62 resultados para Lucan, 39-65.
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This study investigated non-specific immune functions of the F-2 generation of "all-fish" growth hormone transgenic carp, Cyprinus carpio L. Lysozyme activity was 145.0 (+/- 30.7) U ml(-1) in the transgenic fish serum and 105.0 (+/- 38.7) U ml(-1) in age-matched non-transgenic control fish serum, a significant difference (P < 0.01). The serum bactericidal activity in the transgenics was significantly higher than that in the controls (P < 0.05), with the percentage serum killing of 59.5% (6.83%) and 50.8% (8.67%), respectively. Values for leukocrit and phagocytic percent of macrophages in head kidney were higher in transgenics than controls (P < 0.05). However, the phagocytic indices in the transgenics and the controls were not different. In addition, the mean body weight of the transgenics was 63.4 (6.65) g, much higher than that of the controls [39.2 (+/- 3.30) g, P < 0.01]. The absolute weight of spleen of the transgenics [0.13 (+/- 0.03) g] was higher than that of the controls [0.08 (+/- 0.02) g, P < 0.01]. However, there was no difference in the relative weight of spleen between the transgenics and the controls, with the spleen mass index being 0.21% (+/- 0.02%) and 0.20% (+/- 0.03%), respectively. This study suggests that the "all-fish" growth hormone transgene expression could stimulate not only the growth but also the non-specific immune functions of carp. (c) 2006 Published by Elsevier B.V.
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Sediment core samples were collected in the largest urban Lake Donghu (Stations I and II) in China, and the activities of Pb-210, Ra-226 and Cs-137 were measured by gamma-ray spectrometry. The sedimentation rates, calculated by 210Pb constant rate of supply (CRS) model, ranged from 0.11 to 0.65 (average 0.39) cm(.)y(-1) at Station I, and from 0.21 to 0.78 (average 0.46) cm(.)y(-1) at Station II. Sedimentation rate calculated by Cs-137 as a time marker was 0.55 cm(.)y(-1) at Station II. Based on the average sedimentation rate, we obtained 769 and 147 t(.)y(-1) for nitrogen and phosphorus retentions in Lake Donghu sediments, respectively.
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Understanding the population genetic structure is a prerequisite for conservation of a species. The degree of genetic variability characteristic of the mitochondrial DNA control region has been widely exploited in studies of population genetic structure and can be useful in identifying meaningful population subdivisions. To estimate the genetic profile of the Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis), an endangered freshwater population endemic to China, the complete mtDNA control region was examined in 39 individuals belonging to seven different stocks inhabiting the middle and lower reaches of the Yangtze River. Very low genetic diversity was found (nucleotide diversity 0.0011 +/- 0.0002 and haplotypic diversity 0.65 +/- 0.05). The mtDNA genetic pattern of the Yangtze population appears to indicate a founder event in its evolutionary history and to support the marine origin for this population. Analyses by F-st and Phi(st) yielded statistically significant population genetic structure (F-st = 0.44, P < 0.05; phi(st) = 0.36, P < 0.05). These results may have significant implications for the management and conservation of the Yangtze finless porpoise in the future.
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The properties of electron states in the presence of microwave irradiation play a key role in understanding the oscillations of longitudinal resistance and the zero-resistance states in a high-mobility two-dimensional electron gas(2DEG) in low magnetic field. The properties of electron states in a high-mobility and low-density GaAs/Al0.35Ga0.65As 2DEG in the presence of Ka-band microwave irradiation were studied by reflectance-based optically detected cyclotron resonance(RODCR). The influences of the direction of microwave alternating electronic field, wavelength of the laser, and temperature on RODCR results were discussed. The results show that RODCR measurements provide a convenient and powerful method for studying electron states in 2DEG.
