Biological effects of implantation and penetration of nitrogen ion beams on wheat seeds

The biological effects of wheat seeds irradiated by 48MeV/u and 20MeV/u ^14N^7 beams are studied,respectively.The results show.both penetration and implantation of heavy ions can significantly inhibit growing pwer(height of plant stem)of wheat seeds.The greater dose is ,the weaker growing power is,and the implantation influence on growing power is stronger than the penetration;a great variety of chromosomal aberrations were observed in root tip cells of irradiated seeds and the aberration frequencies were several hundred times higher than that of the corresponding control;it has been proved by 3H-TdR incorporation test that unscheduled DNA synthesis exists in irradiated wheat seed embryos.It is found by ESR spectroscopy that the variation of free radical concentration with total dose has different features for the pentrated and implanted seeds.     

氮离子束注入与贯穿小麦种子的生物效应初步研究

采用４７．９ＭｅＶ／ｕ和２０．４ＭｅＶ／ｕ１４Ｎ（７＋）离子束对小麦种子进行生物学效应研究。结果表明：１）重离子的贯穿和注入对小麦种子的生长势均有明显的抑制作用，剂量越大，抑制作用越强，而且注入作用高于贯穿；２）在种子的根尖细胞中出现的染色体畸变具有多种类型，畸变频率高于对照组１９８～５９２倍，而且注入比贯穿作用强；３）注入和贯穿处理两者同样有明显的诱变作用，可引起ＤＮＡ的损伤和修复     

核反应技术在高蛋白小麦选种中的应用

利用13．4MeV的氘束在^14N和^12C内引发的（d,p)反应测量了10个品系小麦种子中的^14N/^12C，由此选出高蛋白质含量的小麦种子。     

离子注入植物种子的生物效应研究

用３５－１８０ｋｅＶ离子束对玉米、水稻、小麦、黑麦等材料种子进行了氮或磷离子注入。结果发现，在被处理的当代种子中，发芽率，生长速度，植物株型等方面均出现了变异；对染色体行为的观察发现有丝分裂基本正常，减数分裂出现异常，对注入离子在种子内的分布进行了ＲＢＳ测量，并以ＴＲＩＭ程序进行理论估算。对离子束作为诱变源的前景及机理进行了讨论。     

氯化胆碱在对小麦的辐射保护作用中无效

前一工作报道存在于十字花科植物中的芥子碱对小麦和元麦有辐射保护作用。芥子碱的水解产物为芥子酸和胆碱。为了探索芥子碱辐射保护作用的有效成分,本文用氯化胆碱预处理小麦萌发种子后用X射线辐照。6天后的生长表明氯化胆碱对小麦萌发种子没有辐射保护作用。     

Study of nuclear reaction method for the determination of protein content in wheat seeds

A 13.4 MeV deuteron beam from the 1.2 meter cyclotron of Sichuan University was used to determine the protein content in wheat seeds on the basis of （d,p） reactions. The influence of the variation of the water content in seeds has been investigated.     

An important mechanism of crop breeding with ultralow energy ion implantation

The characteristic X-rays excited in carbon compounds of seeds by ultralow energy (110 keV) ions implanted in wheat seeds were simulated with carbon-light of synchrotron-radiation. After the seeds were irradiated with the C-light, the through-germination survival fraction of the seeds and the micronucleus frequency in their root-tip cells could be measured. The data verify that the characteristic X-rays excited by the ultralow energy ions implanted in the seeds provide an important mechanism of crop breeding.     

中能氩离子束辐照麦胚自由基的ESR研究

用ＥＳＲ波谱技术，研究了室温下中能氩离子辐照小麦种子胚部产生的自由基，观察了自由基的稳定性，实验结果表明，种子中自由基浓度随种子含水量线性增加，自由基浓度随辐照剂量增加，然后趋于饱和，讨论了自由基与种子损伤的关系。根据实验数据和 自由基扩散理论估算了自由基在麦胚中扩散距离。     

中能氮离子束辐照小麦种子产生自由基的研究

用ＥＳＲ波谱术研究了室温下中能氮离子辐照小麦种子产生的自由基，发现氮离子贯穿和注入小麦种子产生的自由基浓度随剂量的变化具有不同的特征。对氮离子贯穿小麦种子产生的自由基浓度随剂量率的变化规律也进行了研究。     

Penetration depth and concentrationdistribution for implanted heavy ions with low energies in plant seeds bySEM and EDS

The penetration depth and concentration distribution of implanted ions have been studied for low energy heavy ions implanted in the dry seeds of plant,such as peanut,mung bean,sunflower,wheat and radish seeds,etc.by SEM EDS.The results show that the maximum penetration depth is about 12μm for V^ with an energy 200keV implanted in cotyledon of the peanut,18μm,15μm,20μm for V^2 with 90keV implanted in sunflower,wheat,radish seeds,respectively.The penetration depth of implanted Cu^2 with 80keV is about 90μm in the remainder funicle derivative of the mung bean seeds.The experimental result of the maximum penetration depth of implanted V^ in the peanut seeds was compared with the calculated value of the TRIM95.     

