91 resultados para Scilla thunbergii


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本文采用物种生物学的方法分析了绵枣[Scilla sinensis (Lour.) Merr.]多倍体复合体细胞地理、形态、生态适应和发育节律的变异。此外,还对AA细胞型居群进行了等位酶分析和杂交实验。结果如下: 1. 细胞学检查秀自中国境内45个居群,检出AA、AB、BB、AAA、BBB和AABB 6个细胞型。多数居群由1种细胞型组成。AA几乎占据着该复合体在中国的整个分布区。BB仅局限于华中和华东地区。AABB分布于华中和华东地区的北侧、东北地区的东南部及台湾岛。45个居的细胞型组成以细胞地理分布图表示。总结前人与我们的工作,该复合体中已发现12个整倍体细胞型(AA、AB、BB、AAA、ABB、BBB、AAAA、AABB、ABBB、BBBB、AABBB和AAABBB)和各种基于多倍体的非整倍体。其基本细胞型为AA、BB和AABB。AA分布于除日本和大陆上BB分布区中心外该复合体的整个分布区。BB分布中国华东和华中地区、朝鲜的济州岛和日本。AABB分布日本、朝鲜和中国东北地区的东南部及华中、华东地区的东侧。另外,BB居群染色体数量最多,AABB次之,而AA最低。 2. 野外调查和栽培实验表明AA细胞型在中国东部和西部地区间存在形态和生态分化,东部居群形态变异较小,其共同特征是纺锤形鳞茎,红褐色;根茎短柱状;叶多灰绿色,蜡质明显,斜升;花葶较强壮而直立;花紫红色;子房每室1胚珠。西部为AA细胞型的现代变异中心,居群间形态变异大,区别于东部居群的特点是鳞茎纺锤形或近球形,根茎短柱状或盘状,叶鲜绿色,蜡质不明显,平卧地面;花葶1-4枝,直立,多花葶时斜升;花白色或淡红色,子房每室胚珠1 ~ 2枚。AA和BB细胞型是向着适于不同地理区的环境发展,因而具有不同的形态和生物学特性的两个类型。BB鳞茎近球形,黄褐色,根茎不明显,为盘状;叶墨绿色,柔软而平卧地面,是适于阴湿的林下环境的结果。春季萌发较早,约在3月初,其夏季休眠特性刚好可渡过华中地区东部夏季的高温多雨,待秋季温度下降时开花结实。而AA划适应了光照较强而干旱的山坡草地灌丛的类型。其发育节律变异较大,但萌动较BB晚,无夏季休眠。AABB细胞型的形态介于两祖先二倍体之间,没有形成独特的生态适应和发育节律。 3. 对AA细胞型的等位酶分析表明,该种的居群表现出较高的遗传变异(A = 2.0, P = 58.6%, H_o = 0.172 和 H_e = 0.185)。居群间存在较明显的分化(F_(ST) = 0.314)。东西两地区间也存在遗传分化。 4. AA居群间多数组合的F_1都低于对照的花粉育性和结实率。尤其是东部和西部居群间组合的F_1花粉育性和结实率极低,几近不育。如果仅仅考虑该复合体的形态变异,它只能作为一个形态复杂多变的种,Scilla sinensis (Lour) Merr.。可是如此处理就掩盖了其细胞型间清晰的进化关系。为弥补这一缺陷,当研究细胞型间的进化关系时,可采用生物学和概念。AA细胞型为S. sinensis (Lour.) Merr., 可分两亚种:subsp. sinensis 和 subsp. alboviridis (Hand.-Mazz.) K. Y. Ding。BB细胞型为S. thunbergii Miyabe et Kudo。而ABB及含有A和B染色体组的多倍体作为杂交种S. x sino-japonica K.Y.Ding。两个二倍体种形态界限很清楚,但AABB的存在湮灭了两者的间断。

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We evaluated the effects of high molecular-weight phlorotannins from Sargassum thunbergii (STP) on ADP-induced platelet aggregation and arachidonic acid (AA) metabolism in New Zealand white rabbits and Wistar rats. The inhibition of STP on platelet aggregation was investigated using a turbidimetric method, and the levels of the terminal products of AA metabolism were measured using the corresponding kits for maleic dialdehyde (MDA), thromboxane B-2 (TXB2) and 6-keto-prostaglandin F-1 alpha (6-keto-PGF(1 alpha)) by colorimetry and radioimmunoassay, as appropriate. We found that STP could inhibit ADP-induced platelet aggregation, and the inhibitory ratio was 91.50% at the STP concentration of 4.0 mg/mL. Furthermore, STP markedly affected AA metabolism by decreasing the synthesis of MDA (P < 0.01) and increasing the synthesis of 6-keto-PGF(1 alpha), thus changing the plasma TXB2/6-keto-PGF(1 alpha) balance when the platelets were activated (P < 0.01). Therefore, STP altered AA metabolism and these findings

