Direct somatic embryogenesis and related gene expression networks in leaf explants of Hippeastrum ‘Bangkok Rose’

Hippeastrum, a highly diverse genus in the Amaryllidaceae family, is a valuable ornamental bulbous flowering plant. Somatic embryogenesis(SE) is an efficient method for mass production of Hippeastrum plantlets. Previous studies have been devoted to the in vitro propagation of Hippeastrum, but the SE and its regulatory networks are rarely reported. In this study, we established a direct SE method of Hippeastrum Bangkok Rose' using leaf bases as explants. MS supplemented with 1.00 mg·L^(-1)NAA +1.00 mg·L^(-1)KT + 0.25 mg·L^(-1)TDZ was the optimal medium for SE. Histological observations showed that the bipolar somatic embryo originated from the epidermal cell layer and underwent initiation,globular, scutellar and coleoptile stages. During SE, endogenous hormones of IAA, CTK, ABA, and SA were highly accumulated. Transcriptomic analysis revealed the genes encoding auxin biosynthesis/metabolic enzymes and efflux carriers were induced, while the auxin receptor of TIR1 and ARF transcriptional repressor of Aux/IAA were down-regulated and up-regulated, respectively, leading to suppression of auxin signaling. In contrast, cytokine signaling was promoted at the early stage of SE, as biosynthesis, transport, and signaling components were up-regulated.Various stress-related genes were up-regulated at the early or late stages of SE. Chromatin remodeling could also be dynamically regulated via distinct expression enzymes that control histone methylation and acetylation during SE. Moreover, key SE regulators, including WOXs and SERKs were highly expressed along with SE. Overall, the present study provides insights into the SE regulatory mechanisms of the Hippeastrum.

方法与反方法——艺术史的诗学

21世纪需要什么样的艺术史?新一代艺术史家应该如何面对过去的艺术史研究方法,又应该如何实践新型艺术史研究?本文在回顾艺术史学史的同时,畅想艺术史学科的未来。文中的关键论题包括:过往艺术史研究方法的利与弊,近年新兴的全球艺术史、技术艺术史、地球艺术史等领域之间密不可分的关系,艺术史在复原历史记忆时所起到的不可或缺的作用,创新写作在未来学科发展中扮演的重要角色,以及数字技术对于艺术史研究的影响等。

生物炭吸附重金属的研究进展

生物炭是一种废弃物资源化利用的产物。作为新型环境功能材料,生物炭以其优良的环境效应和生态效应成为环境科学等学科研究的前沿热点。因其孔隙结构发达、比表面积巨大和独特的表面化学性质,对环境介质中的重金属离子有很强的吸附作用,进而影响了重金属离子的迁移与归宿。主要从生物炭的材料来源、吸附重金属离子的机制、影响因素以及对土壤中重金属生物有效性的影响等方面进行综述,并提出生物炭吸附重金属离子的未来研究方向。

汞污染对水稻土微生物和酶活性的影响

通过盆栽试验,研究了两种水稻土中不同汞处理的微生物学和酶学效应.结果表明:水稻收获后,除部分土壤的呼吸强度和代谢商随汞处理浓度的增加而持续增加外,不同浓度汞处理后土壤微生物量碳、呼吸强度、土壤脲酶、酸性磷酸酶和脱氢酶均表现为在低浓度汞处理(<2mgHg·kg-1)时升高,而在高浓度汞处理(≥2mgHg·kg-1)时则下降.土壤微生物商是对汞处理比较敏感的微生物学指标.黄红壤不同浓度汞处理的土壤酶活性大于小粉土.对重金属生态剂量ED50进行分析表明,汞对小粉土脲酶活性和黄红壤磷酸酶活性的生态毒性均较强.

青紫泥-水稻作物系统中汞污染的微生物学效应

选择长江三角洲地区代表性人为耕作土壤青紫泥为研究对象,通过网室盆栽试验研究了青紫泥-水稻作物系统中汞的微生物学效应。结果表明:水稻收获后,除土壤的代谢商随汞处理浓度的增加而增加外,不同汞处理后土壤微生物量碳、呼吸强度和微生物生物商均表现为在低浓度汞处理(≤1.5 mg/kg)时有促进作用,在高浓度汞处理(≥2 mg/kg)时则表现出抑制作用。综合来看,土壤微生物商是汞处理后比较敏感的微生物学指标。此外,种植水稻后,随处理水平的增加,与对照相比,青紫泥各汞处理土壤微生物群落的代谢剖面AWCD值均降低;青紫泥中各处理的AWCD值均随培养时间的增加而增强,且呈"S"型指数增长模式;青紫泥中各处理的Simpson指数和McIntosh指数均比对照低,其中Simpson指数和外加汞浓度之间存在显著的相关性,可作为反映青紫泥微生物群落结构受汞污染程度的有效指标。

