首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
林跳鼠亚科分布在亚洲和北美洲,虽然种类及数量都不多,但对该亚科的分类和系统发育关系一直存在争议,近几年对林跳鼠哑科分子系统学的研究,产生了一些与形态学、生物地理学等研究不同的结果.本文对林跳鼠亚科系统学研究的一些工作加以述评,归纳出林跳鼠亚科在系统学方面还存在的问题,并对林跳鼠亚科系统学的进一步研究提出了一些建议.  相似文献   

2.
竹亚科系统学和生物地理学研究进展及存在的问题   总被引:8,自引:1,他引:8  
郭振华  李德铢 《云南植物研究》2002,24(4):431-438,462
对近年来在竹亚科作为一个单系类群的界定、其系统位置的确定、内部系统演化趋势以及地理分布和起源方面研究所取得的进展进行了评述。竹亚科作为一个单系类群仅包括了木本的竹族(Bambuseae)和一个草本的莪利竹族(Olyreae),其中莪利竹族分布在新几内亚的伊里安竹(Buergersiochloa)处于Olyreae最基部。禾本科12个亚科中除了3个亚科为基部类群以外,其余9个亚科分成PACCAD(包括黍亚科,狭义的芦竹亚科,广义的虎尾草亚科,假淡竹叶亚科,三芒草亚科和扁芒草亚科)和BOP单系分支(包括竹亚科,稻亚科和早熟禾亚科)。在BOP支中,竹亚科与早熟禾亚科相近缘,共同组成稻亚科的姐妹群。竹亚科分成草本和木本两个单系类群,木本竹子又分成热带和温带支系,热带支系进一步分成新世界热带和旧世界热带两个单系类群。从现有的化石证据和基部类群的地理分布推断,竹亚科很可能起源于晚白垩纪的冈瓦纳古陆。最后,本文就竹亚科研究尚存在的问题做了初步探讨。  相似文献   

3.
中国紫草科天芥菜亚科花粉形态及其系统学意义   总被引:1,自引:0,他引:1  
为了深入研究紫草科Boraginaceae的分类问题,用光学显微镜和扫描电子显微镜观察了中国紫草科天芥菜亚科Heliotropioideae天芥菜属Heliotropium 6种,砂引草属Messerschmidia 2种和紫丹属Tournefortia 1种植物的花粉形态.它们的花粉为长球形,赤道面观为椭圆形,极面观为六裂圆形或八裂圆形,少数为三角形.萌发孔有三种类型:(1)三孔沟与三假沟交替排列;(2)四孔沟和四假沟交替排列;(3)三孔沟.外壁表面具微弱的小穿孔,皱波状纹饰或表面近光滑.上述结果表明天芥菜亚科三个属之间有密切的亲缘关系.花粉特征表明紫丹属在天芥菜亚科中可能是比较原始的,天芥菜属的演化水平比紫丹属和砂引草属要高,而砂引草属介于其他两个属之间.花粉形态特征显示天芥菜亚科是厚壳树亚科Ehretioideae到紫草亚科Boraginaceae的过渡类型.紫丹属的花粉具三孔沟的萌发孔类型表明天芥菜亚科与破布木亚科Cordioideae有一定的亲缘关系.  相似文献   

4.
5.
为探讨鲴亚科(Xenocyprinae)鱼类系统发育关系, 研究基于2种线粒体基因和5种核基因序列对鲴亚科各物种的系统发育关系和分化时间进行评估。结果显示: 不同方法和数据类型获得了基本一致的拓扑结构。3个属的单系性都得到了很好地支撑; 但是, 它们之间的进化关系却随着分子标记的不同而改变。这一结果可能是由于早期的基因流或谱系的随机分选所致。此外, 银鲴(Xenocypris argentea)、云南鲴(Xenocypris yunnanensis)和黄尾鲴(Xenocypris davidi)之间呈现出嵌套型的谱系关系, 暗示它们之间存在基因交流的可能性。基于化石地层年代校正的分子钟估算结果显示, 鲴亚科主要类群的分化发生在中新世晚期, 约15—12 百万年前(Millions of years ago, Ma), 这与东亚季风强盛时期的时间相吻合。  相似文献   

