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1.
郭水良 《植物学报》2002,19(5):567-574
车前属植物是理论生态学、生理生态学、进化生物学研究的理想材料。本文综述了近年来国内外学者在车前属生态学、进化生物学、系统分类学方面的研究概况。  相似文献   

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生态学与进化生物学   总被引:2,自引:0,他引:2  
生态学,这门研究生物与环境之关系的学科,在19世纪就已成为一门有较明确定义的科学,至今已发展成为一门涉及到多个科学与文化领域的综合性学科。现代生态学的一些研究动态现代生态学的研究与发展,很重要的方面是在时间与空间尺度上不断向微观和宏观扩展。从一般的时间单位(秒、小时、日等)到地质量度单位(百万年);从细胞、个体到整  相似文献   

4.
中国车前属植物一新记录   总被引:2,自引:0,他引:2  
首次报道圆苞车前Plantago ovata Forsk.在中国的归化新记录,并提供该种的详细描述。  相似文献   

5.
车前属两种植物的核型研究   总被引:2,自引:0,他引:2       下载免费PDF全文
张华宣   《广西植物》1998,18(2):119-122
本文对我国两种车前属Plantago植物的核型进行了分析。2个种的染色体数目均为2n=2x=12。它们的核型是:海滨车前P.camtschaticaLink,Enum.2n=2x=12=8m+4sm;毛车前P.jehohlensisKoidz.2n=2x=12=6m+4sm+2st。它们的核型均属“2A”型。由12条染色体组成。  相似文献   

6.
郑太坤  万绪山 《植物研究》1992,12(4):373-374
本文发表了车前属一新变种, 即小芒苞车前Plantago aristata Michx.var.minuta T.K.Zheng et X.S.Wan, var.nov.  相似文献   

7.
北美车前生物与生态学特征的研究   总被引:11,自引:0,他引:11       下载免费PDF全文
本文调查了北美车前分主然害现状,对其生物生态学特征进行了研究,旨在掌握其生长发育过程中的薄弱环节,为综合防除该害草提供依据。结果表明,北美车前在华东地区已有较广分布;在金华地区,北美车前是一种过渡性的先锋群落性物种;具自花传粉及风媒传粉两种授粉机制,气候条件,种群密度,人为干扰影响着风媒传粉的比例;种群的分布具明显的伴人特征;光合作用特征为光补偿点高,光合速率较低。  相似文献   

8.
首次报道了毛瓣车前Plantago lagocephala Bunge在中国的分布,确认了一个鲜为人知的中国特有种——苣叶车前P.perssonii Pilger,并提供了二者的详细描述。  相似文献   

9.
中国车前属(车前科)一新组合——丰都车前   总被引:1,自引:0,他引:1  
将Plantago erosa Wall. var. fengdouensis Z. E. Zhao & Y. Wang提升为一独立的种,即丰都车前P. fengdouensis (Z. E. Zhao & Y. Wang) Y. Wang & Z. Y. Li。该种由于花冠无毛,花丝着生于花冠近基部,子叶在种子中与腹面(种脐面)相平行,应属于车前亚属subgen. Plantago。丰都车前P. fengdouensis以植株干后变黑和种子较大的特征接近湿生车前P. cornuti Gouan,但其叶具牙齿或羽状锐裂,具3脉,苞片三角状卵形,花冠裂片狭三角形,蒴果纺锤状椭圆球形,近中部周裂,种子腹侧具1纵槽而不同于后者。  相似文献   

10.
慈姑属(Sagittaria L.)隶属于泽泻科,是世界广布的水生植物,其生境多样、叶形和繁殖表型复杂,进化地位较特殊,是生态和进化生物学研究较典型的材料。笔者在查阅相关慈姑属研究的大量文献的基础上,对前人研究的物种、探讨的问题及研究结果进行了归纳与总结:慈姑属物种存在广布种和濒危种,且个别物种的濒危现状可能与其生境条件相关;慈姑属的个别种类成为稻田入侵杂草,其竞争能力因慈姑种类及水稻栽培品种的不同而各异;环境对慈姑属植物有很强的塑造作用,不同环境还会造成慈姑所在的水生植物群落结构发生变化;慈姑属植物具有较高的遗传多样性;在繁殖方面,慈姑属植物体现出不同繁殖方式和两性功能的权衡,以及在繁育系统上从雌雄同株到雌雄异株的进化途径。本文还提出了相关研究存在的不足、研究中应注意的科学问题,并对慈姑属植物未来的研究方向提供了新思路。  相似文献   

