CO2浓度升高对2个品种水稻Cu吸收、根形态和植物络合素合成的影响

为探讨CO2浓度升高条件下不同水稻品种粤杂889 (YZ)和荣优398(RY)对耐Cu胁迫性的变化特征,利用水培试验研究不同Cu浓度下CO2浓度升高对2种水稻幼苗生物量、Cu含量、根形态及植物络合素(GSH和PCs)的影响.结果表明,低铜处理对水稻生长具有促进作用,增加2种水稻生物量及根系根毛数、总根长、表面积和体积.随着Cu处理浓度升高,根系GSH和PCs含量分别呈现渐减和渐增趋势.CO2浓度升高条件下,2种水稻生物量显著增加,600 μmol/L Cu处理时增加比例最大,YZ和RY分别增加59.8％和49.0％;水稻根、茎叶Cu含量降低,但根系形态各个指标明显增加,且在高Cu处理下其增加比例较大.CO2浓度升高显著增加根系PCs合成,50 μmol/L Cu处理时增加比例最大,YZ和RY分别增加121.6％,78.7％.在CO2浓度正常与升高条件下,根系GSH、PCs含量与Cu浓度都具有显著相关性.CO2浓度升高通过增加根系形态和PCs含量以增强水稻对Cu的抗逆性,但存在着品种差异,YZ的增加比例大于RY.     

Soil morphological and chemical properties in homegardens on sandy beach ridges along the east coast of Peninsular Malaysia

The morphological and chemical properties of homegardens in the beach ridges with interspersed swales (BRIS) soils were evaluated in order to find a clue for developing sustainable agricultural management. Field survey and soil sampling were conducted at the homegardens and secondary forests in Sungai Ular Village and in the experimental farm of Malaysian Agriculture Research Institute (MARDI), Cherating Station. Chemical fertilizers including ash, charcoal waste and plant litter were applied to the homegardens in both the inland-ward area (HG-I) and in the shoreline area (HG-S). Manure was applied in HG-I and seafood waste from fish processing was buried in the soils in HG-S. High correlation was found between total carbon (T-C) and cation exchange capacity (CEC), indicating soil organic matter was the determinant factor for CEC in the very sandy BRIS soils. The levels of T-C, total nitrogen (T-N), and CEC at 0–10 cm in HG-I in parallel with increasing ages of homegardens. The soils in 0–10 cm and 20–30 cm showed higher levels of T-C and T-N with higher C/N ratios in HG-I than in HG-S and the MARDI farm. The high levels of exchangeable Ca, Mg, and K in HG-I compared with the MARDI farm, suggesting that improved CEC with increasing soil organic matter in HG-I heighten the retention of basic cations supplied as chemical fertilizer, ash, and manure. The level of available P was higher in HG-S than HG-I, attributed by the seafood waste application in the shoreline area. Thus, on the BRIS, the levels of soil organic matter and nutrients can be sustained by the homegarden management although it cannot be regarded as a closed system compared with those in the other tropical regions because chemical fertilizer was used and a certain amounts of nutrients seemed to leach down beyond plant rooting depth.     

具核梭杆菌体外对小鼠巨噬细胞超微形态和机能的影响

本研究对具核梭杆菌(F.nucleatum)感染鼠巨噬细胞进行共同培养之后,分别在10个时段采取上清液和巨噬细胞,用ELISA、qRT-PCR法和扫描电镜检测TNF-α、 IL-1α、 IL-6和IL-8细胞因子,并观察巨噬细胞的超微形态变化。结果显示,4种细胞因子均有高水平表达;IL-8在共培养6～72 h呈高水平表达;IL-6和TNF-α表达水平也较高;IL-1从3 h表达,12 h达最高值,48 h后无表达。qRT-PCR检测结果显示,TNF-α的RNA表达呈波浪式,分别于6,60 h各出现1个高峰值;IL-1α和IL-6呈现正态表达,从3 h开始明显表达至60 h达峰值,此后缓慢下降;IL-8从6 h逐渐上升,至72 h仍呈高水平表达。超微形态观察显示,在F.nucleatum感染的前24 h,巨噬细胞呈收缩状,其表面和周围有大量发育良好F.nucleatum,并呈团块状黏附,巨噬细胞逐渐伸出伪足。30 h后F.nucleatum逐渐发育不良,小而细,而巨噬细胞表面粗糙,有许多大小不一的结节,伪足变粗大。48 h巨噬细胞表面出现胞吐孔,少量细小的F.nucleatum仍然黏附于...     

油菜新雄性不育系Xin1的不育性与恢复性

本文比较了新不育系Xin1 CMS(cytoplsmic male sterility)与我国主要的细胞质雄性不育类型Pol(Polima)CMS、Shan2A CMS、Ogu CMS的花器形态,F1代育性情况及其恢保关系,研究分析了orf224基因Xin1 CMS与Pol CMS等在线粒体基因组上的差异。结果表明新不育系Xin1 CMS花器形态与Pol CMS、Shan2A CMS和Ogu CMS的花器有显著差别。与RF01杂交,得到有正常结构的花器,花粉生活力为90.8%。所试26个测交材料中,有13对(50%)测交F1表现出育性反应不同,在14个Pol CMS和Shan2A CMS的保持系测交Xin1 CMS的F1中,6个Pol CMS和Shan2A CMS的恢复系测交Xin1 CMS的F1中,有5个材料能保持Xin1 CMS,有1个表现为半不育,1个材料能半恢复Xin1 mtRNA CMS。测交结果表明Xin1 CMS与Pol和Shan2A的恢保关系不同。对新不育系Xin1、Polima和Ogu的orf224基因的扩增结果表明Xin1有1条与Pol相同的谱带,缺失Pol的另一条谱带;说明Xin1 CMS是不同于Pol CMS的新不育系。     

