60^Co γ射线辐照对3种国兰生长的影响

以不同剂量的^(60)Coγ射线对‘铁骨素’建兰、‘十八学士’建兰、‘长汀’墨兰3种国兰成熟植株进行辐照,对各处理植株的新长幼芽、假鳞茎、花期、植株形态等进行观测。结果显示:在10～50Gy剂量范围内,受照植株成活率随剂量的加大下降,而辐照效应却增强。不同品种的国兰耐辐照能力有所差异,‘长汀’墨兰>‘铁骨素’建兰>‘十八学士’建兰;同一植株不同器官组织,不同发育阶段的耐辐照能力也有所不同,成熟假鳞茎>幼芽>花芽;植株形态变异一般只在VM1代的幼芽上有所发生。3种国兰成熟植株辐射诱变适宜的处理剂量为16～18Gy。

切花月季无性系60^Co γ射线离体诱变研究

以月季叶片愈伤组织和再生的不定芽2种材料为外植体,对其体细胞无性系进行离体辐射诱变,研究了^(60)Coγ辐照对叶片愈伤组织再生率、不定芽增殖率及后期生长情况的影响。结果表明,^(60)Coγ射线处理大大降低了叶片愈伤组织的再生频率,叶片再生不定芽更适宜作为离体辐照诱变材料。不定芽的适宜诱变剂量为50～60Gy,由回归方程导出其致死剂量为122Gy,半致死剂量约为76Gy。

SRAP Marker Analysis of Genomic Mutation Induced by ^(60)Coγ-Ray Irradiation in Potato (Solanum tuberosum)

[Objective] This study was to explore the mutagenic effect of 60Co γ-ray on Solanum tuberosum chromosomes.[Method] The 60Co γ-ray at different irradiation doses was applied to treat the minitubers of potato variety ＇Favorita＇,and the genomic mutations in VM1 and VM2 gene rations in treatments with different doses were analyzed by SRAP markers.[Resalt] Thirty pairs of SRAP primers out of 88 pairs exhibited polymorphism with a rate of 34.1％ in the bulked selection of VM1 generation.A total of 225 bands were obtained,of which 64 were polymorphic with a rate of 28.4％.The polymorphism was reflected in the forms of deleted bands and added bands.Based on the result of the bulked selection of VM1 generation,25 primers with polymorphism were selected to scan VM2 generation.Five primers performed poorly,and nine of the rest 20 pairs revealed polymorphism and obtained nine polymorphic bands,of which only four bands were detected in VM1 generation and the other five ones were newly deleted bands.Only 9.8％ of the bands detected in VM1 generation were obtained in VM2 generation.Eventually,nine stable and dear polymorphic bands were recovered and cloned,and DNA sequences of six bands of them were acquired by sequencing.According to the comparative analysis,five fragments sequences were similar to potato chromosome with a similarity rate of 77％-89％,three of them located at the resistance gene cluster; another one fragment had a similarity of 93％ with some regions of the No.5 chromosome in tomato.[Conclusion] 60Co γ-ray irradiation can cause mutation of genomic DNA in potato;there is no significant correlation between the number of polymorphic bands and the irradiation dose; potymorphic bands are characterized by a larger number of deleted bands than that of the added ones.

Mutagenic Effect of ^(60)Co γ-rays Irradiation on Turf Characteristics of Buchloe dactyloides (Nutt.) Engelm.

[Objective] This study aimed to investigate the mutagenic effect of 60 Co γ-rays irradiation on turf characteristics of Buchloe dactyloides （Nutt.） Engelm. [Method] Buffalo grass were irradiated with 60 Co γ-rays at five different radiation intensities （1 200, 1 400, 1 600, 1 800, 2 000 Gy） to determine the related turf characteristics and analyze the mutagenic effect of 60 Co γ-rays at different radiation intensities on buffalo grass. [Result] Germination rates of buffalo grass irradiated by different radiation intensities of 60 Co γ-rays varied inconsistently, and the root length and bud length were shorter than the control; compared with the control, the height of irradiated seedlings was significantly reduced, and the number of tillers, plant height, leaf length and leaf blade width were smaller than the control; however, the stolon length, stolon diameter and number of stolon nods had no significant difference compared with the control. [Conclusion] This study laid foundation for determining the appropriate radiation intensity of 60 Co γ-rays and selecting useful mutants of buffalo grass.

