碳离子辐射大丽花矮化突变体的RAPD分析

大丽花经兰州重离子加速器提供的80MeV／u12C6＋离子束辐照后产生矮化突变体,用随机扩增多态性（Random Amplified Polymorphic,RAPD）DNA技术对野生型和突变体进行检测分析。结果表明,在所用的25条引物中,1．80×10^8／cm2剂量辐照后有18条引物扩增出现多态性片断,扩增条带多态率19．57％;1．08×10^8／cm2剂量辐照后仅有6条引物扩增出现多态性片断,扩增条带多态率5．76％。用]accard公式对扩增产物进行统计分析,结果表明,两种剂量c6＋辐照后与对照相似性系数分别为0．65和0．92。高剂量辐射后DNA易发生突变,在品种改良和诱变育种中相对较高剂量的选择可能更为有效。     

重离子束辐照对苜蓿外植体离体培养的影响及下胚轴再生体的RAPD分析

采用初始能量为100 MeV/u的重离子束12C6 对紫花苜蓿下胚轴及子叶外植体进行辐照处理,研究重离子辐照对愈伤组织诱导状态及诱导率、愈伤组织相对生长率、体细胞胚诱导率及植株再生的影响.结果表明,重离子辐照对下胚轴及子叶愈伤组织的诱导具有抑制作用,且出愈率随着辐照剂量的增大而降低;在继代培养过程中,其愈伤组织相对生长率均高于对照组,外植体本身对重离子辐照所造成的损伤具有恢复能力;辐照处理对体细胞胚胎诱导也有影响,30Gy时,下胚轴诱导的体细胞胚胎发生较对照组早,数量多,较早地得到再生植株;而50 Gy时,所得到的体细胞胚未能发育成再生植株.同时应用随机扩增多态性DNA (Random amplified polymorphic DNA,RAPD)技术对重离子辐照处理下胚轴所得再生植株进行检测分析,结果表明:所采用的20条随机引物中有11条在对照及处理组所得再生植株之间扩增出差异性多态条带,表明了重离子辐照引起苜蓿再生植株基因组DNA发生变异.     

12C6+重离子辐照油菜诱变效应研究

用30Gy、90Gy和180Gy12C6 重离子辐照油菜干种子,研究其对油菜M1代的诱变效应.结果表明不同剂量12C6 重离子辐照使油菜的出苗率、株高和开花率有不同程度的提高,并使开花期提早;30Gy辐照使单株角果数和单株产量有了一定程度的提高;三种辐照剂量都造成了花粉生活力、千粒重和含油量的降低.RAPD扩增结果表明,42个随机引物中有13个引物扩增出差异条带,30Gy、90Gy和180Gy引起的RAPD变异率分别为22.1%、23.7%和36.2%.研究表明,12C6 重离子辐射能有效地引起油菜DNA序列发生改变,从而诱导基因变异,为油菜育种提供丰富的种质材料.     

重离子辐照对红酵母的诱变作用

应用重离子加速器的50MeV／u^12C^6 重离子对胡萝卜素生产菌-红酵母(Rhodotorula RY Strain)进行辐照处理,经酵母发酵实验,发现50MeV／u^12C^6 重离子对胡萝卜素生产菌-红酵母具有诱变作用。初步筛选到了胡萝卜素产量有变化的辐照变异菌株,并对这些辐照变异菌株进行了RFLP(限制性片段长度多态性)和RAPD(随机扩增DNA多态性)分析,这些工作为工业上利用重离子对胡萝卜素生产菌进行诱变育种展现了新的前景。     

碳离子束辐照大豆当代诱变效应及褐皮突变体的初步研究

利用不同剂量碳离子束辐照大豆"合丰55"干种子,通过对表型、株高、分枝数及产量相关性状的考察以及DNA指纹图谱分析探索离子束辐照大豆的当代诱变效应。结果表明离子束诱变大豆M1代田间出现多种变异表型,辐照处理对M1代株高和分枝数有抑制作用,单株荚数、单株粒数、单株粒重及百粒重随着辐照剂量的增加呈现先降低后升高再降低的趋势,但这些变异与对照相比并未达到显著水平。大豆种子经辐照后M1代筛选到1株褐皮突变体,种皮颜色由黄色变为褐色,而且这种变异在M2代能够稳定遗传。运用随机扩增多态性(Random amplified polymorphic DNA,RAPD)技术对其DNA多态性进行研究发现,辐照后突变体DNA与对照相比扩增条带或增加或减少,相似性系数为0.9513。综合结果表明,碳离子束辐照对大豆当代产生了一定的诱变效应,不仅造成了农艺性状的变异,而且使DNA水平也发生了明显的变化。     

12C6+重离子辐照胡麻种子初步研究

本文研究了6×108 cm-2、1.8×109 cm-2和3.6×109 cm-2的12C6 重离子束辐照对胡麻种子M1代生物学性状和DNA分子多态性等方面的影响.6×108 cm-2辐照处理可引起胡麻发芽率提高,促进植株株高,增强花粉活力.同时辐照处理使胡麻种子千粒重和含油量有不同程度提高,辐射剂量越高,两者数值越大,3.6×109cm-2辐射剂量的胡麻种子千粒重和含油量与对照组的相比分别高出了16.5%和19.9%,此外在此剂量处发现了花粉发生了形态变化.辐照处理对胡麻DNA分子也产生了影响,筛选出的14个随机引物可以扩增出清晰、稳定、重复性好的DNA片段,有52个是多态性DNA片段,比率为52.5%.     

