Authors:D. Horvat, N. Ðukić, D. Magdić, J. Mastilović, G. Šimić, A. Torbica, and D. Živančev
Glutenin polymers composed of HMW and LMW subunits are important contributors to the wheat end-use properties. Twenty-six winter wheat cultivars differing in bread processing quality were collected at the experimental fields of the Agricultural Institute Osijek, Croatia and Institute of the Field and Vegetable Crops Novi Sad, Serbia, in 2008/2009 season. The HMW glutenins composition and glutenin proteins content were determined by SDS-PAGE and RP-HPLC, respectively, with aim to determine the relationship between glutenin protein fractions and wheat quality properties. Significant differences were found between Croatian and Serbian cultivars in several quality attributes (GI, WA, DDT, DS and R/EXT) as well as in the content of total glutenins and LMW glutenins and GLI/GLU ratio. The dominant HMW subunits in analyzed cultivars were 2*, 7 + 9/7 + 8 and 5 + 10. Principal component analysis (PCA) confirmed the presence of association between HMW glutenins composition and GI, dough E, R and R/EXT, while the glutenins quantitative data showed pronounced relation with P, DDT, DS, E, R and R/EXT. GLI/GLU ratio had the opposite effect on these parameters.
Authors:N. Tsenov, D. Atanasova, I. Todorov, I. Ivanova, and I. Stoeva
Seventy-six promising bread winter wheat lines were investigated in relation to the allelic composition of grain storage proteins. The aim of the study was: i) to find out a possible relation between wheat quality and the separate low molecular loci and ii) to examine the potential of some of the existing
alleles to increase the quality. Five indices were investigated that covered almost all aspects of grain quality: sedimentation value, wet gluten content, dough stability, bread volume, quality index and valorimeter. The samples for quality analysis were from a 3-year period of investigation. Different statistical approaches were used to study the influence of
on the level of the indices. The LMW-GS were determined by SDS-PAGE (Payne et al. 1980). It was determined that locus
had the strongest influence on quality among the loci, that determine the low molecular glutenins. The
alleles influenced the end-use quality irrespective of the HMW-GS and LMW-GS composition background against which their effect was expressed. There were important variations among the separate alleles of
locus for their direct effect on end-used quality.
had strong positive effect on the end-use quality against the background of all HMW combinations.
had a similar positive effect. The
allele was connected with high quality in wheat but its effect was weaker than that of
and was not significant for some of the investigated indices.
Authors:N. Tsenov, D. Atanasova, I. Todorov, I. Ivanova, and I. Stoeva
Seventy-three common winter wheat varieties developed throughout the breeding history of the DAI were investigated for their diversity of allelic variants on storage proteins component composition in grain. The high- and low molecular weight protein structures were determined by the widely used SDS-PAGE method of Payne et al. (1980). The ratio between the individual alleles on the loci of high and low molecular weight glutenin was analyzed. The change in the HMW-score was followed according to the period when the respective varieties were developed. The configuration
, which was established in about 45% of the investigated genotypes, was most frequent in the high-molecular variants of glutenin. Concerning the low-molecular weight glutenins in 21 out of the 73 investigated varieties, the combination
was observed; it coincided with the spectrum of the widely used variety Bezostaya 1. Highest diversity was established in the allelic variants of
, in which 6 and 5 alleles, respectively, were observed. The quality of the varieties developed at DAI was relatively high (score 8.1). About a quarter of them are with high end-use quality confirmed in production. This is mainly due to the concentration of “strong” positive alleles in glutenin as a result from the intensive use of parents directly or indirectly related to Bezostaya 1, which lead to decrease of the percent of
(2 + 12). Quality should be further increased by additional diversity of combinations between “possitive” as effect on end-use grain quality alleles. Concerning HMW loci to keep of high grain end-use quality, it is necessary to maintain the status of
(2*), as well as of
(5 + 10).
Authors:X.L. Jiang, G.F. Chen, X.J. Li, G. Li, Z.G. Ru, and J.C. Tian
This study aimed to clarify the genetic mechanisms behind wheat flour color. Flour colorrelated traits (L*, a*, and b*) and polyphenol oxidase (PPO) activity are important parameters that influence the end-use quality of wheat. Dissecting the genetic bases and exploring important chromosomal loci of these traits are extremely important for improving wheat quality. The diverse panel of 205 elite wheat varieties (lines) was genotyped using a highdensity Illumina iSelect 90K single-nucleotide polymorphisms (SNPs) assay to disclose the genetic mechanism of flour color-related traits and PPO activity. In 2 different environments and their mean values (MV), 28, 30, 24, and 12 marker-trait associations (MTAs) were identified for L*, a*, b* traits, and PPO activity, respectively. A single locus could explain from 5.52% to 20.01% of the phenotypic variation for all analyzed traits. Among them, 5 highly significant SNPs (P ≤ 0.0001), 11 stable SNPs (detected in all environments) and 25 multitrait MTAs were identified. Especially, BS00000020_51 showed pleiotropic effects on L*, a*, and b*, and was detected in all environments with the highest phenotypic contribution rates. Furthermore, this SNP was also found to be co-associated with wheat grain hardness, ash content, and pasting temperature of starch in previous studies. The identification of these significantly associated SNPs is helpful in revealing the genetic mechanisms of wheat colorrelated traits, and also provides a reference for follow-up molecular marker-assisted selection in wheat breeding.
