Establishment of a transformation system in close relatives of wheat under the assistance of TaWOX5

Species closely related to wheat are important genetic resources for agricultural production,functional genomics studies and wheat improvement.In this study,a wheat gene related to regeneration,TaWOX5,was applied to establish the Agrobacterium-mediated transformation systems of Triticum monococcum,hexaploid triticale,and rye(Secale cereale L.)using their immature embryos.Transgenic plants were efficiently generated.During the transformation process,the Agrobacterium infection efficiency was assessed by histochemical staining forβ-glucuronidase(GUS).Finally,the transgenic nature of regenerated plants was verified by polymerase chain reaction(PCR)-based genotyping for the presence of the GUS and bialaphos resistance(bar)genes,histochemical staining for GUS protein,and the QuickStix strip assay for bar protein.The transformation efficiency of T.monococcum genotype PI428182 was 94.4%;the efficiencies of four hexaploid triticale genotypes Lin456,ZS3297,ZS1257,and ZS3224 were 52.1,41.2,19.4,and 16.0%,respectively;and the transformation efficiency of rye cultivar Lanzhou Heimai was 7.8%.Fluorescence in situ hybridization(FISH)and genomic in situ hybridization(GISH)analyses indicated that the GUS transgenes were integrated into the distal or near centromere(proximal)regions of the chromosomes in transgenic T.monococcum and hexaploid triticale plants.In the transgenic hexaploid triticale plants,the foreign DNA fragment was randomly integrated into the AABB and RR genomes.Furthermore,the transgene was almost stably inherited in the next generation by Mendel’s law.The findings in this study will promote the genetic improvement of the three plant species for grain or forage production and the improvement of cereal species including wheat for functional genomics studies.

硅基Ⅲ-Ⅴ族量子点激光器的发展现状和前景

本文简要综述了硅基Ⅲ-Ⅴ族量子点激光器的研究进展.在介绍了量子点激光器的优势和发展后,重点介绍了近年来硅基、锗基Ⅲ-Ⅴ族量子点材料生长上的突破性进展及所带来的器件性能的大幅提高,如实现了锗基和硅基1.3μm InAs/GaAs量子点激光器的室温激射,锗基量子点激光器的阈值电流低至55.2 A/cm^2并可达60℃以上的连续激射,通过锗硅虚拟衬底,在硅基上实现了30℃下以16.6 mW的输出功率达到4600 h的激光寿命,这些突破性的进展为硅基光电子集成打开了新的大门.

植物单倍体诱导技术发展与创新

单倍体育种是培育作物新品种的主要育种技术之一,提高单倍体诱导频率和简化诱导程序是单倍体育种技术的关键。随着单倍体诱导技术的发展与改进,单倍体育种技术已被广泛应用于许多重要植物的育种研究中,展现出基因纯合快速、育种年限缩短、育种效率提高等优势。单倍体诱导技术与杂交育种、诱变育种、反向育种和分子标记辅助选择育种等技术相结合,在作物品种改良上的作用更加显著。单倍体和双单倍体在遗传群体构建、基因功能鉴定、转基因研究、细胞学研究等方面具有重要应用价值。本文从单倍体诱导技术、单倍体和双单倍体应用等方面综述了植物单倍体诱导技术的发展,尤其是近年来利用基因组编辑技术创制主要作物单倍体诱导系的进展,并分析了目前研究中存在的问题和今后的发展方向,以期促进单倍体诱导技术尤其是利用基因编辑创造诱导系技术在作物育种中的应用。

Recent progress in epitaxial growth of Ⅲ–Ⅴ quantum-dot lasers on silicon substrate

In the past few decades,numerous high-performance silicon(Si)photonic devices have been demonstrated.Si,as a photonic platform,has received renewed interest in recent years.Efficient Si-basedⅢ–Ⅴquantum-dot(QDs)lasers have long been a goal for semiconductor scientists because of the incomparable optical properties of Ⅲ–Ⅴcompounds.Although the material dissimilarity betweenⅢ–Ⅴmaterial and Si hindered the development of monolithic integrations for over 30 years,considerable breakthroughs happened in the 2000s.In this paper,we review recent progress in the epitaxial growth of various Ⅲ–ⅤQD lasers on both offcut Si substrate and on-axis Si(001)substrate.In addition,the fundamental challenges in monolithic growth will be explained together with the superior characteristics of QDs.