Atmospheric pressure gliding arc discharge plasma treatments for improving germination,growth and yield of wheat

Wheat (Triticum aestivum) seeds were treated with atmospheric pressure gliding arc discharge plasmas to investigate the effects on water absorption, seed germination rate, seedling growth and yield in wheat. The surface architectures and functionalities of the seeds were found to modify due to plasma treatments. 6min treatment was provided 95%–100% germination rate. For the treatment duration of 3 and 9 min the growth activity, dry matter accumulation, leaves chlorophyll contents, longest spikes, number of spikes/spikelet and total soluble protein content in shoots were improved. The grain yield of wheat was increased ∼20% by 6min treatment with H ₂ O/O ₂ plasma with respect to control.     

Soil-to-Plant Transfer Factors of Stable Elements and Naturally Occurring Radionuclides: (2) Rice Collected in Japan

The critical paths of radionuclides and the critical foods in Japan are different from those in European and North American countries because agricultural products and food customs are different. Consequently, safety assessment in Japan is required to consider rice and vegetables as the critical foods. In this study, we measured soil-to-plant transfer factors (TFs) for rice using naturally existing elements as analogues of radionuclides under equilibrium conditions. Rice and associated soil samples were collected from 50 sampling sites throughout Japan and TFs of 36 and 34 elements for brown rice and white rice, respectively, were calculated on dry weight basis.

Probability distributions of TFs of elements for brown rice and white rice were a log normal type. Except for As and Mo, the TFs for brown rice were usually lower than those for wheat and barley especially for K, Fe, Sr (t-test: p < 0:05) and slightly lower than those for Ba, rare earth elements, Th and U. When the TFs of brown rice were compared with those of white rice, TFs of Th and U were higher in white rice, but, for many other elements, the TFs were lower in white rice than those in brown rice. Comparison of the data with previously reported values for Sr and Cs showed that the TFs of stable Sr and Cs were close to the respective values of fallout ⁹⁰Sr and ¹³⁷Cs observed in field experiments. Thus, the TFs of naturally existing elements can be used as TFs of those radionuclides which have been in contact with the environment for a long time and have reached equilibrium conditions.     

电子射线对小麦萌发种子的辐照及诱变效应

本文报道了电子静电加速器产生的两种能量的电子射线(0.8 MeV和0.5 MeV)在小麦辐射 育种中应用的初步结果。试验表明:电子射线对小麦萌发种子的辐照后,其辐照当代的小麦植株生长上 即表现出受到抑制,其程度随剂量的增加而增加。当剂量达到1600rad时,辐照当代的存活率便明显 减少,并达到了接近于萌发种子辐照的半致死剂量水平。 从电子射线辐照的小麦M_2代发生变异分离表明,电子射线对小麦种子的诱变具有变异谱较少,变 异频率较高的效应。按穗行变异统计,其平均突变频率为3.5％,而在产生变异的穗行内,突变频率范围为 2.6～6.1％。     

低能重离子束注入小麦种子诱导根尖细胞有丝分裂畸变的研究

比较研究了低能重离子束注入小麦干种子和萌动的种子对种子发芽及根尖细胞有丝分裂畸变的影响。结果表明,离子注入对萌动的种子的发芽有明显的影响,而对干种子的发芽影响不明显。在一定剂量范围内(0-6×1016/cm2),N+注入诱导的萌动种子的有丝分裂畸变率略高于干种子,并且随辐射剂量的升高而升高;但超过一定的剂量(>6×1016/cm2),无论是干种子还是萌动种子的有丝分裂畸变率达到一定程度的饱和。就实验结果对N+离子束注入诱变的机理进行了一些探讨。     

~(137)Cs辐照小麦干种子M_1代的辐射效应和细胞学分析

~(60)Co-γ射线辐照小麦干种子对M_1代的生物学和细胞学效应产生影响,这方面已有报道,而铯-137的辐射效应报道较少。本试验利用我所的铯-137和钴-60源不同剂量照射小麦干种子,比较M_1代的生物学及细胞学效应,为育种提供依据。     

纳秒级强脉冲电子束与Ar~＋离子束辐照作物种子后自由基产额的变化

应用多极板放电室产生的纳秒级强脉冲电子束与Ａｒ~＋离子束辐照蕃茄、黄瓜、辣椒和小麦的种子，分别测定辐照种子中的自由基产额，统计胚根根尖细胞中的染色体畸变频率和种子的萌发能力，藉以比较两种不同脉冲处理的辐照效果。实验发现：辐照处理时间的长短与自由基产额、染色体畸变率以及种子的萌发能力密切相关。辐照处理时间长，自由基产额高，染色体畸变率高，萌发生长能力低。四种作物种子的重复实验证明，电子脉冲的辐射效应明显强于Ａｒ~＋离子脉冲。     

不同能区重离子束在小麦育种上的比较研究

介绍了三个不同能区的重离子用于小麦育种的室内实验方法和大田培育情况，并对半致死剂量，细胞学观察和育种情况分别给出了初步结果，最后探讨了三种不同能区的重离子在作物育种上诱变机理。