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1.
六个中国固有绵羊品种遗传关系的微卫星标记分析   总被引:7,自引:0,他引:7  
用5对微卫星引物对哈萨克羊、蒙古羊、兰州大尾羊、同羊、大尾寒羊、小尾寒羊共6个中国固有绵羊品种基因组进行了扩增, 对扩增结果用7种聚类方法(欧氏距离、欧氏平方距离、夹角余弦、皮尔逊相关、车贝雪夫距离、街区距离、明考夫斯基距离)进行了分析.结果表明, 分布在我国西北部的绵羊品种哈萨克羊、蒙古羊、兰州大尾羊在大多数情况下总是先聚在一起, 相对分布于中原地带的同羊、小尾寒羊和西北部的3个品种间距离较远,同羊和小尾寒羊之间距离也很远,大尾寒羊和小尾寒羊之间没有明显的遗传关系, 此结果与《中国绵羊品种志》中记载的情况基本一致.同时, 本研究结果也说明7种聚类方法均适用于微卫星标记资料的遗传分析.  相似文献   

2.
分析10个微卫星位点在岷县黑裘皮羊群体中的遗传多样性及与生产性状的关联效应,为该品种种质资源的保护、利用和性状改良提供理论依据。选取12、24和36月龄的岷县黑裘皮羊各48只,测定其体重、体高、体长、胸宽、胸深和胸围性状,利用10对微卫星引物,采用PCR扩增和毛细管电泳技术,对岷县黑裘皮羊进行遗传多样性检测,并分析各位点基因型与生产性状的关联效应。10个位点在该群体中共检测到112个等位基因,平均等位基因数为11.2个,平均有效等位基因数为4.4508,平均观测杂合度为0.521 8,平均期望杂合度为0.765 7,平均多态信息含量为0.728 9;且10个位点均与不同月龄岷县黑裘皮羊体重、体高、体长、胸宽、胸深及胸围具有不同程度的关联效应。所选的10个微卫星位点多态性丰富,可用于评估岷县黑裘皮羊的遗传资源。此外,所选位点与生产性状均具有不同程度的关联性,可用于指导岷县黑裘皮羊的性状改良及育种工作。  相似文献   

3.
我国主要地方绵羊品种随机扩增多态DNA研究   总被引:1,自引:0,他引:1  
对蒙古羊、湖羊、滩羊、小尾寒羊、乌珠穆沁羊、藏绵羊、阿勒泰羊7个地方绵羊品种和无角陶赛特羊、德国美利奴羊、萨福克羊3个引入品种基因组DNA进行了RAPD分析。结果表明:(1)RAPD可作为一种有效的标记用于绵羊品种之间遗传亲缘关系的分析。(2)在所使用的43种随机引物中,有35种引物扩增出多态谱带,多态频率为66.24%,说明RAPD技术用于研究绵羊核DNA的遗传变异具有较高的检出率和灵敏度。(3)总群体平均遗传多样性指数(HSP)为0.9139,说明绵羊群体具有较为丰富的遗传多样性。(4)我国地方绵羊品种间的分子聚类关系与其所处的地理位置、考古学结果,以及细胞遗传学研究结果基本一致,引入品种间的分子聚类关系也与其育成史基本一致。 Abstract:The genetic polymorphism and relationship of 7 indigenous sheep breeds of China and 3 imported sheep breeds were studied using random amplified polymorphic DNA (RAPD).The results indicated that the RAPD was an effective marker for the analysis of genetic relationship among sheep breeds.Among 43 arbitrary primers,35 were polymorphic.The percentage of polymorphic markers was 66.24%,which indicated that the RAPD had higher efficiency of polymorphism detection and sensitivity in studying the genetic variation among sheep breeds.The average index of genetic polymorphism for whole population (Hsp) was 0.9139,which showed that the genetic polymorphism was abundant between sheep populations.The genetic relationship between different indigenous sheep breeds in China was in accord with their localities,the results from archeology and cytogenetics and the genetic relationship between imported sheep breeds was in accord with their breeding history.  相似文献   