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AlGaN/AlN/GaN high electron mobility transistor (HEMT) structures with high mobility GaN channel layer were grown on 50 min diameter semi-insulating (SI) 6H-SiC substrates by metalorganic chemical vapor deposition and large periphery HEMT devices were fabricated and characterized. High two-dimensional electron gas mobility of 2215 cm(2)/V s at room temperature with sheet electron concentration of 1.044 x 10(13)/cm(2) was achieved. The 50 mm diameter HEMT wafer exhibited a low average sheet resistance of 251.0 Omega/square, with the resistance uniformity of 2.02%. Atomic force microscopy measurements revealed a smooth AlGaN surface with a root-mean-square roughness of 0.27 nm for a scan area of 5 mu mi x 5 pm. The 1-mm gate width devices fabricated using the materials demonstrated a very high continuous wave output power of 9.39 W at 8 GHz, with a power added efficiency of 46.2% and power gain of 7.54 dB. A maximum drain current density of 1300 mA/mm, an extrinsic transconductance of 382 mS/mm, a current gain cutoff frequency of 31 GHz and a maximum frequency of oscillation 60 GHz were also achieved in the same devices. (C) 2007 Elsevier Ltd. All rights reserved.
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350kW低温热水驱动的两级溴化锂吸收式制冷机已研制成功,并已连续运转5年。该机以热电厂冬季采暖管道输送的86℃热水为热源,在冷却水温度32℃的条件下,制取9℃冷媒水,供5000m2办公大楼空调。该机可在热源温度70~86℃下运行,热源出口温度为60℃,机组的制冷系数为0.33~0.39。两级吸收式制冷机可在回收工业废热、太阳能、地热能等方面得到广泛的应用。
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一 结构因子相角的代数解法晶体结构研究中的相角问题,一直是晶体学工作者努力探求的基本问题。几十年来,关于相角问题的研究已经取得了巨大的进展,直接法的成熟和普遍应用就是这个进展的显著标志。在直接法相角问题研究中,历来存在两种基本方法,即概率法和代数法。当前直接法的迅猛发展,则主要以概率法为基础,其应用的基本公式即是来自∑关系中的∑_2关系和由此发展出的TANGENT公式,并结合一系列的基本理论和辅助公式,从而使直接法的发展一直呈方兴未艾之势。与此形成鲜明对照的是,相角问题的代数法研究则有日趋下降之势,尤其近十年来则显著落后了。作者从近年来的∑关系研究中,看到要解决相角问题,代数法仍然有其潜在的应作价值,并认为在概率法可以得到应用的许多方面,在代数法那里都应找到对应的类似内容,而代数法在研究和应用中所表现出的不同于概率法的那些方面也正是在相角问题研究中最令人感兴趣的问题,这就是我们进行代数法研究的目的和出发点。(一)1.5和2.5阶代数式的提出及对±2~(II)型相角的估算。(二)一般类型相角的估算(三)结构相角通用代数式的推导。代数法不仅可用于结构半不变量O,π型相角的计算,而且可用于非结构半不变量的种种类型相角的估算,其中包括型和一般类型相角,而且其应用效果完全可以和概率法相比拟,在机时利用上前者有一定优势。通用代数式的获得将为代数法的普遍应用和计算机计算创造了方便条件。二稀土杂多酸根配合物K_8H_5[La(SiWMo_(10)O_(39))(SiW_3Mo_8O_(39))]·nH_2O的晶体结构采用低温技术,在-90 ℃的干燥氮气保护下,收集晶体衍射数据,以直接法解出结构。a = 17.485(5), b = 27.096(6), c = 21.642(5)A, β = 107.79(2)°, z = 4。最后的R值为0.097。中心离子La(III)同两个杂多酸根提供的8 个氧配合。而其中的W、Mo同氧的配位情况基本相同,者是与氧六配位,形成变形配位八面体。
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研究了基于InP基的In_(0.65)Ga_(0.35)As/In_(0.52)Al_(0.48)As赝型高迁移率晶体管材料中纵向磁电阻的Shubniko-de Haas (SdH)振荡效应和霍耳效应,通过对纵向磁电阻SdH振荡的快速傅里叶变换分析,获得了各子带电子的浓度,并因此求得了各子带能级相对于费米能级的位置.联立求解Schrodinger方程和Poisson方程,自洽计算了样品的导带形状、载流子浓度分布以及各子带能级和费米能级位置.理论计算和实验结果很好符合.实验和理论计算均表明,势垒层的掺杂电子几乎全部转移到了量子阱中,转移率在95%以上.