12C6+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 ionresearch 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.     

各种自由基清除剂在γ射线辐照DNA损伤中的作用

为了对重离子辐照致DNA损伤中的自由基作用进行评估,本文利用γ射线对添加了各种自由基清除剂(甘露醇,维生素C和茶多酚)的质粒DNA进行辐照,凝胶电泳分析的结果表明,三种自由基清除剂对DNA均有很好的保护作用.在相同自由基清除剂浓度的情况下,甘露醇比维生素C具有更强的清除自由基的作用.与重离子辐照情况相比,这几种自由基清除剂对γ射线产生的自由基的清除作用更为明显.     

氩离子束辐照拟南芥干种子的生物学效应

以拟南芥(Columbia生态型)为材料,利用氩离子束辐照干种子,通过对存活率、根长、下胚轴长和株高的测定来研究不同剂量的氩离子束辐照对拟南芥的生物学效应。结果显示,随着吸收剂量的增大,拟南芥的根长、下胚轴长和株高都呈现出下降趋势;但存活率在低剂量辐照时无显著变化,高剂量辐照时逐渐降低。运用随机扩增多态性DNA(Random amplified polymorphic DNA,RAPD)技术对氩离子辐照后拟南芥的DNA指纹图谱进行分析,结果表明,各个处理组和对照组之间的相似性系数在0.556~0.944之间,并且相似性系数与剂量之间没有显著相关性。对照组与处理组之间的差异体现为扩增条带数目的减少和增多以及条带亮度的不同。综合分析表明,氩离子束辐照拟南芥干种子产生显著的当代损伤效应,较高剂量下会抑制生长发育,同时引起基因组DNA一定程度的多态性变化。     

12C6+重离子辐照大葱的生物学效应

用30Gy、90Gy和180Gy 12C6 重离子辐照处理大葱干种子,研究了它对大葱的生物学效应.经过不同剂量12C6 重离子照射过的大葱,幼苗发芽率、株高等表型随着辐照剂量的增大,呈现明显的"抛物线"趋势.适量的12C6 重离子照射(30Gy)能提高大葱发芽率和抗旱、抗倒伏能力,促进生长发育.重离子辐照能有效地诱导大葱根尖细胞微核和染色体畸变形成,180Gy处理的大葱微核率和染色体畸变率最高达到9.09%和10.03%.本实验为大葱的重离子辐照育种打下基础.     

Flower color mutants induced by carbon ion beam irradiation of geranium(Pelargonium × hortorum,Bailey)

In an attempt to elucidate the biological effects and underlying mutations involving flower color in ornamental plants following carbon ion beam radiation,shoots of geranium were exposed at dosages of 0,10,15,30,and40 Gy,and one flower color mutant was obtained.The morphological characteristics,physiological aspects,and DNA polymorphisms between wild-type and flower color mutants were analyzed.The colors of petal,peduncle,pistil,and stamen of the mutant displayed significant differences compared to those of the wild-type.Compared to the original plants,the total anthocyanin content in the petals of the mutant significantly decreased,resulting in a light pink petal phenotype.DNA polymorphisms detected by random amplified polymorphic DNA analysis showed that the ratio of different bands between the wild-type and mutant reached up to 13.2%.The present study demonstrates that carbon ion beam irradiation is effective in inducing genomic variations,resulting in flower color geranium mutants within a relatively short period of time.Meanwhile,the developed flower-color mutants may be potentially used in future mutational research studies involving ornamental plants.     

RAPD analysis of alfalfa DNA mutation via N~+ implantation

Germination capacity of alfalfa seeds under low energy N+ implantation manifests oscillations going down with dose strength. From analyzing alfalfa genome DNA under low energy N+ implantation by RAPD (Random Amplified Polymorphous DNA), it is recommended that 30 polymorphic DNA fragments be amplified with 8 primers in total 100 primers, and fluorescence intensity of the identical DNA fragments amplified by RAPD is different between CK and treatments. Number of different polymorphic DNA fragments between treatment and CK via N+ implantation manifests going up with dose strength.     

