滇杨种群遗传多样性与遗传结构

滇杨(Populus yunnanensis)是我国西南地区的特有树种, 具有速生、易无性繁殖、适应性强等优良特性, 是典型的南方型杨属树种。研究滇杨遗传多样性及种群结构对其种质资源的收集、保存和利用具有重要的意义。本研究从我国滇杨主要分布区云南和四川共采集了6个种群, 包括云南的昭通(ZT)、会泽(HZ)、嵩明(SM)、洱源(EY)、拉市海(LS)以及四川的美姑(MG), 共64个个体, 利用34对SSR分子标记和3对cpDNA叶绿体标记开展遗传多样性与遗传结构研究。SSR引物共检测到154个等位基因, 平均等位基因数为4.529, 观测杂合度(Ho)与期望杂合度(He)分别为0.552和0.472, 遗传分化系数(Fst)平均值为0.238, 多态性信息含量指数(PIC)平均值为0.421, 基因流(Nm)为0.806。滇杨的遗传结构分析(DAPC)与遗传距离的主坐标分析(PCoA)、UPGMA聚类分析均将6个种群划分为3个亚类: 第І亚类包括昭通种群、会泽种群和嵩明种群的4个个体, 第ІІ亚类包括嵩明种群的6个个体以及洱源种群和拉市海种群, 第III亚类为美姑种群; 嵩明种群包含第І和第ІІ两个亚类的混合遗传成分。3个cpDNA联合序列中共检测到35个变异位点, 分为13个单倍型, 其中单倍型H5在种群中分布最为广泛, 其余的单倍型均为种群特有的单倍型。分子方差分析(AMOVA)表明种群内的遗传变异大于种群间变异。研究表明滇杨不同种群的遗传分化具有地域性, 可选择就地保护; 昭通种群遗传多样性最高, 且包含7种叶绿体单倍型, 单倍型类型最多, 应优先保护。     

川金丝猴遗传多样性的蛋白电泳及其保护生物学意义

利用同功酶粉凝胶电泳技术检测了严自甘肃摩天岭和陕西秦岭两个地区的１９只川金丝猴（Ｒｈｉｎｏｐｉｔｈｅｃｕｓｒｏｘｅｌｌａｎａｅ）的４４个遗传座位,没有发现多态座位。其平均遗传杂合度为０。这与滇金丝猴的平均遗传杂合度处于同一水平。     

不同海拔高度木荷种群遗传多样性的ISSR分析

利用ISSR分子标记技术分析了浙江天台山不同海拔高度木荷种群的遗传多样性和遗传分化.用12个引物对4个木荷种群共80个样品进行扩增,共检测到170个位点,其中多态位点154个,多态位点百分率(P)为90.59%.木荷总的Shannon信息指数(I)为0.5033,Nei指数(h)为0.3408,表明种水平的遗传多样性较高.而种群水平的遗传多样性比种水平低,P平均为63.68%,I平均为0.3789,h平均为0.2608.AMOVA分子差异分析表明,在总的遗传变异中,29.56%的变异存在于种群间,70.44%的变异存在于种群内,种群间的基因分化系数(Gst)为0.2348.木荷种群间的基因流为1.6293,4个种群间的平均遗传距离为0.1500.     

不同海拔高度川滇高山栎群体遗传多样性的变化

采集海拔２２００～３８００ｍ川滇高山栎（ＱｕｅｒｃｕｓａｑｕｉｆｏｌｉｏｉｄｅｓＲｅｈｄ．ｅｔＷｉｌｓ．）８个群体的样品,应用同工酶电泳的方法研究其遗传变异水平,并发现遗传变异水平随着海拔高度变化呈以下趋势：海拔２４００～３３００ｍ川滇高山栎的遗传变异水平较高,而海拔３８００ｍ及２２００ｍ群体的遗传变异水平均有降低的趋势。另外,还发现人为干扰、日照多少对遗传变异水平均有影响。     

川金丝猴遗传多样性研究进展

川金丝猴目前处于生境破碎、种群隔离的濒危境地,对其进行遗传多样性研究是有效保护这一物种的必要前提.结合文献,比较了川金丝猴遗传研究中常用样品采集方法、标记方法等,总结了其遗传多样性的研究现状,并建议通过建立遗传谱系来避免或减少近交,建立生态走廊促进群间基因交流,以提高其遗传变异能力.     