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于2010-11-23批量导入
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由于大部分集体山林由集体统一经营,存在林木产权不明晰、经营机制不灵活、利益分配不合理等突出问题,林农作为集体林业经营主体的地位没有得到有效落实,严重制约了林业生产力的进一步发展。为解放林业生产力,就迫切需要对集体林权制度进行深化改革。为此,辽宁省自2005年3月1日在本溪市开展集体林权制度改革试点工作,至11月份在全省推开。目前辽宁省林权改革的主体改革已经基本完成,工作的重点已经转向了配套改革。 本文采用问卷调查、专家座谈、统计资料相结合的方式,主要从林农家庭尺度入手,分析了改革对当地居民和社会的影响;在此基础上,比较分析了辽宁省各种改革经营模式的特点;综合当地政府、金融、协会等机构在技术、政策、资金等方面的支撑,将尺度上推到区域尺度,分析了林权改革后林业产业的发展进程,为产业集群和区域经济的发展提供建议;分析改革过程中出现的问题和困难,并提出相应的整改方案和优化对策,从而为各方面利益关系的梳理和林业的健康发展提供建议。 结果表明,改革工作已取得一定积极成效:1)林权改革有效激发了林农的生产积极性,加速了林业投资。从2005年开始林业投资额增速明显加快,尤其是2004-2005和2007-2008年间,增长率分别达到了75.88%和39.42%。2)促进了林业增收。2004年后林业收入增长明显加速,尤其是2007年林业收入增长幅度达到57.44%。3)促进了林农就业。90.42%的林农表示从事林业生产的劳动时间有所增加。从2006年开始,外出务工人员增长率明显放缓,研究区在2005-2008年共有9.85万外出务工林农返乡务林。4)促进了当地公益事业的发展与社会和谐。辽宁省用于公益事业的资金占林权改革直接经济收益的9.30%;改革在一定程度上缩小了贫富差距,促进了农村民主进程、经济发展与和谐稳定。5)“林权交易中心”成立后,林权交易蓬勃发展,联户经营的林农户数和林地面积分别占调查总数的14.65%和25.44%,从而为林业产业的发展创造了条件。6)根据各地的资源特点,改革发展了不同特色的经营模式。辽东以抚顺、本溪、丹东为代表,主要经营模式有林下参、五味子、细辛等中草药,红松果和核桃等经济林,山野菜,柞蚕,用材林,鹿业养殖等;辽中以铁岭为代表,主要经营模式有中草药、山野菜、榛子和梨等经济林等;辽西以朝阳为代表,经营模式以山杏、大扁杏、大枣、梨、桃、苹果等经济林为主。 但在改革的过程中也出现了一些问题,这些问题主要表现为:1)由于利益分配等的不同,不同利益主体对林权改革的关注和认知存在一定差异,有些差异可能影响林权改革工作的推进。2)许多林农即使获得了林业资源的经营权,自身也难有财力支撑其经营投入,林权改革工作资金缺口大。有林业贷款的林农仅占调查总数的15.71%,而最近几年有林业贷款意愿的林农却占调查总数的32.95%。3)在金融借贷、林业保险和生态补偿机制、法律规章制度、协会等合作机制等方面,改革配套措施进展缓慢。4)市场培育和产业发展太慢。仅有34.97%和88.56%的林农和林业工作人员表示对当地林产品的市场走向有所了解,且其所掌握的市场信息往往比较简单和模糊,远远不能准确、及时和充分满足市场需求。5)林业部门职责转变太慢。林权改革前后,林农从林业部门获得的主要服务基本上没有什么变化。 针对改革过程中遇到的困难,只有适时跟进配套改革措施,采取有效方法和机制梳理各方面利益关系,才能实现林业的大发展。 林权改革突破了林业发展长期以来的体制障碍和产权禁区,实现了林地所有权与林木所有权的分离,对林地资源、农村就业和经济、产业发展、生态安全等方面都将产生重大而深远的影响。加强对林权改革的长期监测和持续评价工作,具有积极意义。
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民勤绿洲位于我国西北干旱区内陆河石羊河流域的下游。近些年来,随着该流域中、上游地区大量截留水资源,使进入民勤绿洲的地表水资源量逐年减少,导致绿洲生态环境不断恶化,生态安全面临着严重危机。本论文应用景观生态学原理与方法,综合运用3S技术,通过多时相遥感数据的对比分析,系统研究了民勤绿洲景观格局动态演变过程、形成原因及其与重要生态过程的相互作用,并在此基础上对绿洲生态安全的时空变化进行了综合评价。主要研究成果:1.景观格局影响生态过程,研究景观格局可以揭示生态过程变化的内在原因。因此,景观空间格局研究一直以来是景观生态学研究的核心与热点之一。应用景观空间格局分析软件FRAGSTATS对绿洲近14年的景观格局及其变化过程的定量研究表明,开荒与弃耕始终存在于景观的演变过程中,导致景观中林地、荒草地、耕地与沙地斑块类型的相互转化。开荒作用主要发生在1987-1998年间并导致林地与荒草地斑块转化成耕地斑块,绿洲耕地面积在此时期逐渐增加;弃耕作用主要发生在1998年至2001年间并导致耕地斑块逐渐转化成沙地斑块或荒草地斑块,耕地面积在此时期逐渐减少014年来,绿洲沙漠化过程逐年发展,主要表现为林地与荒草地斑块与耕地斑块逐渐转变成沙地斑块,导致沙地斑块面积(CA)逐渐增加,而斑块数量(NP)逐渐减少,使得沙地平均斑块大小(MPS)逐渐增大,沙地斑块呈现集中连片式的分布趋势。