Spatially Bandgap-Graded Mo S2（1-x）Se2x Homojunctions for Self-Powered Visible–Near-Infrared Phototransistors

Ternary transition metal dichalcogenide alloys with spatially graded bandgaps are an emerging class of two-dimensional materials with unique features,which opens up new potential for device applications.Here,visible–near-infrared and self-powered phototransistors based on spatially bandgap-graded MoS2(1−x)Se2x alloys,synthesized by a simple and controllable chemical solution deposition method,are reported.The graded bandgaps,arising from the spatial grading of Se composition and thickness within a single domain,are tuned from 1.83 to 1.73 eV,leading to the formation of a homojunction with a builtin electric field.Consequently,a strong and sensitive gate-modulated photovoltaic effect is demonstrated,enabling the homojunction phototransistors at zero bias to deliver a photoresponsivity of 311 mA W−1,a specific detectivity up to^10^11 Jones,and an on/off ratio up to^10^4.Remarkably,when illuminated by the lights ranging from 405 to 808 nm,the biased devices yield a champion photoresponsivity of 191.5 A W−1,a specific detectivity up to^1012 Jones,a photoconductive gain of 10^6–10^7,and a photoresponsive time in the order of^50 ms.These results provide a simple and competitive solution to the bandgap engineering of two-dimensional materials for device applications without the need for p–n junctions.

Ⅲ–Ⅴ ternary nanowires on Si substrates: growth, characterization and device applications

Over the past decades, the progress in the growth of materials which can be applied to cutting-edge technologies in the field of electronics, optoelectronics and energy harvesting has been remarkable. Among the various materials, group Ⅲ–Ⅴ semiconductors are of particular interest and have been widely investigated due to their excellent optical properties and high carrier mobility. However, the integration of Ⅲ–Ⅴ structures as light sources and numerous other optical components on Si,which is the foundation for most optoelectronic and electronic integrated circuits, has been hindered by the large lattice mismatch between these compounds. This mismatch results in substantial amounts of strain and degradation of the performance of the devices. Nanowires(NWs) are unique nanostructures that induce elastic strain relaxation, allowing for the monolithic integration of Ⅲ–Ⅴ semiconductors on the cheap and mature Si platform. A technique that ensures flexibility and freedom in the design of NW structures is the growth of ternary Ⅲ–Ⅴ NWs, which offer a tuneable frame of optical characteristics, merely by adjusting their nominal composition. In this review, we will focus on the recent progress in the growth of ternary Ⅲ–Ⅴ NWs on Si substrates. After analysing the growth mechanisms that are being employed and describing the effect of strain in the NW growth, we will thoroughly inspect the available literature and present the growth methods, characterization and optical measurements of each of the Ⅲ–Ⅴ ternary alloys that have been demonstrated. The different properties and special treatments required for each of these material platforms are also discussed. Moreover, we will present the results from the works on device fabrication, including lasers, solar cells, water splitting devices, photodetectors and FETs, where ternary Ⅲ–Ⅴ NWs were used as building blocks. Through the current paper, we exhibit the up-to-date state in this field of research and summarize the important accomplishments of the past few years.

Preface to the Special Topic on Compound Semiconductor Materials and Devices on Si

The research in silicon photonics has been booming due to its potential for lowcost,reliable,energy-efficient and high-density chip-wise integration using widely available CMOS technology,featuring the tremendous success in modulator,detector and other passive waveguide components in industry.However,the absence of efficient and reliable electrical to optical converter on Si platform has been considered as“the last piece of the puzzle”,hindered by the in-direct bandgap property of Si bulk materials.CompoundⅢ–Ⅴsemiconductor devices offer highly efficient optical light emitting sources and optical amplifiers,hence the compound semiconductor materials and devices on Si platform are drawing more and more attention nowadays as it could make possible the long-dreamed light sources on Si substrates by combining their advantages with silicon ICs,enabling the fabrication of full functional optoelectronic circuits,chip-to-chip and even system-to-system optical chips.

