Effects of nitrogen and phosphorus on the microstructure and ultrastructure of tomato leaves (Solanum lycopersicum)

This study aims to evaluate the effects of nitrogen (N) and phosphorus (P) on tomato leaves at the microscale in order to propose new methods to detect N and P conditions of plants. N and P solutions composed of three N levels (N0.25, 1.75; N1, 7; and N1.5, 10.5 mmol L^?1) and three P levels (P0.25, 0.17; P1, 0.67; and P1.5, 1.01 mmol L^?1) with ten replications. Results showed a significant decrease in the leaf thickness among plants treated with N0.25, N1.5N and P0.25, whereas showed an increase among plants treated with P1.5 (p < 0.05). Stomatal density was reduced in P0.25- and N0.25-treated plants, whereas increased in N1.5- and P1.5-treated plants (p < 0.05). Moreover, N0.25-treated plants showed reduced trichome density, whereas N1.5-treated plants exhibited the highestamount of trichome density (p < 0.05). The densest veins occurred in the leaves of P1.5P-treated plants, then density reduced in plants with N1.5, N1P1, N0.25, P0.25 treatments, in a decreasing order (p < 0.05).     

继电保护用电流互感器的暂态特性数字仿真及电磁优化设计

本文在分析CT的暂态特性及其动态磁化过程的基础上,建立了计及铁芯饱和、局部磁滞回环、动态剩磁影响的CT单、复励磁暂态过程数字仿真模型,提出了继电保护用P、TPX、TPY、TPz级CT的电磁优化设计方法,编制了计算机程序,用于CT的电磁优化设计及数字仿真分析.     

磨盘山水库总氮、总磷变化倾向的灰预测

氮和磷是磨盘山水库水体非点源污染最主要的污染物。根据汇入水库的支流水体中TN、TP的历年实际监测结果,可以模拟虚构历年水库水体中TN、TP的浓度,并以此作为灰预测所需数据,运用灰色模型预测水库水质TN、TP的变化倾向。经4种检验证明,建立的GM(1,1)模型精度较高,预测结果与实际监测浓度接近。从利用单一的GM(1,1)模型和GM(1,1)模型群预测比较可以看出,以模型群统计平均值作为最终预测值,使得预测精度更加准确,提高了预测结果的可信度,从而避免由于信息不稳定性在单一灰色模型所造成的缺陷。     

台湾线虫草单次生子囊孢子菌株交配型基因的初步研究

首次对台湾线虫草无性型—黄山被毛孢菌株的交配型基因进行了较为系统的研究.采用稀释涂布平板法和显微定位法获得台湾线虫草的单次生子囊孢子,并对单次生子囊孢子菌株的交配型基因进行PCR扩增和子实体人工诱导实验.结果表明,在34株单次生子囊孢子菌株中,14个菌株含有MAT1-1基因,4个菌株含有MAT1-2基因,其余16个菌株同时含有MAT1-1和MAT1-2基因;人工诱导子实体的结果显示,含有2种交配型基因的菌株可以生长出更多的子实体.提示台湾线虫草的交配类型可能为同宗配合.     

共轭亚油酸对动物免疫调节的研究

共轭亚油酸是一种功能性脂肪,具有抗癌、抗动脉硬化、抗糖尿病、抗氧化、降低脂肪沉积、促进骨生成、提高免疫力和缓和狼疮等功能。     

鹅细小病毒河北流行株HBZF07 NS1基因的克隆与序列分析

鹅细小病毒HBZF07株经13日龄鹅胚增殖后收集尿囊液,提取病毒基因组总DNA,采用PCR方法,一次性扩增出与预期大小相符的特异性条带.将扩增产物提纯回收后克隆入pMD18-T载体,经转化、筛选及酶切鉴定后,对阳性克隆进行了序列测定和序列分析.测序后拼接的基因长1 892 bp,包含完整的NS1开放阅读框(1 884 bp),编码623个氨基酸.与GenBank中其它毒株的NS1基因核苷酸序列相比,同源性分别为DY(EF515837)98.4%,与B(GPU25749)为99.2%,与HG5/82(AY506546)为93.9%,与YG(AF416726)为93.9%,与SHM319(GPU34761)为97.0%.     