6.
王向东 《古生物学报》1994,33(1):118-129
运用分支系统学方法,考察有可能归入Antiphyllinae亚科的各属。根据个体发育极向标准对选取的7个性状进行分析,这7个性状为:主隔壁的长短,主内沟的形状和大小,对隔壁的长短和加厚程度,侧隔壁的长度,一级隔壁的排列,一级隔壁从轴部退缩程度,轴部构造等。据以上各性状在每个属中的表现编制出性状极向数据矩阵,输入计算机运算,得到分支图。并得到以下结果:AntiphyllinaeIlina应包括下列10属:ActinophrentisIvanowski,1967;FalsiamplexusFedorowski,1987;LongiclavaEaston,1962;LytvolasmaSoshkina,1925:NeozaphrenlisGrove,1935;MonophyllumFomichev,1953:FasciculophyllumThomson.1883:BradyphyllumGrabau.1928:RotiphyllumHudson,1942;ClaviphyllumHudson,1942。  相似文献   

7.
水龙骨亚科植物叶表皮微形态及其系统学意义   总被引:1,自引:0,他引:1  
利用光学显微镜对水龙骨亚科(Subfam.Polypodioideae Nayar)4属11种1变种植物,即篦齿蕨、日本水龙骨、光茎水龙骨、栗柄水龙骨、假毛柄水龙骨、假友水龙骨、中华水龙骨、友水龙骨、柔毛水龙骨、喜马拉雅水龙骨、蒙自拟水龙骨和穴果棱脉蕨植物的叶表皮微形态进行了观察比较。结果表明:该亚科植物的叶表皮细胞都为不规则型,垂周壁为波状或深波状。它们的气孔器类型有7种,为极细胞型、共环极细胞型、腋下细胞型、聚腋下细胞型、不等细胞型、不规则四细胞型和不规则细胞型。对篦齿蕨属与多足蕨属、栗柄水龙骨与篦齿蕨、光茎水龙骨与日本水龙骨的亲缘关系进行了讨论。  相似文献   

8.
目前甘肃鼢鼠Myospalax cansus、高原鼢鼠 M.baileyi、秦岭鼢鼠M.rufescens的分类地位一直存有争议,多涉及到与中华鼢鼠M.fontanierii的分类关系.本文分别从成体甘肃鼢鼠、高原鼢鼠、秦岭鼢鼠、中华鼢鼠标本的胡须、头部、背部、腹部、前肢取毛样,经清洗和处理后,在倒置显微镜下观察,用目镜测微尺分别测量和计算其5个部位毛发的毛髓质指数.结果表明:甘肃鼢鼠与中华鼢鼠除胡须髓质指数无显著性差异外,其它部位及各部位综合均有显著差异.高原鼢鼠与秦岭鼢鼠除前肢毛髓质指数无显著性差异外,其它部位及各部位综合均有显著差异;与中华鼢鼠除前肢毛髓质指数无显著差异,其它部位及各部位综合均有显著差异.秦岭鼢鼠除与甘肃鼢鼠的腹部及与中华鼢鼠、高原鼢鼠的前肢毛髓质指数无显著差异外,与其它鼢鼠其余部位及各部位综合均有显著性差异.综合考虑,本研究结果支持甘肃鼢鼠、高原鼢鼠、秦岭鼢鼠各自独立为种的观点.  相似文献   