由于林草地斑块的逐渐减少以及耕地与沙地斑块的增加导致绿洲的多样性(SHOI)、均匀性(SHEI)与平行与并列指数(IJI)逐渐降低,而连通性(CONGTAG)逐渐增强,绿洲景观格局越来越强烈地受到沙地与耕地斑块类型的控制。绿洲景观的连通性上升的幅度(CONTAG)是坝区>泉山区>湖区。景观的多样性(SHDI)与均匀性(SHEI)下降的幅度是坝区>泉山区>湖区。坝区景观的衰退过程(沙地面积的增幅)与人类对该灌区的开发强度(耕地面积的增幅)与都强于泉山区与湖区。2.景观变化的主要驱动因素包括自然、社会与经济因素。绿洲景观格局的演变是以上因素综合作用的结果。干早区绿洲的形成机制决定了其发展与演变强烈地受到水资源的质与量的支配,水资源条件的变化是驱动该绿洲景观演变的主导因素。由于中、上游地区为满足经济发展的需要,大量截留地表水资源使进入下游民勤绿洲的地表水资源从50年代的年平均5.42亿m3锐减到2001年的0.73亿m3,致使绿洲地下水的补给量减少,而耕地面积的扩大导致地下水的超采量增加,引发土地干旱化与盐碱化,大量沙生植被枯萎、死亡,弃耕地增加。民勤绿洲用水模式进步缓慢、管理效率低下、人口的快速增长、农业技术推广速度缓慢以及土地使用制度等因素共同作用形成了推动景观变化的复杂人文机制。水资源的减少与人文机制共同作用驱动着绿洲景观的演变过程。3.指出绿洲景观的生态安全应包括景观的格局安全与过程安全两个方面。景观格局与生态过程密不可分,绿洲景观格局影响生态过程,生态过程“塑造”景观格局。利用ARCv正W的空间分析功能,从景观格局的空间邻接特征角度研究景观斑块类型受沙漠化威胁与盐碱化威胁的程度,并在此基础上分析生态安全。结果表明坝区耕地、林地、荒草地受沙漠化威胁程度高于其它两个灌区,湖区的耕地、林地、草地受盐碱化威胁的程度高于其它两个灌区。水对干旱区绿洲的重要性决定了水生态过程研究是绿洲生态安全研究的重要方面。利用ARCMAP的空间插值的地统计分析功能对绿洲的地下水埋深与地下水矿化度进行空间插值,得到地下水埋深与地下水矿化度的时空分布,结果表明:各时期绿洲地下水埋深为中心深,边缘浅,表明地下水降落漏斗的存在与不断加深。14年来地下水位的平均下降速率,坝区最快,泉山区次之,湖区最慢,三灌区分别为0.75m、0.7m与0.60m。绿洲北部地下水矿化度显著升高,14年来泉山区地下水矿化度上升为1.36倍,湖区南部地下水矿化度上升1.47倍,湖区北部地下水矿化度上升为1.43倍,地下水矿化度平均值达到5.6g/L,成为绿洲地下水矿化度最高地带,也是作物产量锐减的地带,因此地下水矿化度的上升导致作物安全生长潜在格局发生变化,作物安全生长区面积缩小,而中度以上不安全生长区面积扩大,造成了作物的减产与农业产业结构调整的空间缩小,难度加大。4.绿洲为水、土、植被、气候、社会经济与人类活动等众多方面所组成的、彼此相互联系的复杂的社会一经济一生态复合系统。因此绿洲的生态安全的综合评价涉及吸素众多,必须采用定量与定性相结合的方法进行科学地评价。采用目前较为成熟的环境综合评价方法一层次分析法AHP,并构建绿洲景观生态安全评价指标体系,对绿洲景观生态安全进行综合评价,结果表明:绿洲及各灌区生态安全水平逐年降低,目前生态安全值与1987年的相比,绿洲为68%,坝区73.7%,泉山区为63.6%,湖区为65.2%。三灌区中坝区的生态安全水平在各时期都是最高的,其次为泉山区,湖区最低。14年间生态安全下降幅度较大的为泉山区与湖区,坝区生态安全水平下降幅度较小。5.将绿洲生态环境恶化所导致的经济损失值量化,运用市场价值法与机会成本法对近14年来由于绿洲的环境恶化导致对社会经济发展所产生的不良后果从植被死亡、土地盐渍化导致作物减产、弃耕地出现导致的土地生产力的丧失与地下水位下降所导致的机井报废与提水成本增加四个方面进行经济效益损失估算,结果为经济损失值是湖区>坝区>泉山区,分别达到53786万元、44276.22万元、39247.36万元。坝区以林木死亡所造成的经济损失最大,湖区与泉山区以土地盐渍化所造成的经济损失最大。经济损失值占同期当地国民生产总值的百分比是湖区>泉山区>坝区,分别达到76.39%、55.04%、28.48%。可见绿洲的社会经济发展是以牺牲生态环境,降低生态安全水平为代价,这将严重制约绿洲今后的可持续发展。
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本文系统研究了沈阳城市森林的布局与结构、城市森林功能、城市森林病虫害发生与树木健康状况和城市自然资源与社会经济状况等指标对沈阳城市森林生态系统健康与管理的影响。同时一,采用2种生态系统健康评价方法对沈阳城市森林生态系统健康状况进行了评价,并提出了沈阳城市森林生态系统健康管理的对策。研究结果如下:1、截至2004年末,沈阳城市森林植被覆盖率已经达到35%,城市森林林地分布基本合理,但需要进一步加强道路林地、居住区林地和城郊大面积生态林建设。2、沈阳城市森林以乔木为主,乔灌株数比为1.7:1,乔灌的覆盖度比约为7:1。3、沈阳城市森林不同类型林地中植物组成不同。