稻菜轮作制下汞胁迫的土壤微生物学和酶学效应

通过盆栽试验研究了稻菜轮作下不同浓度汞污染对土壤微生物和酶活性的影响,从而为稻菜轮作体制下土壤重金属污染防治、诊断提供科学理论依据。结果表明:青菜收获后,不同浓度汞处理后土壤各微生物学指标和酶学指标均表现为在较低浓度汞处理(<2 mg/kg)时有促进作用,在较高浓度汞处理(≥2 mg/kg)时表现出抑制作用。综合比较,土壤代谢商是对汞处理比较敏感的微生物学指标。青紫泥不同浓度汞处理的土壤酶活性大于小粉土。脲酶是对土壤汞胁迫比较敏感的生化监测指标,且汞对小粉土脲酶和脱氢酶活性的生态毒性强于青紫泥。

水旱轮作下水稻土汞污染的微生物和酶活性比较研究

选择长江三角洲地区代表性人为耕作土壤小粉土和黄红壤为研究对象,通过网室盆栽试验研究了水旱轮作下小粉土和黄红壤汞污染的微生物和酶活性的变化。结果表明:收获水稻后和收获青菜后土壤微生物和酶活性变化的共同点是,随Hg处理浓度增加,土壤微生物量碳、呼吸强度、代谢商、土壤酶活性(脲酶、酸性磷酸酶、脱氢酶)均表现为先上升后下降,其峰值浓度因土壤类型、土壤酶类型和栽培作物种类不同而不同。收获水稻后和收获青菜后土壤微生物和酶活性变化的不同点是:土壤类型相同,除代谢商外,水稻收获后的土壤微生物量碳、土壤呼吸强度、土壤酶活性均高于青菜收获后的;栽培作物相同,除呼吸强度和代谢商外,黄红壤的土壤微生物量碳和土壤酶活性均高于小粉土的;与栽培作物类型无关,小粉土酶活性的变异系数明显大于黄红壤。

进化的特征--由可穿戴艺术展引发的思考

从首届国际可穿戴艺术展的主题"进化的特征"出发,梳理人类生活方式中穿戴行为的发展,辨析可穿戴艺术与服饰艺术、可穿戴技术等关联概念。从审美、与传统服饰文化的关联、材料特性三个方面探讨可穿戴艺术的当代属性,并对可穿戴艺术中呈现的艺术与科技融合的特征进行分析,最后提出对可穿戴艺术在未来不断进化发展的展望。

推剪式樱桃采摘器设计与试验

新鲜樱桃果实娇嫩,收获期短,并且要求带柄采摘。然而目前主要采用人工采摘方式,劳动强度大、作业危险且效率低,难以满足当前新鲜樱桃产业发展的要求。针对这一问题,仿照理发的原理,研制一款推剪式樱桃辅助采摘器,通过连续快速地推剪樱桃果柄,从而实现樱桃的快速带柄采摘。同时,还分析影响樱桃果柄剪切效果的因素,并通过果柄剪切对比试验,得出在静刀片齿距为3.5 mm,动刀片齿距为3.0 mm,动刀片行程为3.5 mm以及电机转速为7000 r/min时,采摘器的采摘效果最佳。果园试验表明,使用该装置辅助人工采摘樱桃,平均半小时内采摘樱桃9.7 kg以上,带柄合格率98%以上,损伤率1%以下,实现快速高效带柄采摘樱桃,并且不碰伤樱桃果实及果树,具有较好的参考与应用价值。

地域性特殊优势之“市场溢价”理论透视：由来、定位、实践与未来趋向

作为处于经济结构转型期的中国,其最新衍生出的地域性特殊优势因素下的市场溢价理论,对于BEPS计划及其传统转让定价规则的本土适用具有重要意义。一方面,因特殊的市场供求关系产生的市场溢价理论,在置于整个中国经济社会特殊发展历史记忆与主体诉求中加以考量,具有历时性;另一方面,将市场溢价视为可比因素,明晰税收与实质经济活动和价值创造相匹配的理念,用市场发展和市场转移理论呼唤国际税收规则的理性回归,具备可行性。继而,综合适用BEPS一揽子计划、系统优化征管制度并提升软实力,是当前解决市场溢价问题的重要基础;而在"一带一路"背景下以"税基重构与利润分享"理念升级BEPS方略,或将成为中国乃至全球国际税收发展的理想方向。