9.
通过对臭蚁亚科7属16种昆虫(凹头臭蚁属philidris因未采集到除模式标本以外的标本,故未包含在其中)线粒体DNA的COⅠ、COⅡ和Cyt b基因部分序列(1 801 bp)进行测定,并从GeneBank下载Leptomyrmex unicolor相应基因片段序列,以江华多刺蚁Polyrhachis jianghuaensis和聚纹双刺猛蚁Diacamma rugosum作外群,重建了中国臭蚁亚科系统发育关系.研究结果支持(狡臭蚁属Technomyrmex+(酸臭蚁属Tapinoma+光胸臭蚁属Liometopum)的关系,虹臭蚁属Iridomyrmex+凹臭蚁属Ochetellus为姐妹群,强烈支持臭蚁属Dolichoderus的单系性,8种臭蚁的遗传关系稳定:((((((平背臭蚁D.flatidorsus+黑腹臭蚁D.taprobanae)+(皱头臭蚁D.rugocapitus+费氏臭蚁D.feae)+双疣臭蚁D.thoracicus)+凹头臭蚁D.incisus)+西伯利亚臭蚁D.sibiricus)+毛臭蚁D.pilosus).系统发育树显示细臭蚁属Leptomyrmex在臭蚁亚科进化过程中的分类地位不确定,没有与同族的虹臭蚁属和凹臭蚁属聚在一起,而是与穴臭蚁属Borhriomyrmex聚在一起互为姐妹群,这与传统的形态分类观点不一致,还有待于进一步研究.  相似文献   

10.
甘肃鼢鼠和中华鼢鼠繁殖特性的研究   总被引:2,自引:0,他引:2  
有关中华鼢鼠(Myospalax fontanieri)繁殖的研究国内已有一些报道(王祖望等,1973,灭鼠和鼠类生物学研究报告,第1集,61—72;郑生武,1980,动物学研究,1(4):465;梁杰荣等,1982,动物学杂志(3):13—16)。有关甘肃鼢鼠(Myospalax cansus)的繁殖尚未见报道。研究种群的繁殖特征对分析种群动态具有重要意义。本文作者于1988年3—10月分别在陕西省延安地区和山西省临汾地区对甘肃鼢鼠和中华鼢鼠的种群繁殖特征进行了研究,现报道如下。  相似文献   

11.
我国放线菌系统学研究历史、现状及未来发展趋势   总被引:4,自引:5,他引:4       下载免费PDF全文
放线菌系统学是以实现对放线菌进行分类、鉴定、命名为目标的基础学科, 因此它是放线菌资源研究和开发利用的重要理论基础。自20世纪50年代起, 我国放线菌系统学的奠基人阎逊初院士及同事们就开创了我国放线菌系统学的研究, 经过近六十年、几代人的艰苦努力, 我国放线菌系统学工作者在国际微生物系统学权威杂志(International Journal of Systematics and Evolutionary of Microbiology, IJSEM)发表的有关放线菌新分类单元的论文数量连续十年排名稳居前列, 部分学者在国际上发表的某些改良的分类技术和新修订的分类系统等为国际同行所广泛采用, 这些均标志着我国放线菌系统学研究在国际上已成为微生物系统学界的一支重要力量。本文全面介绍了我国放线菌系统学研究的发展历程, 同时对其发展现状给予理性分析, 并就未来发展方向进行了展望。  相似文献   

12.
The systematics of the beavers (Castoridae) are reviewed and definitions are presented for each subfamilial group. Four subfamilies are recognized: primitive Agnotocastorinae (divided into two tribes, Agnotocastorini and Anchitheriomyini); burrowing beavers, Palaeocastorinae; giant beavers, Castoroidinae (containing two tribes, Castoroidini and Trogontheriini); and the Castorinae. The agnotocastorines are viewed as the ancestral group for all later subfamilies. The Palaeocastorinae is viewed as a side-branch, not ancestral or closely related to any of the later subfamilies. The Castorinae and Castoroidinae may represent a distinct clade united by dental features.  相似文献   

13.
Simulation games designed as training exercises have been used in a wide variety of fields. With the exception of medical education they have as yet been little used in teaching science. Lebemo is a game simulating research in bacterial genetics. The player has to manipulate data, interpret results, plan an overall strategy, and decide upon appropriate experimental protocols; a combination of features found in research and project work but rarely in traditional laboratory classes. In its present form Lebemo is self-instructional and takes a few hours to play. Lebemo and games like it might prove useful adjuncts to traditional laboratory classes and could perhaps replace more time-consuming project work.  相似文献   

14.
    