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Morphology and culture studies on germlings of Sargassum thunbergii (Mertens et Roth) Kuntze were carried out under controlled laboratory conditions. Growth characteristics of these germlings grown under different temperatures (from 10 to 25A degrees C), irradiances (from 9 to 88 mu mol photons m(-2) s(-1)), and under blue and white light conditions are described. The development of embryonic germlings follows the classic "8 nuclei 1 egg" type described for Sargassaceae. Fertilized eggs spent 5-6 h developing into multicellular germlings with abundant rhizoids after fertilization. Under conditions of 20A degrees C, 44 mu mol photons m(-2) s(-1) and photoperiod of 12 h, young germlings with one or two leaflets reached 2-3 mm in length after 8 weeks. Temperature variations (10, 15, 20, 25A degrees C) under 88 mu mol photons m(-2) s(-1) significantly influenced the growth rate within the first week, although this effect became less obvious after 8 weeks, especially at 15 and 20A degrees C. Variation in germling growth was highly significant under different irradiances (9, 18, 44, 88 mu mol photons m(-2) s(-1)) at 25A degrees C. Low temperature (10A degrees C) reduced germling growth. Growth of germlings cultured under blue light was lower than in white light. Optimal growth of these germlings occurred at 25A degrees C and 44 mu mol photons m(-2) s(-1).

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Genetic variation of four populations of Sargassum thunbergii (Mert.) O. Kuntze and one outgroup of S. fusiforme (Harv.) Setchell from Shandong peninsula of China was studied with random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. A total of 28 RAPD primers and 19 ISSR primers were amplified, showing 174 loci and 125 loci, respectively. Calculation of genetic diversity with different indicators (P%, percentage of polymorphic loci; H, the expected heterozygosity; I, Shannon's information index) revealed low or moderate levels of genetic variations within each S. thunbergii population. High genetic differentiations were determined with pairwise Nei's unbiased genetic distance (D) and fixation index (F-ST) between the populations. The Mantel test showed that two types of matrices of D and FST were highly correlated, whether from RAPD or ISSR data, r=0.9310 (P = 0.008) and 0.9313 (P=0.009) respectively. Analysis of molecular variance (AMOVA) was used to apportion the variations between and within the S. thunbergii populations. It indicated that the variations among populations were higher than those within populations, being 57.57% versus 42.43% by RAPD and 59.52% versus 40.08% by ISSR, respectively. Furthermore, the Mantel test suggested that the genetic differentiations between the four populations were related to the geographical distances (r > 0.5), i.e., they conformed to the IBD (isolation by distance) model, as expected from UPGMA (unweighted pair group method with arithmetic averages) cluster analysis. As a whole, the high genetic structuring between the four S. thunbergii populations along distant locations was clearly indicated in the RAPD and ISSR analyses (r > 0.8) in our study.

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The Scilla rock avalanche occurred on 6 February 1783 along the coast of the Calabria region (southern Italy), close to the Messina Strait. It was triggered by a mainshock of the Terremoto delle Calabrie seismic sequence, and it induced a tsunami wave responsible for more than 1500 casualties along the neighboring Marina Grande beach. The main goal of this work is the application of semi-analtycal and numerical models to simulate this event. The first one is a MATLAB code expressly created for this work that solves the equations of motion for sliding particles on a two-dimensional surface through a fourth-order Runge-Kutta method. The second one is a code developed by the Tsunami Research Team of the Department of Physics and Astronomy (DIFA) of the Bologna University that describes a slide as a chain of blocks able to interact while sliding down over a slope and adopts a Lagrangian point of view. A wide description of landslide phenomena and in particular of landslides induced by earthquakes and with tsunamigenic potential is proposed in the first part of the work. Subsequently, the physical and mathematical background is presented; in particular, a detailed study on derivatives discratization is provided. Later on, a description of the dynamics of a point-mass sliding on a surface is proposed together with several applications of numerical and analytical models over ideal topographies. In the last part, the dynamics of points sliding on a surface and interacting with each other is proposed. Similarly, different application on an ideal topography are shown. Finally, the applications on the 1783 Scilla event are shown and discussed.