SPA护理中的音乐疗法

源起随着SPA护理在世界各地有如浪潮般席卷了所有的度假村、健康农场、健身俱乐部、高级会所…,以及规模大小不一的美容中心之后,有关如何充实扩展SPA护理项目的研究就成了健康美容业界最迫切的课题。但由于SPA护理的特质必须和「减压」、「排毒」、「净化」有关,因此从各民族,各领域里去寻找已经流传了许多世纪,而且又卓有成效的古老健康护理艺术,遂成为充实和发展SPA技术项目的重要方法。印度的古老养生哲学「艾邬薇达」,蕴涵中国医理智慧的「香穴疗法」、「太极」;以及撷取日本传统治病医学的「浪越指压」等等,都是在这样的情境和前提之下被发觉,并且在西方的健康养生领域中,以另一种形式被发扬光大的。随着古老东方的养生艺术被近乎崇拜式的介绍到西方之后,SPA研究者的心情和目光开始转向了虽然年资短浅,但却将养生护理艺术发挥得更精致化的欧洲贵族身上。

Genome resequencing and transcriptome profiling reveal structural diversity and expression patterns of constitutive disease resistance genes in Huanglongbing-tolerant Poncirus trifoliata and its hybrids

Huanglongbing(HLB)is the most destructive bacterial disease of citrus worldwide.While most citrus varieties are susceptible to HLB,Poncirus trifoliata,a close relative of Citrus,and some of its hybrids with Citrus are tolerant to HLB.No specific HLB tolerance genes have been identified in P.trifoliata but recent studies have shown that constitutive disease resistance(CDR)genes were expressed at much higher levels in HLB-tolerant Poncirus hybrids and the expression of CDR genes was modulated by Candidatus Liberibacter asiaticus(CLas),the pathogen of HLB.The current study was undertaken to mine and characterize the CDR gene family in Citrus and Poncirus and to understand its association with HLB tolerance in Poncirus.We identified 17 CDR genes in two citrus genomes,deduced their structures,and investigated their phylogenetic relationships.We revealed that the expansion of the CDR family in Citrus seems to be due to segmental and tandem duplication events.Through genome resequencing and transcriptome sequencing,we identified eight CDR genes in the Poncirus genome(PtCDR1-PtCDR8).The number of SNPs was the highest in PtCDR2 and the lowest in PtCDR7.Most of the deletion and insertion events were observed in the UTR regions of Citrus and Poncirus CDR genes.PtCDR2 and PtCDR8 were in abundance in the leaf transcriptomes of two HLB-tolerant Poncirus genotypes and were also upregulated in HLB-tolerant,Poncirus hybrids as revealed by real-time PCR analysis.These two CDR genes seem to be good candidate genes for future studies of their role in citrus-CLas interactions.

楚艺术几何纹样在当代服饰语境下的反思与重构

在国家大力倡导文化自信新时代背景下,为加强文化自信理论研究,建设社会主义文化强国,必须高度重视中华优秀传统文化的研究和再整理。楚文化作为中华传统文化的重要组成部分,是中国历史上极具特色的区域文化。而楚艺术作为楚文化视觉样式的展现,其器物的形制、纹样、色彩等元素具有独特的中华文化特征和历史底蕴。本文以楚艺术几何纹样为研究对象,重点探讨楚艺术中漆器、青铜器、丝织品中的几何纹样表现形式、运用规律、美学价值,以及在当代服饰设计中的重构新生。通过对传统几何纹样关键要素的系统性研究分析和元素的提取再构,将几何纹样元素的艺术性、文化性在当代服饰设计中应用实践。从传统元素中找到符合当代审美的创作路径,以求对传统文化的传承与创新,为中国当代服饰设计与理论研究,以及中华传统文化传播寻找更有价值的中国方案。

Clarifying sub-genomic positions of QTLs for flowering habit and fruit quality in U.S. strawberry (Fragaria×ananassa) breeding populations using pedigree-based QTL analysis

The cultivated strawberry(Fragaria×ananassa)is consumed worldwide for its flavor and nutritional benefits.Genetic analysis of commercially important traits in strawberry are important for the development of breeding methods and tools for this species.Although several quantitative trait loci(QTL)have been previously detected for fruit quality and flowering traits using low-density genetic maps,clarity on the sub-genomic locations of these QTLs was missing.Recent discoveries in allo-octoploid strawberry genomics led to the development of the IStraw90 single-nucleotide polymorphism(SNP)array,enabling high-density genetic maps and finer resolution QTL analysis.In this study,breeder-specified traits were evaluated in the Eastern(Michigan)and Western(Oregon)United States for a common set of breeding populations during 2 years.Several QTLs were validated for soluble solids content(SSC),fruit weight(FWT),pH and titratable acidity(TA)using a pedigree-based QTL analysis approach.For fruit quality,a QTL for SSC on linkage group(LG)6A,a QTL for FWT on LG 2BII,a QTL for pH on LG 4CII and two QTLs for TA on LGs 2A and 5B were detected.In addition,a large-effect QTL for flowering was detected at the distal end of LG 4A,coinciding with the FaPFRU locus.Marker haplotype analysis in the FaPFRU region indicated that the homozygous recessive genotype was highly predictive of seasonal flowering.SNP probes in the FaPFRU region may help facilitate marker-assisted selection for this trait.

