Continuous-flow polymerase chain reaction microfluidics by using spiral capillary channel embedded on copper

This paper presents a novel method for performing polymerase chain reaction (PCR) amplification by using spiral channel fabricated on copper where a transparent polytetrafluoroethylene ( PTFE) capillary tube was embedded. The channel with 25 PCR cycles was gradually developed in a spiral manner from inner to outer. The durations of PCR mixture at the denaturation, annealing and extension zones were gradually lengthened at a given flow rate, which may benefit continuous-flow PCR amplification as the synthesis ability of the Taq polymerase enzyme usually weakens with PCR time. Successful continuous-flow amplification of DNA fragments has been demonstrated. The PCR products of 249, 500 and 982 bp fragments could be obviously observed when the flow rates of PCR mixture were 7.5, 7.5 and 3.0 mm s(-1), respectively, and the required amplification times were about 25, 25, and 62 min, respectively. Besides, the successful segmented-flow PCR of three samples ( 249, 500 and 982 bp) has also been reported, which demonstrates the present continuous-flow PCR microfluidics can be developed for high-throughput genetic analysis.

Tunable parametric fluorescence using a single crystal

In this paper, we investigate the mechanism of tunable parametric superfluorescence (PS) based on the second harmonic generation and parametric processes taking place in the same nonlinear crystal (BBO). The tunable spectra of PS has been generated between 480 nm and 530 nm, which is pumped by the second-harmonic from the high-power Ti: sapphire laser system at 1 kHz repetition rate. We present the generation mechanism of PS theoretically and simulate the process of PS ring using the amplification transfer function. The experiment and the theory show that PS will appear when the phase matching angle for second-harmonic generation is close to the optimal pump angle for optical parametric generation, and then the tunable spectra of PS are generated by slightly adjusting the crystal angle. The result provides a theoretical basis for controlling the generation of PS and quantum entanglement states, which is of great significance for the development of quantum imaging, quantum communications and other applieations.

Pulse-front matched ultra-broadband optical parametric chirped pulse amplifier for sub-12 fs pulse generation

We propose a LBO-based ultra-broadband chirped pulse optical parametric amplifier employing pulse-front-matching to yield transform-limited sub-12-fs pulses. Measurement of the maximum possible gain bandwidth for the LBO-based OPCPA demonstrates more than 60nm gain bandwidth FWHM. For the generation of TL pulses by the use of this OPCPA, a suitable combination of OPCPA and PFM is first presented. The PFM pump geometry realizes tilt-free signal amplification, and permits this OPCPA to generate TL sub-12-fs pulses.

Non-collinear CPOPA seeded by an Yb3+-doped self-starting passive mode-locked fiber laser

Using a home-made seed at 1053 nm from a Yb3+-doped passively mode-locked fiber laser of 1.5 nJ/pulse, 362 ps pulse duration with a repetition rate of 3.842 MHz, a compact, low cost, stable and excellent beam quality non-collinear chirped pulse optical parametric amplifier omitting the bulky pulse stretcher has been demonstrated. A gain higher than 4.0 x 10(6), single pulse energy exceeding 6 mJ with fluctuations less than 2% rms, 14 nm amplified signal spectrum and recompressed pulse duration of 525 fs are achieved. This provides a novel and simple amplification scheme. (c) 2007 Optical Society of America.

Spectrum shape compression and pedestal elimination employing a Sagnac loop

We report on the experimental demonstration of a spectrum shaping filter, which is formed by inserting a fiber polarization controller (PC) in to a Sagnac loop. Pedestal free and narrow spectrum with line width at 1.4-1.7 nm is obtained, which is advantageous for further power amplification and effective frequency doubling. (C) 2008 Elsevier B.V. All rights reserved.

