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1.
项贤领  席贻龙  胡好远 《生态学报》2007,27(6):2443-2448
运用随机扩增多态DNA(RAPD)技术研究了于2005年春季和夏季采自芜湖市镜湖的萼花臂尾轮虫(Brachionus calyciflorus)种群基因组DNA多态性。从44个随机引物中筛选出10个谱带清晰、重复性好的引物。10个引物共检测到76个位点,其中65个位点显多态性,多态位点比例(P)为85.5%。对RAPD扩增结果进行聚类分析,基于遗传距离指数构建了萼花臂尾轮虫的UPGMA和ME系统树。经计算,各克隆平均遗传距离指数为0.5219,春季种群内遗传距离指数(0.4416)大于夏季种群内遗传距离指数(0.4304);两季节种群间遗传距离指数为0.6010,明显大于季节种群内遗传距离指数。16个克隆分别聚在2个主要簇群中,在UPGMA系统树中,春季种群和夏季种群明显分聚在两个主要支系中;而在ME树中,除了夏季Su2克隆和春季种群聚到一个支系外,其它夏季种群则聚在一个独立支系中。上述结果表明,春季种群和夏季种群在遗传上具有较大的差异;镜湖萼花臂尾轮虫种群存在着明显的季节更替,而Su2克隆可能是春季和夏季种群间的过渡。  相似文献   

2.
大仓鼠年龄组及性别群体的遗传多样性   总被引:4,自引:0,他引:4  
本应用随机扩增多态性DNA(RAPD)技术,采用多态位点率、Shannon信息多样性指数和Nei遗传多样性指数作为种群遗传变异的指标,研究了1998和1999年大仓鼠种群性别群体和年龄组群体的遗传多样性。主要的结论是:性别群体间遗传分化较小,年龄组群体间分化较大;年龄组相距越大,遗传分化也就越大;幼年组的遗传多样性高于老龄组的遗传多样性;1999年秋季种群的年龄组遗传分化和差异要比1998年四季种群更为明显。大仓鼠不同年龄组群体间的遗传分化支持遗传结构由于受时空上的选择压力而产生变异和适应性观点。大仓鼠幼体的遗传多样性比成体和老体的较高,这一结果倾向于支持Ford的假说,说明种群繁殖出的幼体遗传多样性高,其中有遗传质量好的,也有遗传质量差的,但在生存过程中,随着选择压力的作用,种群趋于适应,与环境不相适应的类型遭到淘汰,低质的幼体由于自然选择压力的增加而从种群中消失,致使成年和老年群体多态性逐渐降低。  相似文献   

3.
华北地区大仓鼠种群的遗传变异   总被引:3,自引:0,他引:3  
应用随机扩增多态性DNA(RAPD)方法对华北地区不同大仓鼠种群的遗传变异进行了研究。结果表明,大仓鼠群体内具有较丰富的遗传变异,不同地区种群的多态位点率均高于60%,Nei’s基因多样度值范围在0·204~0·326之间,Shannon信息指数为0·306~0·484;分析遗传分化指数表明,大仓鼠种群内具有潜在的遗传结构,30·9%的变异来源于种群间存在的遗传变异。结果表明,大仓鼠在不同空间分布区内存在遗传多态性差异,地区种群间已有一定程度的遗传分化,群体间有限的基因流及遗传漂变可能对大仓鼠种群的遗传分化产生了重要的作用。  相似文献   

4.
观光木种群遗传多样性研究   总被引:25,自引:1,他引:24       下载免费PDF全文
 应用随机扩增多态DNA(RAPD)标记方法检测了广东南昆山和车八岭、广西靖西和海南霸王岭等4个观光木种群的遗传多样性。利用45个10聚寡核苷酸引物共检测出224个位点,其中多态位点175个,占78.13%,4个种群的遗传多态位点百分率分别为47.89%(海南)、53.96%(靖西)、55.00%(车八岭)和56.35%(南昆山)。观光木的遗传多样性分析结果显示,Shannon 指数为0.3565,其中36.58%来自种群间, 63.42%来自种群内; Nei指数为0.2597,种群间的遗传分化系数(GST  相似文献   

