濒危灌木长叶红砂遗传多样性的RAPD分析

应用RAPD分子标记对濒危灌木长叶红砂(Reaumuria trigyna)种群遗传多样性进行了分析.应用18条随机引物对长叶红砂5个种群的95个个体进行扩增,检测到118个位点,其中多态位点105个.结果表明:长叶红砂种群的多态位点比率(P)为88.98%,显示出长叶红砂种群存在较高的遗传多样性.Shannon多样性指数(0.4966)、Nei基因多样性指数(0.3303)和基因分化系数(Gst=0.1425)的分析结果显示,长叶红砂种群遗传变异大多存在于种群内,种群间的遗传分化占14.25%.聚类分析表明,长叶红砂种群遗传距离与地理距离之间无直接相关关系.遗传多样性水平与物种特性和所处不同群落有关,濒危植物并不一定表现为遗传变异水平的降低.     

珍稀濒危植物金毛狗的SRAP分析

利用SRAP分子标记技术,对7个居群79株金毛狗进行遗传多样性分析。结果表明:10对SRAP引物组合共得到107条扩增条带,多态性条带比率为85.98%,Nei’s基因多样性指数为0.229 6,Shannon’s多样性指数为0.358 6,表明金毛狗居群水平具有较高的遗传多样性;金毛狗7个居群的总基因多样度为0.229 6,居群内遗传多样度为0.135 4,居群间的遗传分化指数为0.410 6,表明有41.06%的变异存在于居群间,有58.94%的变异存在于居群内;居群间基因流为0.717 8,表明居群间基因交流频率较低;遗传一致度和UPGMA聚类分析结果显示,生境条件相似的居群优先聚集,说明金毛狗种质亲缘关系与地理分布相关性不显著。     

Genetic diversity and population structure of Butea monosperma (Lam.) Taub.- a potential medicinal legume tree

Three molecular marker systems, Random Amplified Polymorphic DNA (RAPD), Inter-Simple Sequence Repeats (ISSR) and Sequence-Related Amplified Polymorphism (SRAP) were employed to investigate the genetic structure and diversity among the 14 natural populations of Butea monosperma collected from different geographical regions of India. Detected by 17 RAPD, 15 ISSR and 11 SRAP primer combinations, the proportions of polymorphic bands were 84.2 %, 77.2 % and 91.9 %, respectively, and the mean Nei’s genetic distances among the populations were 0.13, 0.10 and 0.13, respectively. Partitioning of genetic variability by Analysis of molecular variance (AMOVA) revealed that the high genetic diversity was distributed within the populations. AMOVA also revealed that the coefficient of gene differentiation among populations based on F_ST was very high irrespective of markers used. The overall gene flow among populations (Nm) was very low. Cophenetic correlation coefficients of Nei’s distance values and clustering pattern by Mental test were statistically significant for all three marker systems used but poor fit for ISSR data than for RAPD, SRAP and combined data set of all three markers. For all markers, a high similarity in dendrogram topologies was obtained, although some differences were observed with ISSR. The dendrogram obtained by RAPD, SRAP and combined data set of all three markers reflect relationship of most of the populations according to their geographic distribution.     

Genetic structure and variation in the relict populations of Alsophila spinulosa from southern China based on RAPD markers and cpDNA atpB-rbcL sequence data