Broad-spectrum and long-lifetime emissions of Nd3+ ions in lead fluorosilicate glass

A novel Nd3+-doped lead fluorosilicate glass (NPS glass) is prepared by a two-step melting process. Based on the absorption spectrum a Judd-Ofelt theory analysis is made. The emission line width of NPS glass is 44.2nm. The fluorescence decay lifetime of the 4F3/2 level is 586±20μsec, and the stimulated emission cross-section is 0.87×10-20cm2 at 1056nm. A laser oscillation is occurred at 1062nm when pumped by 808nm Diode Laser. The slope efficiency is 23.7% with a 415mJ threshold. It is supposed that NPS glass is a good candidate for using in ultra-short pulse generation and amplification by the broad emission bandwidth and long fluorescence lifetime.

A COMMON-CAVITY 2-SECTION INGAASP/INP BISTABLE LASER WITH A LOW OPTICAL SWITCHING POWER

The characteristics of the steady-state and the transient response to external light excitation of a common-cavity two-section (CCTS) bistable semiconductor laser is investigated. The results on the relation of light output versus light input, the wavelength match, optical amplification and optical switching are presented. Experimental results are compared to the results of a computer simulation.

Influence of a tilted cavity on quantum-dot optoelectronic active devices

Quantum-dot laser diodes (QD-LDs) with a Fabry-Perot cavity and quantum-dot semiconductor optical amplifiers (QD-SOAs) with 7° tilted cavity were fabricated. The influence of a tilted cavity on optoelectronic active devices was also investigated. For the QD-LD, high performance was observed at room temperature. The threshold current was below 30 mA and the slope efficiency was 0.36 W/A. In contrast, the threshold current of the QD-SOA approached 1000 mA, which indicated that low facet reflectivity was obtained due to the tilted cavity design.A much more inverted carrier population was found in the QD-SOA active region at high operating current, thus offering a large optical gain and preserving the advantages of quantum dots in optical amplification and processing applications. Due to the inhomogeneity and excited state transition of quantum dots, the full width at half maximum of the electroluminescence spectrum of the QD-SOA was 81.6 nm at the injection current of 120 mA, which was ideal for broad bandwidth application in a wavelength division multiplexing system. In addition, there was more than one lasing peak in the lasing spectra of both devices and the separation of these peak positions was 6-8 nm,which is approximately equal to the homogeneous broadening of quantum dots.

Pulse Compression by Filamentation in Argon with an Acoustic Optical Programmable Dispersive Filter for Predispersion Compensation

We have experimentally demonstrated pulses 0.4 mJ in duration smaller than 12 fs with an excellent spatial beam profile by self-guided propagation in argon. The original 52 fs pulses from the chirped pulsed amplification laser system are first precompressed to 32 fs by inserting an acoustic optical programmable dispersive filter instrument into the laser system for spectrum reshaping and dispersion compensation, and the pulse spectrum is subsequently broadened by filamentation in an argon cell. By using chirped mirrors for post-dispersion compensation, the pulses are successfully compressed to smaller than 12 fs.

Design of Photonic Crystal Semiconductor Optical Amplifier With Polarization Independence

Slow-light effects in photonic crystal (PC) waveguides can enhance light-mater interaction near the photonic band edge, which can be used to design a short cavity length semiconductor optical amplifier (SOA). In this paper, a novel SOA based on slow-light effects in PC waveguides (PCSOA) is presented. To realize the amplification of the optical signal with polarization independence, a PCSOA is designed with a compensated structure. The cascaded structure leads to a balanced amplification to the TE and TM polarized light.

