Estimation of genetic diversity and relationship in sugar beet pollinators based on SSR markers

BackgroundGenetic diversity studies are important for the selection of parents with a greater combination capacity that, when crossed, increase the chances of obtaining superior genotypes. Thus, 26 polymorphic simple sequence repeat (SSR) primers were used to assess the genetic diversity of 140 individual samples from 12 diploid sugar beet pollinators (pollen parents) and two cytoplasmic male sterile (cms) lines (seed parents). Eight pollinators originated from three research centers in the United States Department of Agriculture, while four pollinators and cms lines were from the Institute of Field and Vegetable Crops, Novi Sad, Serbia.ResultsIn total, 129 alleles were obtained, with a mean of 3.2 alleles per SSR marker. The observed heterozygosity ranged from 0.00 to 0.87 (mean = 0.30). Expected heterozygosity and Shannon's information index were the lowest for marker BQ590934 and the highest for markers SB15s and FDSB502s; the same markers were the most informative, with PIC values of 0.70 and 0.69, respectively. Three private alleles were found in pollinator EL0204; two in pollinator C51; and one in pollinators NS1, FC221, and C93035. Molecular variance showed that 77.34% of the total genetic variation was attributed to intrapopulation variability. Cluster and correspondence analysis grouped sugar beet pollinators according to the breeding centers, with few exceptions, which indicate that certain amount of germplasm was shared, although centers had their own breeding programs.ConclusionsThe results indicate that this approach can improve the selection of pollinators as suitable parental components and could further be applied in sugar beet breeding programs.     

High genetic diversity and small genetic variation among populations of Magnolia wufengensis (Magnoliaceae), revealed by ISSR and SRAP markers

BackgroundGenetic diversity and genetic variation of 10 populations and subpopulations of Magnolia wufengensis, a new and endangered endemic species, were examined by inter simple sequence repeat (ISSR) and sequence-related amplified polymorphism (SRAP) molecular markers. Compared with other endangered endemic Magnolia taxa, M. wufengensis holds a relatively high level of genetic variation.ResultTotal genetic diversity was found to be 87.7% for ISSR and 88.0% for SRAP markers. For polymorphic loci (P), the effective mean number of alleles (Ae) was 1.414 for ISSR markers and 1.458 for SRAP markers, while the mean expected heterozygosity (H) was 0.256 using ISSR and 0.291 for SRAP markers. Within-population variation was estimated for P as 74.9% using ISSR and 74.6% with SRAP markers; the number of alleles Ae was 1.379 with ISSR and 1.397 for SRAP and H 0.235 with ISSR and 0.247 for SRAP markers.ConclusionThe analysis of molecular variation of both ISSR and SRAP marker systems indicated that most genetic variation is within populations, with values of 90.64% and 82.92% respectively. Mantel tests indicated a moderate association between the two marker systems and a low correlation between genetic and geographic distances. High levels of genetic diversity and low levels of population divergence suggest that genetic drift is not currently of great concern for this species. Severe habitat loss and fragmentation, predominantly ascribed to anthropogenic pressures, caused in-situ developing restriction of this species. Action for conserving this rare species for its long-term survival should be taken immediately.     

Analysis of genetic diversity and differentiation of sheep populations in Jordan

BackgroundGenetic diversity of sheep in Jordan was investigated using microsatellite markers (MS). Six ovine and bovine MS located on chromosomes 2 and 6 of sheep genome were genotyped on 294 individual from ten geographical regions.ResultsThe number of alleles per locus (A), the expected heterozygosity (H_e) and observed heterozygosity (H_o) were measured. Overall A, H_e and H_o were 12.67, 0.820 and 0.684, respectively. On the other hand, genetic distances undoubtedly revealed the expected degree of differentiation among the studied populations. The finding showed closeness of three populations from south (Maan, Showbak and Tafeilah) to each other. Populations from the middle regions of Jordan (Karak, Madaba, Amman, AzZarqa and Mafraq) were found to be in one cluster. Only two populations of the middle region were an exception: AlSalt and Dead Sea. Finally, sheep populations from Irbid were located in separated cluster. It was clear that the studied predefined populations were subdivided from four populations and would be most probably accounted as ancestral populations. These results indicate that number of population is less than the predefined population as ten based on geographical sampling areas.ConclusionsThe possible inference might be that geographical location, genetic migration, similar selection forces, and common ancestor account for population admixture and subdivision of Awassi sheep breed in Jordan. Finally, the present study sheds new light on the molecular and population genetics of Awassi sheep from different regions of Jordan and to utilize the possible findings for future management of genetic conservation under conditions of climate changes and crossbreeding policy.     

