四个鲤鱼种群遗传多样性的AFLP分析

本文采用AFLP技术对黑龙江野鲤、黄河鲤、建鲤和荷包红鲤4个鲤鱼种群共96个个体进行了遗传多样性分析。结果显示,8对选择性扩增引物共扩增得到502个位点,其中多态性位点273个,多态性比率为54．38％。同时对4个种群的Shannon多样性指数,Nei’s基因多样性等参数进行了分析,结果表明,4个种群的Shannon多样性指数分别为0．2114±0．2705,0．1825±0．2694,0．1888±0．2587和0．1600±0．2426,Nei’s基因多样性指数分别为0．1398±0．1872,0．1225±0．1863,0．1235±0．1774和0．1036±0．1636;总基因多样性（H4）平均值为0．1721±0．0350;种群内基因多样性（Hs）平均值为0．1224±0．0190;基因分化系数（Gst）为0．2892,种群内的基因多样性占总群体的71．08％,种群间为28．92％,而基因流系数（Nm）为1．2291。另一方面,分子方差分析（AMOVA）结果表明,种群平均近交系数（Fst）为0-31191,变异31．19％来自种群间,68．81％来自种群内。4个种群中黑龙江野鲤的种内多态性比例最高,而荷包红鲤种群最低,并且4个鲤鱼种群当前的种质资源良好,具有一定的种群稳定性;建鲤已经开始分化,与亲本荷包红鲤亲缘关系逐渐分化,逐步形成自己稳定的遗传结构。本研究为探讨鲤鱼种群的遗传特性和遗传分化提供参考,也为其种质资源的保护及合理利用提供科学依据。     

三个野生种群马氏珠母贝遗传多样性的RAPD分析

摘要：为了解野生种群马氏珠母贝（Pimctada martensii (Dunker.)）的遗传结构背景和开展遗传改良育种,运用RAPD技术分析了海南三亚（SW）、广东大亚湾（DW）和广西北海（BW）3个野生种群的遗传多样性。采用了18个10碱基的随机引物对3个野生种群进行分析,其中6个引物能扩增出清晰的多态带谱,扩增的DNA片段大小在含0.2~3.0 kb之间。SW、DW和BW 3个种群内的遗传相似性指数分别为0.642、0.672和0.688,Shannon多样性值分别为0.266、0.211和0.174。马氏珠母贝3个野生种群的遗传相似性依次为SW< DW < BW,而遗传多样性依次是SW > DW> BW。DW和SW相对遗传距离为0.104;DW和BW相对遗传距离为0.094;SW和BW相对遗传距离为0.212。讨论了马氏珠母贝野生种群遗传多样性差异的可能原因、种群间杂交子代的杂交优势预测及人工养殖对野生种群遗传结构的可能影响。     

泰国产方斑东风螺养殖群体遗传多样性的RAPD分析

用随机扩增多态性DNA(RAPD)技术对泰国产方斑东风螺养殖群体的遗传多样性进行检测,从100个随机引物中筛选出21个引物对方斑东风螺的DNA进行扩增,结果表明:21个引物共检测到222条清晰且重复性好的条带,每个引物可扩增出4~16条带,分子量在200~2200bp之间,其中多态位点为156个,占70.27%;群体的Shannon多样性指数为0.2818,Nei基因多样性指数为0.2491;个体间最大遗传距离为0.291,最小遗传距离为0.066。通过与其他贝类遗传多样性的研究结果比较,可初步判断泰国产方斑东风螺养殖群体的遗传多样性比较丰富。     

我国甘蔗亲本遗传多样性的AFLP标记分析

采用15对多态性较好的AFLP引物对我国自育的78个甘蔗亲本材料遗传多样性进行分析,结果表明,每对引物的多态性位点平均为65．67,多态陆位点率为82．55％。78个甘蔗亲本的遗传相似系数在0．4535～0．8927之间,平均为0．6821。相同组合后代的遗传相似系数较高,平均为0．7656。以遗传相似系数阈值约为0．700划分,聚类分析把78个亲本分为7大类,系谱记录中亲缘关系密切的亲本品系,大多数都能归为同一类。遗传多样性指数分析显示,不同年代亲本多样性指数差异明显,20世纪80年代最高,为0-3185,70年代最低,为0．2645;不同省区的亲本遗传多样指数变化更显著,在0．1952～0．2999之间,广东最高,云南最低。     

