Genome-wide association study exposed the pleiotropic genes for yield-related and oil quality traits in Brassica napus L.

Oilseed rape(Brassica napus L.) is an allotetraploid(AACC,2n=38) crop,valued for its edible oil and protein content.seed yield and nutritional composition of rapeseed are influenced by its yield and oil quality traits.However,the genetic basis of yield-related and oil-quality traits remain ambiguous.A panel of 266 diversified oilseed rape accessions was genotyped using 223 simple sequence repeat(SSR) markers covering all 19 chromosomes to identify significant markers associated with yield and quality traits.Twelve yield-related and six quality traits were investigated in two consecutive years(2014 and 2015),with three replications in two environments(Changshun,CS;and Qinghe,QH).Using the model GLM with population structure and kinship(Q+K),a total of 25 significant SSR markers(P <0.001) were detected to be associated with these twelve yield-related and six quality traits,explaining 4.56%-19.17% of the phenotypic variation for each trait.Based on these markers,BnaA03g23490D, BnaC09g46370D,BnaA07g37150D,BnaA01g32590D, and BnaC09g37280D were identified as pleiotropic genes controlling multiple traits.These candidate genes illustrated the potential for the genetic understanding of yield and oil quality traits.Most importantly,these significant markers can be used for marker-assisted breeding of oilseed rape in different environments.

Large scale identification of SSR marker in perilla by next generation sequencing

Perilla frutescens (L.) is an edible, medicinal crop, and most popular in East Asia. Its molecular breeding and research are hampered by the paucity of molecular markers. Simple sequence repeat (SSR) markers are ubiquitous and widely used in eukaryotic genomes. EST-SSRs identification of perilla was performed in 116,387 reads generated by Illumina paired-end sequencing technology. In total 25,449 unigenes containing SSR and 33,867 SSR loci were identified, and 19,400 primer pairs were designed. Polymorphism of SSR primers was conducted by searching for insertions and deletions (INDELs), and 1,567 unique SSRs were predicted. Totally, 200 SSR primer pairs were selected for polymorphic validation among 23 perilla accessions. Results showed that 175 primer pairs produced amplicons, and 30 pairs exhibited polymorphism. Polymorphic ratio was higher by using INDEL method than using conventional primers. Phylogenetic analysis showed the 2 distinct groups: P. frutescens var. frutescens and P. frutescens var. crispa. Wrinkled leaf trait and seed trait were distinct between these 2 groups. However, no clear leaf color or geographic relationship was detected. The large scale development and identification of SSR marker in this research laid a foundation for genetic analysis and marker assisted breeding of cultivated perilla.

Synthesis and Characterization of Fine Grained High Density La_2Mo_2O_9-based Oxide-ion Conductors

A cost-efFective technique, including nanocrystalline powder preparation using a modified Pechini method and a two-step low-temperature sintering route, was developed for the synthesis of high performance La2Mo2O9- based oxide-ion conductors. The optimum parameters of the compaction pressure, the first step and ＇the second step sintering temperatures for the synthesis of fine grained, high density and uniform La2Mo2O9- based oxide-ion conductors were determined by a series of sintering experiments. High density and uniform sintered La2Mo2O9 samples with average grain size from 0.8 to 5 μm and La1.96K0.04Mo2O8.96 sample with average grain size as small as 500 nm were synthesized by using this cost-efFective method. The impedance measurement results show that the as-fabricated La2Mo2O9-based ceramics possess much higher ionic conductivity than that obtained by solid state reaction method. It is found that in the range of 0.8-5μm the grain size of dense La2Mo2O9 samples prepared from the nanocrystalline powders has little influence on their conductivities.

Low-threshold bistable reflection assisted by oscillating wave interaction with Kerr nonlinear medium

Owing to the enormously enhanced oscillating wave,a minute variation of the incident light intensity will give rise to a change in the dielectric constant of the Kerr nonlinear medium and lead to a bistable reflection with an ultra-low threshold intensity,which is closely related to the angle of incidence and the thickness of the Kerr nonlinear medium.The criterion for the existence of optical bistability is derived.Our bistability scheme is simple and not limited to the TM-polarization.