Analysis of the genetic relationships and diversity among 11 populations of Xanthoceras sorbifolia using phenotypic and microsatellite marker data

BackgroundAssessments of genetic diversity are essential for germplasm characterization and exploitation. Molecular markers are valuable tools for exploring genetic variation and identifying germplasm. They play key roles in a Xanthoceras sorbifolia breeding program.ResultsWe analyzed the genetic diversity of populations of this species using 23 simple sequence repeat (SSR) loci and data on kernel oil content. The 11 populations included in the study were distributed across a large geographic range in China. The kernel oil content differed significantly among populations. The SSR marker analysis detected high genetic diversity among the populations. All SSRs were polymorphic, and we identified 80 alleles across the populations. The number of alleles at each locus ranged from two to six, averaging 3.48 per primer pair. The polymorphism information content values ranged from 0.35 to 0.70, averaging 0.51. Expected heterozygosity, observed heterozygosity, and Shannon's information index calculations detected large genetic variations among populations of different provenance. The high average number of alleles per locus and the allelic diversity observed in the set of genotypes analyzed indicated that the genetic base of this species was relatively wide. The statistically significant positive correlation between genetic and geographic distances suggested adaptations to local conditions.ConclusionsMicrosatellite markers can be used to efficiently distinguish X. sorbifolia populations and assess their genetic diversity. The information we have provided will contribute to the conservation and management of this important plant genetic resource.     

茶树EST资源中SSR的信息分析

从NCBI公共数据库下载获得1989条茶树EST,去除其中的低质量的和冗余的序列,得到全长为734．54 kb的1589条无冗余EST。共在这些序列中发掘出了281个EST-SSR,分布于246条EST中,出现频率是17．68%。这些EST-SSR的平均长度为33．06 bp,平均分布频率是1/2．61 kb。茶树EST—SSR中,二核苷酸重复是主要的重复类型,出现最多的重复基元类型是AG/CT重复。本研究为茶树EST-SSR标记的建立和进一步应用奠定了基础。     

青海春小麦Glu-1位点遗传多样性与谷蛋白溶胀指数分析

为了解青海省春小麦Glu-1位点的遗传多样性及其品质状况,检测了49个青海省代表性春小麦品种的高分子量麦谷蛋白亚基(HMW-GS)组成情况,并测定了每一品种的谷蛋白溶胀指数.共检测出15种高分子量麦谷蛋白亚基组合类型.在Glu-1位点检测到13种等位变异,其中Glu-A1位点2个、Glu-B1位点7个、Glu-D1位点4个.实验数据表明,青海省春小麦品质较差,尚待改进.     

中国含笑属核型分析

 对我国木兰科Magnoliaceae含笑属Michelia 12个种的核型进行了研究,核型公式如下:火力楠 M．macclurei var．sublanea 2n=34m(2SAT)+4sm;白兰M．alba 2n=34m+4sm;多花含笑M.flori- bunda 2n=30m+8sm;黄兰M.champaca 2n=32m+6sm;石碌含笑M.shiluensis 2n=32m+6sm;阔 瓣含笑M . platypetala 2n=32m+6sm(2SAT);含笑M．figo 2n=32m+6sm;深山含笑M．maudiae 2n=32m+6sm;长蕊含笑M.  longistamina 2n=32m=6sm;金叶含笑M.foveolata 2n=34m=4sm; 野含笑M.skineriana 2n=30m+8sm;峨嵋含笑M.wilsonii 2n=30m+8sm(2SAT)。该属核型全部为 对称核型,除多花含笑为1A类型外,其他均为2A核型。含笑属种间核型具有很大相似性,核型资料对该属属以下的分类帮助不大。        