凝胶型保水缓释氮肥形貌结构及盐分的影响

采用环境扫描电镜和红外光谱观察和解析凝胶型保水缓释氮肥的形貌及物理结构和化学特征。结果表明,保水缓释氮肥干样品相结构是一个整体不均匀而局部较均匀的凝胶。保水缓释氮肥凝胶吸水膨胀体为透明的水凝胶,具有网络结构和孔隙,这是其存贮水分的物理空间。盐分影响或破坏保水缓释氮肥的物理和化学结构,破坏程度为氯化钠小于氯化钙,氯化钙对保水缓释氮肥网络物理结构的破坏用蒸馏水洗涤几乎不可逆转。因此,提高保水缓释氮肥的耐盐性是提高保水缓释氮肥吸水倍率的重要因素。     

泥石流流域地貌形态的统计分形

流域面积、主沟长度和沟床比降等地形地貌要素,在泥石流的发育和形成中起重要作用,研究证明三者与泥石流沟分布之间存在非线性关系,具有明显的分形特征。回顾了泥石流流域地貌的分形研究,并通过大量的资料分析,对原来泥石流流域地貌的分维计算进行了改进,得到的分维结果更具有关联性。同时,建立了泥石流流域地貌的统计分形模型,对泥石流流域地貌分维的意义进行了详细论述。这为泥石流发育、形成和分布的非线性研究提供了一条定量化途径。     

上海地区杂草稻形态学和农艺性状多样性研究

为了明确上海地区杂草稻形态学和农艺形状的多样性,为杂草稻的田间识别和利用提供理论支持,采用杂草稻田间育苗移栽方法,对杂草稻形态学和农艺性状进行观察,明确上海地区杂草稻形态学和农艺性状多样性。结果表明,上海地区杂草稻形态学和农艺性状多样性较丰富,变异程度较大。上海地区杂草稻主要以籼型和偏籼型为主。通过聚类分析可将36份杂草稻样本主要分为3类。主成分分析结果表明,上海地区杂草稻穗形因子、生育期因子、株型因子、粒型因子、分蘖角因子、结实率因子6个指标累计贡献率达到了85%以上。     

鲨鱼皮微电铸复制工艺研究

采用微电铸技术对生物表面形貌进行直接复制以成形出与生物原型形貌相接近的仿生表面,是生物复制成形技术由高聚物成形向金属沉积成形扩展的新途径。以鲨鱼皮为生物模板,针对其表皮微形貌结构特征,通过倾斜溅射方式先在其鳞片表面沉积导电层,进而采用正负间断脉冲电流对鲨鱼皮生物模板进行微电铸复制,成形出鲨鱼皮微电铸模板及仿鲨鱼表面。复制精度分析结果表明,采用微电铸生物复制成形工艺可以实现对鲨鱼皮外端沟槽微形貌的高逼真复制,证明该工艺可以应用于微尺度、复杂生物表面形貌的直接复制。     

基于视觉的甜瓜形态信息的无损获取

以甜瓜果实的直径微变测量为目标,提出了基于数学形态学和改进的spline插值的图像处理算法,开发了基于视觉的高分辨无损检测系统,实现了甜瓜面积和纵横径等表征形态信息的高精度非接触提取。该算法运算简单,相比传统边缘检测算法更易于提取出较为理想的边缘信息,为揭示甜瓜形态与关键环境因子间的组合响应关系和时空变化特征提供了理论依据。     

Effects of Azospirillum brasilense on root morphology of common bean (Phaseolus vulgaris L.) under different water regimes

 The effects of inoculation with Azospirillum brasilense Cd on root morphology and growth of common bean (Phaseolus vulgaris L.) were studied under different growth systems and water regimes. The root systems were evaluated by image analysis. In a PVC-tube growth system, inoculation with A. brasilense at 10⁷ colony forming units (CFU) ml^–1 increased root length, root projection area, specific root length (m g^–1) and specific root area (cm² g^–1), as compared with non-inoculated controls, resulting in root systems with longer and thinner roots. Water stress induced similar root responses to those observed after inoculation with A. brasilense. No increase in plant biomass was observed in inoculated plants, suggesting that under the tested growth conditions, a relatively larger amount of resources is required for the maintenance of the thinner roots. In water-stressed potted plants, the effect of A. brasilense on tap root length was inoculum-concentration dependent. At 10⁷ CFU ml^–1 this effect was significant as compared to non-inoculated controls. In a pouch system without water stress, inoculation with A. brasilense at a concentration of 10⁵–10⁷ CFU ml^–1 2 days after germination resulted initially (2 days after inoculation) in an increase in root length (95%) and root fresh weight (66%), but reduced root diameter (20%), compared to controls. At this early stage of growth the distribution of root length among the different root diameter classes changed: the thinner-root classes had the largest proportion of longer roots. Received: 3 January 2000