Genomic selection for target traits in the Australian lentil breeding program

Genomic selection (GS) uses associations between markers and phenotypes to predict the breeding values of individuals. It can be applied early in the breeding cycle to reduce the cross-to-cross generation interval and thereby increase genetic gain per unit of time. The development of cost-effective, high-throughput genotyping platforms has revolutionized plant breeding programs by enabling the implementation of GS at the scale required to achieve impact. As a result, GS is becoming routine in plant breeding, even in minor crops such as pulses. Here we examined 2,081 breeding lines from Agriculture Victoria’s national lentil breeding program for a range of target traits including grain yield, ascochyta blight resistance, botrytis grey mould resistance, salinity and boron stress tolerance, 100-grain weight, seed size index and protein content. A broad range of narrow-sense heritabilities was observed across these traits (0.24-0.66). Genomic prediction models were developed based on 64,781 genome-wide SNPs using Bayesian methodology and genomic estimated breeding values (GEBVs) were calculated. Forward cross-validation was applied to examine the prediction accuracy of GS for these targeted traits. The accuracy of GEBVs was consistently higher (0.34-0.83) than BLUP estimated breeding values (EBVs) (0.22-0.54), indicating a higher expected rate of genetic gain with GS. GS-led parental selection using early generation breeding materials also resulted in higher genetic gain compared to BLUP-based selection performed using later generation breeding lines. Our results show that implementing GS in lentil breeding will fast track the development of high-yielding cultivars with increased resistance to biotic and abiotic stresses, as well as improved seed quality traits

Improving pulse crops as a source of protein, starch and micronutrients

Pulse crops have been known for a long time to have beneficial nutritional profiles for human diets but have been neglected in terms of cultivation, consumption and scientific research in many parts of the world. Broad dietary shifts will be required if anthropogenic climate change is to be mitigated in the future, and pulse crops should be an important component of this change by providing an environmentally sustainable source of protein, resistant starch and micronutrients. Further enhancement of the nutritional composition of pulse crops could benefit human health, helping to alleviate micronutrient deficiencies and reduce risk of chronic diseases such as type 2 diabetes. This paper reviews current knowledge regarding the nutritional content of pea (Pisum sativum L.) and faba bean (Vicia faba L.), two major UK pulse crops, and discusses the potential for their genetic improvement

Investigations into reaming processes using a frequency-decomposition technique

Reaming is carried out after twist drilling to enlarge and finish the holes accurately. The experiments were carried out on mild-steel workpieces at different reaming conditions and the accuracy and surface finish values are very briefly compared with the results of earlier investigators. A detailed analysis of the harmonic contents of the axial and transverse profiles of the reamed holes was carried out to bring out the process characteristics. A preliminary study of the cutting forces in reaming based on the spectral analysis is also reported. © 1990 Taylor & Francis Group, LLC

Establishing reference figures for form evaluation of engineering surfaces

A generalized algorithm is presented in this paper to establish the reference figures as specified in the international and national standards on form errors. This algorithm is guaranteed to give optimal results and is well suited for implementation on a computer-interfaced, form-measuring instrument or a coordinate measuring machine. © 1991

Signature of machine tool errors on surface texture by DPS

The dynamic effect of machine tool errors leaves its signature on machined surfaces. This paper proposes an application of data dependent systems (DDS) methodology to recover this signature from the surfaces in a comprehensive manner and provides a realistic basis for machine-tool acceptance. The approach is illustrated by experimental results from three different lathes. It is shown that relative contributions due to the feed wavelength reveal the dynamic performance of the machine tools. The deviation from the nominal and the spread of the estimated feed wavelength quantify the accuracy and rigidity, the feed wavelength being precisely maintained with minimal spread in a machine tool with high accuracy and high rigidity. Presence of other wavelengths and their relative contribution to the RMS surface roughness serve as quantitative indicators of other machine tool errors. © 1992 by ASME

Practical measurement strategies for verification of freeform surfaces using coordinate measuring machines

Freeform surfaces have wider engineering applications. Designers use B-splines, Non-Uniform Rational Bsplines, etc. to represent the freeform surfaces in CAD, while the manufacturers employ machines with controllers based on approximating functions or splines. Different errors also creep in during machining operations. Therefore the manufactured freeform surfaces have to be verified for conformance to design specification. Different points on the surface are probed using a coordinate measuring machine and substitute geometry of surface established from the measured points is compared with the design surface. The sampling points are distributed according to different strategies. In the present work, two new strategies of distributing the points on the basis of uniform surface area and dominant points are proposed, considering the geometrical nature of the surfaces. Metrological aspects such as probe contact and margins to be provided along the sides have also been included. The results are discussed in terms of deviation between measured points and substitute surface as well as between design and substitute surfaces, and compared with those obtained with the methods reported in the literature