应用ISSR-PCR分析蒙古栎种群的遗传多样性

本研究应用ISSR标记技术对东北地区的优势树种蒙古栎(Quercus mongolica)的25个种群遗传多样性进行了分析, 目的是为蒙古栎早期选择提供依据。从60条ISSR引物中筛选出10个特异性强、稳定性好的引物进行ISSR分析。共获得位点数71个, 其中多态位点数56个, 多态位点百分率为78.87%。PopGene分析结果表明: 种群的平均多态位点百分率为45.2%, Shannon表型多样性指数(I)平均值为0.25, 具有较高的遗传多样性, 种群间存在一定程度的基因流(N_m为1.3818)和遗传分化(Nei’s信息多样性指数平均值为0.1068, G_st平均值为0.2657), 种群内的基因多样度占总种群的73.43%, 种群间占26.57%, 表明蒙古栎种群的变异主要来源于种群内。结合聚类分析和地理变异规律把种群划分为两个大的种群组: 小兴安岭种群组和长白山种群组。以上结果可为栎属种质资源的保护和利用以及物种分化研究提供基础资料。     

大别山山核桃种群遗传多样性研究

为了更有效地保护和合理开发大别山山核桃(Carya dabieshanensis)资源,该文利用RAPD分子标记技术,对3个天然大别山山核桃种群的90个单株的遗传多样性、种群内和种群间的遗传变异进行了研究,结果表明:20对10 bp随机引物共检测到238条谱带,其中多态带为162条,占68.1%。遗传多样性分析结果显示: Shannon多样性指数为0.476 1,58.18%的变异分布于群体内,而种群间变异占了41.82%;Nei指数群体总基因多样度为0.314 5,群体内平均基因多样度(H_S)为0.186 5,群体间的基因多样度(H_ST)为0.128 0,群体Nei基因分化系数(G_ST)为0.406 7,说明40.67%的变异存在于种群间,群体内的变异占了总变异的59.33%,与Shannon多样性指数相比基本一致,均表明种群内有较丰富的遗传变异,这为优良品种选育提供广阔前景;种群间的基因流(N_m)为0.730 6,证明种群间遗传交换较小,这与环境适应性和高山阻隔有一定的关系。     

濒危植物翅果油树种群的遗传多样性和遗传分化研究

利用微卫星（SSR）标记对来自山西和陕西两省的7个翅果油树（Elaeagnus mollisDiels）种群进行遗传多样性和遗传结构研究。10对SSR标记共检测到126个位点,其中多态位点114个。在物种水平上,平均多态位点百分率为90.79%,有效等位基因数（Ne）、Nei基因多样性指数（H）和Shannon多样性指数（I）分别为1.6072、0.3166、0.4603;在种群水平上,多态位点百分率为61.99%,有效等位基因数（Ne）、Nei’s基因多样性指数（H）、Shannon多样性指数（I）分别为1.5445、0.2683、0.3815。遗传分化系数GST为0.2074,表明了翅果油树种群的遗传变异主要存在于种群内。基因流Nm为1.9111〉1,说明种群间基因交流可以阻止由于遗传漂变导致的遗传分化。聚类结果表明,翅果油树种群间的遗传距离与地理距离有一定的相关性,经Mantel检验,种群的地理距离与遗传距离之间呈正相关,但未达到显著水平（p〉0.05）。结果表明,遗传多样性水平与物种本身特性和不同干扰生境有关,濒危植物并不一定表现为遗传变异水平的降低。     

地域环境对青藏高原特有植物藏川杨生物学特性的影响

通过对西藏中、南部16个藏川杨种源地环境特征、植株和枝叶形态特征、生长习性等生物学特性的观测比较,发现藏川杨为高大、长寿乔木,株龄逾千年、株高达45 m、冠幅22 m,分布海拔高度2000～4500 m、分布区域跨越湿润、半湿润、半干旱和干旱区,随着分布区环境变化,不同种源藏川杨的树皮、枝条、芽、叶等形态特征呈现规律性变化,空气湿度增加、树干颜色变深、枝条被毛加重、顶生冬芽变窄、叶片长/宽比增加;半湿润区和灌溉区植株的叶面积、枝条长度增加,湿润区、阴湿地或环境条件恶劣地区植株叶片和枝条生长不佳,枝条干湿比相对较小。结果表明:藏川杨具有很强的环境适应能力和可塑性,耐旱,喜光、抗强光辐射,耐贫瘠、喜中性或弱碱性土壤,具有很高的生态和经济价值。     

