中国栅蛛属2新种记述(蜘蛛目:栅蛛科)

本文记了分别采自云南高黎贡山的栅蛛科栅蛛属Hahnia 2新种:垭口栅蛛,新种S.yakouensis sp.nov.和肾形栅蛛,新种S.reniformis sp.nov..垭口栅蛛后眼列前曲,交媾腔大,扁圆形,交媾孔1个,位于交媾腔下缘,交媾管粗,呈"人"字形下行分成2支再向两侧扭曲.纳精囊有一肓管斜向上伸出,鉴于上述特征而与Hahnia mridulae Tikader,1970不同.肾形栅蛛交媾孔2个,位于生殖厣腹面中央,纳精囊1对,大,肾形,插入器始于生殖球左下方,鉴于上述特征而与Hahnia xinjiangensis Wang et Liang,1989不同. Abstract： The present paper deals with two new species of the genus Hahnia collected from the Gaoligong Mountains Region of Yunnan Province, China: Hahnia yakouensis sp. nov., Hahnia reniformis sp. nov..     

注重发挥博士后科研生力军作用

中国医科大学博士后科研流动站始建1995年。目前学校设有基础医学、临床医学和生物学3个博士后科研流动站。但由于每年国家财力有限,资助名额很少,在有限条件下建立、健全博士后制度,加强对博士后人员的培养,调动博士后人员的积极性是一项重要的研究课题。     

遗传物质的发现者之一——麦卡锡

1944年,3位科学家艾弗里、麦卡锡和麦克劳德在DNA遗传本质方面的发现是20世纪最重要的发现之一,这个发现打开了生物学革命的大门,从而改变了人类对自然界的看法,这项研究还为1953年沃森和克里克DNA双螺旋结构的发现奠定了坚实的基础,但不幸的是3位科学家都未曾荣获诺贝尔奖.通过介绍麦克林·麦卡锡的科学研究,从而对这项发现的基本状况有一个基本的了解.     

生命之树与进化模式:导言

One and half centuries ago, Charles Darwin (1859) presented overwhelming evidence and argued that all life on the earth shared common descent, and "from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved". Ernst Haeckel (1886) and several of his contemporaries attempted to trace the pattern of descent among all extant and extinct forms in what Darwin referred to as "the great Tree of Life". Ever since then, systematists and evolutionary biologists have been exploring morphological, cytogenetic, chemical, developmental and molecular characters, and actively developing theories and methods to infer phylogenetic relationships among organisms from these characters. This endeavor has been especially stimulated by the rise of molecular biology and the emergence of computer science over the past 50 years. At the beginning of the 21st century, we are presented with an unprecedented opportunity to reconstruct the entire Tree of Life, and further, to study evolutionary processes and mechanisms in the context of a robust phylogenetic framework.     

我国微生态学的奠基人——魏曦

魏曦,字东升,1903年12月25日出生于湖南岳阳一个小职员家庭,父亲任职于邮政局.1914～1921年他在家乡湖滨中学读书,毕业后考入长沙湘雅医学院,学习两年后曾参加北伐军,任第四集团军警卫团三等军医.后退出军队,在长沙广雅中学任教.1928年入设立在上海的中央大学医学院(1932年独立为上海医学院)学习,1933年毕业,获博士学位.     

高黎贡山北段东西坡种子植物区系的比较研究

高黎贡山北段的东西坡由于在降雨量和热量分配等方面存在着显著的差异,致使东西坡在植物的种类、组成及区系特征等方面表现出明显的差异.东坡记载野生种子植物152科,580属,1475种及192变种(亚种),西坡记载野生种子植物162科,659属,1804种及186变种(亚种).东西坡种子植物科、属、种的对比分析表明:1)东西坡现代种子植物区系具有相同的历史渊源,但其区系联系减弱了,东西坡区系相似性程度,依科、属、种的顺序依次递减;2)西坡现代种子植物区系比东坡具有更为深刻的热带起源烙印.就科、属、种三个水平来说,东坡的热带成分低于西坡,温带成分高于西坡.许多典型的泛热带大科在西坡比东坡有着更为丰富的种类,其中有些泛热带科分子在东坡缺乏分布,而在西坡找到了合适的驻留之地;3)西坡现代种子植物区系与东喜马拉雅植物区系的联系比东坡紧密,而东坡与高黎贡山以东的区系联系比西坡密切,由于高黎贡山山脉的阻隔,近代植物物种的东西坡交流发生了障碍;4)西坡生态地理环境比东坡更有利于物种的生存、繁衍和分化,它既是古老成分的避难所,又是孕育新生成分的摇篮.     

