Fiber Optic Sensors

[No abstract available

Fibre optic sensing system for monitoring of current collectors and overhead contact lines of railways

Fibre optic sensors are excellent tools to use for monitoring high-voltage current collectors. Because of their small cross section and electrical neutrality, they are easily integrated into the current collector strip and are well specialized for detection of high-speed load events. The conventional contact force measurement with four force sensors below the collector strips can also be simplified by using fibre optic force and acceleration sensors

NIRS for vicine and convicine content of faba bean seed allowed GWAS to prepare for marker-assisted adjustment of seed quality of German winter faba beans

Die antinutritiven Inhaltsstoffe Vicin und Convicin (V, C) in Samen von Winterackerbohnen wurden einer GWAS unterzogen. V-, C- und V + C-Werte von 189 Inzuchtlinien (fünf Umwelten) wurden mittels NIRS ermittelt. In diesen Linien kommt das starke „vc-“-Allel (VC1-Locus) nicht vor. Labor-Resultate von 646 Proben führten zu unserer NIRS-Kalibration, die gut für V und V + C tauglich war allerdings nicht tauglich für C. Die Erblichkeit war hoch für V und V + C (0,911; 0,868) und niedriger für C (0,737). Von den 2542 kartierten SNPs waren 47 signifikant mit V und einer mit V + C assoziiert. Vier SNPs, die nahe beim VC1-Lokus kartierten, waren für V signifikant. Anscheinend trugen nicht-„vc-“-Allele an diesem Locus zur V-Variation bei. Markergestützte Züchtung in diesem Genpool kann die V + C-Gehalt auf etwa 0,44 % reduzieren, im Vergleich zur aktuell niedrigsten Linie mit 0,55 %. Weitere Forschung wird zeigen, wie diese Ergebnisse der Agronomie und Züchtung dienlich sein werden.GWAS was applied to the antinutritive compounds vicine and convicine (V, C) in winter faba bean. V, C and V + C data for 189 inbred lines (five environments) were predicted by NIRS. These lines do not carry the strong “vc-“ allele (locus VC1). Lab data for 646 samples enabled our NIRS calibration, which performed well for V and V + C yet poor for C. Heritability was high (0.911; 0.868) for V and V + C and lower for C (0.737). From the 2542 mapped SNPs, 47 were significantly associated with V and one with V + C. Four SNPs mapped near to the VC1 locus and were significant for V. Seemingly, non-“vc-“ alleles at that locus contributed to V variation. Marker-assisted breeding with this germplasm can reduce the V + C content to about 0.44%, compared to the current lowest line with 0.55%. Further research will show inasmuch this can serve agronomy and breeding

Extent and structure of linkage disequilibrium in canola quality winter rapeseed (Brassica napus L.)

Linkage disequilibrium was investigated in canola quality winter rapeseed to analyze (1) the prospects for whole-genome association analyses and (2) the impact of the recent breeding history of rapeseed on linkage disequilibrium. A total of 845 mapped AFLP markers with allele frequencies ≥0.1 were used for the analysis of linkage disequilibrium in a population of 85 canola quality winter rapeseed genotypes. A low overall level of linkage disequilibrium was found with a mean r2 of only 0.027 over all 356,590 possible marker pairs. At a significance threshold of P = 2.8 × 10−7, which was derived by a Bonferroni correction from a global α-level of 0.1, only 0.78% of the marker pairs were in significant linkage disequilibrium. Among physically linked marker pairs, the level of linkage disequilibrium was about five times higher with more than 10% of marker pairs in significant linkage disequilibrium. Linkage disequilibrium decayed rapidly with distance between linked markers with high levels of linkage disequilibrium extending only for about 2 cM. Owing to the rapid decay of linkage disequilibrium with distance association analyses in canola quality rapeseed will have a significantly higher resolution than QTL analyses in segregating populations by interval mapping, but much larger number of markers will be necessary to cover the whole genome. A major impact of the recent breeding history of rapeseed on linkage disequilibrium could not be observed