5.
华北地区油松种群遗传多样性分析   总被引:4,自引:0,他引:4  
李毳  柴宝峰  王孟本 《植物研究》2006,26(1):98-102
用酸性聚丙烯酰胺凝胶(APAGE)技术分析了华北地区5个油松种群在醇溶蛋白水平上的遗传多样性。95份材料分离出12条带,其中11条具有多态性,得到23种不同的带型。种群多态位点比例在16.67%~66.67%之间。Shannon信息指数和Nei’s指数的统计结果表明:关帝山油松种群的遗传多样性高于其它种群;华北地区油松种内遗传多样性为0.248 9;种群内的遗传多样性为0.150 7,占总变异的60.55%;种群间的遗传多样性为0.098 2,占总变异的 39.45%。  相似文献   

6.
大猿叶虫四地理种群遗传多样性的RAPD分析   总被引:1,自引:1,他引:0  
以大猿叶虫Colaphellus bowringi Baly 4个地理种群的基因组DNA为材料, 进行RAPD分析。从80条引物中筛选出11条稳定性好、多态性高的引物进行扩增, 共得到65个扩增位点, 53个多态位点, Nei氏遗传多样性指数为0.1049~0.2061, Shannon多样性指数为0.1641~0.3167。结果表明所分析的大猿叶虫遗传变异很高, 其中江西龙南种群遗传变异最小, 山东泰安种群遗传变异最高。种群间的遗传距离范围为0.0636~0.3200, 其中江西龙南种群和江西修水种群间的遗传距离最小, 哈尔滨种群与江西龙南种群间的遗传距离最大, 种群遗传距离的大小与其相对地理距离的远近吻合。结果提示种群遗传距离的大小与它们生物学上的相似性有关联。  相似文献   

7.
陈建  曹福祥  魏小玲 《生物学通报》2013,(10):14-17,F0003
使用单因素筛选和均匀设计实验建立并优化了观光木ISSR—PCtL的最佳反应体系.从100条ISSR引物中筛选出8条多态性好、扩增稳定的ISSR引物,106份材料共扩增出12l条条带,其中109条呈现多态性,多态位点百分率(PPB)达90.08%。扩增片段为250~2000bp,平均每个引物扩增出15条片段.说明观光木种群间存在丰富的遗传多样性。观光木种群间的Nei’s基因多样性指数(He)=0.3557,Shannon信息指数(I)=0.5276,种群间的分化系数(Gst)=0.6480,而种群内的He=0.1261,I=0.1939,Gst=0.3520,说明观光木种群间的遗传多样性是观光木遗传变异的主要来源。  相似文献   

8.
蜡梅种质资源遗传多样性的ISSR分析   总被引:3,自引:0,他引:3  
赵冰  张启翔 《植物研究》2008,28(3):315-320
利用ISSR分子标记技术,对蜡梅种质资源7个野生种群和2个栽培种群的遗传多样性进行了研究。用11条引物,共扩增出124条谱带,其中110条多态带,多态位点占88.70%。用POPEGEN1.31版软件对数据进行分析,结果显示:种群总的Nei’s基因多样性指数为0.272 6,Shannon信息多态性指数为0.411 7,蜡梅总的遗传多样性水平较高。蜡梅不同种群遗传多样性水平差异较大,种群多态位点百分率在52.94%~90.00%之间,Nei’s基因多样性指数为0.143 4~0.378 2,Shannon信息多态性指数为0.232 2~0.546 6。神农架种群(SN)和保康种群(BK)的遗传多样性水平较高。种群间的基因分化系数为0.353 6,种群内的遗传变异大于种群间的遗传变异。用NTSYS2.01版软件对样品进行UPGMA聚类分析,结果9个种群并没有按地理距离进行聚类。种群间的地理距离和遗传距离之间没有显著的相关性(r=0.437 1,P=0.921 3)。  相似文献   

