共查询到19条相似文献，搜索用时 109 毫秒
1.
《资源与生态学报(英文版)》2020,(5)
利用SSR(简单重复序列)标记研究红椿分布区天然居群的遗传多样性,为红椿种质资源的保护和开发提供理论依据。本文筛选7对SSR引物,分析了湖北等5省(区)24个居群的192份红椿种质的遗传多样性,利用Data Formater、Popgene、NTSYS、TFPGA等软件进行遗传数据转换、遗传参数估算、树状聚类图和遗传变异分析。结果显示:(1)7对引物共检测到17个等位基因(N_a),平均每个引物为2.2602个,其中引物S11和S422检测到的等位基因数最多,均为4个。Nei's遗传多样性指数均值(H)为0.4909,Shannon信息指数均值(I)为0.7321,多态信息含量(PIC)平均值为0.5182;平均期望杂合度(H_e)和观测杂合度(H_o)分别为0.1055和0.4956。居群Nei's遗传距离介于0.000–2.635之间,均值为0.548;居群遗传多样性平均水平(H=0.1044)低于物种水平(H=0.4909)。(2)居群遗传分化系数(F_(st))介于0.2374–0.9148,平均为0.7727;居群基因流(N_m)均值为0.0735,表示居群间遗传交流水平低,遗传变异主要来自居群内。(3)在遗传一致度为0.99时,24个居群UPGMA聚类为3大群组:贵州和广西居群聚为一组,湖南聚类为1组;湖北聚类为1组。Mantel检验结果显示居群间的遗传距离与地理距离间呈现显著相关性(r=0.6318,P=0.0090.05)。红椿居群遗传多样性处于偏低水平,地理隔离是红椿种源间产生遗传分化的重要的原因。进行红椿种质资源保护时,应侧重选育群体遗传多样性最高的居群(如P14);遗传多样性低的居群,应就地保护与迁地保护相结合,综合生态和用材目标,最大化保存和利用好红椿的多样性。 相似文献
2.
崔文娟林玉红石有太欧巧明罗俊杰 《中国沙漠》2018,(6):1267-1274
采用EST-SSR分子标记,对来自7个主要栽培区的兰州百合(Lilium davidii var.willmottiae)种质资源进行遗传多样性分析。结果显示:(1)兰州百合在物种水平上具有较高的遗传多样性,多态性位点百分率(PPB) 90.91%,Nei’s遗传多样性指数(H) 0.3256,Shannon’s遗传多样性信息指数(I) 0.4875;各栽培居群遗传多样性为西果园>榆中>魏岭>阿干>黄峪>金沟>永靖。(2)兰州百合栽培群体基因分化度Gst为0.2395,基因流(Nm)为1.5876,各栽培居群间遗传分化水平低,遗传差异主要存在于居群内。(3)兰州百合种质材料69个采样点的聚类结果显示,84.05%的材料都聚合到一个类群,这与STRUCTURE遗传结构分析的结果一致,说明兰州百合种质资源的遗传基础相对狭窄。兰州百合种质资源的遗传多样性主要由小部分种质的遗传变异引起,收集研究这些稀有特异种质,将为兰州百合育种改良及优异基因发掘提供重要参考。 相似文献
3.
《中国沙漠》2018,(6)
采用EST-SSR分子标记,对来自7个主要栽培区的兰州百合(Lilium davidii var.willmottiae)种质资源进行遗传多样性分析。结果显示:(1)兰州百合在物种水平上具有较高的遗传多样性,多态性位点百分率(PPB) 90.91%,Nei’s遗传多样性指数(H) 0.3256,Shannon’s遗传多样性信息指数(I) 0.4875;各栽培居群遗传多样性为西果园榆中魏岭阿干黄峪金沟永靖。(2)兰州百合栽培群体基因分化度Gst为0.2395,基因流(Nm)为1.5876,各栽培居群间遗传分化水平低,遗传差异主要存在于居群内。(3)兰州百合种质材料69个采样点的聚类结果显示,84.05%的材料都聚合到一个类群,这与STRUCTURE遗传结构分析的结果一致,说明兰州百合种质资源的遗传基础相对狭窄。兰州百合种质资源的遗传多样性主要由小部分种质的遗传变异引起,收集研究这些稀有特异种质,将为兰州百合育种改良及优异基因发掘提供重要参考。 相似文献
4.