Sorting of circulating tumor cells (MV3-melanoma) and red blood cells using non-inertial lift

We demonstrate the method of non-inertial lift induced cell sorting (NILICS), a continuous, passive, and label-free cell sorting approach in a simple single layer microfluidic device at low Reynolds number flow conditions. In the experiments, we exploit the non-inertial lift effect to sort circulating MV3-melanoma cells from red blood cell suspensions at different hematocrits as high as 9%. We analyze the separation process and the influence of hematocrit and volume flow rates. We achieve sorting efficiencies for MV3-cells up to E_MV3 = 100% at Hct = 9% and demonstrate cell viability by recultivation of the sorted cells.     

对我国省级政府门户网站信息构建(IA)的调查与分析

依据信息构建（IA）理论,把政府网站划分为四大系统：导航系统、检索系统、组织系统、标识系统,逐项对我国省级政府门户网站的信息构建状况进行调查与分析,在此基础上就改进我国省级政府门户网站的信息构建提出了若干建议。     

基于因果和岭回归的新疆人口结构与CO2排放关系分析

利用新疆1958-2011年CO2排放量和人口数据,运用格兰杰因果检验和岭回归模型对新疆人口因素变化与CO2排放之间的因果关系和作用力进行实证分析,结果如下.1)在改革开放前,所有人口指标均与CO2排放呈现双向的因果联系;但改革开放后,农村居民消费与CO2排放失去因果关系.2)人口因素对CO2排放的推动作用在不同的发展阶段变化较大;随着改革开放政策的实施,生活方式发生较大变化,家庭户数与消费逐步取代就业结构和人口总量成为CO2排放最主要的推动因素.     

基于文献计量的我国互联网金融研究(2011-2014)

本文利用文献计量方法,对2011-2014年收录于CNKI的2 327篇互联网金融研究的中文论文进行了统计,从研究现状和文献内容两方面入手,通过分析年发文量、核心作者、地区分布、被引频次、关键词分布、学科类别和期刊分布的特点,为研究者提供参考。     

《中国农业科学(中文版)》作者群分析

通过统计《中国农业科学(中文版)》各栏目载文量分布、投稿和发文作者的单位以及第一作者的年龄、学位、职称和基金资助状况,说明《中国农业科学》拥有高水平的作者群,他们对刊物的质量起关键作用,认为今后应当重视保护和发展期刊的高质量作者群。     

我国科技文献资料共享的现状分析(下)

3优势分析 3.1有利的内外环境 我国的图书情报事业发展较快,现已初具规模,无论是人员素质、新技术应用和业务工作模式,还是馆际协作,都为文献资源共享打下了一定基础,创造了有利的内部环境.     

我国公共危机信息管理研究的可视化分析(2006-2015)

以2006-2015年CNKI数据库收录的2698篇国内公共危机信息管理研究论文为研究对象,运用文献计量法和CiteSpace可视化软件,对该领域文献增长规律、来源分布、主题内容和前沿热点等研究现状进行分析。结果表明,近十年国内公共危机信息管理研究整体处于稳定发展阶段,初步形成核心研究机构群,研究内容主题结构趋于明显,并挖掘出该领域在"基础理论研究"、"新媒体下信息传播与新闻报道研究"、"突发事件网络舆情研究"、"危机管理中政府信息公开研究"、"公共危机管理信息系统研究"等5个方面的前沿热点。     

中国医药行业上市公司融资结构、股权结构与公司绩效

股权结构和融资结构都是完善公司治理的重要囚素。通过对中国医药行业上市公司的股权结构和融资结构的实证研究，揭示了医药行业股权结构和融资结构对公司治理机制的作用方式，从而对中国医药行业合理安排股权结构和融资结构提出构想。     

近十年(2001—2010)动漫产业研究的文献计量分析

以CNKI(中国学术期刊网络出版总厍)为工具,其收录的科技论文为基础,从文献计量学的角度分析近十年来我国动漫产业研究文献的年代、作者、基金支持及热点问题等几个方面.     