4.
分析了4个微卫星基因座BM143、OarHH35、OarAE101、BMS2508在7个绵羊群体(小尾寒羊、湖羊、乌珠穆沁羊、萨福克羊、多赛特羊、夏洛来羊、多赛特公羊×小尾寒羊母羊F1代杂种羊)286只绵羊中的遗传多态性。结果表明,这4个微卫星标记在7个绵羊群体中的等位基因数分别为9、11、14和9,其多态信息含量/有效等位基因数/杂合度分别为0.7073/3.7231/0.7314、0.8267/6.4399/0.8447、0.5743/2.5178/0.6028、0.6172/3.0712/0.6744,其中OarHH35的遗传变异最大,OarAE101最小。7个绵羊群体中小尾寒羊的遗传变异最大,湖羊的最小。基于Nei氏DA距离和DS标准遗传距离,采用UPGMA方法构建了系统发生树。该发生树将中国地方品种(小尾寒羊、乌珠穆沁羊、湖羊)和法国的夏洛来羊归为一类,将F1杂种羊、英国品种(萨福克羊和多赛特羊)归为另一类。绵羊微卫星基因分型技术为检查品种(群体)之间的遗传关系提供了一个有用的工具。 Abstract:The genetic polymorphisms of four microsatellite loci BM143,OarHH35,OarAE101,and BMS2508 were analyzed in 286 sheep of seven sheep populations (Small Tail Han sheep, Hu sheep, Ujumqin sheep, Suffolk sheep, Dorset sheep, Charolais sheep, F1 of Dorset♂ × Small Tail Han sheep♀). The numbers of alleles for BM143,OarHH35,OarAE101,and BMS2508 are 9, 11, 14 and 9 in seven sheep populations, respectively. The polymorphism information content/number of effective alleles/ heterozygosity of BM143,OarHH35,OarAE101 and BMS2508 were 0.7073/3.7231/0.7314, 0.8267/6.4399/0.8447,0.5743/2.5178/0.6028,0.6172/3.0712/0.6744 in 286 sheep, respectively. The results revealed the greatest genetic variation at OarHH35 locus and the lowest at OarAE101, the greatest genetic variation in Small Tail Han sheep and the lowest in Hu sheep among seven sheep populations. In the unweighted pair group method with arithmetic mean (UPGMA) dendrograms based on Nei's DA distance and Nei's DS standard genetic distance, the Chinese native breeds (Small Tail Han sheep, Ujumqin sheep, Hu sheep) were grouped together, then with Charolais sheep. The F1 crossbred sheep, and the two British native sheep (Suffolk sheep, Dorset sheep) also clustered together. Microsatellite genotyping in sheep provided a useful tool for examining the genetic relationships among breeds(populations).  相似文献   

5.
我国主要地方绵羊品种随机扩增多态DNA研究   总被引:30,自引:2,他引:28  
巩元芳  李祥龙  刘铮铸  李金泉 《遗传》2002,24(4):423-426
对蒙古羊、湖羊、滩羊、小尾寒羊、乌珠穆沁羊、藏绵羊、阿勒泰羊7个地方绵羊品种和无角陶赛特羊、德国美利奴羊、萨福克羊3个引入品种基因组DNA进行了RAPD分析。结果表明:(1)RAPD可作为一种有效的标记用于绵羊品种之间遗传亲缘关系的分析。(2)在所使用的43种随机引物中,有35种引物扩增出多态谱带,多态频率为66.24%,说明RAPD技术用于研究绵羊核DNA的遗传变异具有较高的检出率和灵敏度。(3)总群体平均遗传多样性指数(HSP)为0.9139,说明绵羊群体具有较为丰富的遗传多样性。(4)我国地方绵羊品种间的分子聚类关系与其所处的地理位置、考古学结果,以及细胞遗传学研究结果基本,引入品种间的分子聚类关系也与其育成史基本一致。  相似文献   