11.
芸薹属自交不亲和基因的分子生物学及进化模式   总被引:8,自引:0,他引:8  
芸薹属的自交不亲和性是受单基因座、复等位基因控制的孢子体控制型。自交不亲和基因座位(S-locus)是由多个基因组成的复杂区域,称之为S多基因家族,其大多数成员分布于芸薹属的整个染色体组。目前已鉴定出100多个S等位基因,它们的起源分化始于一千万年前。S-座位上存在的多基因有3种:SRK,SLG和SCR/SPII;SRK和SLG在柱头中表达,SCR/SPII在雄蕊中表达。SRK蛋白在识别同类花粉的过程中起主要作用,而SLG蛋白增强了这种自交不亲和反应。SLG与SRK基因中编码S-结构域的核苷酸序列相似性程度高达85%~98%。基因转换可能是SLG和SRK的高度同源性能够得以保持的原因。SRK,SLG和SCR基因紧密相连,并表现出高水平的序列多样性。SRK与SLG基因间的距离很近,在20~25kb之间。在柱头和花粉中,自交不亲和等位基因之间的共显性关系要比显性和隐性关系更加普遍,这是芸薹属自交不亲和性的一大特点。自交不亲和基因的进化模式存在两种假说:双基因进化模式和中性变异体进化模式;可能存在几种不同的进化方式,它们共同在自然群体中新的S等位基因进化过程中起作用。  相似文献   

12.
Darwin Day is an international celebration of Charles Darwin’s birthday, February 12, and is used as an occasion for education and outreach in evolutionary biology. I describe the history and structure of Darwin Day at the University of Tennessee, one of the oldest Darwin Day organizations in the world. I detail past events including speakers, themes, and advertising ideas that have worked for us and suggestions for getting a Darwin Day started. I encourage interested groups especially those at schools, museums, libraries, nature centers, and other institutions to adapt ideas from our organization to fit their own circumstances and to start planning their own Darwin Days for the celebration of Darwin’s 200th birthday in 2009.  相似文献   

13.
Thirty-nine primers, developed from the sister species Plantago major and P. intermedia, were tested in two Hawaiian Plantago species from the section Plantago. Eight primers were polymorphic, of which three were published earlier, and five are new ones presented here. Amplification and polymorphism levels appeared to be high in these Hawaiian species. These markers will be valuable for further mating system and evolutionary studies in species from the section Plantago that are closely related to P. major and P. intermedia.  相似文献   

14.
Stephen Jay Gould is rightly remembered for many different kinds of contributions to our intellectual life. I focus on his criticisms of uses of evolutionary ideas to defend inegalitarian doctrines and on his attempts to expand the framework of Darwinian evolutionary theory. I argue that his important successes in the former sphere are applications of the idea of local critique, grounded in careful attention to the details of the inegalitarian proposals. As he became more concerned with the second project, Gould was inclined to suggest that the abuses of evolutionary ideas rested on an insufficiently expanded Darwinism. I suggest that what is valuable in Gould's contribution to general evolutionary theory is the original claim about punctuated equilibrium (advanced, with Niles Eldredge in1972), and the careful defense of that claim through the accumulation of paleontological evidence. I try to show that the more ambitious program of a hierarchical expansion of neo-Darwinism is misguided, and that the endeavor to go beyond local critique fails.  相似文献   

15.
对流体中的微纳米材料、细胞、生物分子等进行高精度、高灵活性、无损伤操控的技术在生物医学、生物化学、纳米科学等领域的发展中有着重要的作用。作为捕获和操控的核心技术,光镊的发展和应用也越来越广泛。本文系统地描述了各类光镊的工作原理和独特功能,阐述了不同光镊技术在生物学上的应用,讨论了它们在生命科学的发展前景。  相似文献   

16.
Aging is a multifold process affected by many genes and thus many biochemical pathways. This conclusion is underscored by the failure to find simple central controls for the aging process during the 20th Century. This situation poses a fundamental challenge to anti-aging medicine: how to develop effective therapies for a genomically complex pathology. We propose such a strategy. As a first step, we recommend the use of model systems in which significant genetic intervention is not proscribed or impractical. Second, we propose that work with such model systems begin with selected lines that have genetic enhancements that allow increased lifespan. Third, genomic methods should be used to identify a number of biochemical pathways for increasing lifespan. Fourth, biochemical pathways that have been identified in model systems would then be available for pharmaceutical development, first in rodents, eventually in a clinical human population. This may seem to be a cumbersome R&D strategy, but starting with human populations or inadequately pre-screened compounds would be unlikely to succeed because of the complexity of the aging problem.  相似文献   

