金花茶新变种——防城金花茶

本文论述了将长柱金花茶Camellia chrysantha(Hu)Tuyama form.longistyla S.L.Mo et Y.C.Zhong升格为新变种,即C.chrysantha(Hu) Tuyama van.,longistyla(S.L.Mo et Y.C.Zhong)J.Y. Chen et X.L.Wang,var.D.ncv.的多种理由,主要是花粉在光学显微镜下的形态羞男l】,尤其是扫描电镜下的外壁纹饰差异。同时,相应将中名改称防城金花茶,借以表明其主要产地。     

An upheaval in u.s. Strategic thought

Early this year, the U.S. land-based force of nuclear missiles became vulnerable to a preemptive attack by the Soviet Union, as the Soviets deployed a large number of highly accurate warheads on their own missiles. They first demonstrated this capability in 1977. Since then, U.S. missile vulnerability has come to assume great importance in superpower relations. Western observers have portrayed the Soviet achievement as a sign of aggression, and made missile vulnerability into a symbol of declining American military strength. The government has proposed a vast military buildup of nuclear weapons, supposedly made necessary by this new threat. But the public is increasingly skeptical, and support for some form of arms control is growing. The first article in this series examines how the United States learned of the Soviet accuracy, and why it caused such great alarm. The next article will examine the Reagan Administration's response to this threat.     

Tech.Sight. Phage display. Affinity selection from biological libraries

Phage display is a simple yet powerful technology that is used to rapidly characterize protein-protein interactions from amongst billions of candidates. This widely practiced technique is used to map antibody epitopes, create vaccines and to engineer peptides, antibodies and other proteins as both diagnostic tools and as human therapeutics. We overview the history of phage display and several recent applications.     

链格孢属一新种——沙棘链格孢

【目的】发现链格孢属新种资源,以丰富生物多样性研究,为植物病害的防治提供依据。【方法】采用实地考察、分离培养和鉴定的方法,与我国和世界已经发现的链格孢属的种特征进行了比较分析。【结果】得到的链格孢属新种沙棘链格孢不同于已发现链格孢属种之处主要在于,其孢子深褐色,长倒棒形,一些孢子近圆柱形,只在孢身与喙处才收缩。【结论】沙棘链格孢与已报道的种在孢子颜色、形状等方面均不同,是一链格孢属新种。研究的模式标本（PSNXAAFS19785）保存在宁夏农林科学院植物病害标本室。     

薇甘菊组织培养及体细胞胚胎发生的研究

研究了4种外植体、10种不同浓度激素组合对薇甘菊(Mikania micrantha H.B.K.)离体再生的影响,并对胚性愈伤组织中的体细胞胚发生发育过程进行了组织细胞学观察.结果表明,所用不同浓度激素组合的培养基均能诱导薇甘菊外植体产生愈伤,培养基以MS+6BA 1 mg/L为最宜;不同种类的愈伤组织再分化结果有明显差异,生长良好的胚性愈伤组织转入分化培养基后可诱导体细胞胚的发生.薇甘菊体细胞胚胎发生的形式为单细胞内起源.体细胞胚起源于胚性愈伤组织的胚性细胞,胚性细胞经过一次不均等分裂产生两个细胞,即胚细胞和胚柄细胞.然后依次经过具胚柄的多细胞原胚,再经过球形胚、心形胚、鱼雷胚阶段,发育成具有子叶的成熟胚状体,然后长成为再生植株.     

红刺玫愈伤组织诱导的遗传转化体系建立(英文)

以红刺玫无菌苗为初始材料,通过探讨外植体、培养条件,以及激素配比浓度和暗培养时间对愈伤组织分化芽的影响,建立了红刺玫叶片愈伤组织诱导的再生体系:MS为初始培养基,暗培养21 d,愈伤组织诱导率达到100%。分化培养基为MS+TDZ 1.5 mg/L+NAA0.05 mg/L,暗培养8 d,芽分化率达48%;通过遗传转化条件优化,建立了以红刺玫愈伤组织为转化受体,通过根癌农杆菌介导,以红刺玫的DFR-RNAi为表达载体,GUS为标记基因的遗传转化体系,转化效率达到50%。     

Cell cycle. Replication meets cohesion.