Integration of early disease-resistance phenotyping, histological characterization, and transcriptome sequencing reveals insights into downy mildew resistance in impatiens

Downy mildew(DM),caused by obligate parasitic oomycetes,is a destructive disease for a wide range of crops worldwide.Recent outbreaks of impatiens downy mildew(IDM)in many countries have caused huge economic losses.A system to reveal plant–pathogen interactions in the early stage of infection and quickly assess resistance/susceptibility of plants to DM is desired.In this study,we established an early and rapid system to achieve these goals using impatiens as a model.Thirty-two cultivars of Impatiens walleriana and I.hawkeri were evaluated for their responses to IDM at cotyledon,first/second pair of true leaf,and mature plant stages.All I.walleriana cultivars were highly susceptible to IDM.While all I.hawkeri cultivars were resistant to IDM starting at the first true leaf stage,many(14/16)were susceptible to IDM at the cotyledon stage.Two cultivars showed resistance even at the cotyledon stage.Histological characterization showed that the resistance mechanism of the I.hawkeri cultivars resembles that in grapevine and type II resistance in sunflower.By integrating full-length transcriptome sequencing(Iso-Seq)and RNA-Seq,we constructed the first reference transcriptome for Impatiens comprised of 48,758 sequences with an N50 length of 2060 bp.Comparative transcriptome and qRT-PCR analyses revealed strong candidate genes for IDM resistance,including three resistance genes orthologous to the sunflower gene RGC203,a potential candidate associated with DM resistance.Our approach of integrating early disease-resistance phenotyping,histological characterization,and transcriptome analysis lay a solid foundation to improve DM resistance in impatiens and may provide a model for other crops.

Evolution of the MLO gene families in octoploid strawberry(Fragaria×ananassa)and progenitor diploid species identified potential genes for strawberry powdery mildew resistance

Powdery mildew(PM)caused by Podosphaera aphanis is a major fungal disease of cultivated strawberry.Mildew Resistance Locus O(MLO)is a gene family described for having conserved seven-transmembrane domains.Induced loss-of-function in specific MLO genes can confer durable and broad resistance against PM pathogens.However,the genomic structure and potential role of MLO genes for PM resistance have not been characterized yet in the octoploid cultivated strawberry.In the present study,MLO gene families were characterized in four diploid progenitor species(Fragaria vesca,F.iinumae,F.viridis,and F.nipponica)and octoploid cultivated(Fragaria×ananassa)strawberry,and potential sources of MLO-mediated susceptibility were identified.Twenty MLO sequences were identified in F.vesca and 68 identified in F.×ananassa.Phylogenetic analysis divided diploid and octoploid strawberry MLO genes into eight different clades,in which three FveMLO(MLO10,MLO17,and MLO20)and their twelve orthologs of FaMLO were grouped together with functionally characterized MLO genes conferring PM susceptibility.Copy number variations revealed differences in MLO composition among homoeologous chromosomes,supporting the distinct origin of each subgenome during the evolution of octoploid strawberry.Dissecting genomic sequence and structural variations in candidate FaMLO genes revealed their potential role associated with genetic controls and functionality in strawberry against PM pathogen.Furthermore,the gene expression profiling and RNAi silencing of putative FaMLO genes in response to the pathogen indicate the function in PM resistance.These results are a critical first step in understanding the function of strawberry MLO genes and will facilitate further genetic studies of PM resistance in cultivated strawberry.

A method for the production and expedient screening of CRISPR/Cas9-mediated non-transgenic mutant plants

Developing CRISPR/Cas9-mediated non-transgenic mutants in asexually propagated perennial crop plants is challenging but highly desirable.Here,we report a highly useful method using an Agrobacterium-mediated transient CRISPR/Cas9 gene expression system to create non-transgenic mutant plants without the need for sexual segregation.We have also developed a rapid,cost-effective,and high-throughput mutant screening protocol based on Illumina sequencing followed by high-resolution melting(HRM)analysis.Using tetraploid tobacco as a model species and the phytoene desaturase(PDS)gene as a target,we successfully created and expediently identified mutant plants,which were verified as tetra-allelic mutants.We produced pds mutant shoots at a rate of 47.5%from tobacco leaf explants,without the use of antibiotic selection.Among these pds plants,17.2%were confirmed to be non-transgenic,for an overall non-transgenic mutation rate of 8.2%.Our method is reliable and effective in creating non-transgenic mutant plants without the need to segregate out transgenes through sexual reproduction.This method should be applicable to many economically important,heterozygous,perennial crop species that are more difficult to regenerate.

