高频电磁辐射对生殖系统损伤的研究

本文对关于微波和移动电话辐射等高频电磁辐射对生殖系统的损伤的研究加以总结,系统研究高频辐射对生殖的影响.     

一株新的耐辐射菌WGR702的分离鉴定及耐辐射特性

从辐射污染的土壤中分离到一株新的耐辐射菌WGR702.该菌为革兰氏阳性球菌,直径1.5 μm～2.5μm.菌体呈粉红色、能运动、兼性厌氧及不产孢子.其生长温度和pH范围分别为10℃～35℃和pH 5.0～10.0.(G C)mol%含量为60.5%.UV和γ射线辐射检测表明WGR702具有很强的耐辐射性.16S rDNA序列(EU315117)分析表明,菌株 WGR702与沙雷氏菌属(Serratia)菌株16S rDNA序列有很高相似性(94.79%～98.53%),但与沙雷氏菌属已报道菌株最大不同点是菌株WGR702细胞为球状,且革兰氏阳性.结合形态、生理生化特征分析表明菌株WGR702可能是沙雷氏菌属(Serratia)的一个新种.     

Variations in the Volatile Organic Compound Emission Potential of Plant Functional Groups in the Temperate Grassland Vegetation of Inner Mongolia, China

The biogenic volatile organic compounds (VOC) emitted by the vegetation of a terrestrial ecosystem play a key role in both regional air quality and tropospheric chemistry. To describe the general emission properties of VOC of different plant functional groups (PFG) in a typical temperate grassland in Inner Mongolia, China, we randomly selected 175 plant species and measured the quantities of isoprene and monoterpene in situ. Results showed that most plants had low VOC emission potential at the species level,especially for some dominant plants, such as Leymus chinensis Tzvel., Stipa grandis Smirn., and Agropyron cristatum Gaertn. At the PFG level, the lowest VOC emission potential was found for perennial rhizome grasses, a major PFG in a typical temperate grassland ecosystem. The effects of overgrazing and subsequent vegetation succession on the emission of VOC by different plant life form functional groups (PLFG)were also discussed.     

太湖典型草、藻型湖区紫外辐射的衰减及影响因素分析

2004年4月通过野外原位观测和实验室测定相结合的方法对东太湖和梅梁湾典型草、藻型湖区紫外辐射光谱衰减及影响因素进行了研究。结果表明,320nm(UV-B)、380nm(UV-A)的衰减系数在6.33~19.59m-1、3.41~13.64m-1间变化,对应的1%表面光强穿透深度分别为0.24~0.73m、0.35~1.35m,到达湖面的99%UV-B辐射在0.5m左右表层水就衰减完毕,东太湖和梅梁湾紫外辐射衰减系数存在明显的湖区差异;溶解性有机碳(DOC)的浓度在6.60~17.17mg/L间变化,其均值为(9.99±2.48)mg/L;375nm波长处CDOM吸收系数为1.78~6.25m-1,均值为(3.70±1.10)m-1;在短波部分CDOM吸收与DOC浓度存在显著性相关,相关性大致随波长降低而增加,320nm处的线性关系式:ad320=0.885DOC 2.182;紫外辐射衰减主要受制于水体中的CDOM浓度,衰减系数与DOC浓度、CDOM吸收系数存在显著性相关,340nm处的关系式分别为:Kd340=0.82 1.05DOC、Kd340=1.98 1.49ad340。在太湖紫外辐射衰减还要受悬浮物和叶绿素a浓度的影响,衰减系数与DOC、叶绿素a和悬浮物浓度多元回归的结果明显要高于单独与DOC浓度或CDOM吸收系数的回归结果。     

夏季绿洲生态环境对荒漠背景地表能量过程的扰动

利用观测试验资料,对比分析了夏季典型晴天敦煌绿洲与周围荒漠戈壁背景地表过程的差异,揭示了绿洲生态系统对干旱区荒漠背景地表过程的扰动特征。结果表明:绿洲地表净辐射日平均要高出周围荒漠戈壁背景60 W/m2以上,约占绿洲净辐射的1/4以上。对绿洲高出的净辐射贡献最大的是绿洲相对低的地表长波辐射,其次是较高的太阳总辐射。而绿洲相对较低的大气长波辐射对高出的净辐射有较大的负贡献,特别是地表反射辐射也有很小的负贡献。绿洲高出的地表净辐射主要贡献于加强潜热和地热流量,还有一部分被绿洲地表能量不平衡差额所占,它实际上可能由一般地表热量平衡所不考虑的垂直热量平流来输送。而绿洲明显低于荒漠背景的感热通量则节省了一部分净辐射能量。     