6.
寻找与绵羊生长性状有关的分子标记,以期为绵羊的分子育种提供理论依据。通过琼脂糖凝胶电泳和一代测序技术,在滩羊(TS)、小尾寒羊(STHS)和兰州大尾羊(LFTS)的LHX3基因中检测到了29 bp片段的插入型(AA)、插入/缺失型(AB)以及缺失型(BB)3种基因型,对3个不同品种绵羊的LHX3基因进行遗传多态性分析,并通过一般线性模型分析了3种基因型与3个品种绵羊不同生长性状的相关性。3个品种绵羊LHX3的多态信息含量(PIC)均为0.25 PIC≤0.5,呈中度多态,表明该位点的遗传变异相对较高。LHX3基因型影响3个品种绵羊的一个或多个生长性状,其中LHX3基因型与滩羊的体长(BL)、体重(BW)、胸深(ChD)和管围(CaC)显著相关(P 0.05),且缺失型基因型的生长性状优于插入型基因型和插入/缺失型基因型绵羊;小尾寒羊的缺失型基因型的胸围(ChC)、胸深(ChD)和管围(CaC)显著高于插入型基因型和插入/缺失型基因型绵羊(P 0.01);兰州大尾羊的缺失型基因型的胸围(ChC)、十字部高(HW)、体长(BL)、体重(BW)和管围(CaC)显著高于插入型基因型和插入/缺失型基因型绵羊(P 0.01)。由此可见在绵羊分子育种中,LHX3中29 bp的缺失型可作为绵羊选育的DNA标记位点。  相似文献   

7.
为了探究雌激素受体2 (Estrogen receptor 2, ESR2)基因在绵羊各组织的表达及其多态性与产羔数之间的关系,本研究利用半定量PCR和实时荧光定量PCR技术检测ESR2基因在不同繁殖力小尾寒羊群体组织中的相对表达量,同时采用Sequenom MassARRAY誖SNP技术对多羔品种绵羊(小尾寒羊,湖羊,策勒黑羊)和单羔品种绵羊(苏尼特羊,草原型藏羊,滩羊) ESR2基因g.73324006C>T位点进行检测,并与小尾寒羊产羔数进行关联分析。半定量PCR表明,ESR2基因在单、多羔小尾寒羊子宫中高表达,在其它组织中等或低丰度表达;单羔群体、多羔群体间荧光定量PCR表明,ESR2基因在单羔小尾寒羊垂体表达量显著高于多羔小尾寒羊(p<0.05);群体遗传学分析表明,g.73324006C>T在小尾寒羊群体中表现为低度多态(PIC<0.25),在滩羊群体中处于中度多态(0.25T在小尾寒羊群体处于哈代温伯格平衡状态(p>0.05);关联分析表明,g.73324006C>T位点多态性与小尾寒羊第一胎、第二胎、第三胎产羔数及平均产羔数均显著关联(p<0.05),CC型各胎产羔数均高于TC型。与FecB (A746G)基因组合后发现,GG-CC和AG-CC基因型母羊产羔数显著高于AA-TC、AA-CC、AG-TC基因型组合(p<0.05)。综上,ESR2与小尾寒羊产羔数密切相关,g.73324006C>T可作为绵羊产羔性状选育的潜在分子标记。  相似文献   

8.
封面说明     
大尾寒羊(Large Tailed Han sheep)为我国地方绵羊品种之一。产于河北东南、山东西部和河南中部。在我国存在已有400年的历史,因其品质优良,明朝时即已列为贡品。成年羊体重一般60~70公斤,脂尾肥大下垂,拖至地面,公羊脂尾重15~20公斤。毛被同质性好,可用于纺  相似文献   

9.
利用24个微卫星标记,分析了山东省内原有地方绵羊品种的遗传多样性.结果表明,在来自4个品种共71个种群的164只绵羊中,共检测到等位基因467个,有效等位基因占49.59%,不同微卫星基因座之间的等位基因数差异大于品种之间的差异;发现特有等位基因123个,优势等位基因43个.在所有微卫星基因座中,89%处于Hardy-Weinberg不平衡状态,有50%属于中性基因座.不同品种的微卫星基因座多态信息含量呈高度多态(PIC>0.5),Shannon指数较高(I>1.5),平均观察杂合度(范围0.454~0.560)明显低于期望杂合度(范围0.831~0.849),证明4个地方绵羊种群具有丰富的遗传多样性和广泛的遗传基础,但品种内存在着一定程度的近交.聚类分析表明,山东地方绵羊品种遗传进化关系明确,可划分为鲁西地区的小尾寒羊和大尾寒羊、鲁东地区的山地绵羊和洼地绵羊两大类群,其遗传距离与地理分布距离相一致.  相似文献   

