丽江紫乌头中的二萜生物碱

 对丽江紫乌头中的二萜生物碱进行研究.利用反复硅胶柱层析,重结晶等分离手段从中分离鉴定了6个二萜生物碱:查斯曼宁(chasmanineⅠ),塔拉萨敏(talatizamine Ⅱ),草乌甲素(crassicauline A Ⅲ),丽江乌头碱(foresaconitine Ⅳ),acoforestinine(Ⅴ),滇乌碱(yunaconitine Ⅵ).其中化合物Ⅰ、Ⅲ、Ⅳ、Ⅴ为首次从该种植物中分离得到.     

细叶杜香挥发油抑菌和杀菌作用的研究

应用水蒸气蒸馏法提取细叶杜香挥发油,采用丙酮溶剂溶解杜香挥发油,以青霉菌、酵母菌和金黄色葡萄球菌作供试菌种,在实验中观察不同浓度的细叶杜香挥发油溶液对不同菌种的作用,研究其抑菌和杀菌作用.     

Synergistic defensive mechanism of phytochelatins and antioxidative enzymes in Brassica chinensis L. against Cd stress

Brassica chinensis L. was chosen and exposed to different concentrations of Cd exposure to evaluate its Cd-accumulating capacity and its potential cellular defensive mechanisms. Cd accumulation in the shoots and roots of B. chinensis was up to 1348.3±461.8 and 3761.0±795.0 mg per killogram of dry weight, respectively, under 200 μmol/L of Cd exposure. Increasing Cd accumulation in the plant was accompanied by rapid accumulation of phytochelatins (PCs), and the sequestration of Cd by PCs provided a primary cellular mechanism for Cd detoxification and tolerance of B. chinensis. Furthermore, malondialdehyde formation, hydrogen peroxide content and antioxidative enzyme activities such as superoxide dismutase, catalase, guaiacol peroxidase and ascorbate peroxidase were observed in the shoots of Cd-stressed B. chinensis. Increasing enzyme activities in response to concentrations of 5 to 50 μmol/L Cd showed an efficient defense against oxidative stress, suggesting that the antioxidative system was a secondary defensive mechanism. These resulted in reduced free Cd damage and enhanced Cd accumulation and tolerance. Glutathione plays a pivotal role in these two detoxification pathways. In general, these results suggested that PCs and the antioxidative system are synergistic in combatting Cd-induced oxidative stress and that they play important roles in Cd detoxification of B. chinensis, and also give a deep understanding of the natural defensive mechanisms in plants under heavy metal stress.     

蕨游动精细胞的研究

电镜研究表明蕨精细胞在发育早期为多角形细胞，具有细胞壁，多层结构和微管，但不具鞭毛，核圆形或椭圆形，随着精细胞的发育，质膜退缩远离细胞壁，在细胞壁和质膜之间质下一个空间，细胞核螺旋化并有大量鞭毛形成，最后精细胞发育形成具有鞭毛的游动精子。     

全光自动喷雾嫩枝扦插桧柏的研究

本文报道了利用北京桧柏、丹东桧柏．研究柏树全光雾插在园林绿化繁殖中先进的处理技术，以其在生产上得以推广．     

The modified method of upwind with finite difference fractional steps procedure for the numerical simulation and analysis of seawater intrusion

Numerical simulation and analysis of seawater intrusion is the mathematical basis for modern environmental science. Its mathematical model is the nonlinear coupled system of partial differential equations with initial-boundary problems. For a generic case of a three-dimensional bounded region, the modified method of upwind with finite difference fractional steps procedure is put forward. Optimal order estimates in L² norm are derived for the error in the approximation solution. The present method has been successfully used in predicting the consequences of seawater intrusion and protection projects.     

An antiviral factor fromMelia azedarach L. prevents Tacaribe virus encephalitis in mice

Summary Treatment of neonatal mice with an antiviral factor, (AVF), obtained from the leaves ofMelia azederach L. protected them against lethal encephalitis caused by Tacaribe virus inoculation. The degree of protection obtained varied from 66% to 100% depending on the virus dose. Similarly, administration of AVF to nursing mothers protected their offspring from developing virus encephalitis. AVF does not directly inactivate Tacaribe virus; it inhibits an early step (s) in the replication process in cell cultures.Dedicated to Prof. Luis Leloir on his 80th birthday.Acknowledgment. This study was supported by Grant 9353/84 from the Consejo Nacional de Investigaciones Cientificas y Técnicas (CONICET), Argentina.     

高空气球搭载诱导水稻育性降低突变体RAPD分析

选用300对引物，对经高空气球30km搭载飞行8h后返地种植筛选获得的水稻育性降低突变体基因组进行DNA多态性分析，结果发现：育性降低突变体与原种之间存在多态性．     

美国悬铃木种源苗期的性状变异

总结了美国中南部密西西比州等4州44个悬铃木种源在安徽黄山育苗试验的结果。结果表明：在黄山的地理、气候条件下，苗期生长迅速，当年苗高可达92．5cm，地径0．75cm，表现出较好的速生性能。幼苗叶片对低温、初霜的生理反应有明显差异，但主梢、侧枝均无受冻现象，表明各种源都具有较强的抗寒性，适宜在我国亚热带地区引种栽植。种源间苗高、地径生长量差异均达显以上水平。苗高、地径生长快的悬铃木优良种源，多分布于美国中南部纬度偏低、经度偏高的地区，其中优于均值的阿拉巴马州L—2—10—21^#、路易斯安那州F—1—08—21^#、密西西比州B—1—10—29^#和I—2—02—20^#4个种源可作为我国亚热带地区引种的初选优良种源。