Effects of Three Nitrification Inhibitors on the Nitrogen Conversion in Purple Soil and Its Effect on the Nitrogen Uptake of Citrus Seedlings

Experiments were carried out to study the effects of nitrification inhibitors (NI) on the transformation of soil nitrogen (N) in purple soil and the effects on the N accumulation in different organs of citrus seedlings. In incubation and pot experiments, the rate of nitrification inhibitors 2-chloro-6-trichloro-methyl pyridine (Nitrapyrin), 3,4-dimethylpyrazole phosphate (DMPP) and dicyandiamide (DCD) was 2.4%, 1.0% and 5.0% of N rate, respectively. The trend of different nitrification inhibitors on ammonium nitrogen ( NH+4-N ), nitrate nitrogen ( NO-3-N ) content and pH was compared in incubation experiment;and the effect of different NI on the dry matter quality, N uptake of citrus seedling was studied in pot experiment. The results showed that NI could significantly inhibit soil nitrification in the early culture period (p DMPP > En (calculated as nitrogen application rate). Application of NI increased the height and dry matter accumulation, N accumulation of citrus seedling grown in pot experiment. Thus, application of NI would be helpful for improving N use efficiency in purple soil which is one of major soil types for citrus production in China.

分析化学教学中的课程思政设计与探索

分析化学学科发展迅速,知识体系庞大繁杂,与众多学科相互交错,密切关联,课程教学难度大。在课堂教学过程中,教师应根据课程特点和教学内容,精心挖掘关于教学内容的思政教育元素,巧妙还原教学内容涉及知识点的产生和发展过程,还原科学成果、技术的认知发现过程,教育学生从学科的动态历史发展中体会到如何做学问、如何做人。本文根据分析化学教材章节内容模块,介绍了分析化学教学过程中课程思政的设计与探索,以期为分析化学课程思政教育提供有益参考。

Genome resources for the elite bread wheat cultivar Aikang 58 and mining of elite homeologous haplotypes for accelerating wheat improvement

Despite recent progress in crop genomics studies,the genomic changes brought about by modern breeding selection are still poorly understood,thus hampering genomics-assisted breeding,especially in polyploid crops with compound genomes such as common wheat(Triticum aestivum).In this work,we constructed genome resources for the modern elite common wheat variety Aikang 58(AK58).Comparative genomics between AK58 and the landrace cultivar Chinese Spring(CS)shed light on genomic changes that occurred through recent varietal improvement.We also explored subgenome diploidization and divergence in common wheat and developed a homoeologous locus-based genome-wide association study(HGWAS)approach,which was more effective than single homoeolog-based GWAS in unraveling agronomic trait-associated loci.A total of 123 major HGWAs loci were detected using a genetic population derived from AK58 and cs.Elite homoeologous haplotypes(HHs),formed by combinations of subgenomic homoeologs of the associated loci,were found in both parents and progeny,and many could substantially improve wheat yield and related traits.We built a website where users can download genome assembly sequence and annotation data for AK58,perform blast analysis,and run JBrowse.Our work enriches genome resources for wheat,provides new insights into genomic changes during modern wheat improve-.ment,and suggests that efficientmining of elite HHs can make a substantial contribuutionto genomics-assisted breeding in common wheat and other polyploid crops.

Genome sequencing of Sitopsis species provides insights into their contribution to the B subgenome of bread wheat

Wheat(Triticum aestivum,BBAADD)is an allohexaploid species that originated from two polyploidization events.The progenitors of the A and D subgenomes have been identified as Triticum urartu and Aegilops tauschii,respectively.Current research suggests that Aegilops speltoides is the closest but not the direct ancestor of the B subgenome.However,whether Ae.speltoides has contributed genomically to the wheat B subgenome and which chromosome regions are conserved between Ae.speltoides and the B subgenome remain unclear.Here,we assembled a high-quality reference genome for Ae.speltoides,resequenced 53 accessions from seven species(Aegilops bicornis,Aegilops longissima,Aegilops searsii,Aegilops sharonensis,Ae.speltoides,Aegilops mutica[syn.Amblyopyrum muticum],and Triticumdicoccoides)and revealed their genomic contributions to the wheat B subgenome.Our results showed that centromeric regions were particularly conserved between Aegilops and Triticum and revealed 0.17 Gb of conserved blocks between Ae.speltoides and the B subgenome.We classified five groups of conserved and non-conserved genes between Aegilops and Triticum,revealing their biological characteristics,differentiation in gene expression patterns,and collinear relationships between Ae.speltoides and the wheat B subgenome.We also identified gene families that expanded in Ae.speltoides during its evolution and 789 genes specific to Ae.speltoides.These genes can serve as genetic resources for improvement of adaptability to biotic and abiotic stress.The newly constructed reference genome and large-scale resequencing data for Sitopsis species will provide a valuable genomic resource for wheat genetic improvement and genomic studies.