Microstructural evolution and thermal fatigue damage mechanism of second-phase dispersion strengthened tungsten composites under repetitive thermal loads

In a fusion reactor,plasma-facing tungsten(W)materials inevitably suffer severe thermal shock,and the performance of W materials under repetitive high heat loads is one of the key concerns for long-term stable operation of the reactor.In this work,the microstructural evolution and thermal fatigue resistance of two representative W-0.5 wt.%ZrC(WZC)and W-1.0 wt.% Y_(2)O_(3)(WYO)composites were investigated under cyclic heat loads.Due to the intrinsic properties of ZrC and Y_(2)O_(3)particles such as coefficients of thermal expansion,particle size and distributions in W grains,the WZC composite exhibited a better thermal shock resistance than WYO.After thermal loads with the absorbed power density(APD)≥22 MW/m^(2),WYO showed obvious grain growth,Y_(2)O_(3)particles shedding and degradation of mechanical properties.While,in the case of WZC,these damage behaviors only occurred when APD≥25 MW/m^(2).Furthermore,an interesting crack mechanism in W composites was revealed due to interface debonding and progressive shedding of second-phase particles from the W matrix.The microstructures and tensile properties of the thermally loaded WZC and WYO specimens were also investigated and the correlations between the microstructure evolution and performance degradation are demonstrated.The results are useful for evaluating the thermal fatigue resistance of oxide/carbide dispersion strengthened W composites and their application in future fusion reactors.

Systematic analysis of artificial intelligence in the era of industry 4.0

Artificial Intelligence has been playing a profound role in the global economy,social progress,and people’s daily life.With the increasing capabilities and accuracy of AI,the application of AI will have more impacts on manufacturing and service areas in the era of industry 4.0.This study conducts a systematic literature review to study the state-of-the-art on AI in industry 4.0.This paper describes the development of industries and the evolution of AI.This paper also identifies that the development and application of AI will bring not only opportunities but also challenges to industry 4.0.The findings provide a valuable reference for researchers and practitioners through a multi-angle systematic analysis of AI.In the era of industry 4.0,AI system will become an innovative and revolutionary assistance to the whole industry.

Chromosome engineering of pollen wheat

Chromosome engineering of pollen wheat is the new procedure combining anther culture and chromosome engineering techniques. It could transfer useful alien genes into wheat varieties, enhancing genetic diversity for investigation of genetics and breeding. In the present study, two new procedures, at genome level and single chromosome level, were established.Compared with the classical chromosome engineering, the chromosome engineering of pollen wheat has the following main characters: ( ⅰ ) diversity of products, ( ⅱ ) rapid stability and (ⅲ) high efficiency of selection. Experiments indicated that chromosome engineering of pollen wheat is an efficient way for creating alien translocation line, especially non-Robertsonian translocation line. Meanwhile, using this procedure combined with comprehensive identifying methods, the investigation of useful genes and molecular markers on rye chromosomes 1R and 6R respectively has been done. The roles and relationships between chromosome engineering of pollen

Development, identification and utilization of introgression lines using Chinese endemic and synthetic wheat as donors

Chromosome segmental introgression lines（ILs）are an effective way to utilize germplasm resources in crops.To improve agronomic traits of wheat cultivar（Triticum aestivum） Shi 4185, four sets of ILs were developed. The donors were Chinese endemic subspecies accessions Yunnan wheat（T. aestivum ssp. yunnanense） YN3, Tibetan semiwild wheat（T. aestivum ssp. tibetanum） XZ-ZM19450, and Xinjiang wheat（T. aestivum ssp. petropavlovskyi） XJ5, and synthetic wheat HC-XM1620 derived from a cross between T. durum acc. D67.2/P66.270 with Aegilops tauschii acc. 218.Totals of 356, 366, 445 and 457 simple sequence repeat（SSR）markers were polymorphic between Shi 4185 and YN3, XZZM19450, XJ5 and HC-XM1620, respectively. In total, 991 ILs were identified, including 300 derived from YN3, covering 95%of the genome of Shi 4185, 218 from XZ-ZM19450（79%）, 279 from XJ5（97%）, and 194 from HC-ZX1620（84%）. The sizes and locations of each introgression were determined from a consensus SSR linkage map. Using the ILs, 11 putative Resear quantitative trait loci（QTLs） were identified for plant height（PH）, spike length（SL） and grain number per spike（GNS）.Comparative analyses of 24 elite ILs with the parents revealed that the four donor parents could be important resources to improve wheat SL and GNS. Our work offers a case for utilizing endemic landraces for QTL mapping and improvement of wheat cultivars using introgression lines.