无指盘臭蛙皮肤抗菌肽Odorgrin A和Odorgrin C基因表达载体的构建及其在毕赤酵母中的表达

研究背景与目的：近二十年来，抗生素的广泛使用以及一些不当应用导致临床上出现大量的耐药性病原菌，所以不易产生耐药性的抗菌肽就成为目前研究的热点。本课题组此前的研究表明无指盘臭蛙（Odorrana grahami）皮肤抗菌肽具有广谱抗菌活性，但对真核细胞没有毒性，因此有成为新型药物的潜力。本研究采用毕赤酵母真核表达系统来生物合成抗菌肽Odorgrin A和Odorgrin C，为大量获取抗菌肽资源提供技术支撑。 方法：依照Odorgrin A和C的氨基酸序列、采用酵母偏爱密码子分别设计并化学合成了相应的目的基因序列。目的片段从合成质粒上用Xho Ι和EcoR Ι双酶切下后，与经同样限制酶完全酶切pPIC9K载体所获得的两个大片段直接连接，并转化至大肠杆菌DH5α。用PCR扩增、酶切及测序检测，鉴定正确的重组质粒。提取大量表达载体pPIC9K - Odo A和C并使之线性化后经电击法分别转化毕赤酵母（Pichia pastoris）GS115宿主菌，用营养缺陷型筛选、遗传霉素抗性筛选、PCR扩增和测序检测，鉴定并筛选出对G418具高抗性的Odorgrin A和C重组酵母菌。用甲醇对之进行诱导表达，SDS - PAGE电泳及反相层析检测表达产物，并做抑菌活性检测。 成果：PCR扩增、酶切及测序等结果表明表达载体pPIC9K - Odo A和C构建成功。营养缺陷型筛选、遗传霉素抗性筛选、PCR扩增和测序等证实pPIC9K - Odo A和C已整合入酵母基因组中。SDS - PAGE电泳及反相层析结果表明抗菌肽Odorgrin A和C成功地获得了分泌表达。而抑菌活性实验则检测到部分阳性克隆菌诱导分泌表达的抗菌肽Odorgrin A和C都对测试菌的生长具有较高（>94%）的抑制率。 结论：无指盘臭蛙皮肤抗菌肽Odorgrin A和Odorgrin C基因的表达载体都构建成功，并且都在毕赤酵母系统中获得了成功表达。 Background ＆ Objective: In the recent twenty years, a lot of pathogenic bacteria have come forth in clinic with durable trait derived from making use of and abusing the traditional antibiotics. Therefore, studying antimicrobial peptides, not be easy to be invalidated by durable bacteria, are becomimg popular and important. The skin antimicrobial peptides of Odorrana grahami with broad spectrum antibacterial activity and no toxicity to eukaryotic cell, discovered by previous research work of our workgroup, are looked forward to being potential medication. Pichia pastoris expressional system was used for biosynthesis antimicrobial peptides Odorgrin A and Odorgrin C in this study, for producing abundant antimicrobial peptides. Methods: The foreign fragments which included Odorgrin A or Odorgrin C gene according to their amino acid sequence respectively were synthesized based on the biased codon usage of yeast. The DNA fragments, obtained from the plasmids containing them by digested with Xho Ι and EcoR Ι, were directly ligated with the two bigger fragments obtained from the vector pPIC9K by digested with the same restriction enzymes. And then they were transformed into Escherichia coli DH5α to be selected and amplified positive colonies. The recombinants were testified by using PCR amplification, enzymes digestion and sequencing of the foreign fragment. After the expressional vector pPIC9K - Odo A and pPIC9K - Odo C were linearized, they were transformed into Pichia pastoris GS115 strain by the electroporation. Then the positive colonies which were of the highest geneticin resistant were selected through auxotrophic screening, genetic resistant screening, PCR amplification and sequencing of the inserted fragment. Methanol was used to induce the recombinant yeasts to express the foreign gene. SDS-PAGE electrophoresis, reversed phase chromatography and antibacterial activity experiment were used to testify the expressional products. Results: The evidences of PCR, enzymes digestion and sequence analysis confirmed that the expressional vector pPIC9K - Odo A and pPIC9K - Odo C have been constructed correctly. The results of auxotrophic screening, of genetic resistant screening, of PCR and sequencing of the foreign fragment showed that Odorgrin A and Odorgrin C gene have been homologous integrated with the Pichia pastoris genome. And it was also testified that antimicrobial peptides Odorgrin A and Odorgrin C have been expressed successfully by using SDS - PAGE electrophoresis, reversed phase chromatography and antibacterial activity experiment. Conclusion: The expressional vector of the skin antimicrobial peptides Odorgrin A and Odorgrin C gene of Odorrana grahami have been constructed correctly and both of the genes have been expressed successfully in Pichia pastoris system in this study.