Zokor (Mysopalacinae) is a group of subterranean rodents. Although they are regarded as important components in the ecosystems they belong to, due to their underground lifestyle, very little is known about their ecology and behavior. Development of microsatellite markers can potentially assist in addressing behavioral and ecological questions such as dispersal, mating and social systems. Here we report the development of 11 polymorphic microsatellite loci from the genome of Eospalax cansus using 454 shot-gun sequencing. Genetic diversity was assessed using DNA samples of 47 individuals of E. cansus from a single location. Cross-amplification in Eospalax baileyi was also tested, with five polymorphic markers being amplified successfully. These markers are the first published microsatellites loci from E. cansus and will be invaluable for studies addressing ecological and behavioral questions involving E. cansus and E. baileyi, and potentially other species in Mysopalacinae.  相似文献   

15.
16.
17.
Many contemporary race scholars reject the biological reality of race.Elsewhere I have argued that they have been too quick to do so. Part ofthe reason is that they have overlooked the possibility that races canbe defined cladistically. Since the publication of the cladistic raceconcept, a number of questions and objections have been raised. My aimin this paper is to address these objections.  相似文献   

18.
Echinococcosis is a serious helminthic zoonosis in humans, livestock and wildlife. The pathogenic organisms are members of the genus Echinococcus (Cestoda: Taeniidae). Life cycles of Echinococcus spp. are consistently dependent on predator–prey association between two obligate mammalian hosts. Carnivores (canids and felids) serve as definitive hosts for adult tapeworms and their herbivore prey (ungulates, rodents and lagomorphs) as intermediate hosts for metacestode larvae. Humans are involved as an accidental host for metacestode infections. The metacestodes develop in various internal organs, particularly in liver and lungs. Each metacestode of Echinococcus spp. has an organotropism and a characteristic form known as an unilocular (cystic), alveolar or polycystic hydatid. Recent molecular phylogenetic studies have demonstrated that the type species, Echinococcus granulosus, causing cystic echinococcosis is a cryptic species complex. Therefore, the orthodox taxonomy of Echinococcus established from morphological criteria has been revised from the standpoint of phylogenetic systematics. Nine valid species including newly resurrected taxa are recognised as a result of the revision. This review summarises the recent advances in the phylogenetic systematics of Echinococcus, together with the historical backgrounds and molecular epidemiological aspects of each species. A new phylogenetic tree inferred from the mitochondrial genomes of all valid Echinococcus spp. is also presented. The taxonomic nomenclature for Echinococcus oligarthrus is shown to be incorrect and this name should be replaced with Echinococcus oligarthra.  相似文献   

19.
Comments on the taxonomic treatment of Arenaria section Plinthine (Caryophyllaceae) by D. J.Goyder. Comments are given on the taxonomic treatment of Arenaria section Plinthine presented by D. J.Goyder in a revision of this group recently published in the Botanical Journal of the Linnean Society, 97(1): 9–32.  相似文献   

20.
GOYDER, D. J., 1987. A revision of Arenaria section Plinthine (Coryophyllaceae). The systematics of Arenaria section Plinthine are reviewed and a classification is presented, based on detailed field and herbarium studies. Members of the section are found on the mountains of SW Europe and N Africa. Seven taxa are recognized within five species: A. alfacarensis, A. tetraquetra subsp. tetraquetra, A. tetraquetra subsp. amabilis, A. armerina, A. aggregata subsp. aggregata, A. aggregata subsp. erinacea , and A. querioides. Arenaria armerina and A. aggregata subsp. erinacea are extremely polymorphic and include minor morphological variants which have been treated as separate species in previous systematic treatments of the group.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号