紫茎泽兰群体遗传多样性及遗传结构的AFLP分析

紫茎泽兰是我国最为严重的入侵物种之一。本研究以中国境内的紫茎泽兰为材料，用AFLP方法研究了其群体遗传多样性及遗传分化。用筛选出的3对荧光引物，对5个地区62个群体进行AFLP分析，共扩增出490条带，其中多态性带328条，群体的遗传多样性较高(P = 66.9%，H = 0.171，I = 0.268)，主要存在于群体内，群体间的遗传分化系数Fst为0.287。AMOVA分析表明，在地区水平紫茎泽兰的遗传分化主要存地区内，群体内遗传分化占 70.25%，群体间遗传分化占21.71%，地区间的遗传分化仅占8.04%。UPGMA聚类分析结果表明，62个地理群体主要分为四大类群，并且有明显的地缘关系。Sigmaplot分析表明海拔是影响紫茎泽兰遗传多样性主要地理因子。Mantel检验表明遗传距离与地理距离成正相关(r = 0.34)，但也有例外。由此推断风媒传播可能是紫茎泽兰的主要传播方式，水媒传播可能是紫茎泽兰的另一主要传播途径；随着紫茎泽向东、向北扩散，新入侵地区的遗传多样性逐步降低。     

中国东南沿海15个秋茄种群遗传多样性的SRAP分析

为进一步保护和恢复红树林资源提供分子方面的基础资料和科学依据,本研究采用SRAP标记对15个中国东南沿海红树植物秋茄种群的亲缘关系进行了分析。从120对参试引物组合中选出46对重复性好、条带清晰的引物组合对供试的15份材料基因组DNA进行PCR扩增,得到大小在50～1000bp之间条带270,其中多态性条带107条,多态性位点率为39.63%。15个秋茄种群的遗传相似系数在0.004～0.845之间,平均为0.412,说明中国东南沿海秋茄种群存在较丰富的遗传多样性。聚类分析把15份供试种群材料划分为4个类群。15个秋茄种群的遗传多样性没有明显的地域性差异,同一样地域的不同种群之间具有遗传上的差别。建议在今后我国的红树林保护中,应加强对海南东寨港、深圳福田、湛江东北大堤和湛江附城的秋茄种群保护。     

AFLP分析江西省4个斑点叉尾鮰养殖群体遗传多样性

本文运用AFLP分子标记技术,对江西省4个斑点叉尾鮰(Ictalurus punctatus)养殖群体(GZ、XJ、PYA和PYB)进行遗传多样性分析。结果表明,在64对引物组合中,E3/M2、E4/M7、E3/M8和E5/M5引物从4个群体72个体中共扩增出179个位点,其中多态位点为109,占60.89%。其中,PYA、GZ、XJ和PYB群体的多态位点比例(P)分别为56.54%、56.47%、56.32%和56.14%。Shannon多样性指数(I)分别为0.2890、0.3003、0.2896和0.2852,平均杂合度(H)分别为0.1935、0.2027、0.1938和0.1898。4个群体间的遗传分化系数(Gst)为0.1314,说明群体间发生了一定程度的遗传分化,但分子方差分析(AMOVA)显示,群体的遗传变异90.98%来源于群体内的个体间,9.02%来源于群体间。聚类分析也表明,4个群体所产生的遗传分化主要也来源于群体内。本研究为斑点叉尾鮰种质资源的调查和保护提供参考,为斑点叉尾鮰优良品种的选育提供科学依据。     

白菜类蔬菜遗传多样性的AFLP分子标记研究

首次对白菜（Brassica rapa)类蔬菜的遗传多样性和分类进行了AFLP分子标记研究。共采用了137份材料，从64对引物组合中选择了4对扩增条带多，多态检出率高的3＋3引物组合，检测了210个位点，并对AFLP数据进行了聚类分析，结果表明，芜菁和白菜类蔬菜各自单独聚为一类，它们的亲缘关系较远。在白菜类蔬菜当中，所有大白菜和薹菜聚为一类，它们是比较特殊的类群，且亲缘关系密切，小白菜的聚类结果与其园艺学分类差别较大。小白菜各类型间的相似性程度较低，说明小白菜的起源较大白菜要早。大白菜的聚类表明，大白菜现有品种的遗传多样性较为狭窄。     