以三江平原狭叶甜茅(Glyceriaspiculosa)为研究对象,选取3个不同群落类型:狭叶甜茅优势种群落、狭叶甜茅和毛苔草(Carexlasiocarpa)为共建种的群落以及狭叶甜茅为主要伴生种的群落,共45个材料进行了ISSR分子标记分析。结果从41个引物中筛选出7个有效引物,扩增出80条清晰条带,平均每个引物扩增了11.4条带,其中70个位点是多态的,总的多态位点比率为87.5%,表明被测材料间ISSR标记多态性较高。利用Popgen(version1.32)软件分析了扩增结果,并得到了狭叶甜茅不同群落类型的遗传距离、遗传一致度、Nei和Shannon信息指数等遗传特征。结果表明,对于一个物种来说,当地理距离太近不能成为影响其遗传多样性水平的因素时,其构成的种群在群落中的地位将是影响遗传多样性水平的主要因素之一。 相似文献
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内蒙古中西部草原区五种针茅的遗传多样性研究 总被引：1，自引：0，他引：1
利用RAPD（Random Amplified Polymorphism DNA, RAPD）分子标记技术,对内蒙古中西部草原区16个不同地理种群的五种针茅的遗传多样性及其种间关系进行了研究。从102个10碱基随机引物中筛选出28个有效引物,共扩增出389条带,多态性条带345条,占88.69%,说明针茅属植物具有丰富的遗传多样性,对环境的适应能力较强,PCA分析表明水热成为其地理分布的决定性因素。依据五种针茅的Jaccard相似系数所做的UPGMA聚类分析表明,大针茅和克氏针茅之间的遗传距离比较小聚为一类,它们与本氏针茅、短花针茅和小针茅间的遗传距离都比较大。 相似文献
6.
锦鸡儿属植物的遗传多样性及其种间关系 总被引：10，自引：3，他引：7
利用RAPD技术,对甘肃省自然分布的11种锦鸡儿属(CaraganaFabr.)植物的遗传多样性及其种间关系进行了研究。从34个10碱基随机引物中筛选出能产生稳定多态性标记的引物11个,共扩增出128个位点,主要集中在200~2000bp之间,其中104个表现出多态性,多态性比率高达81.25%;根据POPGENE32软件计算的Shannon多样性指数与Nei指数也较高,分别为0.3889和0.2517。说明锦鸡儿属植物具有丰富的遗传多样性,对环境变化的适应能力较强。应用UPGMA法进行聚类分析,结果表明,RAPD分析所反映的种间遗传关系与传统的形态学分类结果基本一致,但也有个别种的从属地位稍有变化。这说明还需要将分子标记的研究结果与形态学和其他方法结合起来进一步进行研究。 相似文献
7.
《中国沙漠》2016,(2)
采用磁珠富集法构建了红砂(Reaumuria soongarica)基因组微卫星富集文库,通过测序结果对文库的特性进行了分析。结果表明:在获得的13 922条微卫星序列中完美型占88%,非完美型10%,混合型2%。微卫星重复基元显示5种类型,以三碱基基元(GGT)n、(TGG)n、(ACC)n最多,占总数的60.7%;其次为二碱基基元,主要是(AC)n、(GT)n、(CA)n,占38.6%;这5种微卫星重复基元的重复次数多集中在5~10。通过对随机挑选的100条微卫星序列设计引物,并以遗传距离和地理距离较远个体的基因组为模板进行扩增筛选,可有效扩增的引物为62对,并进一步测序筛选获得了12对多态性微卫星引物。磁珠富集法是开发红砂基因组微卫星序列的一种高效、可行的方法,构建的微卫星文库效率较高,富集量大,重复基元类型丰富,为红砂遗传进化和种质资源保护提供了可靠的数据支持和高效的分子遗传标记。 相似文献
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大尺度景观结构指数的因子分析 总被引：12，自引：1，他引：12
基于遥感和GIS技术,尝试对大尺度下陆地景观结构指数进行因子分析。根据生态区划计算描述中国陆地景观结构的13种景观结构指数,包括斑块密度、最大斑块指数、边界密度、面积加权斑块形状指数、面积加权斑块分维度、平均最近斑块距离、最近斑块距离的标准差、最近斑块距离的相异系数、蔓延度、分布邻接指数、结合度、香农多样性指数、辛普森多样性指数。在相关分析的基础上,对其中12种指数进行因子分析,并采用前3个公因子分析中国陆地景观结构,3个公因子的方差累积贡献率达88.8%,分别定义为斑块多样性因子、斑块形状复杂性因子和斑块分布均匀性因子。计算表明,在人类活动影响强烈的生态区,这3个公因子取值都比较小,反映斑块类型多样性减少、形状复杂性降低、分布趋于均匀。 相似文献
10.