糯小麦杂交后代的基因型鉴定及Wx基因的效应研究

糯小麦在食品加工业、淀粉加工业及其它工业上有着重要用途，是近年来许多国家小麦研究的重要课题。国外糯小麦选育尚未突破高产与糯性相结合的难点，国内目前还没有培育出高蛋白强筋型的糯小麦品种，这在一定程度上与缺乏合适的育种方法和高效、实用的糯小麦分子标记辅助育种技术有关。国内外对Wx基因效应的研究主要利用缺体－四体系、重组自交系或近等基因系，还未见有利用遗传背景相同的BC5F2代回交改良群体的报道。 糯性位点近等基因系是小麦淀粉品质育种的重要材料，而我国目前还没有一套中国栽培小麦遗传背景的糯性位点近等基因系。为了选育部分糯小麦、全糯小麦和中国栽培小麦遗传背景的糯性位点近等基因系，我们利用Wx蛋白电泳和高效实用的分子标记技术体系来鉴定糯小麦杂交后代的基因型，结果证明该体系能有效地用于糯小麦的分子标记辅助育种。以中国春糯性位点全套近等基因系为研究材料，对小麦Wx基因的6个STS标记和1个CAPS标记进行了筛选，改良PCR扩增条件以及产物检测方式后，从这些标记中筛选出3个标记，包括鉴定Wx-A1、Wx-D1位点的2个共显性STS标记和Wx-B1位点的1个显性STS标记。利用上述3个分子标记从BC5F2 代回交改良群体中筛选出了8种Wx基因型，经卡方检验，其分离比符合3对基因的分离比例，其中基因型为aabbdd的植株有2株，直链淀粉含量分别为1.81%和0.82%，为全糯小麦；基因型为AAbbdd，aabbDD的部分糯性植株各有1株，直链淀粉含量分别为15.24%和17.57%。以上4株植株的农艺性状和品质性状接近回交亲本“川育12”，并明显优于全糯材料“98Y1441”，表明采用回交法与Wx基因分子标记辅助选择相结合，有助于培育高产、优质的全糯和部分糯小麦。同时，本研究中建立的分子标记技术体系，也为选育具有中国栽培小麦遗传背景的糯性位点近等基因系奠定了基础。 在基因型鉴定的基础上，利用糯小麦杂交后代BC5F2代回交改良群体研究了各基因缺失降低直链淀粉含量的效果和各基因合成直链淀粉的能力，以及直链淀粉含量与农艺性状、品质性状、淀粉糊化特性等的相关性。缺失不同Wx基因的8种基因型，直链淀粉含量差异显著。研究单缺失基因型发现，减少效应最大的是Wx-B1b基因，Wx-B1b和Wx-D1b基因没有显著差异，减少效应最小的是Wx-A1b基因。研究双缺失基因型发现，Wx基因合成直链淀粉的能力，Wx-B1a基因最高，Wx-A1a基因最低，而Wx-B1a和Wx-D1a基因差异很小；直链淀粉含量与株高、穗长、小穗数、穗粒数、千粒重等农艺性状相关不显著，表明淀粉品质育种可以与高产育种实现有机结合；直链淀粉含量与SDS-沉降值呈显著负相关(r=-0.726)，说明直链淀粉含量降低在一定程度上有利于提高小麦营养与加工品质，这一结果至今未见有文献报道；全糯类型的淀粉糊化特性与其他类型显著不同，具有最高的峰值粘度和稀懈值，最低的低谷粘度、最终粘度、反弹值、峰值时间、糊化温度、起始糊化温度，表明糯小麦淀粉在食品和工业上具有特殊用途；稀懈值与直链淀粉含量呈极显著负相关(r=-0.969)，其他粘度参数与直链淀粉含量呈显著正相关(最终粘度r=0.797，低谷粘度r=0.910、反弹值r=0.954、峰值时间r=0.970、糊化温度r=0.962、起始糊化温度r=0.932)。以上结论可为糯小麦品种选育和淀粉品质改良提供理论依据。 Waxy wheat is very important in food processing industry, starch processing industry and the other industries, so it is a focus of wheat research in many countries these years. Foreign wheat breeders have not conquered the difficulty of high yield combined with waxy character, and there is no waxy wheat variety with high protein and strong gluten in China at present，all of which were caused by lacking proper breeding methods and effective, applied molecular markers-assisted selection technique at a certain extent. Until now, research about the effect of waxy genes mainly depended on nullisomic-tetrasomic lines, recombinant lines or near-isogenic lines, and it is lacking the reports of using improved BC5F2 backcross progenies under the common genetic background. Near-isogenic lines at the Wx loci are important materials for wheat starch quality breeding. However, there are no such lines under the Chinese cultivated wheat genetic background. To develop partial waxy wheats, waxy wheats and near-isogenic lines at the Wx loci under the Chinese cultivated wheat genetic background, we use SDS-PAGE of waxy proteins and effective, applied molecular marker-assisted selection technical system to identify the genotype of waxy wheat’s progenies. The results indicated that such a system is applicable in waxy wheat’s molecular marker-assisted selection effectively. A series of Chinese Spring Wx loci near-isogenic lines were used to identify the specific bands of six STS markers and one CAPS marker of Wx genes. After optimizing PCR amplification and separating of PCR products, three co-dominant and dominant STS-markers were identified at the Wx-A1, Wx-D1 and Wx-B1 loci, respectively, which were used to identify the