QTL for phytosterol and sinapate ester content in Brassica napus L. collocate with the two erucic acid genes

Improving oil and protein quality for food and feed purposes is an important goal in rapeseed (Brassica napus L.) breeding programs. Rapeseed contains phytosterols, used to enrich food products, and sinapate esters, which are limiting the utilization of rapeseed proteins in the feed industry. Increasing the phytosterol content of oil and lowering sinapate ester content of meal could increase the value of the oilseed rape crop. The objective of the present study was to identify quantitative trait loci (QTL) for phytosterol and sinapate ester content in a winter rapeseed population of 148 doubled haploid lines, previously found to have a large variation for these two traits. This population also segregated for the two erucic acid genes. A close negative correlation was found between erucic acid and phytosterol content (Spearman’s rank correlation, rs = −0.80**). For total phytosterol content, three QTL were detected, explaining 60% of the genetic variance. The two QTL with the strongest additive effects were mapped on linkage groups N8 and N13 within the confidence intervals of the two erucic acid genes. For sinapate ester content four QTL were detected, explaining 53% of the genetic variance. Again, a close negative correlation was found between erucic acid and sinapate ester content (rs = −0.66**) and the QTL with the strongest additive effects mapped on linkage groups N8 and N13 within the confidence intervals of the two erucic acid genes. The results suggests, that there is a pleiotropic effect of the two erucic acid genes on phytosterol and sinapate ester content; the effect of the alleles for low erucic acid content is to increase phytosterol and sinapate ester content. Possible reasons for this are discussed based on known biosynthetic pathways

Genetic analysis of global faba bean diversity, agronomic traits and selection signatures

Faba bean (Vicia faba L.) is a high-protein grain legume crop with great potential for sustainable protein production. However, little is known about the genetics underlying trait diversity. In this study, we used 21,345 high-quality SNP markers to genetically characterize 2678 faba bean genotypes. We performed genome-wide association studies of key agronomic traits using a seven-parent-MAGIC population and detected 238 significant marker-trait associations linked to 12 traits of agronomic importance. Sixty-five of these were stable across multiple environments. Using a non-redundant diversity panel of 685 accessions from 52 countries, we identified three subpopulations differentiated by geographical origin and 33 genomic regions subjected to strong diversifying selection between subpopulations. We found that SNP markers associated with the differentiation of northern and southern accessions explained a significant proportion of agronomic trait variance in the seven-parent-MAGIC population, suggesting that some of these traits were targets of selection during breeding. Our findings point to genomic regions associated with important agronomic traits and selection, facilitating faba bean genomics-based breeding

Separation of refractive index and temperature measurements using surface plasmon-coupled fiber grating

A new fiber optic sensor based on Bragg reflection influenced by a surface plasmon is presented. This arrangement allows for self-referencing due to its highly polarization-resolved response

Genetic Analysis of Heterosis for Yield and Yield Components in Rapeseed (Brassica napus L.) by Quantitative Trait Locus Mapping

The main objective in this research was the genetic analysis of heterosis in rapeseed at the QTL level. A linkage map comprising 235 SSR and 144 AFLP markers covering 2045 cM was constructed in a doubled-haploid population from a cross between the cultivar “Express” and the resynthesized line “R53.” In field experiments at four locations in Germany 250 doubled-haploid (DH) lines and their corresponding testcrosses with Express were evaluated for grain yield and three yield components. The heterosis ranged from 30% for grain yield to 0.7% for kernel weight. QTL were mapped using three different data sets, allowing the estimation of additive and dominance effects as well as digenic epistatic interactions. In total, 33 QTL were detected, of which 10 showed significant dominance effects. For grain yield, mainly complete dominance or overdominance was observed, whereas the other traits showed mainly partial dominance. A large number of epistatic interactions were detected. It was concluded that epistasis together with all levels of dominance from partial to overdominance is responsible for the expression of heterosis in rapeseed