杭州西湖藻类动态模型研究

该模型按照年度来描述西湖四类藻类(蓝藻门、绿藻门、隐藻门、硅藻门)的动态变化.结果表明,模型作出的状态变量的描述是理想的,并且对于系统强制函数改变能给予合理响应.模型还对引水量,引水或溪流的含磷量及疏竣湖泥量的改变给水体带来的变化进行了预测.       

Inundative field releases and evaluation of three predators for Bemisia tabaci (Hemiptera: Aleyrodidae) management in three vegetable crops

Abstract The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is a global pest on numerous crops, including vegetables. Weekly inundative releases of a coccinellid predator (Coccinella undecimpunctata L. [Coleoptera: Coccinellidae]), a common green lacewing predator (Chrysoperla carnea Stephen [Neuroptera: Chrysopidae]), and a mirid predator (Macrolophus caliginosus[Wagner][Hemiptera: Miridae]) were independently made in three vegetable crops (cabbage [Brassica oleracea var. capitata L.], cucumber [Cucumis sativus L.], and squash [Cucurbita pepo L.]) for the management of the sweetpotato whitefly. Approximately 1 million to 2.5 million larvae or nymphs of each predator were released in the vegetable crops during 20 weeks. Whitefly populations were reduced by ≈ 25%–45% during most of the season in each crop where each predator was released. The effect of each predator was similar on whitefly population reduction. Late in the season (October) when whitefly populations were low, generally no benefit was obtained from releasing the predators. Numbers of predators recovered during sampling in all crops were greatest for C. carnea, but this corresponded with the fact that more individuals of this predator were released than any other predator in the experiment. These results help define the utility of these natural enemies for managing B. tabaci in vegetable crops.     

Semaphorin4D的作用机制与功能

Semaphorins家族是一类以结构中具有sema区域为共同特征的蛋白,Semaphorin4D(Sema4D)是其成员之一.Sema4D与受体丛状蛋白B1(PlexinB1)和分化抗原簇72(cluster of differentiation antigen72,CD72)结合,通过多种信号转导途径,在神经系统的轴突导向,免疫系统中T、B细胞的活化和免疫调节中发挥关键作用.最近发现,Sema4D在许多人体肿瘤组织中高表达,且对血管发生及肿瘤侵袭转移起重要作用.本文旨在对Sema4D的结构、作用机制及生物学功能的研究最新进展作一综述.     

银桦酸和银桦内酯的生源探讨

新的植物产物银桦内酯（I）（Grevillone)（即 6-羟基香豆素,－Hydroxycou－marin）与其结构相应的开环酸——银桦酸（Ⅱ）（Grevillic acid）（即2,5-二羟基-反式-桂皮酸,2,5－Dihydroxy－trans－cinnamic acid）共存于山龙眼科（Proteaceae）的银桦（Grevillea robusta A．Cunn．）叶,提示它们在生物化学上是密切相关的。并且,无论是银桦内酯或银桦酸,在植物界里迄今仅发现于银桦[1]中。桂皮酸（III）（Cinnamic acid）的羟基化衍生物及其结构相应的内酯——香豆素类化合物,都是高等植物的典型代谢产物[4]。在双子叶植物里,苯基丙氨酸（Phenylalanine）是它们的共同前体[4,5]。最常见的羟基桂皮酸类是P-香豆酸（IV）（P-Coumaric acid）,咖啡酸（V）（Caffeic acid）,阿魏酸（Ⅵ）（Ferulic acid）和芥子酸（Ⅶ）Sinapic acid）。它们之中的一个或几个,以酯或甙的结合形式存在于每种高等植物[6]中,并且在代谢上密切相关[3,4]。这几个酚酸的共同特征是在对位碳上连接着氧原子（羟基）。显然,这与几乎所有天然香豆素类（Coumarins）化合物都在 7位碳（C7）上连接着氧原子[7,8]的特征在结构关系上是一致的。表1列出了在高等植物里最常见的几个羟基桂皮酸[2, 4]和香豆素类化合物[4,7]。邻-羟基桂皮酸类[6]（O－Hydroxycinnamic acids）和间-羟基桂皮酸（m-Hydroxycinnamic acid）在植物界里较罕见。     

水稻OsMY1和OsRacD基因互作的分子鉴定

OsRacD是光敏核不育水稻农垦58S光周期育性转换信号通路中的重要分子开关,通过酵母双杂交筛选,从水稻幼穗中分离到一种与OsRacD 互作的新的肌球蛋白重链编码基因的cDNA片段,命名为OsMY1。本文在酵母双杂交体系鉴定的基础上,构建了OsMY1和OsRacD的原核表达载体,表达和纯化了融合蛋白GST-OsMY1 和His6-OsRacD, 通过pull down实验进一步确认了上述互作关系。本研究提示OsMY1和OsRacD可能在功能上相关,为深入研究二者在水稻生理功能上的联系提供了重要线索和依据。     

A NEW SPECIES OF LYCOPODIUM L．FROM SICHUAN

Species L. herteriano Kumm. similis, sed differt foliis angusto-ellipticis vel oblanceolatis, superne dentatis. A L. serrato Th1lnb. foliis subcoriaceis, costis utrinque leyiter visibilibus differt.Caules erecti, circ. 18 cm. alti, multidichotomi, basi 3 min. diametro. Folia spiraliter disposita 6-fariam, reflexa, subcoriacea, angusto-elliptica vel oblanceolata,7-9 mm. longa et 1.5-2 mm. lata, apice acuminata versus basin angustata, superne remote dentatal costis utrinque paullo prominentibus. Sporangia in ramulis juvenalibus, axillaria, reniformia, luteola, 1 mm. longa et l.5 mm. lata.     

THE ALKALOIDS OF RAUWOLFIA YUNNANENSIS TSIANG

Four alkaloids had been isolated from the roots of Rauwolfia yunnanensis Tsiang. Three of them are identified as reserpine, ajmaline and ajmalicine res-pectively by comparing their physical and chemical properties with those of the authentic samples. It seems that the other remained alkaloid is a new compound which has the formula C22H26O4N2 on the elementary analysis of base and it's hydrochloride salf, [α]D+l06' (CHCl3). It should be decomposed by heating without characteristic meltinq point. According to it's IR spectrum it has indole group, hydroxyI group and αβunsaturafed carboxylic metbyl ester and seems to be a serpentine derivative.