensibility) were measured by these different instruments. The results presented are mainly from the Extensograph, which is a major Australian standard for determining release and marketing classification of Australian wheats. Approaches to investigate the data include bulk segregant analysis, distribution of protein alleles in the population, and multiple linear regression. As expected, the HMW glutenin alleles made a major contribution to dough strength, with a minor, but not insignificant, contribution from the LMW glutenin alleles. From a knowledge of their glutenin alleles, a glutenin strength score (GSS) was devised to allow breeders to rank the dough strength of various lines. The GSS scoring system is based on both HMW and LMW glutenin alleles, adding to a total out of 10. Extensibility, on the other hand, was predominantly influenced by protein levels in the flour and environmental conditions such as site and season. However, the LMW glutenin alleles make a significant genetic contribution to the extensibility, which can be assessed by using a glutenin extensibility score. These two glutenin quality scores currently include only the alleles present in the parents, Cranbrook and Halberd, but this could be expanded to include a wider range of alleles by analysis of the quality data from other doubled haploid populations. These quality scores would then be an extremely useful tool for assessing the potential quality of parental and early generation germplasm in wheat breeding programs, by a knowledge of the allelic composition of their HMW and LMW glutenins

Application of Micro Z-arm dough mixer in wheat research - Effect of protein addition on mixing properties of wheat dough

A Micro Z-arm mixer has been developed which needs only four grams of flour per test. The new instrument is suitable for screening new wheat cultivars in the early phase of selection on the basis of dough mixing properties. The micro-scale instrument can also be viewed as a valuable research tool for investigation of the structure/function relationships in flour and the effects of different ingredients and additives on rheological parameters. The effects of protein addition on mixing properties of wheat dough were studied. Alkali-soluble isolates and Osborne protein fractions extracted from wheat, corn-, rice germs and amaranth seeds were used as protein additives. Dough development time, maximum resistance of dough and resistance breakdown was calculated from recorded mixing curves. Results showed that the micro-scale equipment is sensitive enough for detection of the effect of less than 40 mg of protein addition on mixing parameters. The effects of additions depend on the type of proteins added to the wheat flour and the parameters calculated from the mixing curves

Characterisation of glutenin subunits in spelt wheat (Triticum aestivum ssp. spelta L)

Este estudo tem como objecto uma prática profissional de design gráfico, sistemática e continuada e, nesse sentido, a escolha e a reflexão teórica sobre as opções tomadas em cada um dos projectos apresentados servirão o objectivo de demonstrar que aliada a uma prática autoral, cada um destes trabalhos foi executado para servir os objectivos de uma encomenda, ponto de partida essencial em todos eles. São analisadas as diferentes estratégias de abordagem, quer do ponto de vista da formulação e da fundamentação teóricas, quer do ponto de vista da sua materialização. O estudo procura entender em que medida as diferentes abordagens conceptuais e metodológicas respondem aos programas dos diferentes projectos no sentido de tornar claras as mensagens que eles procuram veicular. A investigação divide-se em três partes e uma conclusão. A primeira parte caracteriza o momento da história do design gráfico que corresponde ao nascimento do estúdio. Trata das ideias e das personalidades, da herança e da novidade, da partilha de conhecimentos. Na segunda, são descritas as condições locais que levaram à constituição do estúdio e o seu percurso. Caracteriza-se o espaço físico, o volume de projectos e a sua distribuição por diferentes áreas de actuação e também, os mecanismos de criação de uma cultura do estúdio. Na terceira parte, é analisada uma selecção de projectos que se distinguem pela qualidade dos programas e das equipas e pelos resultados obtidos. O estudo realizado revela que a prática do estúdio fba. assenta no princípio de que o design é encarado como uma forma de clarificação e ilustra o modo como esta posição influencia o processo de design. Adicionalmente, a síntese dos resultados do trabalho, demonstra a utilidade desta tese para a compreensão da prática do estúdio e do seu futuro.Tese de doutoramento em Arte Contemporânea, no ramo de Linguística, apresentada ao Colégio das Artes da Universidade de Coimbr

Expressed Ay HMW glutenin subunit in Australian wheat cultivars indicates a positive effect on wheat quality

Out of the six HMW-GS genes, 1Ay is usually not expressed in bread wheat cultivars. In the current study, an active 1Ay gene has been integrated into two Australian wheat cultivars, Livingston and Bonnie Rock, through conventional backcross approach. Three sister lines at BC4F4 generation for each cross were obtained and underwent a series of quality testing. Results show that the active 1Ay subunit increased the amount total protein, Glutenin/Gliadin ratio and unextractable polymeric protein. The expressed 1Ay also resulted in up to 10% increase of gluten content, 5% increase of glutenin, and hence increased the HMW- to LMW-GS ratio without affecting the relative amount of other subunits. Milling yield and Flour swelling were decreased in the Livingston lines and remained mostly unchanged for Bonnie Rock. Alveograph result showed that Ay improved dough strength in Livingston and dough extensibility in Bonnie Rock. Zeleny sedimentation value was found to be higher in all three lines of Bonnie Rock but only in one of Livingston derivatives. The dough development time and peak resistance, determined on the micro Z-arm mixer were increased in most cases. Overall, the integration of Ay subunit showed significant positive effects in bread making quality