利用RAPD和AFLP标记分析烟草种质资源的遗传多样性

从200条10 bp的RAPD引物中筛选获得28条多态性引物，对48份烟草材料的基因组DNA进行扩增。共获得184条DNA扩增片断带，其中多态性带86条，平均多态检出率为46.7%。用4对AFLP选择性扩增引物对48份烟草材料进行选择性扩增，共获得321条扩增带，其中174条具有多态性，平均多态检出率为54.2%。根据RAPD和AFLP标记的结果，采用UPGMA法进行聚类分析，两种方法获得了相似但不完全相同的结果，两者都可以将48份烟草资源分为两大类群，即黄花烟草(Nicotiana rustica)群和普通烟草(N.tobacum)群，普通烟草可进一步分为4组；48份材料的遗传距离变幅在1.4～11.0之间，其聚类结果与理论上所期望的结果基本一致，AFLP标记技术比RAPD标记技术能更好地从分子水平上揭示烟草种质资源的遗传背景、亲缘关系及演化规律。     

野生斑鳠西江地理群的遗传多样性分析

为了解斑鳠(Mystus guttatus)不同地理种群之间的遗传分化程度,基于RAPD技术,分析了珠江水系西江段野生斑鳠的遗传多样性。利用20个随机引物对30个斑鳠个体的基因组DNA进行了PCR扩增,共扩增出3210条DNA片段,平均每个个体扩增出107条带。在检测到的107个位点中,多态位点数为48个,占44.9%,仅有一个引物S30没有扩增出多态带。个体间最大的遗传距离0.2804,最小的遗传距离0.0467,平均遗传距离0.1526±0.037,种群内个体间平均的相似率为84.7±3.7%。     

中国少鳞鳜不同地理群体遗传变异的AFLP分析

少鳞鳜为东亚特有淡水鱼类,为了解中国少鳞鳜种内不同地理群体的遗传特征,利用AFLP技术对长江、钱塘江、西江、南渡江4个群体共65尾样品的遗传变异进行了分析。10对引物共检测条带1131条,多态性条带603条,平均多态比例为53.32%;而长江、钱塘江、西江、南渡江群体内的多态位点比例、平均基因多样性和Shannon指数均较低。群体间的遗传距离以大陆3群体间较近(0.098～0.189),南渡江群体与其他群体较远(0.507～0.568)。分子方差分析(AMOVA)表明群体间存在极显著的差异(FST = 0.972)。NJ聚类关系显示4群体分为两支,一支为大陆群体;一支为南渡江群体。群体内遗传多样性较低可能与中国少鳞鳜为溪涧性鱼类,群体数量不大,基因库贫乏有关,而群体间缺乏基因交流以及遗传漂变导致了不同地理群体间产生了极显著的遗传分化     

三种笛鲷的野生群体和养殖群体遗传多样性的微卫星分析

摘要：利用微卫星标记技术,采用10对微卫星引物对南海海域红鳍笛鲷、星点笛鲷、紫红笛鲷3种笛鲷鱼的野生种群（HYE、XYE、ZYE）和养殖种群（HYA、XYA、ZYA）进行了遗传多样性分析。10对微卫星引物在6个群体中共检测到78个等位基因,每个位点的等位基因数目在1~8个之间。6个群体的观测杂合度(Ho)为0.2500~1.0000,平均观测杂合度为：ZYE(0.9550)> ZYA(0.8900),HYE(0.8950)> HYA(0.8400),XYE(0.8450)>XYA(0.8100) ;平均多态信息含量(PIC) 为0.3648~0.7964,各野生群体均大于养殖群体;三种笛鲷鱼的野生群体和养殖群体遗传距离HYE与HYA,XYE与XYA,ZYE与ZYA分别为0.1029,0.0371,0.0135,基因分化系数分别为0.0371,0.0211,0.0352。群体遗传结构分析结果表明：红鳍笛鲷、星点笛鲷和紫红笛鲷的遗传多样性较丰富,养殖群体的遗传多样性较野生群体均有一定程度的降低,野生群体和养殖群体分化较弱。     

Genetic Diversity of Tunisian Olive Tree (Olea europaea L.) Cultivars Assessed by AFLP Markers

