Determining wave vector and material property from the phase-shift of spin-wave propagation

Different to conventional ferromagnetic resonance methods, we use the phase-shift of spin-wave propagation to investigate spin-wave in conducting ferromagnetic thin films. Spin-wave wave vector (or wave number) k, a key parameter in the study of spin-wave dispersion and propagation, is extracted from the ratio of the phase-shift to the propagation distance and the ratio of the intercepts to the slopes of the plot of frequency square (f2) vs. the bias field (H). The wave vectors calculated by both methods are in good agreement. The in-plane anisotropy field Hk and saturation magnetization MS can also be extracted from the phase-shift map

Global Transcriptome Sequencing Using the Illumina Platform and the Development of EST-SSR Markers in Autotetraploid Alfalfa

<div><p>Background</p><p>Alfalfa is the most widely cultivated forage legume and one of the most economically valuable crops in the world. The large size and complexity of the alfalfa genome has delayed the development of genomic resources for alfalfa research. Second-generation Illumina transcriptome sequencing is an efficient method for generating a global transcriptome sequence dataset for gene discovery and molecular marker development in alfalfa.</p> <p>Methodology/Principal Findings</p><p>More than 28 million sequencing reads (5.64 Gb of clean nucleotides) were generated by Illumina paired-end sequencing from 15 different alfalfa tissue samples. In total, 40,433 unigenes with an average length of 803 bp were obtained by <i>de</i><i>novo</i> assembly. Based on a sequence similarity search of known proteins, a total of 36,684 (90.73%) unigenes were annotated. In addition, 1,649 potential EST-SSRs were identified as potential molecular markers from unigenes with lengths exceeding 1 kb. A total of 100 pairs of PCR primers were randomly selected to validate the assembly quality and develop EST-SSR markers from genomic DNA. Of these primer pairs, 82 were able to amplify sequences in initial screening tests, and 27 primer pairs successfully amplified DNA fragments and detected significant amounts of polymorphism among 10 alfalfa accessions.</p> <p>Conclusions/Significance</p><p>The present study provided global sequence data for autotetraploid alfalfa and demonstrates the Illumina platform is a fast and effective approach to EST-SSR markers development in alfalfa. The use of these transcriptome datasets will serve as a valuable public information platform to accelerate studies of the alfalfa genome.</p> </div

Plot showing the dependence of unigene length on the number of reads assembled into each unigene.

<p>Plot showing the dependence of unigene length on the number of reads assembled into each unigene.</p

EST-SSR variations at the Ms-29 and Ms-39 loci of 10 alfalfa accessions.

<p>Each accession includes five individual plants. The corresponding detailed information from 10 alfalfa accessions is displayed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0083549#pone.0083549.s001" target="_blank">Table S1</a>. The letter ‘M’ denotes the molecular markers, which are 300 bp, 200 bp, and 150 bp (top to bottom) in Ms-29, and 200 bp, 150 bp, and 100 bp in Ms-39.</p

Alfalfa unigenes mapped to Mt3.5.2 pseudomolecules with a threshold of 95% identity and 90% coverage.

<p>White lines represent alfalfa unigenes that were not mapped to the <i>M. truncatula</i> genome sequence assembly, and black lines represent alfalfa unigenes that were mapped to the <i>M. truncatula</i> genome.</p

The tissues used in this study and all samples shown are from the alfalfa cultivar “Golden queen”.

<p>(A) Callus cells. (B) Germinated seeds (36 hours after seed germination). (C) Germinated seeds (48 hours after seed germination). (D) Roots from a 20-day-old seedling. (E) Cotyledons from a 7-day-old seedling. (F) Unifoliate leaves from a 20-day-old seedling. (G) Compound leaves. (H) Young stem (less lignified). (I) Middle stem (moderately lignified). (J) Old stem (more lignified). (K) Shoot apex. (L) Young inflorescence (diameter 0.4-0.5 cm). (M) Mature inflorescence (diameter 2 cm), (N) Young pod (16 days after pollination). (O) Mature pod (24 days after pollination).</p

The ratio of <i>M. sativa</i> unigene length to <i>M. truncatula</i> unigene coverage depth.

<p>A BLAST search was performed with a cutoff E-value <10E-10 between <i>M. truncatula</i> and <i>M. sativa</i> on the basis of coding sequence similarity. </p