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

Connecting Numerical Relativity and Data Analysis of Gravitational Wave Detectors

Gravitational waves deliver information in exquisite detail about astrophysical phenomena, among them the collision of two black holes, a system completely invisible to the eyes of electromagnetic telescopes. Models that predict gravitational wave signals from likely sources are crucial for the success of this endeavor. Modeling binary black hole sources of gravitational radiation requires solving the Eintein equations of General Relativity using powerful computer hardware and sophisticated numerical algorithms. This proceeding presents where we are in understanding ground-based gravitational waves resulting from the merger of black holes and the implications of these sources for the advent of gravitational-wave astronomy.Comment: Appeared in the Proceedings of 2014 Sant Cugat Forum on Astrophysics. Astrophysics and Space Science Proceedings, ed. C.Sopuerta (Berlin: Springer-Verlag

Molecular discrimination of Bx7 alleles demonstrates that a highly expressed high-molecular-weight glutenin allele has a major impact on wheat flour dough strength

High-molecular-weight glutenin subunits (HMW-GS) are important determinants of wheat dough quality as they confer visco-elastic properties to the dough required for mixing and baking performance. With this important role, the HMW-GS alleles are key markers in breeding programs. In this work, we present the use of a PCR marker initially designed to discriminate Glu1 Bx7 and Glu1 Bx17 HMW-GS. It was discovered that this marker also differentiated two alleles, originally both scored as Glu1 Bx7, present in the wheat lines CD87 and Katepwa respectively, by a size polymorphism of 18 bp. The marker was scored across a segregating doubled-haploid (DH) population (CD87 × Katepwa) containing 156 individual lines and grown at two sites. Within this population, the marker differentiated lines showing the over-expression of the Glu1 Bx7 subunit (indicated by the larger PCR fragment), derived from the CD87 parent, relative to lines showing the normal expression of the Glu1 Bx7 subunit, derived from the Katepwa parent. DNA sequence analysis showed that the observed size polymorphism was due to an 18 bp insertion/deletion event at the C-terminal end of the central repetitive domain of the Glu1 Bx 7 coding sequence, which resulted in an extra copy of the hexapeptide sequence QPGQGQ in the deduced amino-acid sequence of Bx7 from CD87. When the DH population was analysed using this novel Bx7 PCR marker, SDS PAGE and RP HPLC, there was perfect correlation between the Bx7 PCR marker results and the expression level of Bx7. This differentiation of the population was confirmed by both SDS-PAGE and RP-HPLC. The functional significance of this marker was assessed by measuring key dough properties of the 156 DH lines. A strong association was shown between lines with an over expression of Bx7 and high dough strength. Furthermore, the data demonstrated that there was an additional impact of Glu-D1 alleles on dough properties, with lines containing both over-expressed Bx7 and Glu-D1 5+10 having the highest levels of dough strength. However, there was no statistically significant epistatic interaction between Glu-B1 and Glu-D1 loci