公园林地中有74个属,137个种(变种);庭院林地中有53个属,104个种(变种);居住区林地中有45个属,81个种(变种);道路林地中有43个属,94个种(变种);运河风景林地中有75个属,142个种(变种);棋盘山风景林地中有48个属,118个种(变种)。4、公园林地、庭院林地、居住区林地、道路林地和运河风景林地的Shannon一Wiener多样性指数分别为2.78、3.05、3.15、3.18和3.18,均匀度指数分别为0.56、0.66、0.72、0.70和0.64。除了棋盘山风景林地外,沈阳城市森林中栽植总量超过乔木总量5%的乔木树种有7个属,分别为李、柳树、杨树、桧柏、榆树、槐树和银杏,7种树木总量达到了全部乔木总量的82.09%;栽植总量超过灌木总量5%的灌木树种也有7个属,分别为水腊、丁香、李属,小聚、玫瑰、忍冬和连翘,7个属灌木总量达到了全部灌木总量的87.92%。5、公园林地、庭院林地、道路林地和防护林地中OBH<20cm、20cm<DBH<60cm和DBH>60cm树木的比例分别为:57.9%、40.0%、2.1%,49.2%、47.8%、3.0%,65.3%、33.1%、1.6%和64.6%、34.9%、0.5%,表明沈阳城市森林树木的规格总体上偏小。6、经样方调查和CITYgreen模型计算,沈阳城市森林的生态效益约2.0亿USD/yr.。公园林地、庭院林地和风景林地的景观指标相对较高;道路林地和居住区林地的景观效果一般;防护林地的景观效果较差。7、目前已经发现的沈阳城市森林病害约600余种,虫害约700余种,其中杨树主要病虫害39种,柳树的主要病虫害有33种,榆树和槐树的主要病虫害均为,1种。杨柳树腐烂病、光肩星天牛、天幕毛虫、桃红颈天牛和美国白蛾等是近10年来沈阳城市森林中普遍发生和造成严重危害的主要病虫害。沈阳城市森林主要树木的平均健康指数为2.68,处于一般健康状态。8、沈阳城市森林的土壤和水资源状况均不利于树木的健康生长,沈阳的社会经济发展也有待于进一步提高。9、经过生物指示物法(光肩星天牛为生物指示物)、专家权重法、公众问卷调查和对比研究,沈阳城市森林生态系统总体上处于亚健康状态。10、通过对沈阳城市森林资源、管理状况的调查研究和健康状况的评价,本文提出了沈阳城市森林生态系统健康管理的对策,包括合理规划沈阳城市森林林地布局,增加道路林地、居住区林地和城郊林地的面积和植被覆盖率;调整树木种类组成,避免单一或少数树种的大量栽植,提高生物多样性水平;保护大树和古树;增加城市森林管理资金的投入;应用先进技术,采取科学的病虫害防治和植物养护方法,促进树木的健康生长等。This project systematically studied the urban forest ecosystem health and management in Shenyang. The study explored factors, such as urban forest structure, distribution, pests, aesthetic value, ecological benefit, natural resources and socieo-economic status, that affecting the urban forest ecosystem health and management. Two methods were used to evaluate the ecosystem health. This project also proposed Shenyang's urban forest ecosystem health management strategies. The research results can be summarized as follows: 1. As of the end of 2004, urban forest coverage in Shenyang is about 35%, and is in relatively even patch distribution pattern. However, the street trees and roadside forest patches, residential block forest patches should be enhanced. 2. Trees are the major component of the Shenyang s urban forest, followed by shrubs. The quantity ratio of tree to shrub is about 1.7:1, and the coverage ratio of trees to shrub is about 7:1. 