用叶绿体ndhF和核核糖体ITS序列推断李属(蔷薇科)的系统发育

Sequences of the chloroplast ndhF gene and the nuclear ribosomal ITS regions are employed to reconstruct the phylogeny of Prunus (Rosaceae), and evaluate the classification schemes of this genus. The two data sets are congruent in that the genera Prunus s.l. and Maddenia form a monophyletic group, with Maddenia nested within Prunus. However, the ndhF data set is incongruent with the ITS data supporting two major groups within Prunus one consisting of subgenera Laurocerasus (including Pygeum) and Padus as well as the genus Maddenia and another of subgenera Amygdalus, Cerasus, and Prunus. The ITS data, on the other hand, support a clade composed of subgenera Amygdalus and Prunus and Prunus sect. Microcerasus in addition to a paraphyletic grade of subgenera Laurocerasus and Padus (and the genus Maddenia) taxa. In general, the subgeneric classifications of Prunus s.l. are not supported. The ITS and ndhF phylogenies differ mainly in interspecific relationships and the relative position of the Padus/Laurocerasus group. Both ITS and ndhF data sets suggest that the formerly recognized genus Pygeum is polyphyletic and that the distinction of the subgenera Padus and Laurocerasus is not supported. The biogeographic interactions of the temperate and tropical members in the Padus/Laurocera- sus/Maddenia alliance including Pygeum are shown to be highly dynamic and complex.     

鸡的瞬膜

瞬膜(nictitating membrane),又称第三眼睑,是一种保护眼球、防止灰尘的结构.鸟类的瞬膜位于眼眶的前眼角,为半透明的膜,其内缘具有一种羽毛上皮,借以刷洗角膜上的灰尘.在飞行时能遮覆眼球,以避免干燥气流和灰尘对眼球的伤害.由于瞬膜在鸟类睁眼的一瞬间迅速缩回前眼角,很难拍摄到.最近费了好大的周折,终于拍到了理想的鸡瞬膜照片,现予以发表供生物学界的同行共享(友情提示:如引用请注明原作者).     

途经甘肃的3种水鸟新纪录

2007年10月13日至11月5日进行敦煌市湿地鸟类调查时,分别在南湖湿地与候鸟自然保护区及党河水库使用Leica apo77高倍望远镜观察到3种水鸟,在以往的文献资料中未见其分布于甘肃的报道,应为甘肃鸟类新纪录。笔者用500mm镜头分别拍下3种水鸟的照片。1.赤颈(Podiceps grisegena)2007年10月13日13:30时,在南湖湿地与候鸟自然保护区的阳关水库(渥洼池)记录到2只赤颈。当时水面上同时有凤头(P.cristatus)、黑颈(P.nigricollis)以及大量鸭类、潜鸭类游禽活动,赤颈体形较凤头小,而又明显比黑颈大。其中一只赤颈的…     

铜壁关自然保护区藤本植物多样性研究

为了解铜壁关自然保护区藤本植物现状,经实地考察对其组成和多样性进行了研究。结果表明:本区有藤本植物676种,隶属于65科209属,双子叶藤本植物具有明显优势,计56科192属597种。生活型组成以高位芽藤本种类为主,占藤本植物种数的81.51%。攀援方式中缠绕藤本具有明显优势,占藤本植物种数的53.99%,并提出了斜倚类藤本植物的概念。极高的降雨量、悬殊的海拔、多样的生境类型、广泛发育的各类原始阔叶林,是本区藤本植物极为丰富的根本原因。     

藤本植物生活型系统的修订及中国亚热带东部藤本植物的生活型分析

根据中国亚热带东部藤本植物的特征,修订并扩充了Ｍｕｅｌｌｅｒ－Ｄｏｍｂｏｉｓ和Ｅｌｌｅｎｂｅｒｇ生活型系统中藤本植物分类部分。对本区生活型分析的结果表明,中国亚热带东部藤本植物的生活型谱是以高位芽藤本占绝对优势（７２．７％）其次为地下芽藤本（１７．５％）、地面芽藤本（６．２％）、１年生藤本（２．７％）和地上芽藤本（１．５％）,除地下芽藤本比例略高外,与亚热带常绿阔叶林生活型谱十分接近,具有比较明确     

安徽大别山野生藤本植物区系与生活型分析

大别山野生藤本植物共175种,隶属30科67属,其基本特点是:双子叶植物科属种最多,其中又以小型科属和单种科属较多,大科属较少。区系成分分析表明,热带成分居首位(22.4%),其次是东亚成分(19.4%)、东亚北美洲成分(13.4%);生活型以高芽位藤本106种(60.6%)占优,其后依次为地下芽藤本44种(25.1%)、地面芽藤本13种(7.4%)、一年生藤本8种(4.6%)和地上芽藤本4种(2.3%)。     