Soil macrofaunal response to sand dune conversion from mobile dunes to fixed dunes in Horqin sandy land,northern China

The response of macrofauna to dune conversion from mobile dunes to fixed dunes was investigated in Horqin sandy land, northern China. Macrofaunal communities were compared in four major stages: mobile dunes (MD), semi-mobile dunes (SMD), semi-fixed dunes (SFD) and fixed dunes (FD). Macrofauna were collected by hand in the field and identified in the lab on the basis of features observed under a magnifying glass. They were then classified into morphotypes at the order and family level. Environmental parameters indicated a significant alteration of the soil environment in the conversion process. A clear increasing trend in abundance, richness, and diversity of the macrofaunal community could be established from mobile dunes to fixed dunes. Data for the different taxa suggested specific responses to dune conversion. Specific groups in the initial stage were predators (Labiduridae and Myrmeleontidae larvae, presumably feeding on Noctuidae and other small flying insects), which in the intermediate stages were replaced by saprophagous taxa (Diptera larvae, feeding on many decaying roots buried in semi-mobile and semi-fixed dunes), and burrowing Tenebrionidae (adults, then larvae) with herbivorous Hemiptera in later fixation stages with higher plant density and cover. Overall, the conversion process, particularly the fixed dunes, provided more suitable habitats with greater soil organic matter and plant cover supporting macrofaunal communities with higher diversity, which further enhanced the stabilization process, benefiting the restoration of soil and vegetation in this semiarid sandy area.     

不同盐分条件下油菜氮、磷、钾素积累与分配差异

为研究不同盐分浓度对油菜氮、磷、钾积累与分配的影响,以三个甘蓝型油菜品种为试验材料,在低、高两种盐分条件下种植,于成熟期取样测定干物质积累量及氮磷钾元素含量.结果 表明:高盐与低盐处理相比,全株及不同器官干重均显著下降.不同处理氮和磷积累量的变化范围分别为141.39～193.14 kg/hm2和21.95～36.24...     

柳州市蔬菜农药残留现状及其对策

为全面了解和掌握广西柳州市蔬菜农药残留现状,为柳州市政府和相关职能部门提供可靠的管理依据,柳州市农产品质量安全检测中心开展了蔬菜农药残留检测工作.2001-2010年共监测3 674份蔬菜样品,检测结果显示,柳州市蔬菜农药残留检测合格率逐年上升,表明柳州市采取的蔬菜安全监管措施效果明显,为广大市民蔬菜食用提供了安全保障...     

河北省奶牛牛病毒性腹泻/粘膜病病毒的分离鉴定

从河北省某规模化奶牛场牛病毒性腹泻/粘膜病(BVD/MD)疑似病例中采集病料,将处理好的病料接种MDBK细胞,盲传9代,得到了不产生细胞病变的病毒。琼脂扩散试验表明本病毒能与牛病毒性腹泻病毒(BVDV)OregonC24标准阳性血清反应,出现沉淀线;细胞培养物用BVD/MD荧光抗体染色检测,可见到荧光着染的特异性细胞,荧光颗粒出现于胞浆中。双抗体夹心ELISA检测病毒抗原结果BVDVOregonC24VP/N为3.141,分离毒P/N为3.012,P/N>2,与BVDVOregonC24V结果一致;电镜观察到圆形、直径为40～60nm,有囊膜,囊膜表面有突起的病毒粒子,与BVDV颗粒基本一致。经RT-CR检测,扩增出了唯一的315bp的目的条带,进一步证实为牛病毒性腹泻/粘膜病病毒。