17.
Evolutionary biology and feminism share a variety of philosophical and practical concerns. I have tried to describe how a perspective from both evolutionary biology and feminism can accelerate the achievement of goals for both feminists and evolutionary biologists. In an early section of this paper I discuss the importance of variation to the disciplines of evolutionary biology and feminism. In the section entitled “Control of Female Reproduction” I demonstrate how insight provided by participation in life as woman and also as a feminist suggests testable hypotheses about the evolution of social behavior—hypotheses that are applicable to our investigations of the evolution of social behavior in nonhuman animals. In the section on “Deceit, Self-deception, and Patriarchal Reversals” I have overtly conceded that evolutionary biology, a scientific discipline, also represents a human cultural practice that, like other human cultural practices, may in parts and at times be characterized by deceit and self-deception. In the section on “Femininity” I have indicated how questions cast and answered and hypotheses tested from an evolutionary perspective can serve women and men struggling with sexist oppression. Patricia Adair Gowaty studies the evolution of social behavior, particularly mating systems and sex allocation, primarily in birds. She is most well-known for her long-term studies of eastern bluebirds, which began in 1977 and are on-going. She was an undergraduate at H. Sophie Newcomb College of Tulane University (1963–1967). In the late sixties and early seventies, while employed at the Bronx Zoo (New York Zoological Society), she belonged to a feminist “consciousness-raising” group. She started graduate school in 1974 at the University of Georgia and received her Ph.D. from Clemson University (1980). She had a postdoctoral position at the University of Oklahoma (1982–1983) and a visiting faculty position at Cornell University through the Visiting Professorships for Women NSF program (1983–1984) before returning to her bluebird study sites at Clemson in 1985. She has supported herself and her research efforts throughout her academic career on a series of awards and grants. She is currently (1990–1995) supported by a Research Scientist Development Award from The National Institute of Mental Health.  相似文献   

18.
Plantago species differ in their strategy towards salt stress, a major difference being the uptake and distribution of Na+ ions. A salt-sensitive ( Plantago media L.) and a salt-tolerant ( P. maritima L.) species were compared with respect to Na+/H+ antiport activities at the tonoplast. After exposure of the plants to 50 m M NaCl for 6 days isolated tonoplast vesicles of P. maritima showed Na+/H+ antiport activity with saturation kinetics and a Km of 2.4 m M Na+, NaCl-grown P. media and the control plants of both species showed no antiport activity. Selectivity of the antiport system for Na+ was high and was determined by adding different chloride salts after formation of a Δ pH in the vesicles. Specific tonoplast ATPase activities were similar in the two species and did not alter after exposure to NaCl stress.  相似文献   

19.
Evolutionary biology presents a bewildering array of phenomena to scientists and students alike—ranging from molecules to species and ecosystems; and embracing 3.8 billion years of life’s history on earth. Biological systems are arranged hierarchically, with smaller units forming the components of larger systems. The evolutionary hierarchy, based on replication of genetic information and reproduction, is a complex of genes/organisms/demes/species and higher taxa. The ecological hierarchy, based on patterns of matter–energy transfer, is a complex of proteins/organisms/avatars/local ecosystems/regional ecosystems. All organisms are simultaneously parts of both hierarchical systems. Darwin’s original formulation of natural selection maps smoothly onto a diagram where the two hierarchical systems are placed side-by-side. The “sloshing bucket” theory of evolution emerges from empirical cases in biological history mapped onto this dual hierarchy scheme: little phenotypically discernible evolution occurs with minor ecological disturbance; conversely, greatest concentrations of change in evolutionary history follow mass extinctions, themselves based on physical perturbations of global extent. Most evolution occurs in intermediate-level regional “turnovers,” when species extinction leads to rapid evolution of new species. Hierarchy theory provides a way of integrating all fields of evolutionary biology into an easily understood—and taught—rubric.
Niles EldredgeEmail:
  相似文献   

20.
近年来肠球菌逐渐成为院内感染的重要病原菌,尤其引人关注的是万古霉素耐药性肠球菌(VRE)有不断增多的趋势。了解VRE的耐药机制对有效控制其扩散传播具有重要意义。我们就VRE基因组学及蛋白质组学的研究进展情况进行简要概述。  相似文献   

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