Preparation and Characterization of Fe3O4 Magnetic Nano-particles by ^（60）Co γ-ray Irradiation

By using a new method, ^60Co γ-ray irradiation, Fe3O4 magnetic nano-particles were successfully synthesized at room temperature under ambient pressure. The structure, morphology and magnetic properties of these nanoparticles were characterized by X-ray diffraction （XRD）, transmission electron microscope （TEM） and vibrating sample magnetometer （VSM）, respectively. The radiation formation mechanism was also discussed. The results show that the absorbed dose can greatly influence the structure, morphology and magnetic properties of the products. XRD and TEM studies show that the product prepared by γ-ray irradiation （10 kGy） is pure FesO4 phase and the mean diameter of these nano-particles is about 21 nm. The Fe3O4 nano-particles synthesized by γ-ray irradiation （10 kGy） are mainly in small cubic shape and the size uniformity of these particles is good.

Differential Expression of Retrotransposon WIS 2-1A Response to Vacuum, Low-Energy N^+ Implantation and ^(60)Coγ-ray Irradiation in Wheat

Mutagenesis and retrotransposons have a close relationship, but little attention has been paid yet to the activity of retrotransposons produced by physical mutagens. The variation of retrotransposon WIS 2-1A activity in wheat （Triticum aestivum L.） embryos at three different growth times （30 h, 45 h and 60 h） was investigated after they had been treated with N^＋ implantation in a vacuum of 5× 10^-2 Pa and irradiation by ^60Coγ-ray respectively. For each of the three growth times the expression of WIS 2-1A showed almost entirely a same trend of downregulation, upregulation, then downregulation, and upregulation again with the increase in dose of N^＋ implantation, but the expression appeared irregular with the increase in irradiation of ^60Coγ-ray. In conclusion, the acutely activating effect of WIS 2-1A stimulated by vacuum and high dose N^＋ implantation within a shorter incubation time may provide a convenient tool to advance the research on mutagenic breeding and function genes.

Acoustic Trauma of Guinea Pigs Caused by ^(60) Cobalt γ-Ray

Auditory cortical cvokod rcsponse(ACER) and auditory brainstom cvoked response (ABR) were recorded in guinea pigs before and after irradiation of ^(60)Co γ-ray. A single dose of irradiation on head was 90Gy and 70Gy in two groups, respectively. Two h after irradiation. the threshold shift was 12. 5 dB and 9 dB, and the ACER post-irradiation amplitude ex- ceeded the maximum pre-irradiation value by 20% and 37%. Six h after irradiation, the threshold shift increased to 37 dB and the maximum amplitnde decreased to the level of pre-irradiation in 70Gy-group. In another group, right auditory bulla arca was irradiated with a total dose of 45Gy in a course of six fractions/two weeks. Fourteen d after irradiation, the threshold shift of ABR was 118 dB and the latency of wave I was longer. The amplitude-intensity curve was after irradiation. Histological observation using scanning showed that only outer hair- cells in the basal coil of the cochlea were 6 h after irrdiation 50Gy-group. Bul 16 h later, outer, hair cells in all coils of the cochlea were found to be destroyed extensively and inner cells were destroyed slightly. In 45Gy-group, 14 d after irradiation, outer hair cells in all coils of the cochlea were damaged and no inmer hair cell was injured severely.