RAPD markers and sequences of chloroplast DNA (cpDNA) atpB-rbcL intergenic spacers were used to characterize the pattern of genetic variation and the phylogenetic relationships of the relict populations of Alsophila spinulosa located in Jian Feng Ling (JFL) and Diao Luo Shan (DLS), Hainan, and Tang Lang Shan (TLS), Ding Hu Shan (DHS), and Da Xi Shan (DXS), Guangdong, of southern China. 28 random primers generated 118 bands, out of which 26 (22.03%) were polymorphic loci, distinguishing 17 different RAPD phenotypes. Percentage of polymorphic loci, Shannon phenotypic diversity and Nei's gene diversity comprehensively indicated that JFL possessed the highest diversity, TLS and DHS in intermediate and DLS or DXS the least; the corresponding values of the population appeared correlated with the population size. Differentiation was detected among populations of A. spinulosa (1-Hpop/Hsp=0.7453, GST=0.7763, and phist=0.8145). AMOVA showed that 47.44% of the variance was partitioned among regions (Hainan and Guangdong), 34.01% attributed among populations within regions, whereas only 18.55% occurring within populations. Low level of intra-specific diversity was maintained in A. spinulosa with Shannon diversity and gene diversity merely 0.0560 and 0.0590, repectively. Sequence length of atpB-rbcL intergenic spacer varied from 724 bp to 730 bp. Base composition was with A+T content between 63.17% and 63.70%. 13 haplotypes of atpB-rbcL noncoding spacers were identified. UPGMA dendrogram of RAPD phenotypes, principal components analysis based on RAPD patterns, minimum spanning network and neighbour-joining (NJ) tree established on atpB-rbcL haplotypes consistently suggested the geographical subdivision of populations of A. spinulosa between Hainan and Guangdong. Breeding system and conservation strategy of A. spinulosa was discussed based on the information of population genetic structure and variation.     

Comparative Assessment of Genetic Variability in the Populations of Endemic and Endangered Yellow Catfish, Horabagrus brachysoma (Teleostei: Horabagridae), Based on Allozyme, RAPD, and Microsatellite Markers

The comparative assessment of genetic diversity using allozymes, random amplified polymorphic DNA (RAPD), and microsatellite markers was conducted in endemic and endangered yellow catfish (Horabagrus brachysoma) sampled from three locations in Western Ghats river systems of India. Among the three markers, microsatellites show more polymorphism, having 100% polymorphic loci, whereas allozymes show the least (56%). In RAPD, 60.5% of fragments were polymorphic. Observed heterozygosity and F(ST) values were very high in microsatellites, compared with the other markers. Microsatellite and RAPD markers reported a higher degree of genetic differentiation than allozymes among the populations depicted by pairwise F(ST)/G(ST), AMOVA, Nei's genetic distance, and UPGMA dendrogram. The three classes of markers demonstrated striking genetic differentiation between pairs of H. brachysoma populations. The data emphasize the need for fishery management, conservation, and rehabilitation of this species.     

广东省十种卷柏属植物RAPD初步分析

采用RAPD标记对卷柏属10种植物进行了分类鉴定、种间亲缘关系及遗传多样性的初步分析。结果显示:10个RAPD引物很好地区分了10个种,每个种均有2~12个种单态特征位点;UPGMA聚类树与有关文献表型分类结果不尽一致;卷柏属不同种具有不同的遗传多样性水平。     

Examining genetic relationships of Chinese Pleurotus ostreatus cultivars by combined RAPD and SRAP markers

Combined randomly amplified polymorphic DNA (RAPD) and sequence-related amplified polymorphism (SRAP) were used to assess the genetic diversity of Pleurotus ostreatus strains cultivated in China. For the RAPD and SRAP analyses, 479 and 282 polymorphic bands were obtained from 20 P. ostreatus strains using 20 and 13 selected primers or primer pairs, respectively. A combined RAPD/SRAP dendrogram grouped the 20 strains into five clades with a coefficient of 0.690. The comparison of RAPD and SRAP was evaluated in the present study. The combined RAPD/SRAP markers provided reliable information regarding the relationships among the P. ostreatus strains.     

内蒙古小花棘豆遗传多样性的ISSR分析

应用ISSR分子标记对内蒙古西部地区小花棘豆（Oxytropis glabra DC.）6个地理种群进行了遗传多样性研究.结果表明：小花棘豆具有较高的遗传多样性;14个引物共扩增出327个位点,物种水平上Nei＇s基因多样性指数为0.1972,Shannon多样性指数为0.3287;种内总基因多样性为0.1976,种群内基因多样性为0.1653,83.67%的遗传变异存在于种群内,16.33%的遗传变异存在于种群间,种群间的遗传分化系数为0.1633,基因流为2.5613,6个种群间有一定遗传分化,但遗传漂变不会引起遗传分化.UPGMA遗传距离聚类结果表明,生态地理条件相似的种群优先聚集.     