genotype of waxy wheat’s progenies. Eight Wx genotypes were developed from the improved BC5F2 backcross progenies, which follows Mendelian segregation. Among them, there were two aabbdd waxy plants whose amylose content in the BC5F3 seeds were 1.81% and 0.82%, respectively. In addition, there were partial waxy plants (AAbbdd and aabbDD) whose amylose content in the BC5F3 seeds were 15.24 % and 17.57%, respectively. Most agronomic and quality traits of these four plants resembled those of the recurrent parent “Chuanyu 12”, and superior to waxy wheat parent “98Y1441”. This shows that backcross approach in combination with molecular marker-assisted selection of waxy genes is helpful to develop partial and full waxy wheat with good traits in the waxy wheat breeding program. At the same time, molecular marker-assisted selection technical system in this paper, also establish the base for breeding the near-isogenic lines at the Wx loci under the Chinese cultivated wheat genetic background. According to the results of genotype identification, we use waxy wheat’s improved BC5F2 backcross progenies to verify the effects of null alleles on reducing amylose content and determine the amylose synthesis capacity of each Wx gene independently, and investigate the relativity among amylose content with agonomic traits, quality traits, starch pasting properties respectively. There was significant difference in amylose content of the eight genotypes carrying different null Wx alleles. The reducing effect of the single null alleles was the most significant in Wx-B1b, followed by Wx-D1b and Wx-A1b, and there was no significant difference between Wx-B1b and Wx-D1b. The results of the double null lines further demonstrated that for the capacity of amylose synthesis, Wx-B1a was the highest, followed by Wx-D1a and Wx-A1a, and there was no significant difference between Wx-B1a and Wx-D1a. Amylose contents of the eight genotypes were not significantly correlated with plant height, spike length, spikelets per spike, grains per spike, 1000-grain weight, which showed that starch quality breeding could integrate with high yield breeding. Amylose contents of the eight genotypes were negatively significantly correlated with SDS-sedimentation value(r=-0.726), which suggested that reduction in amylose content is propitious to improve quality at a certain extent. Starch pasting properties of the full waxy type was significantly different from the other seven types, with the highest peak viscosity and breakdown, and lowest valley viscosity, final viscosity, setback, peak time, pasting temperature and starting pasting temperature. It indicated that waxy wheat starch has special use in food and industry. Breakdown was negatively significantly correlated with amylose contents (r=-0.969), and the other parameters were positively significantly correlated with amylose contents (r=0.797 for final viscosity, r=0.910 for trough viscosity, r =0.954 for setback, r =0.970 for peak time, r=0.962 for pasting temperature and r=0.932 for starting pasting temperature ). The results of the study are very useful for waxy wheat variety breeding and starch quality improvement.