基于粪便DNA的青藏高原雪豹种群调查和遗传多样性分析

基于非损伤性取样,利用mtDNA和微卫星DNA遗传标记,对来自青藏高原三江源国家级自然保护区、羌塘国家级自然保护区和甘肃党河南山地区等地的277 份疑似雪豹粪便样品进行了物种鉴定、个体识别和遗传多样性研究。结果显示：在190份成功扩增的mtDNA cyt b基因片段中,确定有89份属于雪豹;微卫星分析确定其属于48个不同的个体。在48个雪豹mtDNA cyt b基因片段中,共检测出13个多态性位点,定义了9个单倍型,单倍型多态性为0.776,核苷酸多态性为 1.50%, 9个单倍型的遗传距离为 0.009-0.058。研究表明在研究区域均存在雪豹分布,并具有一定的遗传多态性,地理距离分布较远的羌塘国家级自然保护区和甘肃党河南山地区的雪豹样品具有一定的遗传差异。     

新疆杨高效遗传转化系统的建立

选择新疆杨(Populus alba L.var．pyramidalis Bge．)为遗传转化受体材料,为建立根癌农杆菌介导新疆杨高效遗传转化系统,从预培养时间、侵染时间、共培养时间、添加乙酰丁香酮(AS)的时机、共培养培养基中添加乙酰丁香酮浓度、侵染菌液的制备方法、外植体继代方式等7个方面优化筛选。结果显示较合适的转化系统为：预培养8h,农杆菌菌液(OD600=0．4)侵染15min,共培养5d,侵染菌液的最优制备方法是液体培养活化农杆菌2次加离心收集菌体重悬,共培养培养基中添加乙酰丁香酮80μmol／L。新疆杨叶盘转化频率可达38．10％。     

Genome-wide genetic diversity,population structure and admixture analysis in African and Asian cattle breeds

Knowledge about genetic diversity and population structure is useful for designing effective strategies to improve the production, management and conservation of farm animal genetic resources. Here, we present a comprehensive genome-wide analysis of genetic diversity, population structure and admixture based on 244 animals sampled from 10 cattle populations in Asia and Africa and genotyped for 69 903 autosomal single-nucleotide polymorphisms (SNPs) mainly derived from the indicine breed. Principal component analysis, STRUCTURE and distance analysis from high-density SNP data clearly revealed that the largest genetic difference occurred between the two domestic lineages (taurine and indicine), whereas Ethiopian cattle populations represent a mosaic of the humped zebu and taurine. Estimation of the genetic influence of zebu and taurine revealed that Ethiopian cattle were characterized by considerable levels of introgression from South Asian zebu, whereas Bangladeshi populations shared very low taurine ancestry. The relationships among Ethiopian cattle populations reflect their history of origin and admixture rather than phenotype-based distinctions. The high within-individual genetic variability observed in Ethiopian cattle represents an untapped opportunity for adaptation to changing environments and for implementation of within-breed genetic improvement schemes. Our results provide a basis for future applications of genome-wide SNP data to exploit the unique genetic makeup of indigenous cattle breeds and to facilitate their improvement and conservation.     

天目山不同海拔檫木群体遗传多样性和遗传结构

采用13对SSR引物,运用Bioptic Qsep100全自动核酸分析系统,分析了天目山5个海拔檫木群体的遗传多样性和遗传结构及其在不同海拔下的变化模式.结果表明: 天目山檫木群体具有较高的遗传多样性水平,其中期望杂合度和观察杂合度分别为0.84和0.61.根据Shannon指数,天目山檫木中海拔(500～800 m)群体的遗传多样性水平大于低海拔(200 m)和高海拔(1100～1400 m)群体的遗传多样性水平.由基因分化系数和AMOVA分析可知,檫木种群的遗传变异主要存在于群体内.STRUCTURE分析和UPGMA聚类分析表明,中、低海拔被划为一个群体,而高海拔被划为另一个群体.低海拔和中海拔檫木群体遗传距离的差异表明,人为干扰对物种多样性具有负面效应,而自然保护区对物种多样性的保护起到了积极作用.     

Initial genetic diversity enhances population establishment and alters genetic structuring of a newly established Daphnia metapopulation