毛乌素沙地柠条群体分子生态学初步研究:RAPD证据

毛乌素沙地柠条群体是一个杂种带,为了进一步阐明分子变异和基因流与生境或生态过渡带的联系,应用ＲＡＰＤ标记开展了柠条群体的分子生态学研究。根据ＲＡＰＤ数据利用Ｓｈａｎｎｏｎ信息指数估计了６个柠条群体的遗传多样性,发现大部分的分子变异存在于柠条群体之内（８２．４％）,只有少部分的分子变异存在于群体之间（１７．６％）,又利用ｅｉ指数统计了ＲＡＰＤ数据,也证实了大部分的遗传变异存在于群体之间,柠条锦鸡儿群     

内蒙古地区刺叶柄棘豆(Oxytropis aciphylla Ledeb.)种群遗传多样性分析

用ISSR分子标记对内蒙古地区刺叶柄棘豆(Oxytorpis aciphylla Ledeb.) 5个地理种群进行了种群遗传多样性分析。结果表明：刺叶柄棘豆种群具有较高的遗传多样性,11个ISSR引物扩增出215条带,总的多态位点百分率为98.14%,Shannon多样性指数I=0.2108,Nei基因多样性指数 H=0.341 6,种内总基因多样性(H_t) 为0.2108,种群内基因多样性(H_s)为0.160 4, 大部分遗传变异(76.11%)的遗传变异存在于种群内, 23.89%的遗传变异存在于种群间。遗传分化系数(Gst)为0.238 9,基因流(Nm)为1.592 9。5个居群间已有遗传分化趋势,遗传漂变不会引起遗传分化。UPGMA遗传距离聚类结果表明, 5个地理种群中,植被类型为荒漠草原的4个种群之间遗传距离较近,与1个荒漠种群距离较远。     

山西霍山五角枫不同海拔种群遗传多样性研究

利用SRAP分子标记分析山西霍山不同海拔五角枫种群的遗传多样性和遗传结构。11对引物组合共得到88个重复性好的位点;Nei基因多样性指数（ h）在0.1996～0.3163之间,平均为0.2373;Shannon多样性指数（ I）范围为0.2995～0.4936,平均为0.3535;在物种水平上,多态位点百分率（ PPB）为98.86％,表现出较高地遗传多样性。 ANOVA分析表明,遗传变异主要存在于五角枫种群内（79％）,21％的分子变异分布在种群间。基于遗传距离进行UPGMA聚类分析,5个五角枫种群聚为明显的2支。相关分析显示：五角枫的多样性指数与地理梯度均无显著或极显著相关。     

Effects of life history traits and sampling strategies on genetic diversity estimates obtained with RAPD markers in plants

A compilation of studies using RAPD markers for evaluating population differentiation resulted in 78 estimates of AMOVA-derived Φ_ST and 31 estimates of Nei's G_ST, as well as in 41 estimates of Nei's within-population diversity. In outcrossing taxa, estimates of between-population diversity were closely correlated with maximum geographic distance between sampled populations. A corresponding association was not found in selfing taxa. These results suggest that RAPD can be a sensitive method for detection of genetic structuring according to the isolation-by-distance model. However, it also means that sampling strategies, as applied in individual studies, can seriously influence the resulting estimates of between-population diversity. Other sampling strategies, like number of plants per population and number of scored polymorphic markers, do not seem to impart any serious artefacts. As previously verified with allozyme data, RAPD markers showed that long-lived, outcrossing, late successional taxa retain most of their genetic variability within populations. By contrast, annual, selfing and/or early successional taxa allocate most of the genetic variability among populations. Estimates for between- and within-population diversity, respectively, proved to be negatively correlated, as previously reported for allozyme data. The only major discrepancy between allozymes and RAPD markers concerns geographic range; within-population diversity was strongly affected by distributional range of the investigated species in the allozyme data but not in the RAPD data. Moreover, RAPD-based values for between-population diversity increased with increasing distributional range whereas the opposite has been reported in a large allozyme data compilation. Contrary to allozymes, RAPD marker-derived within-population diversity is probably therefore not a very good predictor of total species genetic diversity.     