When a cell replicates its DNA during S phase of the cell cycle, the sister chromatid pairs must stick together like glue until they are separated to opposite ends of the cell (and hence into separate daughter cells) at anaphase. How the cell achieves this is still unclear but, as Takahashi and Yanagida explain in their Perspective, new findings in yeast have identified one molecule, Trf4p, that may be involved both in DNA replication and sister chromatid cohesion (Wang et al.).     

U.K. science budget. Gene jocks, data crunchers hit jackpot

Unveiling its science spending plan for the next 3 years, the U.K. government last week announced major new investments in three key areas: tracking disease genes, leveraging the Internet for data analysis, and supporting emerging industries such as nanotechnology and bioengineering. Although these programs cut across a range of disciplines funded by the U.K.'s science councils, the government also bestowed a long-anticipated gift on astronomers: membership in the European Southern Observatory, which will give U.K. researchers access to the world's largest optical telescope.     

吸水链霉菌桂林新变种的分类研究

从广西桂林的土壤中分离到一株链霉菌（编号为２３４５），它的发酵产物对线虫、菜青虫、松毛虫等畜禽寄生虫及作物害虫等的防治效果显著，它对一些格兰氏阳性菌也有明显的抑制作用，对其进行分类学研究的结果如下：按照链霉菌的分类法，该菌细胞成份属于细胞壁Ｉ型，糖Ｃ型。该菌在高氏培养基、ＩＳＰ－４等培养基上产生丰富的孢子，在斜面上则呈现一片褐色斑。该菌在培养特征、碳源利用以及形态特征等方面均近似于淡紫灰吸水链霉菌，但对淀粉利用能力很强。另外，它对枯草杆菌、藤黄八叠球菌等阳性菌的抗菌作用强，尤其是它的发酵产物可以杀死禽畜体内的线虫，故属淡紫灰吸水链霉菌桂林变种Ｓｔｒｅｐｔｏｍｙｃｅｓｌａｖｅｎｄｕｌｏｈｙｇｒｏｓｃｏｐｉｃｕｓｖａｒ．ｇｕｉｌｉｎｎ．Ｘｉａ．     

Genetics. Motivating hotspots

Only recently have we begun to characterize fine-scale recombination rates in mammals. In her Perspective, Przeworski discusses the work by Myers et al. in which linkage disequilibrium data have been used to produce a high-resolution recombination map for most of the human genome. More than 25,000 putative hotspots have been identified, as well as the first motifs that appear to influence their intensity.     

Myths and realities of u.s. Competitiveness

Most discussion of U.S. competitiveness misstates the problem, focusing on the trade deficit and on fears that an economy whose productivity lags that of its rivals will face economic disaster. In fact, strong automatic forces ensure that the U.S. economy will remain in business and indeed roughly balance its trade even if its productivity performance is dismal. The real issue is the effect of international competition on the mix of goods that the U.S. economy produces. In some industries high productivity is an effect as well as a cause of international competitiveness. There is an intellectually respectable but politically problematic case for government action to create or preserve advantage in such industries.     

Tech.Sight. Gene therapy. Hurdles and hopes for cancer treatment

Remarkable progress has been achieved in the field of gene therapy over the past decade. The initial excitement in this young field has led to the development of more than 500 gene therapy protocols approved for evaluation in clinical trials. As these clinical trials progress, many obstacles have been identified that investigators in the field will need to overcome. Among the most important areas of investigation in the field of cancer gene therapy are 1) development of novel vectors to improve gene delivery, 2) development of tumor-selective binding to improve specific tumor targeting, and 3) improvement of the therapeutic window to reduce the toxicity of gene therapy administered alone or in combination with conventional agents. The challenge is not to replace current strategies for cancer therapy with gene therapy but to incorporate gene therapy as a more rational, molecularly based approach to increase our therapeutic armamentarium.     

Stem cell research. U.K. backs use of embryos, sets vote

The U.K. government last week endorsed a report that advocates tapping embryos for their stem cells, unspecialized cells that may ultimately serve as seed material for growing tissues to treat diseases. It also opens the door to cloning human embryos for research--an activity that has triggered sharp debate. Legislation implementing the recommendations will go to Parliament for a vote this fall.     