When newly created habitats are initially colonized by genotypes with rapid population growth rates, later arriving colonists may be prevented from establishing. Although these priority effects have been documented in multiple systems, their duration may be influenced by the diversity of the founding population. We conducted a large‐scale field manipulation to investigate how initial clonal diversity influences temporal and landscape patterns of genetic structure in a developing metapopulation. Six genotypes of obligately asexual Daphnia pulex were stocked alone (no clonal diversity) or in combination (‘high’ clonal diversity) into newly created experimental woodland ponds. We also measured the population growth rate of all clones in the laboratory when raised on higher‐quality and lower‐quality resources. Our predictions were that in the 3 years following stocking, clonally diverse populations would be more likely to persist than nonclonally diverse populations and exhibit evidence for persistent founder effects. We expected that faster growing clones would be found in more pools and comprise a greater proportion of individuals genotyped from the landscape. Genetic composition, both locally and regionally, changed significantly following stocking. Six of 27 populations exhibited evidence for persistent founder effects, and populations stocked with ‘high’ clonal diversity were more likely to exhibit these effects than nonclonally diverse populations. Performance in the laboratory was not predictive of clonal persistence or overall dominance in the field. Hence, we conclude that although laboratory estimates of fitness did not fully explain metapopulation genetic structure, initial clonal diversity did enhance D. pulex population establishment and persistence in this system.     

在韩国境内Potentilla fragarioides var .sprengeliana的遗传多样性和种群结构(英文)

根据 2 2个等位酶位点遗传变异 ,探讨了韩国境内委陵菜 (PotentillafragarioidesL .var.sprengeliana)的遗传多样性和种群结构。酶位点的多态位点百分比为 5 9 1%。种和种群水平上的遗传多样性比较高 ,分别为Hes=0 .2 10 ,Hep=0 .199;而种群的分化水平则相对较低 (GST=0 .0 74)。 19个种群中随机交配的偏差为FIS=0 .331。每代迁移数的间接估计 (Nm=3.15 )表明该种在韩国的种群间基因流较高。另外 ,固定指数分析显示在一些种群和位点有轻微的杂合子缺乏。种群间平均遗传一致度为 0 985。这些韩国委陵菜种群存在于较为均一的生境 ,这很有可能是造成其种群遗传一致性较高的原因。     

陇南地区不同海拔区域内小麦条锈菌群体遗传多样性的分析

小麦条锈病是世界范围内小麦上最重要的流行性病害之一,可造成严重的产量损失。陇南地区是我国小麦条锈菌主要越夏易变区和新小种发源地,了解该地区不同海拔高度区域内条锈菌遗传多样性有重要意义。本研究采用TP-M13-SSR荧光标记技术对11个种群330个小麦条锈菌分离株基因组DNA进行了SSR标记分析。不同海拔区域的条锈菌遗传多样性有明显的差异,高山区的遗传多样性比较丰富,半山区次之,川道区相对比较低。不同生态区域内,小麦条锈菌群体遗传分化程度不同,高山区和半山区遗传分化程度大,基因流小,川道区群体遗传分化程度比较小,基因流大。来自不同海拔区域的菌系具有相同的基因型,这一结果从分子水平证明了在陇南地区小麦条锈菌在山区与川地之间存在广泛的菌源交流,可就地完成周年循环。     

Microsatellite analysis revealed genetic diversity and population structure among Chinese cashmere goats

Most cashmere goats are found in northern China and Mongolia. They are regarded as precious resources for their production of high quality natural fibre for the textile industry. It was the first time that the genetic diversity and population structure of nine Chinese cashmere populations has been assessed using 14 ISAG/FAO microsatellite markers. In addition, two Iranian populations and one West African goat population were genotyped for comparison. Results indicated that the genetic diversity of Chinese cashmere goats was rich, but less than those of the Iranian goat populations. All pairwise F_ST values between the Chinese cashmere goat populations reached a highly significant level (P < 0.001), suggesting that they should all be considered as separate breeds. Finally, clustering analysis divided Chinese cashmere goats into at least two clusters, with the Tibetan Hegu goats alone in one cluster. An extensive admixture was detected among the Chinese goat breeds (except the Hegu), which have important implications for breeding management.     

Patterns of Genetic Diversity and Population Structure of the Clonal Herb,Potentilla fragarioides var. sprengeliana (Rosaceae) in Korea

The genetic diversity and population structure of Potentilla fragarioides var. sprengeliana(Rosaceae) in Korea were investigated using genetic variation at 22 allozyme loci. The percent of polymorphic loci within the enzymes was 59.1%. The genetic diversity at the species level and at the population level was high (Hes=0.210; Hep=0.199, respectively), whereas the extent of the population divergence was relatively low (GST=0.074). FIS, a measure of the deviation from random mating within the 19 populations, was 0.331. An indirect estimate of the number of migrants per generation (Nm=3.15) indicates that gene flow is high among Korean populations of the species. In addition, analysis of fixation indices revealed a slight heterozygote deficiency in some populations and at some loci. The mean genetic identity between populations was 0.985. It is highly probable that the trend of genetic uniformity in a relatively homogeneous habitat is thought to be operated among Korean populations of P. fragarioides var.sprengeliana.