3. Species composition varies by location. There are 74 genera, 137 species (including varieties) in the public parks; 53 genera, 104 species (and var.) in the green spaces of the institution (including school), factory, and company; 45 genera, 81 species (var.) in residential blocks; 43 genera, 94 species (var.) in streets and roadside forest patches; 75 genera, 142 species (var.) in the Canal landscape forest patches; 48 genera, 118 species (var.) in the Qipan Mountain recreation forest. 4. The Shannon-Woener indices varies in parks, in institution, factory, and company yards, in streets and roadside forest patches, in residential blocks.there are 2.78, 3.05, 3.18, 3.15, 3.18, respectively; and the evenness indices are 0.56, 0.66, 0.70, 0.72, 0.64, respectively. Besides the Qipan Mountain forest patches, trees of 7 genera, Prunus spp., Salix spp., Populus spp., Sabina spp., Ulmus spp., Robinia spp. and Ginkgo biloba are of more than 5% the total urban trees, respectively. In fact, trees from these 7 genera are about 82% of all trees in Shenyang's urban forests. In terms of shrubs, species of 7 genera, Ligustrum spp., Syringa spp., Prunus spp., Berberis spp., Rosa spp., Lonicera spp., and Forsythia spp. are more than 5% the total urban shrubs, respectively. 88% of all the shrubs in Shenyang s urban forest are from these 7 genera. 5. The diameter class of DBH<20cm, 20cm
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本研究通过我国CDBI、 KUN、PE、SZ等主要标本馆约3, 500份馆藏标本的研究和野外考察相结合,对我国蔷薇属(Rosa L.)芹叶组(Sect. pimpinellifoliae DC. ex Ser.)植物以及相关组的一些种进行了性状特征、形态和微形态的研究,对该组的一些种的形态特征描述进行了补充,同时给出详细的地理和海拔范围分布图。综合花粉以及种子(瘦果)形态的研究结果重新制订了分种检索表,同时,对该组一些形态相近容易混淆的种进行了对比研究,特别对一直存在争议的绢毛复合体(绢毛蔷薇R. sericea Lindl.和峨眉蔷薇R. omeiensis Rolfe)进行了大量宏观形态特征的研究,并用光学显微镜(LM)和扫描电镜(SEM)对二者的花粉及种子形态、微形态进行对比研究和分析,主要研究内容包括: 1. 芹叶组孢粉研究 对芹叶组的10个种及相关的4个组共17个种(18个样品)的植物花粉进行了光镜和扫描电镜观察和比较研究。研究结果表明:蔷薇属植物花粉粒大小为中等偏小,极轴长23.98[21.82(R. graciliflora Rehd. et Wils.)~29.18(R. tsinglingensis Pax. et Hoffm.)] μm,赤道轴长28.65[24.15(R. graciliflora)~34.70(R. davidii Crép.)] μm;花粉属辐射对称等极单花粉,花粉形态赤道面观呈球形到超长球形;极面观为三裂圆形或近圆形,三孔沟,孔缘加厚,具中部突起的桥状盖。花粉外壁纹饰为条纹状,光镜下形态特征相差不大;在电镜下外壁条纹和脊沟内穿孔的形状、大小和频度等特征,常具组至种水平上的可见变异,可作为组至种水平划分的依据。 根据花粉外壁条纹特征及穿孔形状和数目等特征,本研究将这些植物的花粉归为5个类型,并编制了分组检索表。同时,根据条纹状的清晰度,排列方式、条纹形状、穿孔大小及其频度等方面的差异,各有特点,对该组的10个种编制了分种检索表。 2. 芹叶组种子形态研究 应用光学显微镜和扫描电镜对我国蔷薇属芹叶组14个种及相关组5个组共36种植物的种子宏观形态及种皮微形态特征进行了观察研究。结果显示,蔷薇属种子形态多样,形状分别为肾形、卵形或锥形等;种子颜色以淡棕色、褐色以及土黄色为主;种子大小种间相差悬殊,相对体积为(长×宽×厚)36.66(4.79~114.47) mm3。