【作者】 尹美强；

【导师】 马腾才；

【作者基本信息】 大连理工大学 ， 等离子体物理， 2006， 博士

【摘要】 等离子体是物质的第四态。在电子、材料、环境等方面已得到广泛的应用,而在农业上的应用起步较晚。大连理工大学在上世纪80年代用离子注入方法处理种子,并对种子早期的生物效应进行了一些探讨。中科院等离子体所应用离子注入技术在杀菌、品种改良及转基因方面取得了一定的经济效益。 作物基因表达一方面受到遗传基因的控制,另一方面,环境中的生物与非生物因素对基因表达也起到重要的调节作用。一般情况下,大多数基因处于沉默状态而不表达。通过一定方式的外界刺激,激发基因表达,促进作物生长,提高抗逆性能,是提高作物产量一条新的技术途径。各种外界环境对作物的刺激效应都是通过改变作物体内的各种物质代谢和能量代谢过程来实现的,作物的一些生理指标的变化在一定程度能够反映外界因素对作物的作用效果。磁化弧光等离子体中所包含的臭氧、强紫外光、激发态的氧、自由基、磁场等在适当强度下能促进种子发芽、幼苗生长,增强抗逆性,减轻病虫害,从而达到增产目的。本文通过磁化弧光等离子体处理小麦、番茄和大豆种子,从形态指标、种子活力与产量相关的指标、幼苗抗旱性及杀菌等方面进行了研究,主要结果如下: 1.磁化弧光等离子体对小麦、番茄、大豆三种作物具有明显的刺激效应。可以促进种子发芽和幼苗生长,小麦的分蘖数明显增加,产量提高10.51%-19.73%;番茄产量增加最多可达20.7%,主要通过每株果实个数的增加来提高产量;大豆产量提高9.36%-16.99%,豆荚数量增多是主要的增产因素。 2.不同作物之间最佳处理剂量有不同规律。大豆和番茄的最佳处理剂量存在一定的阈值,番茄最佳范围在1.0-1.5A,最佳点在1.5A。大豆在1.0-2.5A之间都有明显的效应,是一个较宽的范围,最佳范围在2.0-2.5A。小麦最佳剂量存在两个峰值,分别为1.0A和2.0A。同一种作物不同品种之间的最佳剂量也存在较大差异,POD同工酶对环境的变化较敏感,用这一指标对三种作物不同品种的剂量进行了筛选,不同品种之间的POD同工酶谱表现出较大差异。 从呼吸、能量和酶活性的角度对筛选的剂量进行证实,几个指标随剂量的变化趋势与形态指标基本一致,有趣的是根系和叶片对不同处理剂量的刺激表现出的敏感度也有差别。 3.磁化弧光等离子体能够提高幼苗的抗旱能力。在PEG 6000胁迫的条件下,处理后的小麦和番茄幼苗中SOD和POD活性明显增强,MDA含量降低,表明磁化弧光等离子体能有效增加幼苗中抗氧化酶系统活性,幼苗抗旱能力增强。 4.物理因子对生物的刺激效应与其诱导生物体内产生的自由基浓度有关。芝麻种更多还原