The effects of ^(60)Co γ-ray irradiation on the DC characteristics of enhancement-mode AlGaN/GaN high-electron-mobility transistors

The effects of ^60Co γ-ray irradiation on the DC characteristics of AlGaN/GaN enhancement-mode high-electron- mobility transistors （E-mode HEMTs） are investigated. The results show that having been irradiated by^60Co γ-rays at a dose of 3 Mrad （Si）, the E-mode HEMT reduces its saturation drain current and maximal transconductance by 6% and 5%, respectively, and significantly increases both forward and reverse gate currents, while its threshold voltage is affected only slightly. The obvious performance degradation of E-mode A1GaN/GaN HEMTs is consistent with the creation of electronegative surface state charges in the source-gate spacer and gate-drain spacer after being irradiated.

^(60)Co γ射线辐照对水果蔬菜中维生素C的影响

维生素C是水果蔬菜中重要营养成分之一,是人体中重要的生物活性物质,但很多因素会影响水果蔬菜中的维生素C含量。有关^(60)Coγ射线辐照对水果蔬菜中维生素C含量有一定的影响,但文献报导差异性较大,一些报道辐照能降低水果蔬菜中维生素C的含量,也有一些文献认为辐照对维生素C含量无明显影响。导致辐照对水果蔬菜中维生素C影响结果不一致的因素主要有抗坏血酸氧化酶、水果蔬菜本身化学成分、辐照剂量、辐照环境、水果蔬菜生理代谢等。辐照处理是果蔬保藏的重要技术手段,虽然辐照对维生素C含量有一定的影响,但不足以影响辐照技术在果蔬贮藏保鲜方面的应用,况且通过合适的技术处理还可以避免或减少其影响的程度。本文对相关文献的研究结果进行了归纳分析,为更好地利用辐照技术在水果蔬菜保鲜加工中的科学应用提供借鉴。

^(60)Coγ辐射对毛竹种子活力及早期幼苗生长的影响

以毛竹(Phyllostachys edulis)干种子为材料,采用室内发芽实验、电导率测定和TTC活力测定以及早期幼苗生长分级等4种方法研究了60Coγ射线对种子活力及早期幼苗生长的诱导效应。结果表明:当辐照剂量低于100Gy时,辐照能加快种子萌发进程,提高发芽率;而当剂量超过100Gy,则对毛竹种胚组织造成损伤,抑制细胞生长和分裂,不同程度地延迟了毛竹种子发芽过程,降低了种子活力,造成早期苗高和根生长受到明显抑制,抑制作用随辐照剂量的增大而增强。毛竹种子发生诱变效应的最佳辐照剂量范围为100~175Gy。24h电导率与发芽率、发芽指数、活力指数、苗高和根生长等活力指标间存在极显著线性关系,是快速检验毛竹种子活力的重要指标。24h电导率和苗高又可作为检查辐射后毛竹种子活力变化和发生诱导效应的有效指标。

^(60)Co γ辐照对低温贮藏蓝莓品质和膜脂过氧化作用的影响

为探索^(60)Co γ辐照处理对蓝莓果实保鲜效果的影响,采用不同辐照剂量处理"蓝丰"蓝莓,定期检测其冷藏期间感官品质、营养品质、呼吸作用和膜脂过氧化作用的相关指标。结果表明:0.5 kGy辐照处理对蓝莓果实的保鲜效果不明显,3.0 kGy辐照处理能够加速贮藏后期蓝莓果实的衰老进程;辐照处理后,蓝莓果实的可溶性固形物含量和可滴定酸含量变化不明显,但VC含量和花青素含量均有所下降,且与辐照剂量呈负相关;辐照处理后,蓝莓果实的呼吸强度和乙烯释放量提高,且与辐照剂量呈正相关,同时伴随脂氧合酶活性、丙二醛含量和细胞膜透性相对对照略微提高;1.0~2.5 kGy的辐照处理能够通过抑制贮藏期间蓝莓果实的呼吸作用和膜质过氧化作用,推迟蓝莓果实的衰老进程,延缓蓝莓果实中营养物质的降解;2.5 kGy辐照处理对蓝莓果实的保鲜效果最佳,既能有效降低蓝莓果实腐烂率,又能最大程度地保持蓝莓果实的营养品质。因此,^(60)Co γ辐照处理对于采后蓝莓的低温保鲜是一个行之有效的方法。