百岁兰栽培技术

从非洲纳米比亚引进百岁兰（Welwitschia mirabilis Hook.f.）种子,在成功育苗的基础上,通过百岁兰栽植的小气候环境的对比试验、移植方法的探索以及生长量的测定,总结出一整套百岁兰在国内温室栽培技术,为保存植物界“老寿星”和“活化石”提供技术支持.     

苹果属－亚种──中国苹果

苹果属－亚种──中国苹果李育农（西南农业大学）关键词：苹果属；西洋苹果；亚种ＭＡＬＵＳＤＯＭＥＳＴＩＣＡＳＵＢＳＰ．ＣＨＩＮＥＮＳＩＳＹ．Ｎ．ＬＩ．－ＡＳＵＢＳＰＥＣＩＥＳＯＦＭＡＬＵＳＭＩＬＬ．￥ＬｉＹｕｎｏｎｇ（ＳｏｕｔｈｗｅｓｔＡｇｒｉｃｕｌｔ...     

谢君魔芋染色体数目的观察研究

谢君魔芋(AmorphophallusxieiH.Li,F.GaoetZ.L.Dao,sp.nov)是近年来新发现的极具生产潜力的魔芋新种,其染色体数目目前尚无报道。对谢君魔芋染色体数目采用常规压片法进行了观察研究,表明谢君魔芋染色体数目为26条。     

Energy and the u.s. Economy: a biophysical perspective

A series of hypotheses is presented about the relation of national energy use to national economic activity (both time series and cross-sectional) which offer a different perspective from standard economics for the assessment of historical and current economic events. The analysis incorporates nearly 100 years of time series data and 3 years of cross-sectional data on 87 sectors of the United States economy. Gross national product, labor productivity, and price levels are all correlated closely with various aspects of energy use, and these correlations are improved when corrections are made for energy quality. A large portion of the apparent increase in U.S. energy efficiency has been due to our ability to expand the relative use of high-quality fuels such as petroleum and electricity, and also to relative shifts in fuel use between sectors of the economy. The concept of energy return on investment is introduced as a major driving force in our economy, and data are provided which show a marked decline in energy return on investment for all our principal fuels in recent decades. Future economic growth will depend largely on the net energy yield of alternative fuel sources, and some standard economic models may need to be modified to account for the biophysical constraints on human economic activity.     

宁夏灌区红叶黄栌种子育苗技术

红叶黄栌是一种优良园林绿化观叶树种。主要从种子育苗关键技术中的精选种子、选地、播种、苗期田间水肥管理和病虫害防治等方面阐述了宁夏灌区种植红叶黄栌种子育苗技术。     

卢斯垫刃线虫新种和广东垫刃线虫新种描述（线虫门：垫刃科）

卢斯垫刃线虫新种 (Tylenchuslucin .sp .)和广东垫刃线虫新种 (Tylenchusguangdongensisn .sp .)分别采集于广东省深圳光明农场的玉米 (Zeamays)和宝安马田菜场的葱 (Alliumfistulosum)根际土壤。前者以角质层无明显环纹、有明显的后阴子宫囊等特征明显区别于相似种小垫刃线虫 (TylenchusminorXie&Feng ,1997)和拟小垫刃线虫 (TylenchusparaminorXie&Feng ,1997) ;以口针长 8.3～ 10 .4μm、后阴子宫囊明显和尾短于或等于肛阴距等特征明显区别于相似种微针垫刃线虫 (TylenchusstylolusXie&Feng ,1995 )。后者以头部环纹明显、后阴子宫囊显著等特征区别于相似种小垫刃线虫 (T .minor)和拟小垫刃线虫 (T .paraminor) ;以尾长于肛阴距 ,交合刺较长等特征区别于相似种卢斯垫刃线虫新种 (T .lucin .sp .)和亚戴维恩垫刃线虫 (T .subdavaineiMukhina,1981)。     

青梗白菜细胞核雄性不育基因向乌塌菜中的转育

为解决乌塌菜杂交种生产中的杂交制种手段问题。以大白菜核不育"复等位基因遗传"假说为指导,以青梗小白菜核基因雄性不育系08S02作不育源,采用杂交、自交、兄妹交方法,向乌塌菜可育品系08S05中转育不育基因。选育出具有50%乌塌菜遗传性状、不育株率为100%的核基因雄性不育系,拓宽了青梗白菜核不育基因的应用范围。