光镜下,种子宏观形态特征具组内一致性,在扫描电镜下种子表面结构特征因种而异,其纹饰以网纹为主,可分为3种类型,即近平滑型、负网纹型和网纹型。研究结果表明,蔷薇属种子表面纹饰与地理分布关系不大,具有组及种内稳定性。其种子形态、大小、表而纹饰类型等特征可作为蔷薇属组及种水平上的分类依据。 结合蔷薇属花粉形态研究结果,得出蔷薇属种皮微形态特征与花粉外壁纹饰特征相吻合,在代表组及种的特征上具相关性的结论。同时根据种子形态、微形态结构特征的组间区别和种间差异编制了分组及芹叶组14个种的分种检索表。 3. 绢毛蔷薇复合体的研究 通过对大量标本的研究、野外观察以及扫描电镜对绢毛蔷薇复合体的花粉形态和种皮表面结构进行研究,通过对小叶、花粉及种子的形态定量分析结果支持Rowley (1959)的观点,将峨眉蔷薇处理为绢毛蔷薇的一个变种。 综上研究结果得出,蔷薇属植物的小叶片数目、花被基数以及花粉及种子形态等性状是较为稳定的,这些特征可很好的作为分类学依据。 The morphology, pollen exine sculpture and seed coat structure of the species of Rosa sect. Pimpinellifoliae and related sections were studied.About 3,500 herbarium specimens at CDBI, KUN, PE, and SZ were examined. Field work in Sichuan and Yunnan were conducted. Revisions of some species were carried out and a new key to species of sect. Pimpinellifoliae was proposed based on morphology, pollen exine sculpture and seed coat structure, Detailed morphological descriptions, geographical distributions and the altitudinal ranges of some taxa are given. The systematics of the species complex, the Rosa sericea complex (R. sericea Lindl. & R. omeiensis Rolfe), was emphasized. This thesis focused on the following three aspects: 1. Pollen morphology of Rosa sect. Pimpinellifoliae The pollen morphology of 18 samples representing 10 species of the Eurasian Rosa sect. Pimpinellifoliae and 7 additional species of related sections was investigated under LM and SEM. The pollen grains are monadic, actinomorphic, equipolar, medium-sized, spheroidal to perprolate in equatorial view, 3-lobed circular or semi-circular in polar view, crassimarginate, pontoperculate, and with striate exine sculpture. The striate sculpture varies among sections and species. The equatorial axis ranges from 17.97 μm (R. sikangensis) to 29.18 μm (R. tsinglingensis) with an average of 23.98 μm in length, while polar axis varies from 24.15 μm (R. gracilifolra) to 34.70 μm (R. davidii) with an average of 28.65 μm in length. The pollens can be divided into five types based on striate sculpture and a key to the sections sampled was proposed accordingly. The pollen morphology of species of sect. Pimpinellifoliae is more homogeneous and different from other sections sampled and did not support the two-series subdivisions in sect. Pimpinellifoliae. A key is also provided based on characers of pollen morphology among species in sect. Pimpinellifoliae. 