主轴切削加工振动测试信号的EEMD提纯

针对主轴切削加工状态下的转子振动测试信号存在噪声干扰严重的问题,提出一种基于EEMD信号处理技术的加工振动测试信号提纯方法,该方法能够有效滤除噪声干扰实现信号提纯,并且该方法能够解决加工状态下转子振动测试信号非平稳特征的有效提取,相比于EMD方法能够有效避免模态混叠现象的发生,具有更好的信号处理效果,通过仿真分析和实验验证本方法在主轴加工状态下的转子振动测试信号提纯中具有很好的效果。该方法为主轴切削加工状态下的故障诊断提供必要的基础。

基于深度学习的大豆豆荚类别识别研究

作物表型调查是作物品种选育过程中的一项关键工作。传统表型调查主要依靠人力,使得表型调查的结果难以达到自动化、高精度、高可靠性的要求。在大豆的表型调查中,对豆荚类别的正确识别是豆荚个数、长度和宽度等表型准确提取的关键和前提。本文针对成熟期大豆豆荚的图片,通过利用深度学习迁移5种不同的网络模型[AlexNet、VggNet(Vgg16,Vgg19)、GoogleNet、ResNet-50],对一粒荚、二粒荚、三粒荚、四粒荚进行识别。为提高训练速度和准确率,本试验微调模型,选择不同的优化器(SGD、Adam)对网络模型进行优化。结果表明,在针对豆荚辨识问题中,Adam的性能优于SGD,而Vgg16网络模型搭配Adam优化器,豆荚类别的测试准确率达到了98.41%,在所选的网络模型中体现了最佳的性能。在十折交叉验证试验中也体现了Vgg16网络模型具有良好的稳定性。因此本研究认为Vgg16网络模型可以应用到实际的豆荚识别中,为进一步实现豆荚表型自动提取提供一条重要的解决途径。

根瘤菌Ⅲ型效应因子NopAA的突变及其对大豆共生结瘤的影响

大豆根瘤固氮为大豆生长发育提供必不可少的氮源。根瘤菌Ⅲ型效应因子是大豆与根瘤菌共生体系建立过程中重要的信号分子。本研究以根瘤菌HH103 Ⅲ型效应因子NopAA为研究对象,通过生物信息学手段分析了其基本信息,利用三亲杂交构建NopAA突变体,并利用Southern blot对突变体进行鉴定。表达分析发现,NopAA突变显著降低了大豆免疫相关基因PR1的表达;在根瘤成熟之后,根瘤菌依旧能够表达NopAA。最后通过结瘤能力鉴定,发现NopAA突变能够显著抑制根瘤的产生。该研究为揭示根瘤菌Ⅲ型效应因子NopAA的作用机制奠定了基础,同时为大豆农业生产过程中共生固氮的利用提供理论基础。

Identification of novel soybean oil content-related genes using QTL-based collinearity analysis from the collective soybean genome

Soybean is a global principal source of edible plant oil. As more soybean oil-related quantitative trait loci(QTLs) have been located in the collective genome, it is urgent to establish a classification system for these distributed QTLs. A collinear platform may be useful to characterize and identify relationships among QTLs as well as aid in novel gene discovery. In this study, the collinearity MCScan X algorithm and collective soybean genomic information were used to construct collinearity blocks, to which soybean oil-related QTLs were mapped. The results demonstrated that 666 collinearity blocks were detected in the soybean genome across 20 chromosomes, and 521 collinearity relationships existed in 231 of the 242 effective soybean oil-related QTLs. This included 214 inclusion relationships and 307 intersecting relationships. Among them, the collinearity among QTLs that are related to soybean oil content was shown on a maximum of seven chromosomes and minimum of one chromosome, with the majority of QTLs having collinearity on two chromosomes. Using overlapping hotspot regions in the soybean oil QTLs with collinearity, we mined for novel oil content-related genes. Overall, we identified 23 putatively functional genes associated with oil content in soybean and annotated them using a number of annotation databases. Our findings provide a valuable framework for elucidating evolutionary relationships between soybean oil-related QTLs and lay a foundation for functional marker-assisted breeding relating to soybean oil content.