9.
冷蒿种群在放牧干扰下遗传多样性的变化   总被引:17,自引:2,他引:15  
王静  杨持  尹俊  王铁娟  刘朋涛 《生态学报》2004,24(11):2465-2471
通过随机扩增多态性 DNA(RAPD)方法检测了放牧干扰下冷蒿种群遗传多样性的变化。 17条 (组 )引物进行 RAPD分析 ,扩增共产生 2 5 4条带 ,其中 2 4 0条为多态性带 ,多态位点百分率达 94 .4 9%。随着放牧强度的增加 ,冷蒿种群多态位点百分数 ,Nei遗传多样性指数、Shannon信息指数均下降 ,种群内个体平均遗传一致度增加。放牧梯度上 4个冷蒿种群 H t=0 .2 116 ,Hs=0 .170 0 ,Dst=0 .0 4 16 ,种群间基因分化系数 Gst=0 .196 5 ,基因流 N*m=2 .0 4 5 1;同时随着放牧强度的增加 ,种群间的 Dst、Gst增加 ,N*m 降低。说明放牧限制了种群间的基因交流 ,使种群发生遗传分化。放牧梯度上的 4个冷蒿种群的遗传距离很小 ,但是随着放牧强度的增加 ,遗传距离在缓慢的增加 ,种群间的遗传一致度降低。根据遗传距离所构建的 U PGMA聚类图中冷蒿 4个种群随着牧压的增加 ,逐级聚在一起。这表明冷蒿种群的遗传分化与放牧强度的关系  相似文献   

10.
采用RAPD方法对不同海拔和植被盖度下的鹅绒委陵菜(Potentilla anserinaL.)6个种群的遗传多样性水平进行了研究。结果表明,13条随机引物共扩增出132条带,多态性位点为117;鹅绒委陵菜物种水平的遗传多样性较高,且种群间分化明,多态位点比率(88.64%)、Nei’s基因多样性(0.3180)、Shannon信息多样性指数(0.4732)均远高于多数克隆植物。6个种群内的遗传多样性水平变化较大,多态位点在各种群中分布不均衡,种群间分化系数(GST)为47.7%,基因流较低(Nm=0.5482),多态位点比率在31.06%~74.24%之间,Shannon信息指数在0.1711~0.3625之间,Nei基因多样性指数在0.1164~0.2425之间。多样性水平的变化与海拔没有明显的相关性,而与生境盖度呈显著正相关。从而推断在盖度低、资源丰富的环境中,该物种可能更倾向于克隆繁殖。  相似文献   

11.
Summary Yamada's method of estimating genetic co-variances between traits measured in different experimental units is discussed. It is shown that if the data are unbalanced, this method gives biased estimates of genetic covariances unless the traits have identical genetic and residual variances. An alternative unbiased procedure is suggested.  相似文献   

12.
植物种质群体遗传结构改变的测度   总被引:21,自引:1,他引:20  
本文旨在探讨植物种质资源保存中由于人为和自然缘故导致遗传结构改变的评价指标和评价方法.在介绍植物种质资源保存研究一些基本概念的基础上,归纳了测度种质库(收集品)遗传潜势的6种遗传多样性统计指标,包括同一变异层次的类型数、类型分布均衡度、遗传相似性与遗传距离、遗传方差与遗传变异系数、多元变异指数以及亲本系数.指出若无遗传丰富度相伴,单有遗传离散度并未提供遗传多样性的完整测度.探讨了人为条件导致植物种质资源遗传结构改变的遗传流失、环境胁迫所致植物种质资源遗传结构改变的遗传脆弱性和种子扩繁所引发的植物种质资源遗传结构改变的遗传漂变和遗传漂移等的统计指标.文末给出了自花授粉植物和异花授粉植物群体适宜样本容量研究的个例.  相似文献   