10.
绵羊线粒体DNA控制区5′端序列PCR-SSCP与序列分析   总被引:3,自引:0,他引:3  
通过绵羊线粒体DNA控制区左功能域(5′端序列)PCR-SSCP和序列分析,发现小尾寒羊、乌珠穆沁羊、湖羊、萨福克羊和夏洛来羊以及多赛特公羊与小尾寒羊杂交家系共202只绵羊可归纳为两种类型:突变型和野生型,提示现代绵羊品种在起源上存在两种主要的进化途径。  相似文献   

11.
Nuclear genetic diversity and differentiation of 341 sheep belonging to 12 sheep breeds from Croatia and Bosnia and Herzegovina were examined. The aim of the study was to provide the understanding of the genetic structure and variability of the analysed pramenka sheep populations, and to give indications for conservation strategies based on the population diversity and structure information. The genetic variation of the sheep populations, examined at the nuclear level using 27 microsatellite loci, revealed considerable levels of genetic diversity, similar to the diversity found in other European indigenous low-production sheep breeds. Population-specific alleles were detected at most loci and in breeds analysed. The observed heterozygosity ranged from 0.643 (in Lika pramenka) to 0.743 (in Vlasic pramenka), and the expected heterozygosity ranged from 0.646 (in Lika pramenka) to 0.756 (in Dalmatian pramenka). Significant inbreeding coefficients were found for half of the populations studied and ranged from 0.040 (Pag island sheep) to 0.091 (Kupres pramenka). Moderate genetic differentiation was found between the studied sheep populations. The total genetic variability observed between different populations was 5.29%, whereas 94.71% of the variation was found within populations. Cres island sheep, Lika pramenka and Istrian sheep were identified as the most distinct populations, which was confirmed by the factorial analysis of correspondence and supported through a bootstrapping adjustment to correct for the difference in the sample sizes. The population structure analysis distinguished 12 clusters for the 12 sheep breeds analysed. However, the cluster differentiation was low for Dalmatian, Vlasic, Stolac and Krk pramenka. This systematic study identified Lika pramenka and Rab island sheep as those with the lowest diversity, whereas Istrian sheep and Pag island sheep had the highest. Conservation actions are proposed for Istrian, Rab and Cres island sheep, Lika and Kupres pramenka because of high estimated coefficients of inbreeding.  相似文献   

12.
Extinction of breeds threatens genetic diversity of livestock species. The need to conserve genetic diversity is widely accepted but involves in general two questions: (i) is the expected loss of diversity in a set of breeds within a defined future time horizon large enough to establish a conservation plan, and if so (ii) which breeds should be prioritised for such a conservation plan? The present study uses a marker assisted methodology to address these questions. The methodology combines core set diversity measures with a stochastic method for the estimation of expected future diversity and breed marginal diversities. The latter is defined as the change in the total diversity of all breeds caused by a one unit decrease in extinction probability of a particular breed. The stochastic method was validated by means of simulations. A large field data set consisting of 44 North Eurasian cattle breeds was analysed using simplified determined extinction probabilities. The results show that the expected loss of diversity in this set within the next 20 to 50 years is between 1 and 3% of the actual diversity, provided that the extinction probabilities which were used are approximately valid. If this loss is to be reduced, it is sufficient to include those three to five breeds with the highest marginal diversity in a conservation scheme.  相似文献   

13.
农业动物种质资源面临着严重危机, 有必要构建一个科学、有效的保护方案, 合理分配有限的资金, 以期保护最大的多样性。本文应用边际多样性方法, 以中国18个地方猪种为例, 通过对灭绝概率、现实多样性、边际多样性和保护潜力的分析, 应用3种模型分析了未来群体期望多样性变化趋势, 并提出了相应的资金优化配置方案。在文中所涉及的模型中, 加性模型(Model A)被评定为资金优化配置的最佳模型; 共有10个品种获得保护资金, 其中杭猪获得最高比例(16%)的保护资金; 其次为赣中南花猪(万安猪)、嵊县花猪, 各获得14%; 阳新猪、乐平猪各获得11%; 五指山猪、玉山乌猪、赣中南花猪(冠朝猪)、清平猪、武夷黑猪和嘉兴黑猪分别获得10%、9%、9%、2%、2%和2%的保护资金。结果表明, 分配保护资金需综合考虑群体的受威胁程度、群体遗传多样性和经济重要性等。  相似文献   