Dough mixing properties are important in determining wheat processing and end-use quality. The Reomixer is a mixograph type device which provides mixing curves, described in detail by a total of 17 parameters. We analyzed the Reomixer mixing parameters of 26 breeding lines grown in 2007, in four contrasting environments (with and without Nitrogen fertilization, under water stress or irrigated). Using these data, we attempted to condense the information by identifying the most suitable parameters for use in a breeding program. We used the following criteria: high reproducibility (minimum coefficient of variation among repetitions), high genotype influence (i.e. high heritability), larger amount of information about overall variation of the other mixing parameters and complementarity of information (low correlation with other selected parameters). Mixing parameters varied widely for all criteria and no one parameter was best for all of them. Based on average performance we selected: “initial slope”, “peak time”, “peak height”, “end width” and “breakdown”, as having better ranking for the first three criteria and being less correlated between themselves than other mixing parameters. The five selected parameters cover all phases of dough development and describe all basic rheological aspects of mixing properties.
Authors:A. Harasztos, G. Balázs, P.N. Csőke, S. D’Amico, R. Schönlechner, and S. Tömösközi
The positive nutritional impact of dietary fibres (DF) gives growing interest to their role in the formation of wheat product quality. Although we are getting closer to characterize the effect of DF on the end use quality, the roles of individual components are not well described yet. Arabinoxylans (AX) are the main compounds of wheat DF, therefore getting more knowledge about its behaviour in wheat based food systems, like dough or end products, could be useful from both theoretical and practical points of view. The aim of this study was to investigate the impact of the AX content on wheat flour quality using a dough model system provided by blends of flour and AX isolate. Rapid Visco Analyser (RVA) and recently developed micro Zeleny test were used for characterization of mixtures.
We found that although Zeleny values are basically related to protein-dependent quality, the addition of AX isolate has major impact on the sedimentation volume of flour. In the RVA studies we demonstrated that AX has influence not only on the viscosity values but also on the rate of viscosity change. The effect of AX addition was compared to that of starch addition and was corrected by the rate of dilution. The model system and the experimental method applied here can be suitable to separate the individual effects of non-starchy carbohydrates.
Authors:F. S. Pelser, M.T. Labuschagne, B. Wentzel, and A. van Biljon
The mixograph performs certain rheological measurements during dough mixing and is a good predictor of wheat end-use quality. The aim of this study was to determine the expression and the heritability of mixing characteristics measured with Mixsmart® software and some quality characteristics in hard red spring wheat parents and their F1 progeny. Six parents varying in midline peak time and envelope peak time were crossed in a half diallel design. Parents and progeny were planted in three different environments. General combining ability (GCA) was a significant source of variation for the measured characteristics, and parents differed widely in terms of GCA effects. Midline-development time, -peak integral and -peak time showed high narrow sense heritability. Envelope peak-integral and -tail width displayed high narrow sense heritability for some, but not all locations. High GCA:SCA (specific combining ability) ratios indicated the prevalence of additive gene effects for midline-development time, -peak integral and -peak time, indicating that these characteristics are largely genetically determined, and that selection for them should lead to genetic gain.
Authors:H. Khoshro, M. Bihamta, M. Hassanii, M. Omidi, and M. Aghaei
Low molecular weight glutenin subunits are important components of wheat seed storage protein, and play a significant in determining the end-use quality characteristics of wheat varieties. Allelic variation of the LMW-GS is associated with the significant differences of dough quality in bread and durum wheat, and has been widely evaluated at protein level in wheat and its relatives. In this study seven specific primers, specifically amplify genes located at the
loci, were employed to assay the length variation of LMW-GS genes in the A and D-genomes of diploid wheats. A total of 86 accessions of diploid wheats, including 10 accessions of
and 76 accessions of
, were investigated. Seven alleles were detected in accessions of
locus) by two pairs of specific primers and eighteen alleles were detected in accessions of
locus) by five pairs of specific primers. A higher level of allelic variation of LMW-GS was found in accession
with Nei’s genetic variation index (H) of 0.82 and 0.92, respectively. This allelic variation could be used as valuable source for the enrichment of genetic variations and the alteration of flour-processing properties of the cultivated wheat.