华南藤本植物的生态学特性

本文从生态学观点出发,概述华南藤本植物的区系分布、生物学生态学特性、生长型及参与森林结构的作用,以供有关方面参考。     

Influences of herbaceous vines on community characteristics in pioneer succession stages

In the continental tropics, herbaceous vines and lianas are roughly equal in abundance, and the former are even more abundant in the temperate region. However, only little attention has been paid to the study of biological and ecological characteristics of herbaceous vines. In particular, research about effects of herbaceous vines acting as a biological control on plant communities has not been carried out in depth. Herbaceous vines are widely distributed and abundant also in humid subtropical areas, especially in the early stages of forest community succession, but their ecology is little known. The aim of our study is to understand the effect of local herbaceous vines on community characteristics in pioneer succession stages. The hypothesis was tested that herbaceous vines would have predominantly negative effects on co-occurring species, thereby reducing their diversity. Based on a quadrate method, a detailed survey of shrub and herb communities covered by herbaceous vines was conducted in the Jinyun Mountain Nature Reserve of Chongqing, SW China. The sample plots were selected based on the numbers and coverage of vines, distinguishing among high vine coverage plots, middle vine coverage plots and low vine coverage plots. All species in the plots with different herbaceous vine coverage were identified and measured. The measurements for each species included number, average height and coverage. Because of abundant tree seedlings in the habitat of forest edge plots, we only recorded the number of tree seedlings in those plots to evaluate the overall effects of vines on tree seedling regeneration. After the field investigation, herbaceous vines and other species in the plots were harvested respectively, then oven dried and weighed. The results showed that herbaceous vines had high productivity and produced a lot of branches, which caused above-ground competition and mechanical stress to other species. Herbaceous vines seriously affected species composition and species importance values of self-supporting species. In all three habitats, the number of species and families in low coverage samples was larger than that in high coverage samples, and furthermore the identities of species were different between them. Species richness significantly decreased with increasing herbaceous vine coverage, illustrating that some species disappeared. Herbaceous vines reduced species diversity of communities, and as a result, community complexity was decreased, which might also decrease community stability. Biomass of communities of self-supporting species significantly decreased with increasing herbaceous vine coverage, which suggested that herbaceous vines significantly decreased community productivity. The number of seedlings also significantly decreased with increasing herbaceous vine coverage, and seedlings were mainly distributed in lower coverage samples. Herbaceous vines reduced the light exposure in the understory, which may be the mechanistic explanation for the negative influence of vines on the performance of tree seedlings. It was concluded that herbaceous vines affected seedling quantitative dynamics and distribution, and inhibited the natural succession from shrub and herb communities to tree communities. Thus herbaceous vines not only had significant influences on community characteristics in pioneer succession stages, but also on subsequent succession stages.     

Influences of herbaceous vines on community characteristics in pioneer succession stages

In the continental tropics, herbaceous vines and lianas are roughly equal in abundance, and the former are even more abundant in the temperate region. However, only little attention has been paid to the study of biological and ecological characteristics of herbaceous vines. In particular, research about effects of herbaceous vines acting as a biological control on plant communities has not been carried out in depth. Herbaceous vines are widely distributed and abundant also in humid subtropical areas, especially in the early stages of forest community succession, but their ecology is little known. The aim of our study is to understand the effect of local herbaceous vines on community characteristics in pioneer succession stages. The hypothesis was tested that herbaceous vines would have predominantly negative effects on co-occurring species, thereby reducing their diversity. Based on a quadrate method, a detailed survey of shrub and herb communities covered by herbaceous vines was conducted in the Jinyun Mountain Nature Reserve of Chongqing, SW China. The sample plots were selected based on the numbers and coverage of vines, distinguishing among high vine coverage plots, middle vine coverage plots and low vine coverage plots. All species in the plots with different herbaceous vine coverage were identified and measured. The measurements for each species included number, average height and coverage. Because of abundant tree seedlings in the habitat of forest edge plots, we only recorded the number of tree seedlings in those plots to evaluate the overall effects of vines on tree seedling regeneration. After the field investigation, herbaceous vines and other species in the plots were harvested respectively, then oven dried and weighed. The results showed that herbaceous vines had high productivity and produced a lot of branches, which caused above-ground competition and mechanical stress to other species. Herbaceous vines seriously affected species composition and species importance values of self-supporting species. In all three habitats, the number of species and families in low coverage samples was larger than that in high coverage samples, and furthermore the identities of species were different between them. Species richness significantly decreased with increasing herbaceous vine coverage, illustrating that some species disappeared. Herbaceous vines reduced species diversity of communities, and as a result, community complexity was decreased, which might also decrease community stability. Biomass of communities of self-supporting species significantly decreased with increasing herbaceous vine coverage, which suggested that herbaceous vines significantly decreased community productivity. The number of seedlings also significantly decreased with increasing herbaceous vine coverage, and seedlings were mainly distributed in lower coverage samples. Herbaceous vines reduced the light exposure in the understory, which may be the mechanistic explanation for the negative influence of vines on the performance of tree seedlings. It was concluded that herbaceous vines affected seedling quantitative dynamics and distribution, and inhibited the natural succession from shrub and herb communities to tree communities. Thus herbaceous vines not only had significant influences on community characteristics in pioneer succession stages, but also on subsequent succession stages.     