13.
Electrohoretically detectable enetic variation for 29 kinds of blood protein encoded by 33 loci was analyzed for 78 Asian eletants (Elephas maximus) which were collected from its four local populations: Sri Lanka, Souti India, Thailand and Nepal. Elehants in Sri Lanka are classified into the subspecies E.m. maximus, and those from the other tlree localities into the subspecies E. m. indicus. Six variable loci were detected, and one of them, the tetrazolium oxidase locus, was observed to show a complete allele substitution between the subspecies. Average heterozgosity within local populations were in a range of 0.0152 ? 0.0303. Whereas the Nei's genetic distance among three local populations of the subspecies indicus were 0.0013 ? 0.0031, the distance between the subspecies indicus and maximus were 0.0328 ? 0.0370, indicating that the two subspecies were well differentiated genetically.  相似文献   

14.
Genetic polymorphism in varietal identification and genetic improvement   总被引:5,自引:0,他引:5  
Summary New sources of genetic polymorphisms promise significant additions to the number of useful genetic markers in agricultural plants and animals, and prompt this review of potential applications of polymorphic genetic markers in plant and animal breeding. Two major areas of application can be distinguished. The first is based on the utilization of genetic markers to determine genetic relationships. These applications include varietal identification, protection of breeder's rights, and parentage determination. The second area of application is based on the use of genetic markers to identify and map loci affecting quantitative traits, and to monitor these loci during introgression or selection programs. A variety of breeding applications based on these possibilities can be envisaged for Selfers, particularly for those species having a relatively small genome size. These applications include: (i) screening genetic resources for useful quantitative trait alleles, and introgression of chromosome segments containing these alleles from resource strain to commercial variety; (ii) development of improved pure lines out of a cross between two existing commercial varieties; and (iii) development of crosses showing increased hybrid vigor. Breeding applications in segregating populations are more limited, particularly in species with a relatively large genome size. Potential applications, however, include: (i) preliminary selection of young males in dairy cattle on the basis of evaluated chromosomes of their proven sire; (ii) genetic analysis of resource strains characterized by high values for a particular quantitative trait, and introgression of chromosome segments carrying alleles contributing to the high values from resource strain to recipient strain.Contribution from The Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel, No. 767-E, 1983 Series  相似文献   

15.
Gymnodiptychus dybowskii is endemic to Xinjiang, China and has been locally listed as protected animals. To investigate its genetic diversity and structure, specimens were collected from six localities in Yili River system and Kaidu River. Fragments of 1092bp Cyt b gene were sequenced for 116 individuals. A total of 21 haplotypes were found in all samples, and no haplotype was shared between Yili River system and Kaidu River population. Sequence comparisons revealed 123 variable sites, with eight singleton sites and 115 parsimony informative sites. For all the populations examined, the haplotype diversity (h) was 0.8298 ± 0.0226, nucleotide diversity (π) was 0.2521 ± 0.1202, and average number of pairwise nucleotide differences (k) was 275.3369 ± 118.5660. AMOVA analysis showed that the differences were significant for total populations except for Yili River system populations. The pairwise Fst values revealed same conclusion with AMOVA analysis: Kaidu River population was divergent from Yili River system populations. The genetic distance between two groups was 0.108 and the divergence time was estimated at 5.4–6.6 Ma, the uplift of Tianshan Mountain might have separated them and resulted in the genetic differentiation. The neutrality test and mismatch analysis indicated that both two groups of G. dybowskii had went through population expansion, the expansion time of Yili River system and Kaidu River population was estimated at 0.5859–0.7146 Ma and 0.5151–0.6282 Ma, respectively. The climate changes of Qinghai-Tibetan Plateau might have influenced the demographic history of G. dybowskii.  相似文献   

16.
Genebank seed accessions of predominantly self-pollinating species may be stored either as bulked (mixed) seed lines or as pure line cultivars. If seed lines are bulked in storage then when considered over several regeneration cycles, loss of genetic diversity within heterogeneous self pollinating genebank accessions is shown to be severe. This within-accession loss of diversity represents opportunities foregone through the random loss of individual genotypes. Amongst working collections, the utility and repeatability of genebank accessions is paramount in the justification of the germ plasm resource. Therefore, the only practical solution to the management of predominantly self-pollinating species is to preserve individual accessions as pure lines.  相似文献   

