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1.
Vicia amirensis has pollen grain with swollen mesocipium, terete style, abaxially sprouting stylar hairs and globes stigma, differing from
other five species,V. amoena, V. japonica, V. pseudo-orbus, V. ramuliflora, V. unijuga andV. venosa, in sect.Vicilla of Kupicha’s System. This result further support taxonomic treatmentV. amurensis proposed by Endo and Ohash. The chromosome numbers of 64 populations and karyotypes of 15 populations for sect.Vicilla and sect.Amurense were observed.V. amurensis andV. psendo-orbus have similar karyotype features such as the same karyotype symmetry, comparable chromosome size and the same type, of Sat-chromosomes,
and thereforeV. amurensis in seet.Amurense is assumed to be closely related toV. japonica in sect.Vicilla. The primary study of nuclear DNA amount was carried out on nine populations of six taxa in sect.Vicilla in China. It is primarily discussed that evolutionary trend of karyotype, nuclear DNA amount in sect.Vicilla and geographic distribution of different ploidy cytotypes.
(Responsible Editor: Zhu Hong) 相似文献
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荚(艹迷)属(Viburnum)全世界约有250种,分布于亚洲、欧洲、南美洲和北美洲。我国约有74种,南北均有分布。荚(艹迷)组(Sect.odontotinus)的荚(艹迷)(V.dilatatum Thunb.)广布于陕、豫、冀三省的南部及长江以南诸省(区),但以华东地区为常见;直角荚(艹迷)(V.foetidum Wallvar.rectangulatum(Graebn.)Rehd.)分布于滇、川、甘、陕、黔、桂、湘、鄂、赣、台等省(区);宜昌荚(艹迷)(V.ichangense(Hance)Rehd.)分布在鲁、豫、苏、浙、闽、赣、 相似文献
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以思茅松主产区的思茅居群为参照,对景洪大渡岗居群的校形态结构进行了系统研究。结果为;(1)二者的间期核构形都为复杂染色中心型,前期染色体属于中间型,核型公式均为K(2n)=24=24m,核型不对称性都属于1A型;(2)二者在次缢痕数目及其分布上有明显差异。思茅居群仅有1对染色体具有次缢痕,位于第3对染色体长臂上,景洪大渡岗居群有4对染色体具有次缢痕,分别位于第1、3、6对染色体短臂和第2对染色体长臂上。综合前期对思茅松4个不同居群染色体核型的研究,建议研究思茅松各居群的花粉母细胞减数分裂行为及从等位酶位点和DNA水平上深入研究思茅松居群的遗传结构与分化。 相似文献
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【目的】以云冷杉红松林(Spruce-fir-Korean pine forest)为研究对象,探究林隙干扰后优势种群之间的关系。【方法】基于凉水国家级自然保护区外业调查的基本数据,利用点格局分析方法对优势种群的空间格局进行分析,利用χ2检验和联结系数AC两种方法对优势种群的种间关联性进行分析。【结果】1)红松Pinus koraiensis在空间尺度为0~1.9 m时呈现随机分布,在≥1.9 m时为聚集分布。臭冷杉Abies nephrolepis、白桦Betula platyphylla和红皮云杉Picea koraiensis在所有尺度上均表现为聚集分布,紫椴Tilia amurensis在尺度为0~35 m时呈现聚集分布,在>35 m时为随机分布。2)红松与臭冷杉在所有尺度上均为聚集分布,红松与其他优势种群多为离散分布,红松与其他优势种群的种间关联性表现为无关。臭冷杉与白桦、紫椴在空间格局上主要为聚集分布,种间关联性为极显著负相关,表现为强烈的竞争关系。臭冷杉与红皮云杉在小尺度表现为离散分布,大尺度上为随机分布,种间关联性为不显著的正相关,说明其间的依赖性不强。白桦、红皮云杉和紫椴3种优势种群之间的空间格局主要为聚集分布,红皮云杉与白桦、紫椴与红皮云杉之间的种间关联性为显著负相关,白桦与紫椴之间为显著正相关。【结论】2个树种中优势度较高的树种的胸径决定了其空间格局的聚集程度以及种间关联性的显著程度,即平均胸径大的树种与其他树种表现为空间上离散,平均胸径小的树种之间表现为空间上聚集。 相似文献
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对８个不同杉木地理种源的Ｎ－带带型进行分析，结果表明，Ｎ－显带染色体随体及其相对应的短臂末端均为深着色．着丝粒区域多数有两个明显的小点，其大小、形状和位置与ｃｄ（ｃｅｈｔｒｏｍｅｒｅｄｏｔ）带相同．Ｎ－带显带难度不大，重现性好．易于检出随体染色体、随体的形状和大小，以及着丝位位置．对提高核型分析水平有一定的意义． 相似文献
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Shoot meristem of many flowering plant species consists of threeindependent cell layers (L1 ,L2 and L3) (Tilney-Bassett ,1986) .The cells inthetwo outerlayers (L1 ,L2) divide anticlinallyinthe samelayer whilethoseininnerlayer (L3) divideinany plane (Bartonet al.,1993 ;Li ,2005) .If the genotypes of cells at least twolayers in a plant meristemare different ,theplantis called chimera (Tilney-Bassett ,1986 ; Burgeet al.,2002) . When one or more entire cell layer(s) are geneticallydifferentfr… 相似文献
