翅果油树根瘤超微结构及其内生菌的观察

作者用光学显微镜,透射电镜和扫描电镜对翅果油树(Eldaeagnus mollis D.)根瘤侵染细胞的超微结构及其内生菌的形态进行了观察研究。翅果油树根瘤中的内生菌具有五种不同的发育形态:菌丝、固氮泡囊、孢囊、孢囊孢子和拟类菌体。内生菌的这些不同形态以及它们在共生固氮中的作用,本文也作了讨论。     

新疆伊犁地区侵染蚕豆和三叶草的豌豆花叶病毒的鉴定

从伊犁地区采集的蚕豆花叶病和三叶草花叶病植株获得的病毒分离物,经接种子鉴别寄主,可系统侵染蚕豆、三叶草、豌豆,局部侵染苋色藜和菜豆。可通过蚕豆蚜进行非持久性传播,不通过种子传播。电镜下,病毒粒体呈线条状,平均长度为756nm。在汁液中的热钝化温度是55℃。体外存活期3天。在感病蚕豆叶超簿切片中,可观察到风轮状内含体。血清反应结果证明,该病毒与马铃薯Y病毒、菜豆黄色花叶病毒和菜豆普通花叶病毒有一定相关性。根据上述特性认为,从伊黎地区蚕豆花叶和三叶草花叶植株得到的病毒分离物,为豌豆花叶病毒(PMV)。     

水稻品种超氧物歧化酶(SOD)活性与氧抑光合的关系

O_2抑光合程度不同的水稻品种,SOD活性存在差异。在40％O_2下,SOD活性被诱导增加水平高、延续时间长的品种,表现O_2抑光合程度小,反之则O_2抑光合程度大。在自然条件下,强光、高温都是诱导SOD活性变化的因素。选择SOD活性高、O_2抑光合程度小的种质资源可能有利于适应对光合不利的逆境条件。     

2,4-D和6-BA对向日葵下胚轴愈伤组织生长及钙调蛋白的影响

自 Anderson和 Cormier(1979)从植物中分离提取钙调蛋白(简称 CaM)后,对它的结构功能进行了广泛的研究,发现 CaM在光合作用(Barr等 1980)、酶的激活(Matsumoto等 1983)、蛋白磷酸化(Gideon等1982)等方面均起着重要作用。还证明CaM与生长素、细胞分裂素以及α-淀粉酶的分泌等有密切关系(Elliott 1983,Raghothama等1983;Saunders等1982)Elliott认为植物激素的促     

似鳡属的系统地位及种的分化(鲤形目:鲤科)

似鳡属(Luciocyprinus Vaillant)是鲤科鱼类中属于鲃系(陈湘粦等,1984)的一个属,下咽齿3行,臀鳍无硬刺,具分枝鳍条5根。过去只记载一个种,外形很像鳡鱼,是由于摄食习性相同而导致的趋同现象(林人端,1981),故称似鳡,在广西俗称墨线鳡,云南俗称杆条鱼。分布于西江水系,包括云南中南部的湖泊,与鳡鱼分布于同一水系,但各占一定的水域,互不重叠。 关于似鳡的拉丁名称,惯用Fustis vivus Lin,是林书颜1932年定的新属新种,     

Clastogen-induced chromosomal breakage as a marker for first trimester prenatal diagnosis of Fanconi anemia

Summary Using cultured trophoblast cells obtained by chorionic villus biopsy, we diagnosed Fanconi anemia (FA) in two pregnancies and excluded it in eight pregnancies at risk for the syndrome. Baseline chromosomal breakage and breakage induced by diepoxybutane (DEB) were analyzed. Increased breakage was used as a marker for the syndrome. Our results were unambiguous and provide a reliable method for prenatal detection of FA in the first trimester of pregnancy.     

Preparation of [B23-D-alanine]des-(B25-B30)-hexapeptide-insulin by a combination of enzymic and non-enzymic synthesis.

Des-(B25-B30)-hexapeptide-insulin with B23-glycine replaced by D-alanine was prepared by a combination of enzymic and non-enzymic syntheses. The purified product was homogeneous in polyacrylamide-gel electrophoresis and could be crystallized. The biological activity in vivo of crystalline [B23-D-Ala]des-(B25-B30)-hexapeptide-insulin was determined as 58% of that of standard pig insulin (27 i.u./mg).     

Changes in the biological activity of agropyrene on combined application with humus substances in the cultivation ofScenedesmus obliquus (TURP.) krüger

The work is concerned with the question of the effect of humic acids on the biological action of agropyrene, the effective substance from the rootstock of Agropyron repens (L.) P. BEAUV. The test organism was the alga Scenedesmus obliquus (TURP.) KRÜGER, cultivated in mineral solution. The basic biological test was the determination of the number and size of the cells of this alga. It was found that the way in which agropyrene acts on combined application with humus acids depends on which humus fraction is used. It can display a synergic action if humic acid is used, since this substance probably facilitates the penetration of agropyrene into the cells. On the other hand, fulvic acid counteracts the activity of agropyrene and this most probably by mutual binding and blocking of active groups and links.     

脊髓灰质炎病毒中Ⅰ9株基因组克隆及其部分结构分析

以脊髓灰质炎病毒RNA为模板,反转录合成了长链ds-cDNA。将合成的脊灰病毒中I9株ds—cDNA片段重组到质粒pAT153上,获得了约占脊灰病毒中I9基因组95％以上的cDNA克隆。对克隆的中I9cDNA部分片段作了限制性内切酶图谱分析和部分核酸的序列分析,发现脊灰病毒中I9部分核酸顺序有所改变。     

青霉素G酰化酶α亚基Ser177的突变对酶活性的影响

用盒式突变和定点突变对大肠杆菌青霉素G酰化酶α亚基177位ser进行了突变研究,结果发现所挑选的突变体均无酶的活力,这一结果可能可以用来解释Ser 177附近肽段和一些青霉素结合蛋白青霉素结合区在一级结构上保持同源性的原因。