Studies on the Piscicidal Components of Justicia Hayatai var. decumbens

Justicidin A, C₂₂H₁₈O₇, mp 263°C and B, C₂₁H₁₆O₆, mp 240°C were isolated as fish-killing components from Justicia Hayatai var. decumbens. The piscicidal activities of both compounds were demonstrated to be as strong as rotenone and about ten times stronger than that of pentachlorophenol.     

一株Streptosporangium sp.的次生代谢产物的研究

通过对Streptosporangium sp.菌株发酵液的初步分离纯化,得到二个化合物,由波谱数据解析鉴定其结构分别为YXJE1(1),7,4′-二羟基黄酮(2)。其中化合物1是新化合物。活性实验证明化合物1,2具有一定的抑制乙酰胆碱酯酶活性。     

一株Streptosporangium sp.次生代谢产物研究Ⅰ

通过对Streptosporangium sp．菌株发酵液的初步分离纯化,得到三个化合物,由波谱解析鉴定为：4,6-二甲基-6-羟基-庚烯-2酮(1),2,6-二甲基-2,6-二羟基-庚4酮(2),3,6-二异丙基-2,5-二酮哌嗪(3)。由活体试验证明2和3对粘虫有一定的抑制活性。     

海洋来源放线菌3275化学成分及抗肿瘤活性研究

从海洋来源的放线菌Streptomyces sp．3275中分到7个化合物,经IR,ESI-MS,NMR等光谱数据鉴定及与文献对照,确定其结构为环（脯-缬）（1）,环（脯-酪）（2）,环（脯-甘）（3）,环（脯-异亮）（4）,环（脯-亮）（5）,胆甾醇（6）及1-甲基-1,2,3,4．四氢咔啉-3-羧酸（7）;并采用SRB法对其抗肿瘤活性进行了测试,其中化合物2,3,5对温敏型小鼠乳腺癌细胞tsFT210显示弱的增殖抑制活性。     

链霉菌形态分化与次级代谢产物合成的研究进展

链霉菌是一类具有复杂的形态分化周期和强大的次级代谢能力的高GC含量的放线菌,能够利用其初级代谢产生的前体化合物和能量,合成多种结构复杂、功能多样的具有生物活性的次级代谢产物,在农业、食品、畜牧业、工业以及医药研究等领域都具有重要的价值。在链霉菌的形态分化后期常常伴随着次级代谢产物的生物合成,并且两者都受到复杂的网络调控;同时链霉菌的形态对次级代谢产物的产量和种类造成很大影响。对链霉菌生长周期的全面理解将加深对链霉菌形态分化与次级代谢产物合成关系的认识。本文将对链霉菌的形态分化过程、形态分化和抗生素合成两者共同的调控因子以及链霉菌形态与抗生素产量之间的关系进行综述,这将有助于理解抗生素的合成过程,也将会在缩短发酵周期、构建高产工程菌株、新型杀菌剂的研发以及新型抗生素的合成等方面给予我们启发。     

Metabolism of phenylpropanoids in Hydrangea serrata var. thunbergii and the biosynthesis of phyllodulcin

DL-Phenylalanine-[3-¹⁴C] and cinnamic acid-[3-¹⁴C] were fed to this plant and the label from cinnamic acid was incorporated into gallic acid, phyllodulcin and quercetin. By feeding p- coumaric acid-[U-³H], caffeic acid-[U-³H] and hydrangea glucoside A-[U-³H], it was possible to show that hydroxylation at C-3′in phyllodulcin occurs after the ring closure of dihydroisocoumarin. The biosynthetic pathway of phyllodulcin in this plant is thus: phenylalanine → cinnamic acid → p- coumaric acid → hydrangenol → phyllodulcin.     