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中国硬叶常绿高山栎类植物的起源与演化 总被引：2，自引：0，他引：2
硬叶常绿高山栎类植物是指壳斗科栎亚属中的高山栎组(Quercus subgenus Quercus sect. B rachylepides)的8种植物和1个存疑种植物,以及巴东栎组(Quercus subgenus Quercus sect. Engleriana)的7种植物。本文依据已有的文献,综述了中国硬叶常绿高山栎类植物系统演化、化石历史和现代分布等,讨论了中国硬叶常绿高山栎类植物的起源、演化和扩展途径,为进一步系统研究和解释这类植物对高山环境的适应机制提供基础资料。 相似文献
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4个石榴品种的染色体核型分析 总被引：1，自引：0，他引：1
采用常规根尖压片法对4个石榴品种的染色体数目进行了统计,并进行了核型分析。旨在了解品种间演化关系,为石榴品种间分类研究提供细胞学依据。结果表明:4个石榴品种的染色体数都为18,且核型不对称性类型均为2B型,说明4个品种间的染色体核型变异不大。但核型仍然存在一定的差异,芽变新品种白玉和其母本的核型公式相似,说明两者亲缘关系较近,但母本的臂比大于2的染色体占11.11%,而白玉为22.22%,说明前者较后者原始。大笨子与玉石籽的核型公式具有一定的相似性,说明两者之间亲缘关系也较近。单就臂比大于2的比例来看,芽变新品种白玉较其它3个品种进化。从核型来看,白玉及其母本比另2个品种的核型不对称性强。4个石榴品种的染色体都具有随体,且随体位置相同,但是随体大小稍有不同。4个石榴品种的染色体总体积亦不相同。 相似文献
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《Journal of Sustainable Forestry》2013,32(3):75-90
Abstract The Japanese cedar, Cryptomeria japonica D. Don., is one of the most important endemic species in Japan. A long history of heavy logging has resulted in natural populations being discontinuously distributed and scattered among small, restricted areas. An understanding of the patterns of genetic variability among and within populations of C. japonica is important for conserving the genetic resources of this economically important species. We studied genetic variation by random amplified polymorphic DNA (RAPD) markers in C. japonica of Kyoto prefecture, western Japan. A total of 398 plants sampled from six natural populations were analyzed by ten arbitrarily chosen decamer primers, resulting in 50 highly reproducible RAPD bands. Analysis of molecular variance partitionated the RAPD variation into the among- and within population components. The within-population component accounted for 93.75% of the variation. The among-population component accounted for only 6.25%. Indirect estimates of gene flow indicated that the average number of migrants exchanged among six populations per generation was 3.72. A Mantel test for each population did not yield significant correlations between geographic and genetic distances. The extent and distribution of C. japonica diversity in the Kyoto prefecture is in agreement with the conclusion that long-lived, wind-pollinated, out-crossing species with wide ranges retain a considerable amount of genetic diversity within populations and exhibit little genetic differentiation among populations. 相似文献
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Jules S. Freeman Cristina M. P. Marques Victor Carocha Nuno Borralho Brad M. Potts René E. Vaillancourt 《Annals of Forest Science》2007,64(6):639-647
The Portuguese Landrace of Eucalyptus globulus is of unknown origin, with the earliest plantings of this tree species dating back to the early 19th century. In Portugal it is currently a major seed source for plantations and is also used in breeding programs. Eucalyptus globulus is native to south-eastern Australia. The substantial genetic differentiation of chloroplast and nuclear DNA markers between different native geographic races of this species allowed us to uncover the Australian origins of the Portuguese Landrace and to study its genetic diversity. To achieve this, we sequenced a