^(60)Coγ辐照对草莓花药愈伤组织诱导和分化的影响

研究了不同剂量辐照处理花粉发育处于单核靠边期花蕾对草莓花药愈伤组织诱导率和绿苗分化率的影响。结果表明,辐照处理可以明显提高愈伤组织诱导率和绿苗分化率,以辐照剂量20Gy的效果最好,其中章姬品种的愈伤组织诱导率提高39.09%,丰香提高35.68%;在同一种诱导培养基上,经辐照处理产生的愈伤组织,章姬的绿苗分化率与对照相比,提高6.67%~6.72%,丰香提高了4.73%~6.45%。

^(60)Coγ射线诱变阿维拉霉素筛选高产菌株及培养基优化

用60Coγ射线对绿色产色链霉菌A-05菌株进行了诱变处理,以正突变率为标准确定诱变的适宜剂量为350 Gy。诱变后得到5株较高产突变菌株,其中H-15菌株经连续传代6次,遗传性状稳定,阿维拉霉素发酵单位达到68.5mg/L。采用响应面分析法对菌株H-15生产阿维拉霉素的发酵培养基碳氮源进行了优化设计。在所试验的碳氮源中,可溶性淀粉、核糖分别作为唯一碳源时,阿维拉霉素发酵单位较高,分别达82.67和79.45mg/L,乳糖、果糖、葡萄糖分别作为唯一碳源时菌株的效价较低;3%的豆粕粉和2%的大豆蛋白胨作为氮源时阿维拉霉素发酵单位分别为77.6和62.7mg/L。采用双碳源双氮源更有利于菌株提高阿维拉霉素的发酵单位,响应面分析结果表明,可溶性淀粉、核糖和大豆蛋白胨对阿维拉霉素发酵单位影响较显著。优化后的碳氮源组成为:可溶性淀粉20.12g/L,D-核糖7.81g/L,豆粕粉25.23g/L,大豆蛋白胨5.06g/L。优化后的模型计算出阿维拉霉素发酵单位由原来的71.63mg/L提高到101.48mg/L。

^(60)Coγ射线对海滨雀稗成活率及生长特性的影响

【目的】研究海滨雀稗Paspalum vaginatum Swartz适宜的辐射剂量,为海滨雀稗辐射诱变育种提供理论和技术参考.【方法】以海滨雀稗2个品种Sea Isle 2000和Platinum为材料,设置60Coγ射线剂量为0、40、50和60 Gy,对海滨雀稗匍匐茎进行辐射处理,研究其适宜的诱变剂量及生长特性的变化.【结果和结论】随着辐射剂量的增加,匍匐茎成活率显著降低.Platinum匍匐茎的适宜辐射剂量范围为41.38~49.75 Gy,Sea Isle 2000匍匐茎的适宜辐射剂量范围为54.07~64.89 Gy.辐射处理使2个品种叶片变窄,使Sea Isle 2000匍匐茎节间长度缩短,2个品种的质地均得到明显改善.40~60 Gy可认为是海滨雀稗诱变育种适宜的辐射剂量.

小肠RNA对受^(60)Coγ射线照射后小鼠肠系膜淋巴结细菌移位和血中内毒素含量的影响

目的:探讨小肠RNA对受60Coγ线照后小鼠肠系膜淋巴结细菌移位和血中内毒素含量的影响.方法:选用BALB/c雄性小鼠144只,用1150cGy60Coγ射线进行腹部一次照射,于照后1～3h采用局部肠腔扩张注入法给小鼠空肠肠腔内注入正常大鼠小肠RNA,分别于照后1,3,5d麻醉后解剖,取血,测定内毒素含量;取肠系膜淋巴结,测定细菌移位率;取空肠段,计数肠腺存活率.结果:小肠RNA可降低受照小鼠肠系膜淋巴结细菌移位率和血中内毒素含量,明显提高受腹部照射小鼠空肠的肠腺存活率(P<0.01).结论:小肠RNA可改善受照小鼠肠黏膜机械屏障功能,减少细菌移位.