山区开矿和城镇建设使毛木耳资源日益匮乏，为了合理保护利用毛木耳资源，为新品种选育提供理论依据。也为毛木耳DNA指纹图谱的构建奠定基础，从分子水平上探讨毛木耳种间、品种间遗传关系，用ISSR标记分析毛木耳种质资源。结果表明：从27条ISSR引物中筛选出适合毛木耳种质分析的17个ISSR引物。17个引物共扩增出155条带，多态性位点155；多态性位点比率100％。基于扩增条带数据库建立了Jaccared遗传相关系数矩阵。构建了相似的分子树状图，将55个供试菌株分为5类群：Ⅰ类群含12个菌株，Ⅱ类群含11个菌株，Ⅲ类群含2个菌株，Ⅳ类群含24个菌株，Ⅴ类群含6个菌株。55个菌株的平均遗传相似系数为0．4109。同时类群的划分与菌株来源的地理分布没有关系。菌株间的遗传多样性十分丰富。用ISSR标记技术能将以传统形态特征为分类依据定名的菌株全部分开。 相似文献
11.
In order to provide a theoretical basis for the protection and development of T. ciliata germplasm resources, we studied the genetic diversity of T. ciliata by using SSR (Simple Sequence Repeat) primers to evaluate the genetic diversity of 192 T. ciliata germplasm samples from 24 populations of 5 provinces. DataFormater, Popgene, NTSYS, TFPGA and other software were used for genetic data conversion, genetic parameter estimation, dendrogram construction and genetic variation analysis. The results showed that: 1) a total of 17 alleles (Na) were detected in seven pairs of primers, with an average of 2.260 for each primer. Among them, the highest numbers of alleles (4) were detected in primers S11 and S422.The mean value of Nei’s genetic diversity index (H) was 0.4909, the mean value of Shannon information index (I) was 0.7321, and the mean value of polymorphic information content (PIC) was 0.5182. The mean expected heterozygosity (He) and observed heterozygosity (Ho) were 0.1055 and 0.4956, respectively. The Nei°s genetic distances of the populations ranged between 0.0002 and 2.6346, and the mean was 0.5477. The average genetic diversity level (H=0.1044) of the 24 populations was lower than that of the species (H=0.4909). 2) The genetic differentiation coefficients (Fst) varied from 0.2374 to 0.9148, with an average value of 0.7727. The mean of population gene flow (Nm) was 0.0735, indicating a low level of genetic exchange between populations, and suggesting that the genetic variation mainly came from within populations. 3) With the UPGMA method, the 24 populations were clustered into 3 groups at Nei’s genetic identity (0.99): the populations from Guizhou Province and Guangxi Zhuang Autonomous Region were clustered into one group, the populations from Hunan Province were in another group, and the populations from Hubei Province were in the third group. The Mantel test analysis showed a significant correlation between Nei’s genetic distance and geographic distance (r=0.6318, P=0.009?0.05). The genetic diversity of the 24 populations of T. ciliata was at a low level. Geographic isolation was the main reason for genetic differentiation among T. ciliata provenances. In the protection of germplasm resources of T. ciliata, emphasis should be placed on breeding genetic resources from the populations with higher genetic diversity (P14, for example). As for the populations with low genetic diversity, an ex-situ protection strategy as well as ecological and timber objectives, should be taken into account to maximize the conservation and utilization of the diversity of T. ciliata. 相似文献
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Investigation of the invasion of Prosopis juliflora and its effects on indigenous plant species are important for the control of the species. The study aimed to assess: (1) the effects of Prosopis juliflora invasion on the diversity of plant species in Awash Fentale and Amibara Woredas; (2) the effects of Prosopis juliflora invasion on the regeneration potential of native woody species. Sample collection was performed in habitats of Prosopis juliflora thicket, Prosopis juliflora mixed with native species stands, non-invaded woodlands, and open grazing lands. The vegetation was stratified into invasion levels of Prosopis juliflora and then a random sampling technique for data collection. Among species of plants, the highest proportion of species, 75 (47.8%), was recorded under non-invaded woodlands, but the lowest proportion of species, 22 (14%), was recorded under open grazing lands. The invasion of Prosopis juliflora reduced the Shannon diversity index. The mean values of the Shannon diversity