highly polymorphic region of chloroplast DNA from 47 Portuguese Landrace individuals, and genotyped 34 of these using seven nuclear microsatellites. We compared these individuals to those in a database comprising chloroplast DNA sequence profiles from 292 native trees and seven nuclear microsatellites from 372 native trees. The majority of the Portuguese Landrace samples had closest affinities, in both marker systems, to native trees from south-eastern Tasmania, but some had affinities to trees from south-eastern Victoria. The discrepancies in the affinities indicated by chloroplast versus nuclear DNA markers could be explained by inter-race hybridisation after introduction. The genetic diversity in the Portuguese Landrace was less than that found in native E. globulus at the species level, but was similar to the average diversity found in native races of the species. This study demonstrates the power of using independent marker systems to identify the origins and diversity of domesticated populations, by comparison with variation in native stands. 相似文献
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对鸡足山地区4个多星韭种群的染色体进行核型分析与比较,结果表明：多星韭1号和4号种群为二倍体,核型公式为：2n=2x=14-8sm（2SAT）＋6m和2n=2x=14-10m（SAT）＋4sm,多星韭2号和3号种群为四倍体,核型公式为：2n=4x=28-14m（2SAT）＋14sm和2n=4x=28=18m（2SAT）＋10sm。从植株形态、分布、生境、核型等方面分析表明,多星韭核型进化趋势是由二倍体向四倍体进化的,四倍体多星韭二倍化显著。 相似文献
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Inttxiducti()nSnagandfaIlenwoodwasin1ps)rtantcolllponel1tSofft)restecosystem,nutrientpoolf`'rforestal1in1alsal1dn1icrobes,alsowashoPortantapproachofe11ergyflowa11dmaterialnowinforest.soforestecoIogistsattachedinlportaI1cetostudyonsnagandfallel1woodil1creasinglya11dl1ewlydevelopedd1e"ECologyofWood`lecomPOsitiol1'{"'l.Inresearchworkli1Olal1gbaiMoul1tainForestEcosys-tem,tllestudyl4,7,s,9,1o]lladbeenco11ductedinfallel1woodsince8os,andtheresearchra11gewasverywidespread.Buttl1esestUdieswerenl… 相似文献
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lntroductionBroad-leavedKoreanpineforestisacldriaxforestli1tCm-peratezoneofNortheaster11Cl1ina.ltscharacteristichasIligllstabilityandproductivity.Therewerenlanyresearcl1worksfocusedontl1estructure,dynandcsanditsmain-tainingmechanisn1.Researchontheforestregeneratio11wasamali1approaclltoundersta11dtlleforestdynanlicsI;j.ThereweremanyresearcI1eso11tl1erege11erationofh1iskindofforestsincel95ol5~ll].Butfewoftl1emweredoneundertheconsiderationofcanopygapdistUrbance.Sincel99O's,moreandmoreresearch… 相似文献
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以西南民族地区171个乡村旅游重点村为研究对象,综合运用ArcGIS空间分析、最邻近指数、地理集中指数、核密度分析、地理联系率等统计方法对乡村旅游重点村的空间分布特征及影响因素进行探析。结果表明,研究区乡村旅游重点村的最邻近指数为0.789,表明其在空间上呈凝聚型分布;研究区乡村旅游重点村的地理集中指数G=44.90,大于理想状态分布下的地理集中指数34.2,表明其在空间上呈集聚分布,但集聚度不高;研究区乡村旅游重点村的分布密度呈多核心特征,高核密度值地区有成都市、渝东南地区、渝西南地区、六盘水市、黔南布依族苗族自治州,其中成都市的核密度值最高;研究区乡村旅游重点村的分布受到地形、河流湖泊、资源禀赋、人口分布、经济发展水平、交通分布等因素的影响。 相似文献
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杜仲Eucommia ulmoides的核型分析 总被引：1，自引：0，他引：1
以萌发种子的根尖为材料,对兰州地区引种的杜仲进行了体细胞染色体核型分析。结果显示：杜仲染色体较小,数目均为34条,与前人的研究结果一致;杜仲体细胞染色体核型有2类,第1类为2n=34=20m（2SAT）＋10sm＋4st,第2类为2n=34=20m（2SAT）＋12sm＋2st,在2类核型中均见到了随体染色体,随体均位于中部着丝点染色体的短臂上。2类核型中最长染色体与最短染色体的比值分别小于2,臂比值大于2：1的染色体的比例在1％～50％之间,按照stebbins的核型分类标准应属2A核型,与前人的核型分析结果差异较大。 相似文献
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