含^(60)Co和^(152)Eu放射性废液的水泥固化配方研究

针对含60 Co 3 8× 10 5Bq/L、152 Eu 6 67× 10 5Bq/L、总放射性活度为 2× 10 7Bq的放射性废液进行了水泥固化配方及工艺试验研究。结果表明 :水泥浆流动度和初凝时间随水灰比增大而增大 ,而固化体的抗压强度则随其增大而降低。优选配方的水泥固化体各种性能均满足中低放废液固化体性能要求 :水泥浆流动度≥ 130mm ;水泥固化体 2 8d抗压强度 >7MPa ;4 2d浸出率60 Co为1 84× 10 - 4cm/d、152 Eu为 2 76× 10 - 5cm/d(剂灰比 0 15 ) ,60 Co为 5 4 7× 10 - 4cm/d、152 Eu为1 5 5× 10 - 4cm/d(无添加剂 ) ;总 β的累积浸出分数 (4 2d)分别为 1 7× 10 - 2 cm(剂灰比 0 15 )和3 5× 10 - 2 cm(无添加剂 )

补肝肾益气血方对^(60)COγ射线所致小鼠骨髓有核细胞周期及凋亡的影响

目的 探讨补肝肾益气血方对辐射损伤的防护作用机理。方法 设正常对照组、病理模型组、补肝肾益气血方高、低剂量组、阳性药物组 5组。补肝肾益气血组给予补肝肾益气血方 ,阳性药物组给予复方阿胶浆 ,其余给予生理盐水。灌胃 10天后 ,以6 0 COγ射线全身照射小鼠造成辐射损伤 ,观察补肝肾益气血方对辐照小鼠骨髓有核细胞细胞周期及调亡影响。结果 该方能使受照鼠骨髓有核细胞S期延长 ,G2期阻滞 ,显著提高造血细胞增殖指数。结论 补肝肾益气血方对6 0 COγ射线所致小鼠辐射损伤有较好保护作用 。

^(60)Co-γ射线辐照晋豆24号M_4代突变株系主要农艺性状的遗传关系分析

用60Co-γ射线对晋豆24号风干种子进行了辐照处理,对M4代14个突变株系及CK的10个主要农艺性状进行了相关分析、主成份分析及聚类分析。相关分析表明:单株产量与株重、有效分枝、主茎荚数、株荚数、株粒数呈极显著相关;主成份分析表明:前3个主成份(单株个体因子、株形因子、粒重因子)对变异的贡献率达86.92%;聚类分析把后代分为5类,每类的产量差异显著。结果表明,农艺性状的遗传关系分析对选育新品种具有重要的意义。

2000年泰国北揽府医用^(60)Co源辐射事故介绍

从事故背景、过程、放射病理学、调查结果、结论和经验教训等方面对2000年泰国北揽府医用60Co源辐射事故进行了介绍。该辐射事故的实践表明:医疗设备供应商未获得行政许可接收闲置放射源,并擅自转运、储存于无安全保卫措施的仓库,监督检查和执法工作弱化,是事故发生的主要原因。科学、有效的辐射应急计划,训练有素、装备精良的应急响应队伍,创新的措施和方法,为在复杂地点快速回收放射源并对受照人员开展合适、充分、有保障的医疗救助提供了保障。本文可为辐射事故应急提供借鉴和参考。

^(60)Co-γRay射线诱变水稻突变体的分离和遗传学初步分析

为了研究水稻发育的分子机制,我们利用γ射线对粳稻品种9522进行诱变,共诱变了3 000 g种子,M1代单株收种,M2代移栽5 963个株系于上海农科院.在M2代中筛选突变体,并在M3代中复选,最终得到了叶、株型育性等各类形态突变体666份.对其中162株突变体进行了遗传分析,有53.61%的突变体出现3∶1的分离,这些突变体是隐性的单位点突变.同时,这些突变体的分离也为水稻功能基因分离和功能鉴定等研究打下了良好的基础,并为水稻发育的研究提供了宝贵的材料.