index and species richness under Prosopis juliflora mixed with native species (H′=2.22, R=14) and non-invaded woodlands (H′=2.23, R=13) were significantly higher than Prosopis juliflora thicket (H′=1.96, R=12) and open grazing lands (H′=1.84, R=10). The highest total density (358 stems ha?1) of seedlings was recorded under Prosopis juliflora mixed with native species. But, the lowest total density (153 stems ha?1) of seedlings was recorded under Prosopis juliflora thickets. Moreover, 102 trees ha?1 native woody species were recorded under Prosopis juliflora thicket, but 1252 trees ha?1 native species were recorded under non-invaded woodlands. If the invasion of Prosopis juliflora and its effects on native species diversity continue coupled with a drier climate, plant diversity of the Afar flora region will be highly affected and its ecosystem services will be under question. Thus, the participation of all stakeholders and multidisciplinary research approaches should be designed for the management of the species and rehabilitation of the rangelands in the region. 相似文献
14.
F. Sánchez-Teyer S. Moreno-Salazar M. Esqueda A. Barraza M.L. Robert 《Journal of Arid Environments》2009,73(6-7):611-616
Agave angustifolia is taken from wild populations in the desert of Sonora, Mexico, to make the alcoholic drink known as “bacanora”. An increase in the demand for this beverage has led to overexploitation of these agaves. We used AFLP to measure the genetic variability within and between natural populations of the species. The fixation index (FST) and population genetic distances (GD) were determined for three populations of A. angustifolia. At the clonal level, the expected heterozygosis (HE), the proportion of polymorphic loci (P), and the genetic similarity indices (GSIs) were lower in one population. Total GSI for adults and offshoots was 0.924. There were no differences in the GSI within or between the populations and dendrogram showed three groups that partially reflect the geographical distribution of the populations. Some degree of genetic variation between mother plants and their vegetatively produced rhizomes was observed. At the species level, total expected heterozygosity was high (HT = 0.314) with a P value of 78%, and intermediate gene flow (Nm = 1.18), giving rise to a moderate fixation index (FST = 0.175). Nm, FST and GD values observed, indicate that urgent measures must be implemented to preserve the genetic diversity. 相似文献
15.
《湿地科学》2015,(5)
Chinese medaka(Oryzias sinensis),widely distributed in the plateau lakes,Yunnan Province,which was the indicative specie for the habitat quality of riparian zone in the wetland ecosystems and also was the key specie in the lake ecosystems,and also was one of the fishes who suffered the severe invasion of alien species.There,we investigated that the genetic diversity and population structure of the wild Chinese medaka by using inter-simple sequence repeat(ISSR)analysis.The samples(20 individuals in total)of Chinese medaka in three populations in the drainage area of Dian Lake were obtained.The 7 ISSR primers were picked out to assess the genetic diversity.The ISSR primers combinations revealed 82.69%polymorphism,among 52 genetic loci amplified.The sum of effective number of alleles and observed number of alleles were 1.492 4 and 1.826 9,respectively.The Shannon genetic diversity and Nei genetic diversity indexes of all the populations were 0.434 5 and 0.289 7,respectively.The gene differentiation(GST)was 0.198 9,and the gene flow(NM)was 2.013 2.The AMOVA demonstrated that only 6.65%of genetic variance came from inter-population,and 93.35%of genetic variance came from intra-population.Phylogenetic tree showed that 20 individuals from 3 populations were clustering mixed each other.Also,the principal coordinate analysis(PCA)supported the cluster analysis results.These results indicated that the genetic diversity of Oryzias sinensis was at the middle level,and there was no obvious genetic differentiation among the three populations of Oryzias sinensis. 相似文献
16.