Application of UPLC-QTOF-MS Technology in Quality Stability Evaluation of Moluodan Concentrated Pills

[Objectives]To use liquid chromatography-mass spectrometry technology to analyze the chemical composition of traditional Chinese medicine and explore its application in the evaluation of quality stability of traditional Chinese medicine.[Methods]Ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-QTOF-MS)was used to detect the samples of Moluodan concentrated pills.By comparing and analyzing the detection results of 10 different batches of Moluodan concentrated pills,combined with principal component analysis(PCA),the quality stability of Moluodan concentrated pills was evaluated.[Results]A total of 367 chemical components were identified in Moluodan concentrated pills.The average repetition rate of the chemical components contained in the 10 different batches of samples reached 92%.The overall quality stability of the Moluodan concentrated pills was good.[Conclusions]The UPLC-QTOF-MS technology combined with PCA provides a reference for the overall quality evaluation of Moluodan concentrated pills,and provides new detection methods and ideas for the analysis of the components of Chinese medicine.

High-power,electrically-driven continuous-wave 1.55-μm Si-based multi-quantum well lasers with a wide operating temperature range grown on wafer-scale InP-on-Si(100)heterogeneous substrate

A reliable,efficient and electrically-pumped Si-based laser is considered as the main challenge to achieve the integration of all key building blocks with silicon photonics.Despite the impressive advances that have been made in developing 1.3-μm Si-based quantum dot(QD)lasers,extending the wavelength window to the widely used 1.55-μm telecommunication region remains difficult.In this study,we develop a novel photonic integration method of epitaxial growth of III-V on a wafer-scale InP-on-Si(100)(InPOS)heterogeneous substrate fabricated by the ion-cutting technique to realize integrated lasers on Si substrate.This ion-cutting plus epitaxial growth approach decouples the correlated root causes of many detrimental dislocations during heteroepitaxial growth,namely lattice and domain mismatches.Using this approach,we achieved state-of-the-art performance of the electrically-pumped,continuouswave(CW)1.55-μm Si-based laser with a room-temperature threshold current density of 0.65 kA/cm^(-2),and output power exceeding 155mW per facet without facet coating in CW mode.CW lasing at 120℃ and pulsed lasing at over 130℃ were achieved.This generic approach is also applied to other material systems to provide better performance and more functionalities for photonics and microelectronics.

CRISPR/CasΦ2-mediated gene editing in wheat and rye

The recent advancements in developing the CRISPR/Cas9 system and various derivative tools(e.g.,base editors)have accelerated basic plant science research and crop improvement by creating multiple types of genetic variations(Li et al.,2023a).

Room-temperature continuous-wave topological Dirac-vortex microcavity lasers on silicon

Robust laser sources are a fundamental building block for contemporary information technologies.Originating from condensed-matter physics,the concept of topology has recently entered the realm of optics,offering fundamentally new design principles for lasers with enhanced robustness.In analogy to the well-known Majorana fermions in topological superconductors,Dirac-vortex states have recently been investigated in passive photonic systems and are now considered as a promising candidate for robust lasers.Here,we experimentally realize the topological Diracvortex microcavity lasers in InAs/InGaAs quantum-dot materials monolithically grown on a silicon substrate.We observe room-temperature continuous-wave linearly polarized vertical laser emission at a telecom wavelength.We confirm that the wavelength of the Dirac-vortex laser is topologically robust against variations in the cavity size,and its free spectral range defies the universal inverse scaling law with the cavity size.These lasers will play an important role in CMOS-compatible photonic and optoelectronic systems on a chip.

From past to future:on-chip laser sources for photonic integrated circuits

The realisation of on-chip light sources paves the way towards the full integration of Si-based photonic integrated circuits(PICs).

CRISPR/Cas9 editing of wheat TaQ genes alters spike morphogenesis and grain threshability