【Abstract】 Plasma is called the fourth state of matter, which has been used widely in electron, material and environment, etc. In 1980s, the biological effects of the early seedlings were studied after the seeds treated by ion implantation technique in Dalian university of technology. The transferring-gene, variety improvement, sterilization etc. by ion implantation method have gained economical benefit in institute of plasma physics of CAS.Heredity is controlled by genes, but their expression is turned on and off throughout life depending upon biotic and abiotic factors in environment. Most of genes was usually in silent and could not express. The crop yield could be improved by some outside stimulating, which promote genes expression, improve the stress resistance and accelerate plant growth. The ozone, strong ultraviolet, excite oxygen, free radicals and magnetic field in the magnetized arc plasma could promote seed germination and seedlings growth, improve stress resistance and alleviate plant diseases and insect pests, so the yield could be improved. In this study, the seeds of wheat, tomato and soybean were treated by the magnetized arc plasma, and the shape, physiological parameters, yields structure, free radicals, and sterilization effects were analyzed. The main results as follows:1. The magnetized arc plasma produced distinct stimulating effects for the wheat, tomato and soybean. It could promote seed germination, seedling growth and improve yield: the fertile tiller in wheat increased obviously and the yield improved by 10.51%~19.73%;the 1.5A treatment increased the tomato yield by 20.7% and the fruit number increased was the main reason of yield improvement;the soybean yield improved by 9.36%~ 16.99% and the dominating factor of yield improvement was enhancement of bean-pod number.2. The optimum treatment dose exist a range in tomato and soybean. The better range of tomato was 1.0~2.0A, and the optimum point was 1.5A;there existed a obvious effects in the range of 1.0-2.5A which was a wide range for soybean, and the optimum range was 2.0~ 2.5A. There were two ideal treatment doses, which were 1.0A and 2.0A in wheat. So the best treatment dose in different crops has different regulation. POD isoenzyme is controlled by monogene and changes with environment sensitively. The biological effects of different variety in three crops were compared using POD isoenzyme, the results shows that the optimum treatment dose presented biggish difference.The optimum treatment doses in different crops were approved from respiration, energy and enzyme activity. The change regulation of physiological parameters was consisted of the shape parameters primarily. It was interesting that the sensitivity of roots andleaves/hypocotyls was also different for the magnetized arc plasma.3. The wheat and tomato seeds treated by the magnetized arc plasma germinated under the common conditions. After the seedlings stressed using PEG-6000, SOD, POD activity increased obviously and MDA content declined, which indicated magnetized arc plasma could enhance the drought resistance of plant.4. The stimulating effects on the plant of ionization radiation are relative to the free radical concentration. In this study, we determined the changes of free radical concentration of Sesamum indicum seeds treated with magnetic field, electric field and arc plasma by ESR (Electron Spin Resonance, ESR) spectrum method. The free radical concentration of Sesamum indicum increased with the magnetic field strength and peaked at 82.5mT and then decreased after the sesame seeds were treated by different current strength for 30 min. With the increasing of treatment intensities/time of electric field and arc plasma, the free radical raised continuously.Free radical concentration of sesame seeds treated by magnetic field and arc plasma declined with the storage period. However, the decrease regular of both treatment ways was different: the free radical concentration declined with the storage time almost become a line trend when the seeds treated by magnetic field and present a quick at first and then slow process when the seeds treated by arc plasma. In electric field, the free radical was steady relatively.5. Ozone, ultraviolet, and active particles etc. in the arc plasma could sterilize the fungi and bacilli effectively. In our study, the Ustilago crameri Koern, Ustiago maydis, Sporisorium reilianum and some fungi in cucumber cultured in PDA media, could be sterilized effectively in 4 seconds. The seeds treated by arc plasma for 30s, lmin, 2min, 5min, and the sterilizing effects were appraised in the PDA media. The results show that it was difficult to sterilize the seeds compared with the surface disinfection, while the disinfection rate was about 90%. The sterilizing effects for the three crops seeds were different: the soybean was the easiest and the second was wheat, then the tomato seed was the most difficult. Maybe this was relative to the lubricity and shape of seeds surface.6. The results of organophosphorus and carbamic pesticide degradation by arc plasma show that solvent polarity and initial concentration of pesticide affected the degradation rate. The detailed results as follows: the degradation rates in different solvent for the two organophosphorus and pesticide are listed in the following order, i.e., water >methanol/acetonitrile >acetone >acetoacetate, however, the order of degradation rates for carbofuran in different solvents was acetoacetate >acetone > methanol >water.The half-life of four pesticide in different solvent are listed as follows, in water solvent: carbofuran>chlorpyrifos>monocrotophos>methomyl;in methanol and methanol: chlorpyrifos>carbofuran>monocrotophos>methomyl;in acetoacetate: chlorpyrifos>monocrotophos > carbofuran > methomyl. The half-life of the four pesticides was less than 10 minute, which attributed to the wide spectrum, strong UV and ozone of arc plasma. Arc plasma would degrade the pesticides residue in fruit and vegetable effectively.更多还原