水稻同源四倍体高代自交系农艺性状分析及遗传差异研究

课题组在不断地创制新的同源四倍体材料的同时，连续多年以提高结实率为目的培育、筛选自交系材料，已获得自交繁殖十二年的高代自交系材料。相对于诱导创制初期，材料表现出的结实率低，同种系单株间的差异较大；高代材料已表现出较显著的结实率提升和较一致的农艺性状表型。 本实验选取课题组多年培育的同源四倍体水稻高代自交系材料，通过形态学、农艺性状和细胞遗传学比较，研究水稻同源四倍体与二倍体之间的异同。结果显示，所有同源四倍体材料的染色体组成均为2N=4X=48，花粉母细胞(PMC)减数分裂行为较正常，99%以上的染色体都能在减数分裂中期I（MI）发生联会、配对，形成四价体和二价体，这与理论染色体组构成相符。在减数分裂过程中，结实率较高的材料染色体异常现象较少而结实率较低的材料染色体异常现象较严重。统计分析表明，二价体和四价体的比例对结实率没有显著影响，但是三价体的数目对结实率有一定影响。这一结果表明了结实率和细胞减数分裂行为可能存在相关性，同源四倍体的减数分裂行为为筛选高结实率的同源四倍体种系提供了依据。 然后，对同源四倍体水稻高代自交系材料进行农艺性状和品质性状的统计与分析。主要针对结实率、每穗实粒数、有效分蘖和穗长等主要农艺性状，以及直链淀粉含量这一重要的品质性状进行统计。将统计结果与1996年诱导加倍的初代材料的数据相对比分析，结果显示所有材料经过多代选育培养，其农艺性状已经有了较显著的提高，同时同源四倍体材料的农艺性状稳定性也有了较显著的提升。如结实率的提高幅度较大，所有材料的平均结实率均显著高于加倍初代，而同种材料不同单株间的结实率差异也显著地减少，变异系数（CV）的平均值由1996年的41.15%减少到了2008年的28.81%。其他重要农艺性状也有不同程度的改良，种内变异系数也相应地降低。此外，实验测量了同源四倍体材料和来源二倍体材料的直链淀粉含量。分析结果显示，部分材料的直链淀粉含量与二倍体亲本产生了较显著的差异，这可能是诱导加倍过程中的遗传变异造成的；同源四倍体材料的种内变异系数（CV）平均值由1996年的6%下降到了2008年的3.88%，显示出在品质性状方面，同源四倍体材料的遗传稳定性也有较显著的增加。同源四倍体材料农艺性状经过多年的选育，表现出一定的提升，同时，经过多年自交纯化，所有材料种系内的性状差异逐渐缩小，说明同源四倍体水稻的遗传稳定性随着自交纯化而增强，这为同源四倍体水稻的进一步选育打下了良好的基础。 最后，通过测量连续两年的自交系材料的遗传多态性，分析材料间遗传差异和种群遗传结构，深入研究连续两代材料间的遗传差异，研究同源四倍体水稻与二倍体材料遗传稳定性之间的差异。实验采用18对SSR微卫星标记对连续两代15个材料，共94份样本进行差异分析。通过扩增条带长度多态性分析，计算不同材料以及同种材料不同世代间的遗传距离，构建同源四倍体和二倍体水稻的分子指纹库，并绘制聚类图。结果显示，同源四倍体和二倍体不同材料间的遗传差异比较大，遗传距离处于0.4757至0.2816之间；而相同品种不同世代材料间的遗传差异较小，但也表现出一定的遗传差异。同种同源四倍体材料不同世代间的遗传差异比二倍体材料更大，两代四倍体材料间遗传距离处于0.1359至0.0485之间；而两代二倍体材料间的遗传距离处于均小于0.0388。结果表明，同源四倍体水稻高代材料具有一定的遗传稳定性，但与来源二倍体材料相比，其世代间的遗传变异性仍然较强。这种结果说明，经过多代的自交纯化培育，同源四倍体水稻材料能够建立起相对稳定的遗传结构，同时，其强于二倍体亲本的变异性有能够为新品种的选育，农艺性状、品质性状的改良提供一定的遗传基础。此外，分析结果表明通过分子标记辅助检验，水稻材料间的遗传多态性能够有效地区分不同的品种，这为水稻品种的分子鉴定提供了一定的依据。 本研究从细胞学鉴定，农艺性状统计分析以及分子标记辅助聚类分析多方面地对同源四倍体水稻高代系进行了研究，对探究同源四倍体水稻的遗传规律，进一步揭示其遗传特性、农艺性状的遗传构成，为进一步选育优质的多倍体水稻提供了一定的理论依据。 This group insists on creating new Autotetraploid Rice (Oryza sativa L.) materials, while improving the seed-setting of them for many years, cultivated and selected the inbred line materials, has obtained the high generation inbred lines after twelve years cultivation. Compared to the early induced materials, which shown the low seed setting, and the large difference between the different plants in the same germ-line; the high generation materials have shown significant improvement in seed setting and more uniform phenotype agronomic traits. The autotetraploid rice high generation inbred lines material, which has been cultivated for more than 12 years, was chose in this experiment. The similarities and differences between autotetraploid and diploid rice was studied through morphological, agronomic and cytogenetic ways. The results showed that all the chromosome of autotetraploid materials are composed of 2N=4X=48, the pollen mother cells (PMC) meiosis behavior is normal, more than 99% chromosomes in metaphase I(MI) were federated and paired to form tetravalents or bivalents, which constitutes a consistent theory of genome. In the meiosis process, the material with a higher seed setting showed less chromosome abnormal than the material whose seed setting is lower. However, statistical analysis showed that the bivalent and tetravalent rate had no significant impact on seed setting, but the number of trivalent had a certain impact on seed setting. The result shows that the seed setting may be related to the meiosis behavior, which provides a basis to cultivate new autotetraploid germ line with high seed setting through the meiotic behavior. Furthermore, the agronomic and quality traits of autotetraploid rice high generation inbred material were statistically analyzed. The statistically analysis was focused on major agronomic traits such as: seed setting, grains per panicle, effective tillers and panicle length, as well as the important quality trait amylose content. The statistic data was compared with the data in 1996, when the first induced generation of autotetraploid material, and the result shows that after a multi-generation breeding, the agronomic traits has been significantly improved