QTLs for water absorption and flour yield identified in the doubled haploid wheat population Lang/QT8766

Two key quality traits in milling wheat are flour yield (FY) and water absorption (WA). Ideally, breeders would prefer to use markers to select promising lines rather than time consuming rheology tests. In this study, we measured FY and WA on a wheat mapping population (Lang/QT8766) of 162 individuals grown in two replicated field experiments at three locations over 2 years. We also carried out near infrared reflectance spectroscopy (NIRS) predictions on the grain for these traits to see if NIRS phenotypic data could provide useful mapping results when compared to the reference phenotypic data. Several common QTLs were identified for FY and WA by both sets of data. The QTL on chromosome 4D was a consistently recurring QTL region for both traits. The QTL on chromosome 2A was positively linked to protein content which was supported by genetic correlation data. The results also indicated it was possible to obtain useful phenotypic data for mapping FY and WA using NIRS data. This would save time and costs as NIRS is quicker and cheaper than current rheology methods.

Rapid genome wide mapping of phosphine resistance loci by a simple regional averaging analysis in the red flour beetle, Tribolium castaneum

Background Next-generation sequencing technology is an important tool for the rapid, genome-wide identification of genetic variations. However, it is difficult to resolve the ‘signal’ of variations of interest and the ‘noise’ of stochastic sequencing and bioinformatic errors in the large datasets that are generated. We report a simple approach to identify regional linkage to a trait that requires only two pools of DNA to be sequenced from progeny of a defined genetic cross (i.e. bulk segregant analysis) at low coverage (<10×) and without parentage assignment of individual SNPs. The analysis relies on regional averaging of pooled SNP frequencies to rapidly scan polymorphisms across the genome for differential regional homozygosity, which is then displayed graphically. Results Progeny from defined genetic crosses of Tribolium castaneum (F4 and F19) segregating for the phosphine resistance trait were exposed to phosphine to select for the resistance trait while the remainders were left unexposed. Next generation sequencing was then carried out on the genomic DNA from each pool of selected and unselected insects from each generation. The reads were mapped against the annotated T. castaneum genome from NCBI (v3.0) and analysed for SNP variations. Since it is difficult to accurately call individual SNP frequencies when the depth of sequence coverage is low, variant frequencies were averaged across larger regions. Results from regional SNP frequency averaging identified two loci, tc_rph1 on chromosome 8 and tc_rph2 on chromosome 9, which together are responsible for high level resistance. Identification of the two loci was possible with only 5-7× average coverage of the genome per dataset. These loci were subsequently confirmed by direct SNP marker analysis and fine-scale mapping. Individually, homozygosity of tc_rph1 or tc_rph2 results in only weak resistance to phosphine (estimated at up to 1.5-2.5× and 3-5× respectively), whereas in combination they interact synergistically to provide a high-level resistance >200×. The tc_rph2 resistance allele resulted in a significant fitness cost relative to the wild type allele in unselected beetles over eighteen generations. Conclusion We have validated the technique of linkage mapping by low-coverage sequencing of progeny from a simple genetic cross. The approach relied on regional averaging of SNP frequencies and was used to successfully identify candidate gene loci for phosphine resistance in T. castaneum. This is a relatively simple and rapid approach to identifying genomic regions associated with traits in defined genetic crosses that does not require any specialised statistical analysis.

Susceptibility to sulfuryl fluoride and lack of cross-resistance to phosphine in developmental stages of the red flour beetle, Tribolium castaneum (Coleoptera: Tenebrionidae)

BACKGROUND Our aim was to ascertain the potential of sulfuryl fluoride (SF) as an alternative fumigant to manage phosphine-resistant pests. We tested the susceptibility of all life stages of red flour beetle, Tribolium castaneum (Herbst), to SF and assessed the presence of cross-resistance to this fumigant in phosphine-resistant strains of this species. RESULTS Analysis of dose–response data indicated that the egg was the stage most tolerant to SF under a 48 h exposure period. At LC50, eggs were 29 times more tolerant than other immature stages and adults, and required a relatively high concentration of 48.2 mg L−1 for complete mortality. No significant differences in tolerance to SF were observed among the three larval instars, pupae and adults, and all of these stages were controlled at a low concentration of 1.32 mg L−1. Phosphine-resistant strains did not show cross-resistance to SF. CONCLUSION Our research concluded that the current maximum registered rate of SF, 1500 gh m−3, is adequate to control all the post-embryonic life stages of T. castaneum over a 48 h fumigation period, but it will fail to achieve complete mortality of eggs, indicating the risk of some survival of eggs under this short exposure period. As there is no cross-resistance to SF in phosphine-resistant insects, it will play a key role in managing phosphine resistance in stored-grain insect pests. © 2014 Commonwealth of Australia. Pest Management Science © 2014 Society of Chemical Industry