拟环纹豹蛛种群遗传多样性与其生境的关系

对分布于我国中南、西南和海南岛8个不同生境的拟环纹豹蛛种群进行RAPD分析.筛选出10对引物扩增出清晰稳定的200～2 500 bp片段84条,其中多态性片段62条(占73.8%).表明种群存在明显多态现象.Shannon指数、相似系数和遗传距离测定以及聚类分析的结果表明：拟环纹豹蛛种群总的遗传多样性指数为0.5177,而且种群内遗传变异（64.24%)大于种群间（35.76%）;8个狼蛛种群平均遗传距离为0.2426,变异范围为0.0753～0.3725,表明8个种群由于所处生境条件不同而产生了一定的适应性变异.多元回归统计结果表明,制约拟环纹豹蛛成为稻田优势种的主要因子是年平均气温和农药的长期施用.     

湖北河岸带植物中华蚊母树遗传多样性的SRAP分析

利用SRAP分子标记技术,对湖北省河岸带植物中华蚊母树的4个自然居群和1个迁地居群的遗传多样性和遗传结构进行了分析。结果表明,中华蚊母树物种具有较高水平的遗传多样性,7对SRAP引物进行PCR扩增的多态性位点百分率(PPF)为80.43%,每个位点的等位基因数(A)为2,有效等位基因数(Ae)为1.34,总遗传多样性Nei’s基因多样性指数(Hp)为0.215 9,Shannon信息多样性指数(I)为0.350 9。在居群水平上,5个居群总的遗传变异Ht为0.218 8,居群内的遗传变异Hs为0.193 4,居群间的遗传分化系数Gst为0.116 1,表明在总的遗传变异中有88.39%变异存在于居群内,仅11.61%存在于居群间,居群间的基因流Nm为3.807 2,表明居群间有较大程度的基因交流。UPGMA聚类分析和主成分分析显示中华蚊母树主要分为两个居群组,在长江三峡沿岸香溪和乐天溪由于遗传距离比较近聚为一小类再与高家堰聚为一大类,而沿渡河和三峡植物园居群聚为另一大类,表明迁地居群三峡植物园的中华蚊母树与来自巴东沿渡河居群的样本亲缘关系最近,且三峡植物园迁地保护居群基本保育了其遗传多样性总水平。同时在分析讨论了中华蚊母树遗传多样性与其繁育系统、生境及其起源进化的关系的基础上,评价了中华蚊母树的保护策略,并在评价保护成果的基础上,提出了今后进一步保育的策略。结果还表明SRAP标记是分析中华蚊母树遗传多样性和遗传结构非常可靠的一种标记,而且这是使用SRAP标记研究中华蚊母树的首次报道。     

GENETIC DIVERSITY OF FIVE FRESHWATER MUSSELS IN GENUS ANODONTA (MOLLUSCA: BIVALVIA) REVEALED BY RAPD ANALYSIS

Unionidae(Bivalvia)are distributed infreshwaters,and represent a significanttaxonof benthic community[1].In China,freshwater mussels are abundant resources[2].Since1949,substantial investigations onthe unionidfau-na had been undertakenin China[3—8].Withreference tooverseas research[9,10],a preliminary reorganization onthe Unionidae was performed accordingtosome classifica-tion characteristics such as shell shape,larvae character-istics,and breeding habit[11].Due tothe serious conver-gence of freshwater muss...     

通过RAPD分析揭示五种淡水无齿蚌（软体动物门：双壳类）的遗传多样性

Unionidae(Bivalvia)are distributed infreshwaters,and represent a significanttaxonof benthic community[1].In China,freshwater mussels are abundant resources[2].Since1949,substantial investigations onthe unionidfau-na had been undertakenin China[3—8].Withreference tooverseas research[9,10],a preliminary reorganization onthe Unionidae was performed accordingtosome classifica-tion characteristics such as shell shape,larvae character-istics,and breeding habit[11].Due tothe serious conver-gence o…     