in all the materials, while the stability of agronomic traits also significant upgraded. For instant, the seed setting increased significantly, the average seed setting of all materials was significantly higher than the first induced generation, and the differences between different plants in the same species also significantly reduced, the average of the coefficient of variation (CV) was reduced from 41.15% in 1996 to 28.81% in 2008. Other important agronomic traits had improved in different degrees; the coefficient of variation within species is also reduced accordingly. In addition, the amylose content of autotetraploid and diploid materials was measured in this experiment. The results shows that the amylose content of some of the material differed from diploid parents significantly, it may caused by the genetic change during the inducing, autotetraploid materials intra-specific coefficient of variation (CV) average reduced from 6% in 1996 to 3.88% in 2008, shows that this is a significant increase of quality traits stability in autotetraploid rice. Agronomic traits of autotetraploid material shows some improvement after years of breeding, at the same time, after years of purification, all material within the germ-line gradually narrow the differences in traits indicates that autotetraploid rice genetic stability was enhanced, which laid a good foundation for the further autotetraploid rice breeding. Finally, this experiment studied the genetic differences between materials of two generations and researched the difference of genetic stability between diploid and autotetraploid rice materials through investigating the genetic polymorphism, genetic differences between materials and population genetic structure of inbred line materials of two consecutive years.18 pairs of SSR microsatellite markers for 15 materials of two generations were used in this experiment, and the total of 94 samples were analyzed. Through the amplification length polymorphism analysis of different materials and materials in different generations, the genetic distance between materials and generations was analyzed, a diploid and autotetraploid rice molecular fingerprint database and map rendering cluster were constructed. The result shows that the genetic distance is between 0.4757 to 0.2816 among different autotetraploid and diploid materials; the genetic distance between different generations of same species was less, but also shows a certain degree of genetic differences. The inter-generational genetic differences of autotetraploid materials were greater than of the diploid materials, which are 0.1359 to 0.0485 as the genetic distance; comparing with the 0.0388 of diploid materials. The result shows that high generation inbred autotetraploid rice material has a certain genetic stability, but the genetic variation between generations is still strong comparing with the source diploid materials. It indicates that, after many generations of purification cultivation, autotetraploid rice materials established a relatively stable genetic structure, at the same time, stronger variability than its diploid parents are useful in the breeding of new varieties, provides a genetic foundation to the agronomic and quality traits improvement. In addition, the analysis result shows that the through the molecular marker-assisted testing, rice genetic polymorphism between materials can effectively distinguish different species, provides a certain basis for molecular identification of varieties of rice. A series of investigation such as cytological identification, statistical analysis of agronomic traits, molecular marker-assisted cluster analysis was applied in this experiment to research genetic pattern of autotetraploid rice high generation inbred lines, revealed the genetic characteristics and the genetic composition of agronomic traits, provides a theoretical basis for the further selection of high quality autotetraploid rice.