17.
Chinese pine (Pinus tabulaeformis carr.), endemic to China, is a conifer species with extensive and fragmented distribution in North China. In this study, the genetic diversity and structure of 20 natural populations of this species were investigated using amplified fragment length polymorphism (AFLP) markers. A total of 445 fragments were revealed with 8 pairs of primers, 379 (85.17%) of which were polymorphic. A moderate level of genetic diversity was detected at the species level (Shannon's information index I = 0.356, Nei's gene diversity HE = 0.271) and at the population level (I = 0.219, HE = 0.206). Most of genetic variation was within populations while a considerable level of genetic differentiation was detected (GST = 0.352, ФST = 0.304). The high differentiation could be attributed to the complex and fragmented habitats, and a limited gene flow among populations (Nm = 0.572). The Mantel test indicated that there was significant correlation (r = 0.455, P < 0.001) between Nei's genetic distance and geographical distance among all the populations. The results suggested that proper countermeasures should be taken to prevent the habitat further deterioration and maintain the genetic diversity of this species.  相似文献   

18.
Prince Rupprecht's Larch (Larix principis-rupprechtii Mayr.) is one of dominant components of middle and high elevation forests in North China. Shanxi Province is well known as “the Hometown of Prince Rupprecht's Larch” in China. In this study, six natural populations of this species across Shanxi were selected to investigate the genetic variation of the species using amplified fragment length polymorphism (AFLP) markers. Results showed that in comparison with some other species of Larix, higher genetic diversity was revealed at the species level for L. principis-rupprechtii (percentage of polymorphic loci PPL = 71.9%, Nei's gene diversity HE = 0.225, Shannon information index I = 0.341). Most of genetic variation existed within populations (80.5%), while the genetic differentiation among populations was significant (p < 0.001) and higher (Gst = 0.194) than most other species of Larix. The differentiation can be attributed to the limited gene flow (Nm = 1.035) among populations, which could be due to the spatial isolation and habitat fragmentation. The six populations can be divided into three groups based on the Nei's genetic distances between populations (from 0.033 to 0.076). There was no significant correlation (r = 0.268, p > 0.05) between genetic distance and geographic distance among populations. The measures for in-situ or ex-situ conservation should be taken to preserve the genetic diversity of this species.  相似文献   

19.
Genetic traits     
Recognizing that all traits are the result of an interaction between genes and environment, I offer a set of criteria for nevertheless making sense of our practice of singling out certain traits as genetic ones, in effect making a distinction between causes and mere conditions. The central criterion is that a trait is genetic if it is genetic differences that make the differences in that trait variable in a given population. A second criterion requires that genetic traits be individuated in a way that matches what some genetic factors cause specifically. Clarifying our causal and classificatory language here can help us to avoid confusions of both theoretical and practical significance.  相似文献   

20.
Canavalia ensiformis is an under-exploited legume that has been used as forage, green manure, and a cover crop. Thus far, studies of the C. ensiformis germplasm have focused on morphological traits, which cannot be used to distinguish all known accessions or to evaluate their genetic diversity precisely. In this study, sequence-related amplified polymorphism (SRAP) markers were used to assess the genetic diversity and relationships among 29 C. ensiformis accessions originating from 16 countries. In total, 274 clear bands were amplified and 144 of them (52.6%) were polymorphic. The polymorphism information content values (PIC) ranged from 0.10 to 0.43, with an average of 0.27. An analysis of molecular variance (AMOVA) revealed that the most significant variation (92.0% of the total) occurred among accessions; the remaining 8.0% was attributed to variation within accessions. A cluster analysis and principal coordinates (PCoA) analysis produced similar results, whereby the 29 C. ensiformis accessions were divided into 5 clusters, each of which was composed of different accessions with different phenotypic traits. This study provides the theoretical basis for future biodiversity studies and breeding programs.  相似文献   

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