The Ta Q alleles as one of the AP2-like transcription factors in common wheat(Triticum aestivum) play an important role in the evolution of spike characteristics from wild and domesticated emmer to modern wheat cultivars. Its loss-of-function mutant not only changed threshability and spike architecture but also affected plant height, flowering time, and floret structure. However, the comprehensive functions of Ta AQ and Ta Dq genes in wheat have not been fully elucidated yet. Here, CRISPR/Sp Cas9 was used to edit wheat Ta AQ and Ta Dq. We obtained homozygous plants in the T1 generation with loss of function of only Ta AQ or Ta Dq and simultaneous loss of function of Ta AQ and Ta Dq to analyze the effect of these genes on wheat spikes and floret shapes. The results demonstrated that the Ta AQ-edited plants and the Ta AQ and Ta Dq simultaneously-edited plants were nearly similar in spike architecture, whereas the Ta Dq-edited plants were different from the wild-type ones only in plant height. Moreover, the Ta AQ-edited plants or the Ta AQ and Ta Dq simultaneously-edited plants were more brittle than the wild-type and the Ta Dqedited plants. Based on the expression profiling, we postulated that the VRN1, FUL2, SEP2, SEP5, and SEP6 genes might affect the number of spikelets and florets per spike in wheat by regulating the expression of Ta Q. Combining the results of this report and previous reports, we conceived a regulatory network of wheat traits, including plant height, spike shape, and floral organs, which were influenced by AP2-like family genes. The results achieved in this study will help us to understand the regulating mechanisms of Ta AQ and Ta Dq alleles on wheat floral organs and inflorescence development.

Low-noise 1.3 μm InAs/GaAs quantum dot laser monolithically grown on silicon

We report low-noise, high-performance single transverse mode 1.3 μm InAs/GaAs quantum dot lasers monolithically grown on silicon(Si) using molecular beam epitaxy. The fabricated narrow-ridge-waveguide Fabry–Perot(FP) lasers have achieved a room-temperature continuous-wave(CW) threshold current of 12.5 mA and high CW temperature tolerance up to 90°C. An ultra-low relative intensity noise of less than-150 dB∕Hz is measured in the 4–16 GHz range. Using this low-noise Si-based laser, we then demonstrate 25.6 Gb/s data transmission over13.5 km SMF-28. These low-cost FP laser devices are promising candidates to provide cost-effective solutions for use in uncooled Si photonics transmitters in inter/hyper data centers and metropolitan data links.

Multifunctional two-dimensional glassy graphene devices for vis-NIR photodetection and volatile organic compound sensing

Multifunctional devices are of great interest for integration and miniaturization on the same platform, but simple addition of functionalities would lead to excessively large devices. Here, the photodetection and chemical sensing device is developed based on two-dimensional(2D) glassygraphene that meets similar property requirements for the two functionalities. An appropriate bandgap arising from the distorted lattice structure enables glassy graphene to exhibit comparable or even improved photodetection and chemical sensing capability, compared with pristine graphene. Due to strong interactions between glassy graphene and the ambient atmosphere, the devices are less sensitive to photoinduced desorption than the ones based on graphene. Consequently,the few-layer glassy graphene device delivers positive photoresponse, with a responsivity of 0.22 A W^(-1) and specific detectivity reaching ~10^(10) Jones under 405 nm illumination.Moreover, the intrinsic defects and strain in glassy graphene can enhance the adsorption of analytes, leading to high chemical sensing performance. Specifically, the extracted signalto-noise-ratio of the glassy graphene device for detecting acetone is 48, representing more than 50% improvement over the device based on graphene. Additionally, bias-voltage-and thickness-dependent volatile organic compound(VOC) sensing features are identified, indicating the few-layer glassy graphene is more sensitive. This study successfully demonstrates the potential of glassy graphene for integrated photodetection and chemical sensing, providing a promising solution for multifunctional applications further beyond.

1.3 μm InAs/GaAs quantum dot lasers on silicon with GaInP upper cladding layers

We report on the first electrically pumped continuous-wave(CW) In As/Ga As quantum dot(QD) laser grown on Si with a GaInP upper cladding layer. A QD laser structure with a Ga_(0.51)In_(0.49)P upper cladding layer and an Al_(0.53)Ga_(0.47)As lower cladding layer was directly grown on Si by metal–organic chemical vapor deposition. It demonstrates the postgrowth annealing effect on the QDs was relieved enough with the GaInP upper cladding layer grown at a low temperature of 550°C. Broad-stripe edge-emitting lasers with 2-mm cavity length and 15-μm stripe width were fabricated and characterized. Under CW operation, room-temperature lasing at ~1.3 μm has been achieved with a threshold density of 737 A∕cm^2 and a single-facet output power of 21.8 mW.