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von Carl Sprenger

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anonym

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Von A. Sliwa

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AR

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Thesis (doctoral)--Friedrich-Alexanders-Univesitat zu Erlangen, 1893.

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A presente dissertação analisa a prática missionária do pastor metodista Scilla Franco desenvolvida entre os índios Kaiowá e Terena no MS, nos anos de 1972 e 1979. Apresenta os principais traços da cultura e religião desses povos; os efeitos negativos da colonização européia e de outros movimentos de exploração econômica das áreas onde viviam e o lugar que religião cristã ocupou neste processo através de missionários católicos e protestantes, destacando a atuação dos metodistas no Mato Grosso do Sul. Num segundo momento, descreve a trajetória pessoal e ministerial de Scilla Franco analisando a criação da Missão Tapeporã, a formação do GTME e a natureza do trabalho que desenvolveu, a partir de uma pastoral de convivência. Por fim, a partir da análise do desenvolvimento do trabalho de Scilla Franco, apresenta temas importantes para uma práxis missionária na atualidade e que podem ser vistos na sua ação, como a contextualização e a convivência numa perspectiva ecumênica.

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稻属(Oryza L.)属于禾本科稻族(Oryzeae Dumortier)。本属包括AA,BB,BBCC,CC,CCDD,EE,FF,GG,HHJJ和HHKK十个基因组,二十余种。其中Oryza officinalis复合体包括BB,BBCC,CC,CCDD和EE五个基因组,九个种。众多的学者对该复合体进行了广泛深入的研究,为后续研究奠定了坚实的基础。然而,迄今为止,多倍体物种形成问题许多没有解决,基因组间的关系尚未完全阐明,甚至有些多倍体物种的基因组组成仍未确认。 本文评述了Oryza officinalis复合体中基因组研究的历史和现状,用基因组原位杂位(GISH)的方法,对该复合体四倍体物种的基因组组成作了验证;对B,C,D和E四个基因组间的关系进行了研究。同时对基因组原位杂交的方法,原位杂交鉴定多倍体基因组的组成以及研究基因组间关系的方法作了一些探讨。其主要研究结果如下: 一. 原杂交方法的研究:1)染色体制片:比较研究了不同的制片方法,发现压片法适用于大染色体的材料;将酶解/空气干燥法(Fukui et al., 1992)加以改进后,特别适宜于小染色体植物材料的制片。2)根尖储存时间和条件对原位杂交的影响:发现在-20 ℃的酒精(70%)中储存8个月以内的根尖材料,可用于原位杂交;而在-20 ℃的固定液中储藏18个月的根尖,DNA降解严重,不能用于GISH。3)探针标记:比较了随机引物法、缺口平移法和两步标记法(先用随机引物标记后,再用缺口平移法进行标记的方法)的优缺点。结果显示两步标记法是最佳标记方法。 二. GISH鉴定异源多倍体的方法:用两个异源四倍体Oryza minuta和Scilla sinensis (2n = 34)做染色体制片,进行原位杂交实验,结果表明:1)用二倍体亲本基因组之一做探针而不用封阻DNA, 可以鉴别Oryza minuta而不能鉴别Scilla sinensis中的基因组。2)用一个二倍体亲本做探针而用另一个做封阻,能够区分Scilla sinensis的两个基因组;但过量的封阻DNA将可以造成一些实验假象。3)同时用两个亲本的DNA做探针,不仅能够有效分辨不同的基因组,还能够根据交叉杂交程度推测基因组间的分化程度,是鉴别异源多倍体最有效的方法。 三. GISH鉴定稻属四倍体的基因组组成:1)Oryza minuta, O. punctata和O. malampuzhaensis的基因组的组成都为BBCC。2)Oryza minuta中B基因组和二倍体O. punctata中的B基因组之间存在着明显的基因组内分化。3)O. alta是一个异源多倍体,其基因组组成为CCDD。但C和D之间的分化不彻底,可以认为它不是一个严格意义上的异源多倍体。 四. GISH研究B,C,D和E基因组间的关系:1)B基因组和C基因组之间的关系最远;E和C之间的分化同E和B之间的分化程度接近,但E和C之间的分化比E和D之间的分化要小一些;C和D之间的分化不彻底,关系最近。