转化酶在高等植物蔗糖代谢中的作用研究进展

蔗糖转化酶在高等植物蔗糖代谢中起着关键的作用。研究表明 ,转化酶参与植物的生长、器官建成、糖分运输、韧皮部卸载及调节库组织糖分构成及水平。近年来关于该酶的生化特性、基因表达与调控以及结构与功能等的研究取得了重要进展。本文介绍了转化酶在植物体内的种类、分布、分子结构特点、生理作用及分子生物学研究进展。     

Studies on reproductive strategies of Vitex negundo L. var. heterophylla (Franch.) Rehder (Lamiaceae) based on morphological characteristics and SSR markers

Vitex negundo L. var. heterophylla (Franch.) Rehder (Lamiaceae) is an important tree species for soil and water conservation, yet the reproductive ecology of this species remains to be elucidated. To investigate the reproductive traits of V. negundo var. heterophylla, the phenology, morphological characteristics (a suite of characters was assessed: floral morphology, nectar production, pollen viability, and stigma receptivity) and mating system of this species were systematically revealed for the first time in this study. Phenological observations, morphological measurements, and nectar production analysis were conducted during anthesis. Pollen viability and stigma receptivity at different flowering stages were measured by biochemical methods. Finally, genetic analysis based on SSR markers was used to reveal the mating system; outcrossing index and pollen‐ovule ratio were also calculated to help analysis. V. negundo var. heterophylla showed several obvious characteristics of outcrossing, such as abundant and attractive flowers, secreting nectar, and emitting scent. In addition, mechanisms such as homogamy and a short anther‐stigma distance that can promote self‐fertilization were also identified in this species. The coexistence of selfing and outcrossing characteristics demonstrates a predominantly outcrossed mixed mating system (outcrossing rate, t = 95%). The scientific information provided by this study may contribute to conservation of V. negundo var. heterophylla from a reproductive perspective.     

Effect of sodium chloride on the nitrate reductase of Suaeda maritima var. macrocarpa

The nitrate reductase (NR) activity extracted from Suaeda maritima is reduced by half in the presence of 0.1 M sodium chloride. This effect of sodi     

南方红豆杉盆栽扦插育苗技术研究

南方红豆杉(Taxus chinensis var. mairei)是中国特有的国家一级保护植物。2009-2010年采用2年龄实生苗为采条母株进行室内盆栽扦插试验研究,结果表明:珍珠岩和河沙两种基质相比较,珍珠岩上生根率显著高于河沙,是更佳选择;用市售的"花语牌"快速促根剂配制成5、10、15、2 0mg/mL 4个浓度分别处理插穗基部并以蒸馏水作对照发现,10 mg/mL、15 mg/mL处理有利于生长,15 mg/mL处理后生根率显著高于5 mg/mL、10 mg/mL、20 mg/mL及对照。再以同一浓度生根粉分别浸泡4 h、8 h、10 h作对比发现,8 h和10 h处理后生长效果较好,10 h的生根率显著高于4 h、8 h。     

提高产抗生素链霉菌紫外诱变正变率的研究

将UV诱变了的产抗生素链霉菌（Streptomyces sp.）AP 19-1菌株之孢子,置于适宜的生长温度27℃与接近抑制生长的胁迫温度33℃下培养,结果表明：在33℃下生长获得的子代菌株中,产抗生素水平超过其出发菌株的正向突变体所占的比例,明显比在27℃下培养的高。27℃下培养,正向突变体占总子代菌株数的25.8%,而在33℃下培养则为58.1%。用17种随机引物对出发菌株与UV诱变子代菌株进行总DNA的RAPD测验证明,在接近抑制生长的温度33℃下培养获得的子代,发生在其DNA水平上的变异程度比在27℃的要高得多。这一方法能较大幅度提高链霉菌紫外诱变育种的工作效率,同时也为链霉菌经紫外诱变后突变形成机制的进一步研究提供了新途径。Abstract: UV irradiated spores of Streptomyces sp. AP 19 -1 strain that can produce antibiotics were incubated at 27 ℃, and 33 ℃ which is close to inhibiting growth temperature, respectively. The results showed that there were much more forward mutants, whose level of producing antibiotics is higher than that of original strain, among the offspring of UV irradiated spores grown at 33 ℃, compared to that grown at 27 ℃. The percentage of the forward mutants was 25.8 % at 27 ℃ and 58.1% at 33 ℃. The progeny strains and the original strain were tested by RAPD using total DNA with 17 primers. It was demonstrated that more variations occurred in the chromosomal DNA of the progeny strains grown at 33 ℃ than in that at 27 ℃. This method facilitates increasing the efficiency of induced mutagenesis in breeding and provides a new way to study the mechanisms of mutation formation in UV irradiated Streptomyces sp. cells.     