中国齿鳞草属和假野菰属的订正

The present paper deals with taxonomic studies on the genera Lathraea Linn. and Christisonia Gard. (Orobanchaceae) in China.  In the genus Lathraea, only a single species in China, L. japonica Miq., is recongnized in the paper. It occurs in sou- thern Shaanxi, southern Gansu, southeastern Sichuan, northern Guizhou and northern   Guangdong, also in Japan. L. miqueliana Franch. et Sav., L. chinfushanica Hu et Tang and L. japonica Miq. var. miqueliana (Franch. et Sav.) Ohwi are treated as new synon- yms of L. japonica Miq. in this paper.       In the genus Christisonia, the most of collections from China, which were identi- fied as C. sinensis G. Beck before, are treated as a new synonym of C. hookeri C. B. Clarke.  A few collections of this genus from China, which were mistakenly described as Gleadovia lepoense Hu snd G. kwangtungense Hu, should be transferred to Christi- sonia hookeri C. B. Clarke.  It is distributed in southeastern and south China, westwards to the Himalayas.     

精神生产视域下我国产业结构的内在演变

经济发展进入新的阶段,表现为经济增长从主要依赖传统的物质生产要素转移到技术、知识、文化等精神生产要素上来。精神生产逐渐成为推动我国经济增长的主要动力。同时,传统产业的生产环节出现了分化,形成了专门从事精神生产的行业,并逐渐成为影响经济增长的关键力量。精神产品的生产、传播与扩散深刻影响着产业结构的演变。为适应经济发展模式的转变,本文依据精神产品的分类对产业结构体系重新做了划分,提出分别以精神生产、服务生产以及物质生产为主的创意产业、服务产业和物质产业的划分方式,并对此做了验证性分析。     

Efficiency of RAPD,ISSR, AFLP and ISTR markers for the detection of polymorphisms and genetic relationships in camote de cerro (Dioscorea spp.)

BackgroundAt present, species known as camote de cerro (Dioscorea spp.) are found only in the wilderness in Mexico, but their populations are extremely depleted because they are indiscriminately collected, it is urgent to evaluate the conservation status of these plants in order to design conservation genetics programs. In this study, genetic diversity parameters along with cluster analysis based on Jaccard's coefficient were estimated with the objective to assess the efficiency of Random Amplified Polymorphic DNA (RAPD), Inter Simple Sequence Repeat (ISSR), Amplified Fragment Length Polymorphism (AFLP) and Inverse Sequence Tagged Repeat (ISTR) molecular DNA markers in the Dioscorea genus.ResultsThe polymorphic information contents were quite similar for all markers (≈ 0.48). Genetic variation of Dioscorea spp., in terms of average heterozygosity was lower with ISTR (0.36), and higher when other markers were used (RAPD = 0.43; ISSR = 0.45 and AFLP = 0.47).ConclusionThis indicates an important level of genetic differences despite the fact that the plant is asexually propagated. Based on the diversity statistics, any marker tested in present work can be recommended for use in large-scale genetic studies of populations. However, the low correlations among different molecular marker systems show the importance of the complementarity of the information that is generated by different markers for genetic studies involving estimation of polymorphism and relationships.     

阿尔卑斯山高山-亚高山过渡区高山黄花茅的群体遗传结构和分化研究

应用等位酶分析，在瑞士阿尔卑斯山的阿尔拜特(Arpette)和拜阿尔普(Belalp)，沿三个不同的海拔梯度，研究了高山黄花茅3个自然居群的遗传变异和分化。研究结果表明，平均的多态性位点比例为64．9％，每个位点平均等位基因数为2．37，平均期望杂合性为0．252。亚居群间平均的遗传距离为0．011，发现79％的遗传变异存在于居群内。基于等位酶分析，边缘亚居群与中心亚居群似乎有类似的遗传变异性。相对比较高的遗传分化、低的亚居群间基因流和小的邻居大小值暗示，近交和随后的遗传漂变可能是导致阿尔拜特黄花茅居群遗传变异性较低的主要原因。