Highly integrated photonic crystal bandedge lasers monolithically grown on Si substrates

Monolithic integration of Ⅲ-Ⅴ lasers with small footprint, good coherence, and low power consumption based on a CMOS-compatible Si substrate have been known as an efficient route towards high-density optical interconnects in the photonic integrated circuits. However, the material dissimilarities between Si and Ⅲ-Ⅴ materials limit the performance of monolithic microlasers. Here, under the pumping condition of a continuous-wave 632.8 nm He–Ne gas laser at room temperature, we achieved an InAs/GaAs quantum dot photonic crystal bandedge laser, which is directly grown on an on-axis Si(001) substrate, which provides a feasible route towards a low-cost and large-scale integration method for light sources on the Si platform.

Quantum dot mode-locked frequency comb with ultra-stable 25.5 GHz spacing between 20℃ and 120℃

Semiconductor mode-locked lasers(MLLs)are promising frequency comb sources for dense wavelength-divisionmultiplexing(DWDM)data communications.Practical data communication requires a frequency-stable comb source in a temperature-varying environment and a minimum tone spacing of 25 GHz to support high-speed DWDM transmissions.To the best of our knowledge,however,to date,there have been no demonstrations of comb sources that simultaneously offer a high repetition rate and stable mode spacing over an ultrawide temperature range.Here,we report a frequency comb source based on a quantum dot(QD)MLL that generates a frequency comb with stable mode spacing over an ultrabroad temperature range of 20–120℃.The two-section passively mode-locked In As QD MLL comb source produces an ultra-stable fundamental repetition rate of 25.5 GHz(corresponding to a 25.5 GHz spacing between adjacent tones in the frequency domain)with a variation of 0.07 GHz in the tone spacing over the tested temperature range.By keeping the saturable absorber reversely biased at-2 V,stable mode-locking over the whole temperature range can be achieved by tuning the current of the gain section only,providing easy control of the device.At an elevated temperature of 100℃,the device shows a 6 d B comb bandwidth of 4.81 nm and 31 tones with>36 d B optical signal-to-noise ratio.The corresponding relative intensity noise,averaged between 0.5 GHz and 10 GHz,is-146 d Bc∕Hz.Our results show the viability of the In As QD MLLs as ultra-stable,uncooled frequency comb sources for low-cost,large-bandwidth,and low-energy-consumption optical data communications.

Multiple radial phosphorus segregations in GaAsP core-shell nanowires

Highly faceted geometries such as nanowires are prone toform self-formed features,especially those that are driven by segregation.Understanding these features is important in preventing their formation,understanding their effects on nanowire properties,or engineering them for applications.Single elemental segregation lines that run along the radii of the hexagonal cross-section have been a common observation in alloy semiconductor nanowires.Here,in GaAsP nanowires,two additional P rich bands are formed on either side of the primary band,resulting in a total of three segregation bands in the vicinity of three of the alternating radii.These bands are less intense than the primary band and their formation can be attributed to the inclined nanofacets that form in the vicinity of the vertices.The formation of the secondary bands requires a higher composition of P in the shell,and to be grown under conditions that increase the diffusivity difference between As and P.Furthermore,it is observed that the primary band can split into two narrow and parallel bands.This can take place in all six radii,making the cross sections to have up to a maximum of 18 radial segregation bands.With controlled growth,these features could be exploited to assemble multiple different quantum structures in a new dimension(circumferential direction)within nanowires.

Heterostructure and Q-factor engineering for low-threshold and persistent nanowire lasing

Continuous room temperature nanowire lasing from silicon-integrated optoelectronic elements requires careful optimisation of both the lasing cavity Q-factor and population inversion conditions.We apply time-gated optical interferometry to the lasing emission from high-quality GaAsP/GaAs quantum well nanowire laser structures,revealing high Q-factors of 1250±90 corresponding to end-facet reflectivities of R=0.73±0.02.By using optimised direct-indirect band alignment in the active region,we demonstrate a well-refilling mechanism providing a quasifour-level system leading to multi-nanosecond lasing and record low room temperature lasing thresholds(~6μJ cm^(−2) pulse−1)for Ⅲ-Ⅴ nanowire lasers.Our findings demonstrate a highly promising new route towards continuously operating silicon-integrated nanolaser elements.