~(12)C~(6+)重离子辐照对人肝细胞、肝癌细胞端粒酶活性表达的影响

为探索碳离子束辐照对细胞中端粒酶活性的变化,利用兰州近代物理研究所重离子研究装置(Heavy ion research facility in lanzhou,HIRFL)产生的碳离子(31MeV/μ12C6+),以人肝细胞HL-7702,肝癌细胞SMMC-7721为实验对象,用不同剂量1Gy、2Gy、3Gy、4Gy的重离子分别对两种细胞进行照射,用多聚酶链式反应-银染端粒重复序列扩增法(PCR-telomeric repeat amplification protocol,TRAP-PCR)银染端粒重复序列扩增法检测不同剂量下细胞端粒酶活性的变化。结果显示,人肝细胞HL-7702自身没有端粒酶活性,经1Gy辐照后也没有端粒酶活性,在2和3Gy处出现端粒酶活性,4Gy处端粒酶活性又消失。肝癌细胞SMMC-7721在1～3Gy处随着剂量的增大端粒酶活性升高,在4Gy处又开始下降;在1～3Gy处随着时间的推移端粒酶活性随着时间而加强(p<0.05)。分析得知,重离子辐射可以诱导人肝细胞产生端粒酶活性,也可以改变肝癌细胞的端粒酶活性。端粒酶参与细胞受辐照后DNA单链损伤的修复;辐照后DNA双链断裂导致端粒酶活性减弱。本实验使重离子在辐照治疗中的优势得以体现。

The influence of carbon ion irradiation on sweet sorghum seeds

The aim of this study is to investigate the effects of different doses of 100 MeV/u carbon ions on sweet sorghum seeds in order to improve crop yields and their sugar content. After irradiation, seeds were germinated and grown to 30 days, and others were sown in the field. At the end of harvesting season all planted seeds were picked separately and M2 generations obtained. The differences among the treatments were examined using the RAPID procedure. In the study done by using 38 primers; according to the amplification results, the differences among the various doses treatment were shown.