Sorption and desorption of sulfuryl fluoride by wheat, flour and semolina

Sulfuryl fluoride (SF) has been developed as a fumigant for control of insect pests in stored grain. However, there is very limited information on the sorption behaviour of this fumigant, which can be critical to its bioactivity, application and potential for residues. We undertook a comprehensive laboratory study of the sorption and desorption of SF by wheat (bread and durum), flour and semolina at 15, 25 and 35 °C, moisture contents 12% and 15%, and concentration × time combinations at CT = 1500 mgh/L (4.167 mg/L × 360 h, 8.928 mg/L × 168 h and 31.25 mg/L × 48 h). At each dosage, sorption rate increased as commodity temperature and moisture content increased. The highest rates of sorption occurred at 35 °C and 15% m.c., and lowest rates at 15 °C and 12% m.c., and the rate was independent of initial concentration. Sorption followed first order reaction kinetics described by the exponential decay equation, Ct = C0·e−k*t, where k is the sorption rate constant. The most important factors determining the rate of sorption were commodity particle size (exposed surfaces) and temperature. Little sorption of fumigant occurred within the first 24 h whereas longer fumigation times resulted in significant sorption. Unbound SF was rapidly lost from the commodity upon aeration with no further desorption detected under any of the test conditions.

Effect of compatibilization on mechanical and thermal properties of polypropylene–soy flour composites

A new biobased composite was developed by adding soy flour (SF) to polypropylene (PP). This composite shows an enhanced tensile strength and modulus but decrease in elongation at break. The compatibilizer (coupling agent) appears to have a synergistic effect on tensile strength. The presence of the compatibilizer improves the dispersion of SF in the PP matrix. The addition of glycerol plasticizer to the composite improves the processability resulting in improved performance, as compared to composites without glycerol plasticizer. The optimal compatibilizer content appears to be 6%.

Superconformal transformations of theN=4 supersymmetric Yang-Mills theory

We obtain the superconformal transformation laws of theN=4 supersymmetric Yang-Mills theory and explicitly demonstrate the closure of the algebra.

Path-integral derivation of the superconformal anomaly for the N=1 supersymmetric Yang-Mills theory

Fujikawa's method of evaluating the supercurrent and the superconformal current anomalies, using the heat-kernel regularization scheme, is extended to theories with gauge invariance, in particular, to the off-shell N=1 supersymmetric Yang-Mills (SSYM) theory. The Jacobians of supersymmetry and superconformal transformations are finite. Although the gauge-fixing term is not supersymmetric and the regularization scheme is not manifestly supersymmetric, we find that the regularized Jacobians are gauge invariant and finite and they can be expressed in such a way that there is no one-loop supercurrent anomaly for the N=1 SSYM theory. The superconformal anomaly is nonzero and the anomaly agrees with a similar result obtained using other methods.

Structure constants of beta deformed super Yang-Mills

We study the structure constants of the N = 1 beta deformed theory perturbatively and at strong coupling. We show that the planar one loop corrections to the structure constants of single trace gauge invariant operators in the scalar sector is determined by the anomalous dimension Hamiltonian. This result implies that 3 point functions of the chiral primaries of the theory do not receive corrections at one loop. We then study the structure constants at strong coupling using the Lunin-Maldacena geometry. We explicitly construct the supergravity mode dual to the chiral primary with three equal U(1) R-charges in the Lunin-Maldacena geometry. We show that the 3 point function of this supergravity mode with semi-classical states representing two other similar chiral primary states but with large U(1) charges to be independent of the beta deformation and identical to that found in the AdS(5) x S-5 geometry. This together with the one-loop result indicate that these structure constants are protected by a non-renormalization theorem. We also show that three point function of U(1) R-currents with classical massive strings is proportional to the R-charge carried by the string solution. This is in accordance with the prediction of the R-symmetry Ward identity.

Yang-Mills theory in six-dimensional superspace

The superspace approach provides a manifestly supersymmetric formulation of supersymmetric theories. For N= 1 supersymmetry one can use either constrained or unconstrained superfields for such a formulation. Only the unconstrained formulation is suitable for quantum calculations. Until now, all interacting N>1 theories have been written using constrained superfields. No solutions of the nonlinear constraint equations were known.

In this work, we first review the superspace approach and its relation to conventional component methods. The difference between constrained and unconstrained formulations is explained, and the origin of the nonlinear constraints in supersymmetric gauge theories is discussed. It is then shown that these nonlinear constraint equations can be solved by transforming them into linear equations. The method is shown to work for N=1 Yang-Mills theory in four dimensions.

N=2 Yang-Mills theory is formulated in constrained form in six-dimensional superspace, which can be dimensionally reduced to four-dimensional N=2 extended superspace. We construct a superfield calculus for six-dimensional superspace, and show that known matter multiplets can be described very simply. Our method for solving constraints is then applied to the constrained N=2 Yang-Mills theory, and we obtain an explicit solution in terms of an unconstrained superfield. The solution of the constraints can easily be expanded in powers of the unconstrained superfield, and a similar expansion of the action is also given. A background-field expansion is provided for any gauge theory in which the constraints can be solved by our methods. Some implications of this for superspace gauge theories are briefly discussed.

Development of partially hydrolysed and deodourised fish flour

A process developed for preparation of partially hydrolysed and deodorised (PHD) fish flour, without solvent extraction is described. The PHD fish flour prepared from four varieties of trash fish had creamy white colour and contained 87-92% protein and 7-8% available lysine. The products had shelf life of more than a year at room temperature, and caused no grittiness when incorporated in snacks and bakery products at 10% and 7.5% level respectively. The flour prepared from Nemipterus spp. had a PER 2.32 compared to 2.68 of raw fish meat and 2.5 of standard casein.