Total DNA of Glycyrrhiza uralensis transformed into Hansenula anomala by ion implantation:Preparing Glycyrrhizic acid in recombined yeasts

<正>Glycyrrhizic acid(GA) in Glycyrrhiza uralensis(G.uralensis) is physiologically active.In this study,the total DNA of wild G.uralensis was randomly transformed into Hansenula anomala by implantation of low-energy Ar~+ and N~+,to produce five recombinant yeast strains relating to biological synthesis of the GA or Glycyrrhetinic acid (GAs).After culturing in liquid medium for 96 h,the resultant GA,18α-GAs and 18β-Gas were determined by reversed-phase high performance liquid chromatography(RP-HPLC),and the corresponding concentrations were 114.49,0.56,and 0.81 mg·L~(-1).After one hundred primers were analyzed with random amplified polymorphic DNA (RAPD),the seven different DNA fragments were produced by the N7059 strain of recombined yeasts,and,the polymerase chain reaction(PCR) verified that one of them came from the genome of G.uralensis,indicating a successful transfer of genetic information by ion implantation.     

Study on DNA Damage Induced by Neon Beam Irradiation in Saccharomyces Cerevisiae

Yeast strain Saccharomyces cerevisiae was irradiated with different doses of 85 MeV/u 20Ne10+ to investigate DNA damage induced by heavy ion beam in eukaryotic microorganism. The survival rate, DNA double strand breaks (DSBs) and DNA polymorphic were tested after irradiation. The results showed that there were substantial differences in DNA between the control and irradiated samples. At the dose of 40 Gy, the yeast cell survival rate approached 50%, DNA double-strand breaks were barely detectable, and significant DNA polymorphism was observed. The alcohol dehydrogenase II gene was amplified and sequenced. It was observed that base changes in the mutant were mainly transversions of T→G and T→C. It can be concluded that heavy ion beam irradiation can lead to change in single gene and may be an effective way to induce mutation.     

Plant height revertants of Dominant Semidwarf mutant rice created by low-energy ion irradiation

Dominant Semidwarf mutant rice (Sdd) was obtained from its wild type (WT) by irradiation with a low-energy ion beam. Six tall revertants of Sdd were induced by irradiation. The revertants restored the plant height to that of WT plants. Investigation of the agronomic character and genetic analysis indicate that the revertants are similar to WT plants with putative different inherited mutations. The revertants were checked for DNA differences using the simple sequence repeat technique. Among 408 such primers used, only 2 primers detected mutation sites in the revertants, which provided the molecular evidence for the revertants induced from Sdd. This study indicates that ion irradiation may be used as a mutagen to create revertants for plant architecture studies and could be a new application.     

Genetic Transformation of Watermelon with Pumpkin DNA by Low Energy Ion Beam-mediated Introduction

The No.601 watermelon (citrullus lanatus) seeds were treated with 25 keV N+ implantation at the dosage of 7.8*10 ions/cm2 . After treatment, watermelon seeds were incubated with 380 *g/*l pumpkin (Cucubita, maxima Duch) DNA solution at 35* for 5 hours. By two-generations of selection and resistance screening at seedling stage, one transformed material was selected out, whose rind color is similar to that of the donor pumpkin and whose size of seeds is between that of the donor and the receptor. Using AFLP (amplified fragment length polymorphism) technique, two polymorphic DNA fragments were amplified. This primarily testified that the donor DNA fragments/gene were introduced into the receptor cell and integrated into the genomic DNA of the receptor.     

A~110核区手征双重带寻找

用重离子熔合蒸发反应布居A～110核区缺中子奇奇核^106,108Ag的高自旋态,分别在这两个核中找到了类似¹⁰⁴Rh中基于πg_9/2 νh_11/2组态的手征双带结构。它们的能级能量、旋称及B(M1)/B(E2)随角动量的变化关系符合手征带的特征。然而,进一步分析发现,¹⁰⁶Ag、¹⁰⁸Ag双带之间的转动惯量及准粒子角动量顺排存在较大差别,说明两者的晕带和伴带所基于的核芯形变与角动量耦合模式并不一致。     

The study on nuclear level density of some deformed Dy radionuclides using collective model approach

Nuclear level density(NLD) is a characteristic property of many-body quantum mechanical systems.NLDs are of special importance to make statistical calculations in reactor studies and various theoretical and experimental nuclear physics and engineering applications.In this study,we have investigated a set of particle states in distinct rotational and vibrational bands to calculate nuclear level density parameters and the NLDs of accessible states of some deformed Dy radionuclides using a collective model approach,which included different excitation bands of the observed nuclear spectra.The method used assumes equidistant spacing of collective coupled state bands of the considered nuclei.The results of the calculated NLD have been compared with the experimental and compiled data obtained by the Oslo group,shell model Monte Carlo,Hartree-Fock-Bogoliubov + combinatorial approach,Bardeen-Cooper-Schrieffer approach and are in a good agreement.