卫矛科16种藤本与乔木次生木质部比较解剖学研究

本文对卫矛科(Celastraceae)16种生长于不同生境的藤本和乔木次生木质部的结构,进行比较解剖学的观察,比较它们之间的异同。本科中南蛇藤属(Celastrus L.)独子藤属(Mo-nocelastrus Wang et Tang)和雷公藤属(Tripterygium Hoook.f.)为典型藤本结构,次生木质部特化水平较高;假卫矛属(Microstropis Wall.et Mcissn)、十齿花属(Dipentoden Dunn)和盾柱属(Pleurostylia Wight.et Arn.)为乔木,次生木质部结构特化水平较低;卫矛属(Eu-onymus L.)中既有藤本,又有乔木,其藤本结构与乔木相似,表现出一系列原始性和保守性。本研究初步探讨藤本与乔木的木质部结构、生活习性与生境之间的关系,为进一步研究卫矛科的系统演化提供一些解剖学的证据。     

The differential responses of lianas and vines to rainfall gradients in distribution and abundance in Qinling Mountains, China

To clarify the differential responses of lianas and vines to rainfall, we investigated the distribution and abundance of climbers along the rainfall gradient in the Qinling Mountains of China. In our study, 28 climbing species were investigated across a rainfall gradient of 500?C1,200?mm. Results indicated that most lianas and vines show restricted distribution along the rainfall gradient, which imply their adaptation to different water availabilities. A significant increase in the percentage of the total climbing species with rainfall was observed. The abundance and richness of lianas increased significantly with rainfall, whereas the vines remained constant. This difference implies that lianas have a higher sensitivity to water availability than vines. During drought, lianas may be vulnerable because of the drought-induced embolism, whereas vines are drought-resistant because of their shorter life spans and safer nutrient storage. Further research on the ecophysiological differences between lianas and vines is needed to provide a mechanistic explanation for the patterns described here.     

华中地区藤本种子植物区系的研究

以湖南和湖北两省为代表对华中地区藤本种子植物的区系进行了研究。本区共有藤本种子植物62科175属838种,其中土著种类有60科159属784种。在科、属、种的水平上对藤本种子植物区系特性进行了较深入的统计和分析,并对本区藤本种子植物与邻近地区的关系、本区内的藤本种子植物的地带性分异进行了探讨。统计表明,本区藤本种子植物种数占该区种子植物总种数的11%,且61.7%的种类主要集中在30种以上的大科中;热带分布型明显多于温带分布型;泛热带、热带亚洲、东亚（中国）特有和东亚—北美间断分布科属比较集中,其中许多属为古老成分;本区藤本种子植物特有成分丰富,计有东亚特有科1科、中国特有属6属、中国特有种507种（其中华中地区特有种35种）。通过研究认为：本区藤本种子植物具有种类丰富、分布类型多样、特有成分较多、区系较古老的特点;与本区的全部种子植物区系相比,藤本种子植物区系的热带性更强,具有明显的热带亲缘性,并与喜马拉雅及中国西南有较强的地理渊源。     

Relationship of Grapevine Yield and Growth to Nematode Densities

Yield, growth, and vigor of individual grape vines were correlated with nematode population densities in a series of California vineyards. In a Hanford sandy loam soil, Xiphinema americanum densities showed negative correlations with yield, growth, and vigor of vines. When vines were categorized according to vigor, X. americanurn densities had little relationship to yield of high-vigor vines, but were negatively correlated with yield of low-vigor vines. Densities of Paratylenchus harnatus were positively correlated with yield, growth, and vigor of vines. Correlations between Meloidogyne spp. densities and vine performance were variable, even when the vines were separated according to soil type and plant vigor. Densities of Meloidogyne spp. populations were generally higher on coarser-textured, sandy soils and the vines were less vigorous there. Densities of P. hamatus were greater in fine-textured soils.