自动间断化学分析仪与原子吸收光谱法测定授粉受精期油茶子房的元素含量

为探明油茶授粉受精期的营养元素需求规律,应用全自动间断化学分析仪与原子吸收光谱法测定了授粉受精期的油茶子房主要矿质元素的含量,并且对各矿质元素含量在自交和异交情况下的变化进行了研究分析。结果表明:在油茶授粉受精过程中,九种矿质营养元素含量呈"S"或"W"型曲线变化。N,K,Zn,Cu,Ca,Mn元素含量变化在自交和异交情况下都呈"S"型曲线,N含量在自花授粉20 d达到最高,为3.4458 mg·g~(-1);K含量在异花授粉20 d达到最高,为6.275 5 mg·g~(-1);Zn含量在自花授粉10 d达到最高,为0.070 5 mg·g~(-1);Cu含量在异花授粉5 d到最高,为0.061 0 mg·g~(-1);Ca含量在异花授粉15d达到最高,为3.714 5 mg·g~(-1);Mn含量在自花授粉30 d达到最高,为2.161 5 mg·g~(-1)。Fe,P,Mg元素含量变化自交时呈"S",异交时呈"W"型曲线,Fe含量在自花授粉10 d达到最高,为0.453 0 mg·g~(-1);P含量在自花授粉20 d达到最高,为6.731 8 mg·g~(-1);Mg含量在自花授粉25 d达到最高,为2.724 0 mg·g~(-1)。研究结果可为油茶花期喷施叶面肥,提高油茶结实率和产量提供了一定的资料参考。     

长喙毛莨泽泻双受精过程的细胞学观察

对长喙毛莨泽泻双受精过程进行了细胞学观察，结果表明，开花前３ｈ已可观察到花粉管进入胚囊，开花前２ｈ至开花后８ｈ，大部分雌、雄性核发生融合．合子内的雌、雄性核仁可以融合，以一个大核仁的形式进入分裂期，但核仁正在融合或尚未开始融合的合子同样可以进入分裂期．初生胚乳核内的核仁存在３种情况，即３个核仁或者不融合，或者精子核仁与珠孔端极核核仁融合，或者３个核仁融合成一个大核仁．配子融合属于有丝分裂前的配子融合类型．同一朵花中不同心皮的受精过程有一定顺序，即自花托下部逐渐向上部完成受精作用．     

Airborne Nitrogen Input at Four Locations in the German State of Saxony-Anhalt - Measurements using the 15N-Based ITNI-System

Abstract

The amount of atmospheric N deposition in Germany is actual rather uncertain. Estimates using standard methods indicate an N deposition of 30–35 kg N/ha × year. However, the results of long-term field experiments and newly by the ITNI (Integrated Total Nitrogen Input) system could prove a much higher N input of about 50–60 kg N/ha × year. The reason for this difference is that standard methods use wet-only or bulk collectors, which neglect gaseous and organic N deposition as well as direct N uptake by aerial plant parts. By contrast, the ITNI-system is able to measure the total atmospheric N input using the ¹⁵N isotope dilution method. The input of airborne N into a soil/plant system leads to a dilution of the abundance of a previously applied ¹⁵N tracer over a defined time period. The atmospheric N deposition can be calculated from this dilution.

To estimate the actual N input in Central Germany, ITNI measurements were carried out from autumn 1998 to autumn 2000 at four locations in the German state of Saxony-Anhalt. Atmospheric N depositions between 45 and 75 kg N/ha × year were determined depending on the location. These results closely match to N balances of longterm field experiments. Furthermore, a relationship was found between N deposition and the plant species used as well as plant development.     

同步辐射软X射线近边吸收谱方法研究长期施肥对黑土有机氮官能团的影响

有机态氮是土壤氮素的主要存在形式,在农田生态系统氮循环中占有重要地位。了解土壤有机氮官能团组成,可为制定合理的农田管理措施提供科学依据。同步辐射软X射线近边吸收谱(N K-edge XANES)技术,是原位测定土壤有机氮官能团组成最有效的方法,但利用该技术对长期施肥条件下土壤有机氮官能团组成的研究尚未见报道。本试验利用N K-edge XANES方法,研究了长期(18年)不同施肥措施[即休闲(Fallow)、不施肥(CK)、施氮磷钾化肥(NPK)、有机肥配施化肥(NPKM)、1.5倍量的有机肥配施化肥(1.5NPKM)和玉米秸秆配施化肥(NPKS)]对黑土全土及粘粒中有机氮官能团的影响。结果表明：各处理均在401.2～401.6和402.7～403.1 eV范围内出现特征吸收峰,分别归属为酰胺/胺和吡咯类化合物,粘粒中特征吸收峰通常较全土更为明显。半定量分析结果指出,全土和粘粒均以酰胺/胺的相对比例最高,是有机氮官能团的主要存在形态;与休闲处理相比,对照处理中酰胺/胺的相对比例较低,而吡咯类氮的相对比例较高;有机无机配施条件下,酰胺/胺的相对比例随有机肥量的增加而下降,而吡咯类氮的相对比例则呈相反的变化趋势;全土中以NPKS处理的酰胺/胺相对比例最高,而粘粒中则以休闲处理的腈类/芳香氮相对比例最高。利用N K-edge XANES方法原位测定不同施肥措施下土壤有机氮官能团组成的变化是可行的。     

A Review on Microfluidics: An Aid to Assisted Reproductive Technology

Infertility is a state of the male or female reproductive system that is defined as the failure to achieve pregnancy even after 12 or more months of regular unprotected sexual intercourse. Assisted reproductive technology (ART) plays a crucial role in addressing infertility. Various ART are now available for infertile couples. Fertilization in vitro (IVF), intracytoplasmic sperm injection (ICSI) and intrauterine insemination (IUI) are the most common techniques in this regard. Various microfluidic technologies can incorporate various ART procedures such as embryo and gamete (sperm and oocyte) analysis, sorting, manipulation, culture and monitoring. Hence, this review intends to summarize the current knowledge about the application of this approach towards cell biology to enhance ART.     