Identification of candidate genes related to soluble sugar contents in soybean seeds using multiple genetic analyses

Soluble sugar content in seeds is an important quality trait of soybean. In this study, 57 quantitative trait loci(QTLs) related to soluble sugar contents in soybean seeds were collected from databases and published papers. After meta-overview-collinearity integrated analysis to refine QTL intervals, eight consensus QTLs were identified. To further verify the consensus QTLs, a population of chromosome segment substitution lines(CSSLs) was analyzed. Two lines containing fragments covering the regions of consensus QTLs and the recurrent parent were selected: one line showed high soluble sugar contents associated with a consensus QTL fragment, and the other line showed low soluble sugar contents. Transcriptome sequencing was conducted for these two lines at the early, middle, and late stages of seed development, which identified 158, 109 and 329 differentially expressed genes, respectively. Based on the analyses of re-sequencing data of the CSSLs and the consensus QTL region, three candidate genes(Glyma.19 G146800, Glyma.19 G122500, and Glyma.19 G128500) were identified in the genetic fragments introduced from wild soybean. Sequence comparisons between the two CSSL parents SN14 and ZYD00006 revealed a single nucleotide polymorphism(SNP) mutation in the coding sequence of Glyma.19 G122500, causing a nonsynonymous mutation in the amino acid sequence that affected the predicted protein structure. A Kompetitive allele-specific PCR(KASP) marker was developed based on this SNP and used to evaluate the CSSLs. These results lay the foundation for further research to identify genes related to soluble sugar contents in soybean seeds and for future soybean breeding.

Characterization of chromosome segment substitution lines reveals candidate genes associated with the nodule number in soybean

Soybean is one of the most important food crops worldwide.Like other legumes,soybean can form symbiotic relationships with Rhizobium species.Nitrogen fixation of soybean via its symbiosis with Rhizobium is pivotal for sustainable agriculture.Type Ⅲ effectors(T3Es)are essential regulators of the establishment of the symbiosis,and nodule number is a feature of nitrogen-affected nodulation.However,genes encoding T3Es at quantitative trait loci(QTLs)related to nodulation have rarely been identified.Chromosome segment substitution lines(CSSLs)have a common genetic background but only a few loci with heterogeneous genetic information;thus,they are suitable materials for identifying candidate genes at a target locus.In this study,a CSSL population was used to identify the QTLs related to nodule number in soybean.Single nucleotide polymorphism(SNP)markers and candidate genes within the QTLs interval were detected,and it was determined which genes showed differential expression between isolines.Four candidate genes(GmCDPK28,GmNAC1,GmbHLH,and GmERF5)linked to the SNPs were identified as being related to nodule traits and pivotal processes and pathways involved in symbiosis establishment.A candidate gene(GmERF5)encoding a transcription factor that may interact directly with the T3E NopAA was identified.The confirmed CSSLs with important segments and candidate genes identified in this study are valuable resources for further studies on the genetic network and T3Es involved in the signaling pathway that is essential for symbiosis establishment.

GmDRR1,a dirigent protein resistant to Phytophthora sojae in Glycine max (L.) Merr.

Soil-borne pathogen Phytophthora sojae is an oomycete that causes devastating damage to soybean yield. To mine original resistant genes in soybean is an effective and environmentally-friend approach controlling the disease. In this study, soybean proteins were extracted from the first trifoliolates infected by predominant P. sojae race 1 and analyzed by twodimensional gel electrophoresis. Nineteen differently-expressed protein spots were detected, and 10 of them were further applied for Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry Assay. One protein containing a dirigent （DIR） domain was identified and belonged to the DIR-b/d family. Therefore, it was named as GmDRR1 （Glycine max Disease Resistance Response 1）. Then, GmDRR1 gene was pathologically confirmed to be involved in the resistant to P. sojae in soybean. GmDRR1-GFP （green fluorescent protein） fusion proteins localized in the cell membrane. qRTPCR results showed GmDRR1 gene expressed differently in P. sojae resistant- and susceptible-soybean cultivars. By the promoter analysis, we found a haplotype H8 was existing in most resistant soybean varieties, while a haplotype H77 was existing in most susceptible soybean varieties. The H77 haplotype had seven SNPs （C to A, G to C, C to A, T to A, T to C, T to C, and T to A） and two single nucleotide insertions. The results supported that the expression difference of GmDRR1 genes between P. sojae resistant- and susceptible-soybean cultivars might depend on the GmDRR1 promoter SNPs. The results suggested that GmDRR1 was a dirigent protein involved in soybean resistant to P. sojae and paved a novel way for investigation of the molecular regulatory mechanism of the defense response to P. sojae in soybean.

借鉴常香玉声腔艺术促进民族声乐的发展

常香玉创立的常派声腔具有发声科学、咬吐字清晰圆润、声腔韵味醇厚等艺术特点。民族声乐源于民歌,深受戏曲、曲艺等传统演唱艺术的影响,民族声乐借鉴常香玉声腔艺术中"音柱""音着点"的发声技巧;"重字轻字""喷口"等咬吐字技术;"力度速度""情感反映"等润腔技巧,对民族声乐朝着科学性、系统性、民族性等方面的发展有着积极的促进作用。