UV-B辐射增强对海洋大型藻与微型藻种群生长关系的影响

选用孔石莼和青岛大扁藻为海洋大型藻和微型藻的代表,通过室内添加模拟试验研究了UV-B辐射增强对孔石莼(重量固定)与青岛大扁藻(密度不同)种群生长关系的影响。结果表明:(1)在单养情况下,4个UV-B辐射剂量都对孔石莼的生长产生抑制作用;对青岛大扁藻生长的影响却不同,低剂量(U-1)的UV-B辐射对青岛大扁藻的生长有促进作用,而高剂量的UV-B辐射则有显著的抑制作用;且因初始接种密度不同而各异。(2)在共养情况下,微藻对孔石莼的生长表现出一定的抑制作用,随着微藻初始接种密度的增加,其抑制作用亦增加;反之,在共培养的初始阶段(6 d内)孔石莼对微藻的生长也有抑制作用,但后期阶段(9 d后)表现出促进作用。(3)在共培养的同时附加UV-B辐射处理,随着初始接种密度的增加,青岛大扁藻对孔石莼生长的抑制作用更加明显;同时,与共养相比较,孔石莼对微藻生长的抑制作用亦趋于明显。     

UV-B辐射引起的绿豆幼苗叶片Rubisco量降低与H2O2含量升高有关

为了探讨UV-B辐射引起的Rubisco含量降低的可能机制,研究了两个绿豆品种(秦豆-20和中绿-1)幼苗在UV-B辐射下叶片Rubisco含量、蛋白水解酶活性和H2O2含量的变化.结果表明:UV-B辐射显著加速了两个绿豆品种幼苗叶片H2O2含量和蛋白水解酶活性上升,使Rubiscco含量下降.秦豆-20品种在UV-B辐射下H2O2含量和蛋白水解酶活性的上升程度明显大于中绿-1,相应其Rubisco含量的下降程度也大于中绿-1.抗坏血酸处理能明显降低UV-B辐射下两品种幼苗叶片H2O2含量,同时明显抑制蛋白水解酶活性的上升及Rubisco含量的下降.结果说明UV-B辐射诱导Rubisco含量的降低可能通过提高H2O2水平从而加强蛋白水解酶系统的活化而加速了Rubisco的降解.     

增强UV-B辐射和NaCl复合胁迫下绿豆光合作用的气孔和非气孔限制

研究了0.35 W/m2的UV-B辐射、0.4%NACl及其复合胁迫下绿豆(Phaseolus radiatus L.)幼苗光合作用的气孔和非气孔限制.发现各胁迫处理下,幼苗净光合速率、气孔导度、光合能力、羧化效率和Rubisco含量均明显降低;细胞间隙CO2浓度在各胁迫处理前期低于对照,后期高于对照;气孔限制值除复合处理第5天外,其余均高于对照;复合处理下上述指标的变化程度均大于两胁迫因子单独处理.表明各胁迫下光合速率的降低既有气孔因素也有非气孔因素,但前期以气孔限制为主,后期以非气孔限制为主;Rubisco含量的降低是各胁迫下光合速率降低的非气孔因素.     

Transgenic peanut plants obtained by particle bombardment via somatic embryogenesis regeneration system.

After pre-culture and treatment of osmosis, cotyledons of immature peanut (Arachis hypogaea L.) zygotic embryos were transformed via particle bombardment with a plasmid containing a chimeric hph gene conferring resistance to hygromycin and a chimeric intron-gus gene. Selection for hygromycin resistant calluses and somatic embryos was initiated at 10th d post-bombardment on medium containing 10-25 mg/L hygromycin. Under continuous selection, hygromycin resistant plantlets were regenerated from somatic embryos and were recovered from nearly 1.6% of the bombarded cotyledons. The presence and integration of foreign DNA in regenerated hygromycin resistant plants was confirmed by PCR (polymerase chain reaction) for the intron-gus gene and by Southern hybridization of the hph gene. GUS enzyme activity was detected in leaflets from transgenic plants but not from control, non-transformed plants. The production of transgenic plants are mainly based on a newly improved somatic embryogenesis regeneration system developed by us.     

^60Co—γ射线对唐菖蒲染色体的影响

4组各16枚唐菖蒲种球分别经4Kγ、8kγ和15kγ剂量^60Co-γ射线照射后培养根尖,组织学制片,盐酸地衣红染色,光学显微镜观察。结果表明,与对照组相比,经过照射的样本细胞内具有染色体桥、核空泡化、落后染色体等染色体畸变现象,其中4kγ-8kγ剂量的^60Co-γ射线是较为适宜的唐菖蒲育种的照射剂量。