黑土长期定位施肥土壤富里酸的荧光特性研究

选取哈尔滨长期定位施肥对照处理(CK)、施用氮磷钾化肥(NPK)、有机肥马粪(OM)及有机肥与无机肥混施(MNPK)四个不同处理的土壤样品,利用荧光检测技术对土壤富里酸(Fulvic acid,FA)组分进行分析。荧光发射、激发与同步扫描主要特征峰及三维荧光图谱Peak a,b,c均显示:与CK比较,NPK处理均出现明显蓝移,而OM与MNPK出现不同程度红移,表明NPK可使土壤FA结构趋于简单化,OM与MNPK处理则使FA结构趋于复杂。通过对不同处理土壤FA荧光指数f450/500与A1 370~412 nm/A370~600 nm,A4 538~600 nm/A370~600 nm,A4/A1荧光面积积分比值等参数比较分析,进一步说明NPK处理土壤FA芳构化程度较低,而OM与MNPK长期施肥均使FA缩合度与芳构化程度升高。     

Loss of Pendimethalin in Surface Runoff from Plots Untilled and Tilled with Tobacco

Abstract

The loss of pendimethalin (N-(ethylpropyl)-2,6-dinitro-3,4-xylidine), a selective herbicide in runoff water was determined on sandy-clay-loam soil plots cultivated with tobacco in relation with the use of ammonium nitrate limestone as fertelizer, for a period of two years, 1990 and 1991. The surface slope of plots was 11% and the use of fertilizer decreased the soil erosion from a value 617 g/m²to 320 g/m². The runoff of surface waters were between 16-24% of the rainfall amounts. Reduction in pendimethalin in waterways results from water loss by infiltration, sediment loss, and by attachment adsorption on vegetative and organic matter. Surface runoff levels were highest for the first runoff event after herbicide application, 1.5 g/10 m² and initial concentrations were related to the time lapse between herbicide application and the date of the first run-off event. Maximum concentrations were 5.95 and 8.54 μg/L in 1990 and 1991 respectively. Persistence studies showed that pendimethalin concentration in runoff of 0.5 cm soil layer decreased by 88.2%, from 2.46 to 0.29 μg/g within 233 days, in 1990 and by 87.6%, from 2.42 to 0.30 μg/g within 235 days in 1991. After 310 day the concentration of pendimethalin was only 0.1 μg/g.     

昆明白小鼠与F1代杂交鼠（昆明白×BALB／c）超排,移植效果的比较

本实验比较了昆明白小鼠与Ｆ_１代杂交鼠（昆明白×ＢＡＬＢ／ｃ）的排卵数、怀孕率、百枚卵产仔数．经统计分析，Ｆ_１代杂交鼠的平均排卵数、怀孕率、百枚卵产仔数均极显著的高于昆明白小鼠．     

大麦和硬粒小麦属间试管受精结籽

大麦和硬粒小麦属间的三个杂交组合用试管受精的方法得到28月赘式管种子，结实率为10.2^20.3男，并得到一株幼苗，其根尖染色体数为2n=21，是属间杂种.用F'DA荧光法检测了不同方法消毒的父本花粉，其生活力比对照均有不同程度的降低，其中麦穗用挤干的?5不酒精棉球初步消毒后，再用15w紫外线灯照射20分钟，效果较好.此外描述了离体授粉后种子发育的动态.     

Distinct and independent dielectrophoretic behavior of the head and tail of sperm and its potential for the safe sorting and isolation of rare spermatozoa

Often, in semen samples with minute amounts of sperm, even the single spermatozoon required to fertilize an oocyte cannot be found in the ejaculate. This is primarily because currently, sperm is generally searched for manually under a microscope. In this study, dielectrophoresis (DEP) was investigated as an alternative automated technique for sorting sperm cells. Using a quadrupolar electrode array it was shown that the head and tail of the sperm had independent and unique crossover frequencies corresponding to the transition of the DEP force from repulsive (negative) to attractive (positive). These surprising results were further analyzed, showing that the head and tail have their own distinct electrical properties. This significant result allows for the sperm's head, which contains the DNA, to be distanced from potentially damaging high electric fields using negative DEP while simultaneously manipulating and sorting the sperm using the positive DEP response of the tail. A proof of concept sorting chip was designed and tested. The low crossover frequency of the tail also allows for the use of a higher conductivity, and thus more physiological, medium than the conventional DEP solutions. Although more research is required to design and optimize an efficient, user‐friendly, and high‐throughput device, this research is a proof of concept that DEP has the potential to automate and improve the processing of semen samples, especially those containing only rare spermatozoa.