14.
15.
The domestic sheep (Ovis aries) has been an economically and culturally important farm animal species since its domestication around the world. A wide array of sheep breeds with abundant phenotypic diversity exists including domestication and selection as well as the indigenous breeds may harbor specific features as a result of adaptation to their environment. The objective of this study was to investigate the population structure of indigenous sheep in a large geographic location of the Chinese mainland. Six microsatellites were genotyped for 611 individuals from 14 populations. The mean number of alleles (±SD) ranged from 7.00 ± 3.69 in Gangba sheep to 10.50 ± 4.23 in Tibetan sheep. The observed heterozygote frequency (±SD) within a population ranged from 0.58 ± 0.03 in Gangba sheep to 0.71 ± 0.03 in Zazakh sheep and Minxian black fur sheep. In addition, there was a low pairwise difference among the Minxian black fur sheep, Mongolian sheep, Gansu alpine merino, and Lanzhou fat‐tailed sheep. Bayesian analysis with the program STRUCTURE showed support for 3 clusters, revealing a vague genetic clustering pattern with geographic location. The results of the current study inferred high genetic diversity within these native sheep in the Chinese mainland.  相似文献   

16.
Prioritizing livestock breeds for conservation needs to incorporate both genetic and non-genetic aspects important for the survival of the breeds. Here, we apply a maximum-utility-strategy to prioritize 14 traditional Ethiopian sheep breeds based on their threat status, contributions to farmer livelihoods (current breed merits) and contributions to genetic diversity. Contributions of the breeds to genetic diversity were quantified using Eding''s marker-estimated kinship approaches. Non-genetic aspects included threats (e.g. low population size, low preferences by farmers) and current merits (economic, ecological and cultural merits). Threat analysis identified eight of the 14 breeds as threatened. Analysis of current merits showed that sub-alpine and arid-lowland breeds contribute most to farmer livelihoods in comparison to other breeds. The highest contribution to the genetic diversity conserved was from the Simien breed. Simien showed high between-breed (low between-breed kinship = 0.04) as well as high within-breed diversity (low within-breed kinship = 0.09 and high HE = 0.73 and allelic richness = 6.83). We combined the results on threat status, current breed merits and contributions to genetic diversity to produce a ranking of the 14 breeds for conservation purposes. Our results balance the trade-offs between conserving breeds as insurance against future uncertainties and current sustainable utilization. The ranking of breeds provides a basis for conservation strategies for Ethiopian sheep and contributes to a regional or global conservation plan.  相似文献   

17.
Due to its geo-climatic conditions, Algeria represents a biodiversity hotspot, with sheep breeds well adapted to a patchwork of extremely heterogeneous harsh habitats. The importance of this peculiar genetic reservoir increases as climate change drives the demand for new adaptations. However, the expansion of a single breed (Ouled-Djellal) which occurred in the last decades has generated a critical situation for the other breeds; some of them are being subjected to uncontrolled cross-breeding with the favored breed and/or to marginalization (effective size contraction). This study investigated genetic diversity within and among six of the nine Algerian breeds, by use of 30 microsatellite markers. Our results showed that, in spite of the census contraction experienced by most of the considered breeds, genetic diversity is still substantial (average gene diversity ranging 0.68 to 0.76) and inbreeding was not identified as a problem. However, two breeds (Rembi and Taâdmit) appeared to have lost most of their genetic originality because of intensive cross-breeding with Ouled-Djellal. Based on the above evidence, we suggest Hamra, Sidaoun, and D’man as breeds deserving the highest priority for conservation in Algeria.  相似文献   

18.
本文根据华中型20个猪品种27个微卫星DNA标记的研究数据, 应用Weitzman方法, 即通过估计总体遗传多样性、期望多样性、品种对总体遗传多样性的贡献、边际遗传多样性、保种潜力等指标, 评估华中型20个猪品种的遗传多样性, 并通过构建品种间遗传多样性的最大似然树, 图示化展示20个品种间遗传多样性的相互关系。20个华中型猪品种的总体遗传多样性是11,707, 期望多样性占总的遗传多样性的66.96%, 金华猪、皖南花猪、嵊县花猪和乐平猪是对总体遗传多样性贡献最大的4个品种, 其贡献率分别是8.90%、7.46%、7.40%和7.04%, 保种潜力最大的4个品种分别是金华猪、嵊县花猪、杭猪和大花白猪。根据遗传多样性进行聚类分析, 大致可将华中型猪分为3类: 大围子猪、沙子岭猪、宁乡猪等分布于湖南、湖北的品种为一类; 南城猪、嵊县花猪与杭猪聚成另一类; 金华猪与皖南花猪单独聚成一类。研究结果可为我国华中型地方猪种遗传多样性的最大化保护和利用提供科学决策依据, 本文也对Weitzman方法在应用中的关键性问题进行了探讨。  相似文献   

19.