Nitrogen nutrition in the estuarine zone: the case of Suaeda maritima var. macrocarpa

Suaeda maritima L. var. macrocarpa is a halophytic species distributed in the lower parts of salt marshes of the French coasts. The influence of salinity on nitrogen nutrition and on levels of the key enzymes involved in nitrogen assimilation is analyzed by growing Suaeda under experimental conditions. Use of ¹⁵N-labelled NO₃ ^- and NH₄ ⁺ shows that both ions are effective sources of inorganic nitrogen for Suaeda. The plant is found to use NH₄ ⁺ ions with a good yield, chiefly at high salinities (up to 130 mM). Nitrate reduction and ammonium assimilation by the glutamine synthetase/glutamate synthase pathway occurs mainly in leaves when Suaeda is grown at optimal saline conditions (130 mM NaCl). Absence of NaCl creates less favourable conditions and lowers the activity of nitrate reductase and glutamine synthetase but leads to an important activity of glutamate dehydrogenase in roots. This enzyme could play a major role under suboptimal environmental conditions (i.e., absence of NaCl for Suaeda maritima).Part of this paper is taken from a thesis that was submitted by J. P. Billard in fulfillment of the Doctorat d'Etat degree at the University of Caen, France.     

橐吾属植物的研究进度

对近年来橐吾属植物的研究文献进行综述,主要内容有该属植物的化学成分、药理作用及其它方面的研究情况。     

Studies on the Natural Flavoux Components of Psidium gunajava L. Fruit

In the study Amberlite XAD-4 resin was employed as an adsorbent, which adsorbed the natural flavour sent forth from Psidium guajava L. fruit. The eluant of the adsorbate was concentrated by using a K-D concentrator. The concentrate was analyzed by dual capillary gas chromatography-mass spectrometry and temperature programed retention index on dual columns. A total of 25 substances were identified, which amounted to 98% of the total area of .the peaks. Four acetals were reported for the first time as guava components, i.e., l,l-dietho- xymethane, l,l-diethoxyethane, 1,1-diethoxyhexane and acetaldehyde ethyl cis-3-hexenyl acetal. Evaluation at an odour port during GC showed that the sharp characteristic aroma sent forth from guava fruitis attributed to l,l-diethoxymethane and l,l-diethoxyethane principally. It was discussed that the method of combining the dual column GC-MS with the dual column retention index could increase the reliability of the identification results.     

Studies on the regeneration-restore and karyotype of protoplast in Metarhizium anisopliae var. majus

Abstract:  The characteristics and regeneration-restore of protoplasts and its karyotype of an insect pathological fungus, Metarhizium anisopliae var. majus were studied. Among the protoplasts, 25.3% were without a nucleus, and 74.7% contained a nucleus. Among the nucleus protoplasts, 53.6% contained a single nucleus. The regeneration-restore of protoplasts was of three distinct shapes. Considering the frequency of regeneration and the growing speed of the colony, 0.7 mol/l glucose was the optimum as osmotic stabilizer of culture medium in the regeneration-restore of the protoplasts. The chromosomal DNA molecules of M. anisopliae var. majus have been separated into seven bands by pulsed-field gel electrophoreses. Using the Schizosaccharomyces pombe chromosomes as size standard, the size of chromosomal DNA was estimated to be 1.1–6.5 Mb and its karyotype exhibited polytypism among strains.     

Comparative Studies on the Estimation of Genetic Variances by Several Variance Components Estimation Method

Using a quantitative genetic model, this paper compares four different methods for estimating genetic variance components. Given various genetic parameters, data were generated and estimates computed. The number of negative estimates, the sample mean, the sample variance, and the sample mean squared error were computed for each method. It is shown that, if the genetic values are not very small, the traditional MATHER -JINKS method is at least as good as any other method. The ML method might be preferable only if the genetic values are very small and the number of loci large.