Effect of Compost Amendment on Heavy Metals, Nitrogen and Phosphorus in a Peat-Based Container Medium

A laboratory study was conducted to evaluate the effect of compost amendment on mobility and leaching potential of heavy metals, nitrogen (N) and phosphorus (P) from a peat-based commercial container medium containing 700 g kg-1 peat, 200 g kg-1 perlite and 100 g kg-1 vermiculite at varying amendment rates of compost (0, 0.25, 0.50, 0.75 and 1.00 L L-1). Increasing compost amendment significantly and linearly increased the pH (P < 0.01), the total concentrations of organic carbon (P < 0.05), copper (Cu) (P < 0.01), cadmium (Cd) (P < 0.01), and lead (Pb) (P < 0.01), and increased the bulk density (P < 0.01) of the medium. The electrical conductivity (EC), and total N and P of the medium increased significantly (P < 0.01) and quadratically with increasing compost amendment. The relationship of the C/N ratio of the medium with the compost amendment rate was decreasing, significant (P < 0.01) and cubic, while that of the total Zn was increasing, significant (P < 0.01) and cubic. Extractable P, NO3-N, and NH4-N increased initially with an increasing compost amendment of up to 0.50 L L-1 and then decreased with further increasing compost rate. Increasing compost rates resulted in a highly significant (P < 0.01) and linear increase in total Cd, Cu, and Pb, and a highly significant (P < 0.01) and cubic increase in total Zn in the medium. Increasing compost rates also significantly (P < 0.01) increased extractable Cu (linearly) and Zn (quadratically), but significantly (P < 0.01) decreased extractable Pb (linearly). There was no significant effect of compost amendment on the extractable Cd concentration in the medium. However, with increasing compost rates from 0.25 to 1.00 L L-1, extractability of P, Cd, Cu, Pb and Zn (extractable concentration as a percent of total) was decreased, indicating that compost amendment could lower the leachability of these elements from the medium.

Breeding for FHB Resistance via Fusarium Damaged Kernels and Deoxynivalenol Accumulation as Well as Inoculation Methods in Winter Wheat

FHB is one of the most destructive diseases of wheat. Resistance testing depends strongly on inoculation methods, and on measured traits. Therefore a four-year (2009-2012) study was performed using spray inoculation + polyethylene (PE) bag cover, spray inoculation + mist irrigation, and spawn method supported by mist irrigation on 40 genotypes, 20 from Hungary and 20 from IFA Tulln, Austria. Each year four isolates were used in artificial inoculations except the spawn method where stalk debris served the inoculum. Visual Fusarium head blight (FHB) scores, Fusarium damaged kernels (FDK) and deoxynivalenol (DON) contamination were checked. 7680 FHB and FDK, as well as 3840 DON analyses served as the background for the statistical evaluation. The most reliable method used was the spray + polyethylene (PE) bag;the other two were significantly poorer being valid for all traits. The FHB scores were the least reliable, whereas the FDK was much more consequent and the DON gave the best results. The FDK gave much better predictions for DON contamination than FHB. The cultivars responses correlated well at different epidemic severities. The presence of the kernel resistance was confirmed and a new trait as extra kernel susceptibility was described. Presence of DON resistance was confirmed again, and extra DON susceptibility was described as a new trait. DON performance varied on the most sensitive cultivar between 0.32 and 143 mg/kg (mean 17.52 mg/kg) and on the most resistant genotype between 0.00 and 18.19 mg/kg (mean 1.87 mg/kg). Correlations between stability and resistance level are r = 0.85 for FHB, 0.78 for FDK, and 0.88 for DON, all at a significance level of p = 0.001. The very close correlation between FDK and DON contamination (r = 0.81, p = 0.001) proves that control of DON contamination needs appropriate resistance. In the breeding program evaluation of FDK is the most important, and then DON will be decided. Variety registration must be updated;otherwise no improvement on the field will occur.

用树脂砂生产出口阀门铸钢件

详细介绍了采用呋喃树脂砂生产出口阀门铸钢件的经验,同时对其常见铸造缺陷的产生原因进行了分析并提出了防范措施。