Background

From domestication to the current pattern of differentiation, domestic species have been influenced by reticulate evolution with multiple events of migration, introgression, and isolation; this has resulted in a very large number of breeds. In order to manage these breeds and their genetic diversity, one must know the current genetic structure of the populations and the relationships among these. This paper presents the results of a genetic diversity analysis on an almost exhaustive sample of the sheep breeds reared in France. Molecular characterization was performed with a set of 21 microsatellite markers on a collection of 49 breeds that include five breed types: meat, hardy meat, dairy, high prolificacy and patrimonial breeds.

Results

Values of expected heterozygosity ranged from 0.48 to 0.76 depending on the breed, with specialized meat breeds exhibiting the lowest values. Neighbor-Net, multidimensional analysis or clustering approaches revealed a clear differentiation of the meat breeds compared to the other breed types. Moreover, the group that clustered meat breeds included all the breeds that originated from the United Kingdom (UK) and those that originated from crossbreeding between UK breeds and French local breeds. We also highlighted old genetic introgression events that were related to the diffusion of Merino rams to improve wool production. As a result of these introgression events, especially that regarding the UK breeds, the breeds that were clustered in the ‘meat type cluster’ exhibited the lowest contribution to total diversity. That means that similar allelic combinations could be observed in different breeds of this group.

Conclusions

The genetic differentiation pattern of the sheep breeds reared in France results from a combination of factors, i.e. geographical origin, historic gene flow, and breed use. The Merino influence is weaker than that of UK breeds, which is consistent with how sheep use changed radically at the end of 19th century when wool-producing animals (Merino-like) were replaced by meat-producing breeds. These results are highly relevant to monitor and manage the genetic diversity of sheep and can be used to set priorities in conservation programs when needed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12711-015-0131-7) contains supplementary material, which is available to authorized users.  相似文献   

20.

Background

Determining the value of livestock breeds is essential to define conservation priorities, manage genetic diversity and allocate funds. Within- and between-breed genetic diversity need to be assessed to preserve the highest intra-specific variability. Information on genetic diversity and risk status is still lacking for many Creole cattle breeds from the Americas, despite their distinct evolutionary trajectories and adaptation to extreme environmental conditions.

Methods

A comprehensive genetic analysis of 67 Iberoamerican cattle breeds was carried out with 19 FAO-recommended microsatellites to assess conservation priorities. Contributions to global diversity were investigated using alternative methods, with different weights given to the within- and between-breed components of genetic diversity. Information on Iberoamerican plus 15 worldwide cattle breeds was used to investigate the contribution of geographical breed groups to global genetic diversity.

Results

Overall, Creole cattle breeds showed a high level of genetic diversity with the highest level found in breeds admixed with zebu cattle, which were clearly differentiated from all other breeds. Within-breed kinships revealed seven highly inbred Creole breeds for which measures are needed to avoid further genetic erosion. However, if contribution to heterozygosity was the only criterion considered, some of these breeds had the lowest priority for conservation decisions. The Weitzman approach prioritized highly differentiated breeds, such as Guabalá, Romosinuano, Cr. Patagonico, Siboney and Caracú, while kinship-based methods prioritized mainly zebu-related breeds. With the combined approaches, breed ranking depended on the weights given to the within- and between-breed components of diversity. Overall, the Creole groups of breeds were generally assigned a higher priority for conservation than the European groups of breeds.

Conclusions

Conservation priorities differed significantly according to the weight given to within- and between-breed genetic diversity. Thus, when establishing conservation programs, it is necessary to also take into account other features. Creole cattle and local isolated breeds retain a high level of genetic diversity. The development of sustainable breeding and crossbreeding programs for Creole breeds, and the added value resulting from their products should be taken into consideration to ensure their long-term survival.  相似文献   

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