Development of Triticum aestivume——Leymus mollis Translocation Lines and Identification of Resistance to Stripe Rust

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most widely distributed and destructive fungal diseases worldwide. Since 1995, most Chinese wheat cultivars have lost their stripe rust resistance due to the subsequent emergence of the new races CYR30, CYR31, CYR32, and CYR33 （Han et al., 2010）. Therefore, it is necessary to seek effective resistance genes and develop new resistance germ- plasm for wheat resistance breeding.

Microstructure and mechanical properties of tungsten composite reinforced by fibre network

In this paper the tungsten-fibre-net-reinforced tungsten composites were produced by spark plasma sintering （SPS） using fine W powders and commercial tungsten fibres. The relative density of the samples is above 95%. It was found that the recrystallization area in the fibres became bigger with increasing sintering temperature and pressure. The tungsten grains of fibres kept stable when sintered at 1350℃/16 kN while grown up when sintered at 1800℃/16 kN. The composite sintered at 1350℃/16 kN have a Vickers-hardness of -610 HV, about 2 times that of the 1800℃/16 kN sintered one. Tensile tests imply that the temperature at which the composites （1350℃/16 kN） begin to exhibit plastic deformation is about 200℃-250℃, which is 400℃ lower than that of SPSed pure W. The tensile fracture surfaces show that the increasing fracture ductility comes from pull-out, interface debonding and fracture of fibres.

High damping in Fe-Ga-La alloys:Phenomenological model for magneto-mechanical hysteresis damping and experiment

Ferromagnetic high damping(FHA)alloys with a wide temperature range from-150℃to 300℃have unique application value in extreme environments.In the present work,the damping behaviors of Fe-21 Ga-xLa(x=0.12 wt.%,0.24 wt.%,0.47 wt.%,1.18 wt.%,and 2.33 wt.%La)alloys have been studied in detail,and a new phenomenological model has been proposed.With the increase of La content,the Laves phase(LaGa_(2))in the matrix increases gradually,and the resistance opposing the domain movement increases as well.Combined with the results of synchrotron radiation X-ray diffraction,neutron diffraction,and magnetic domain observation,the resistance mainly comes from three parts:the average stress related to the lattice distortion of the matrix,the average stress related to the increasing area energy of domain walls(DWs),and the ave rage stress related to the increasing demagnetization energy induced by the Laves phase.Different from the traditional method of reducing internal stress through annealing to improve the damping capacity,the proper internal stress barriers are necessary to Barkhausen jumps to dissipate energy.Therefore,proper doping to balance resistance and mobility of DWs is a reliable way to improve damping capacity.Meanwhile,for Fe-Al and Fe-Cr based Alloys,the new model also has a good fitting effect.This study provides a theoretical and experimental reference for improving the functional properties of ferromagnetic alloys.

Directly generating vortex beams in the second harmonic by a spirally structured fundamental wave

Based on nonlinear wave mixing, we experimentally propose a scheme for directly generating optical orbital angular momentum(OAM) by a spirally structured fundamental wave interacting with a nonlinear medium, in which the nonlinear susceptibilities are homogenous. In the experiment, the second-harmonic generation of a fundamental wave carrying positive(negative) integers and fractional OAM states was investigated. This study presents a convenient approach for dynamic control of OAM of vortex beams, which may feature their applications in optical manipulation and optical communication.