2. Seed coat structure of Rosa sect. Pimpinellifoliae The seed coat structure of 39 samples representing 14 species of Rosa sect. Pimpinellifoliae and 12 additional species of related sections was investigated under LE and SEM. The seed relative volume (Length × width × thickness) ranges from 4.79 to 114.47 mm3 with an average of 36.66. mm3. The seeds are reniform, ovate or oblong in shape, with orange-brown, light brown or deep brown color. Seed coat sculpture was reticulate or striate-like reticulate. There was no difference in sculpture character of various speices under LM, while three types of seed coat sculpture were identified under SEM and a key to species based on the seed coat sculpture was provided. The three types of seed coat sculpture were nearly smooth, areolate and reticulate. The study of the seed coat sculpture of same species sampled from different populations showed that characters on the seed coat are stable, and thus the size, shape and seed coat sculpture can be used in species level identification. Interestingly, characters in the seed coat sculpture and the pollen morphology in sect. Pimpinellifoliae are consistent at in specific or sectional levels. A key to the 14 species sampled was given based on seed coat sculpture. 3. The study on Rosa sericea complex The Rosa sericea complex contains R. omeiensis and R. sericea. They are morphologically similar to one another and the systematic status of R. omeiensis has been controversial. In this study we examined large numbers of herbarium specimens of R. omeiensis and R. sericea and conducted field observations in the Hengduan Mts.. We also performed SEM study of pollen morphology and seed coat structure of R. omeiensis and R. sericea. We further carried out intensive morphometric study on the leaflet, pollen, and seed morphology. Our results showed that R. omeiensis should be sunk to be a variety of R. sericea, just as Rowley’s treatment in 1959. In conclusion, the features in the number of leaflet and petal, and the morphological character on pollen and seed are relatively stable. Therefore these characters are very useful in taxon delimition.