扁蓿豆育成品系遗传多样性的RAPD研究

用 RAPD分子标记对4个扁蓿豆育成品系进行遗传多样性分析.结果表明:筛选的12条多态性RAPD引物共检测出126个等位基因位点,平均每条引物检测到10.5个位点,多态位点比率占94.4%.扁蓿豆品系的Nei's遗传多样性指数(H)为0.266 2,Shannon多样性指数(I)为0.414 5.Nei's指数估算和分子方差分析(AMOVA)均证实扁蓿豆品系的遗传多样性主要存在于品系内,品系间有一定的基因交流(基因流为2.756 7).聚类结果表明,品系00-61和00-81遗传差异相对较小,品系90-36与前两者之间的遗传差异较大,品系93-21与各品系的遗传差异最大.     

高山嵩草种群在放牧干扰下遗传多样性的变化

利用SRAP (Sequence-related amplified polymorphism)分子标记, 对放牧干扰下的高山嵩草(Kobresia pygmaea)种群进行了遗传多样性研究, 获得了下述结果: 1) 20对SRAP引物组合共检测出448条清晰条带, 其中376条条带具有多态性, 多态位点百分率为83.93%, 随着放牧强度的增加, 高山嵩草种群多态位点百分数、Nei’s遗传多样性指数、Shannon信息指数均下降。2)高山嵩草种群具有较高的遗传多样性和较低的遗传分化(总的遗传多样性H_t为0.276 6, 种群内遗传多样性H_s为0.243 6, 遗传分化系数G_st为0.119 4, 基于G_st估计的基因流N_m^*为1.843 4), 但随着放牧强度的增加, G_st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。3)不同放牧梯度的高山嵩草种群间的遗传距离很小, 但是随着放牧强度的增加, 种群间的遗传距离逐渐增加, 遗传一致度降低。根据遗传距离所构建的UPGMA聚类图中高山嵩草4个种群随着牧压的增加, 逐级聚在一起。     

Different portions of the maize root system host Burkholderia cepacia populations with different degrees of genetic polymorphism

In order to acquire a better understanding of the spatial and temporal variations of genetic diversity of Burkholderia cepacia populations in the rhizosphere of Zea mays , 161 strains were isolated from three portions of the maize root system at different soil depths and at three distinct plant growth stages. The genetic diversity among B. cepacia isolates was analysed by means of the random amplified polymorphic DNA (RAPD) technique. A number of diversity indices (richness, Shannon diversity, evenness and mean genetic distance) were calculated for each bacterial population isolated from the different root system portions. Moreover, the analysis of molecular variance ( amova ) method was applied to estimate the genetic differences among the various bacterial populations. Our results showed that, in young plants, B. cepacia colonized preferentially the upper part of the root system, whereas in mature plants, B. cepacia was mostly recovered from the terminal part of the root system. This uneven distribution of B. cepacia cells among different root system portions partially reflected marked genetic differences among the B. cepacia populations isolated along maize roots on three distinct sampling occasions. In fact, all the diversity indices calculated indicated that genetic diversity increased during plant development and that the highest diversity values were found in mature maize plants, in particular in the middle and terminal portions of the root system. Moreover, the analysis of RAPD patterns by means of the amova method revealed highly significant divergences in the degree of genetic polymorphism among the various B. cepacia populations.     

黄海和东海小黄鱼遗传多样性的RAPD分析

小黄鱼（Pseudosciaena polyactis）是我国近海重要经济鱼类之一。本文分析了采自黄海和东海5个海区共计48个个体小黄鱼的随机扩增DNA多态性（RAPD）。从40个10 bp引物中选取20个用于群体遗传多样性分析,共检测出145个位点,其中132个（91.03%） 显多态性。用Shannon多样性指数量化的平均遗传多态度为1.93（1.50～2.44）,群体内和群体间的遗传变异比例分别为69%和31%;群体间的平均遗传相似度和遗传距离分别为0.9139和0.0861。用非加权配对算数平均法（UPGMA）聚类分析的结果表明,所分析的5个群体可分为3个地理群系,从分子水平上支持了过去有关学者把黄海和东海的小黄鱼划分为北、中、南3个地理群系的观点。