Numerous domestic scholars have argued that a remote location is the major factor preventing the transformation and sustainable development of resource-exhausted cities. Research to date, however, has not presented relevant evidence to support this hypothesis or explained how to identify the concept of ‘remoteness’. Resource-exhausted cities designated by the State Council of China were examined in this study alongside the provincial capital cities that contain such entities and three regional central cities that are closely connected to this phenomenon: Beijing, Shanghai, and Guangzhou. Spatial and temporal distances are used to calculate and evaluate the location remoteness degrees (LRDs) of resource-exhausted cities, in terms of both resource types and regions. The results indicate that resource-exhausted cities are indeed remote from the overall samples. Based on spatial distances, the LRDs are α1 = 1.36 (i.e., distance to provincial capital city) and β1 = 1.14 (i.e., distance to regional central city), but when based on temporal distances, α2 = 2.02 (i.e., distance to provincial capital city) and β2 = 1.44 (i.e., distance to regional central city). Clear differences are found in the LRDs between different regions and resource types, with those in western China and forest industrial cities the most obviously remote. Finally, the numbers of very remote resource-exhausted cities based on spatial and temporal distances (i.e., α > 1.5 ∩ β > 1.5) are 14 and 19, respectively, encompassing 17.9% and 24.4% of the total sampled. Similarly, 25 and 30 not remote resource-exhausted cities based on spatial and temporal distances (i.e., α ≤1.0 ∩ β ≤ 1.0) encompass 32.1% and 38.5% of the total, respectively. This study provided supporting information for the future development and policy making for resource-exhausted cities given different LRDs. 相似文献
17.
沙冬青（Ammopiptanthus）是蒙新砾质荒漠中唯一常绿阔叶灌木孑遗,且已陷入濒临灭绝的境地。沙冬青属内分类争论已久。利用分子手段对国内沙冬青居群进行了遗传结构分析,以对其保护提供准确的遗传学信息。核序列和叶绿体间隔数据均表明,沙冬青属包含两个明显不同的分支,分别分布于塔里木荒漠与阿拉善荒漠,我们据此建议恢复分布于新疆的沙冬青居群的物种地位,即新疆沙冬青（A.nunas）。沙冬青属属下两个种遗传多样性均比较低,可能由于先天遗传不足及破碎化小居群的遗传漂变与近交作用。新疆沙冬青无明显的遗传结构。蒙古沙冬青（A.mongolicus）在阿拉善荒漠北部与南部出现了明显的遗传分歧,这可能是由于南北部居群由不同的避难所扩张而来。也为沙冬青的保护提出了建议。 相似文献
18.
Most microsatellites are very polymorphic. This makes them powerful markers for observing genetic differentiation between closely related populations. The population structure of the Greenlandic Arctic fox ( Alopex lagopus ) was studied genetically by analysing six polymorphic microsatellite loci of 75 foxes from four populations in different parts of Greenland. Genotypes were determined at the six loci for most of the individuals. Population differentiation was quantified in three different ways both within the total population and pairwise between all populations. The tests were Fisher's exact test, Rho estimates and Fst estimates, all of which supported a highly significant subdivision of the total population, and they showed significant differentiation in allele frequencies between all pairs of localities. It is concluded that the known long-distance migration of the Greenlandic Arctic fox has not resulted in complete genetic mixing of the populations. Fisher's exact test was also used to estimate levels of genetic differentiation between the two colour morphs: white and blue. No difference was found between allele frequencies of the two color morphs in any of the locations, and it was concluded that the white and blue morphs of the Greenlandic Arctic fox share the same habitat, at least during the mating season. 相似文献
19.
垫状植物是高寒地区广泛分布的一类具有特殊形态的植物,被称为高寒生态系统工程师,其在高寒退化草地中的作用如何?本研究以位于西藏当雄念青唐古拉山脉南坡4500m的一处高寒退化草地为例,调查了垫状点地梅覆盖区域内外的物种多样性、土壤养分以及水分的差异。结果表明:垫状点地梅可以显著改善土壤养分,提高幅度大约为16%-48%,其中有机质和总氮(N)分别增加了16.2%和18.9%;局部土壤含水量提高约12%;样方内的物种丰富度(S)、Shannon-Wiener指数(H)和Simpson指数(D)都随着垫状点地梅盖度的增加而呈增加的趋势。垫状点地梅在退化草地中具有显著的改善土壤微环境和提高群落物种多样性的作用,应加强保育以促进高寒退化草地的恢复。 相似文献