GSK3 regulates VRN1 to control flowering time in wheat

The precise control of flowering time is important for the regional adaptability and productivity of many crops.Various categories of genes related to flowering have been isolated and characterized functionally in wheat(Triticum aestivum) in response to vernalization to adjust flowering initiation. Before vernalization, the inhibitory histone modification H3K27me3 is enriched in the promoter and the first intron of the vernalization gene VRN1.

WheatGmap:a comprehensive platform for wheat gene mapping and genomic studies

Bulked segregant analysis(BSA)is an efficient and low-cost strategy that is widely used to identify causal genes in segregating populations.BSA-based methods,such as BSA sequencing(Wenger et al.,2010),bulked segregant RNA sequencing(BSR-seq)(del Viso et al.,2012),and MutMap(Abe et al.,2012),are powerful tools that can be used for rapidly discovering genetic markers and gene mapping.Although BSA is increasingly being used in wheat(Triticum aestivum)gene mapping efforts,few user-friendly BSA tools have been developed for researchers lacking a strong bioinformatics background.Here,we developed the web-based BSA platform WheatGmap(https://www.wheatgmap.org),which integrates multiple BSA mapping models and large amounts of public data to accelerate gene cloning and functional research and facilitate resource sharing.

Ion-exchange polymers modified bacterial cellulose electrodes for the selective removal of nitrite ions from tail water of dyeing wastewater

Ion-exchange polymer and modified carbonization bacterial cellulose(CBC)electrodes were fabricated using varying amounts of cation-exchange polymers(glutaric acid(GA)and sulfosuccinic acid(SSA))and assembled within an asymmetric capacitive deionization unit(p-CDI).The performance of selective NO2-electro-adsorption was studied.The AC/CBCSSA group showed a better salt adsorption capacity(14.56 mg/g)and nitrite removal efficiency(71.01%)than the AC/CBC-GA(10.72 mg/g,47.83%)and AC/AC(4.81 mg/g,12.74%)groups.It was confirmed that the CBC-SSA/GA electrodes enhanced nitrite selectivity and increased the adsorption capacity,and the total amounts of adsorbed anions increased when the applied voltage was increased from 0.8 to 1.2 V,while the molar fraction of nitrate decreased.The competitive and preferential adsorption of anions was further investigated using different binary solutions of anions and occurred in the following sequence:NO2->SO42->NO3->F-≈Cl-.Furthermore,the p-CDI units were applied to remove nitrite in real wastewater samples,and the results showed that they had excellent reusability and application for use in dyeing wastewater treatment.

Nitrogen-enriched micro-mesoporous carbon derived from polymers organic frameworks for high-performance capacitive deionization

Nitrogenization is an effective method for improving the capacitive deionization(CDI)performance of porous carbon materials.In particular,polymer organic frameworks with heteroatom doping,containing an ordered pore structure and excellent electrochemical stability,are ideal precursors for carbon materials for high-performance CDI.In this study,a nitrogen-enriched micro-mesoporous carbon(NMC)electrode was fabricated by carbonizing a Schiff base network-1 at 500,600,and 700℃.Scanning electron microscopy,Fourier transform infrared spectroscopy,X-ray diffraction,N_(2) adsorption-desorption,the contact angle of water,cyclic voltammetry,and electrochemical impedance spectroscopy were used to characterize the morphological structure,wettability,Brunauer–Emmett–Teller surface areas,and electrochemical performance of the NMCs.The results showed that the NMC carbonized at 600℃ achieved the best specific capacitance(152.33 F/g),as well as a high electrosorption capacity(25.53 mg/g)because of its chemical composition(15.57%N)and surface area(312 m^(2)/g).These findings prove that NMC is viable as an electrode material for desalination by high-performance CDI applications.