About 29 olive (Olea europaea L.) cultivars including oil and table olive cultivars originating from Tunisia and other Mediterranean countries, were genotyped using amplified fragment length polymorphism (AFLP) DNA markers. This technique is a rapid and efficient method for producing DNA fingerprints. Using nine AFLP primer combinations, we produced a total of 410 AFLP markers, among which 172 revealed polymorphism. The results demonstrated a high degree of polymorphism in the olive germplasm we examined with an average of 39%. These AFLP markers were analyzed to estimate genetic distances between pairs of cultivars using Jaccard’s similarity coefficient. Furthermore, cluster and principal component analyses were performed in order to identify the genetic variation patterns. Two main groups were obtained: one comprising primarily small-fruited cultivars grown mainly for oil production and the other comprising large fruited cultivars (regardless of their end-use). Our results show no evidence of clustering of olive cultivars according to their geographic origin.     

Optimum Sample Size for Estimating Gene Diversity in Wild Wheat using AFLP Markers

Genetic diversity in five wild types of wheat was estimated using Simpson's index (based on heterozygosity) applied to data from AFLP markers. For such studies, the cost of obtaining the required information increases both with the number of samples required to estimate diversity and with the number of markers used. When the population studied is in Hardy–Weinberg equilibrium (HWE), allelic frequencies follow the binomial expansion and parametric methods can be used to calculate the variance of the diversity index in terms of the number of individuals sampled. Inbred species are never in HWE. With regard to such populations, this study addresses the question of the sample size required to estimate gene diversity using a distribution-free re-sampling method. We studied populations of five wild species (Aegilops speltoides, Triticum urartu, Triticum boeoticum, Triticum dicoccoides, and Triticum araraticum) as sources of diversity. We used bootstrap re-sampling with varying sample sizes to develop a relationship between the precision of the diversity estimate and the sample size. Such a relationship was used to determine the samples required for capturing a given amount of diversity and its precision. We found that 5–6 samples are sufficient to obtain a standard error equal to 10% of the diversity in the populations of the species Ae. speltoides, T. dicoccoides and T. araraticum. However, more than 12 samples would be needed for populations of T. urartu and T. boeoticum. The procedure presented here can be used to obtain the optimum sample size for other crop species as well.     

利用AFLP对桃遗传连锁图的加密及加密前后连锁图的比较分析

以桃(Pruns persica (L.) Batsch)品种大久保与兴津油桃杂交F2 代109株后代为作图群体，利用AFLP分子标记对已构建的桃遗传连锁图进行加密，在原有作图数据的基础上又增加了35个符合孟德尔分离比例的AFLP标记，其中28个新的标记被加到了遗传连锁图上。应用Mapmaker分析软件将所有的144个标记构建到包含11个连锁群的连锁图谱中，连锁群的总长度为1167.6 cM，覆盖了桃基因组范围的97.3%。连锁群的平均长度为106.15 cM，标记间的平均距离为12.04 cM。与已构建的连锁图比较，发现9个新的标记被加到了第9连锁群，而原有的5个标记丢失了；在第6连锁群，不仅标记间的顺序改变了，而且标记间的平均距离也加大了。另外，第3和第11连锁群间、第1和第10连锁群间，一些标记的位置发生了变化，并对产生这些差异的原因进行了初步分析。     

Genetic Diversity among Syrian Cultivated and Landraces Wheat Revealed by AFLP Markers

Genetic diversity among some important Syrian wheat cultivars was estimated using Amplified Fragment Length Polymorphism (AFLP) markers. Five Triticum aestivum L. and 10 Triticum turgidum ssp. durum were analyzed with 11 EcoRI–MseI primer pair combinations. Of the approximately 525 detected AFLP markers, only 46.67% were polymorphic. Cluster analysis with the entire AFLP data divided all cultivars into two major groups reflecting their origins. The first one contained T. aestivum L. cultivars, and the T. turgidum ssp. durum cultivars and landraces were grouped in the second. Narrow genetic diversity among all cultivars was detected with an average genetic similarity of 0.884. The lowest similarity index (0.9) was found between Cham5 and Hamary (durum wheat), whereas this value was 0.93 between Salamony and Bouhouth 4 (T. aestivum L.). The narrow genetic diversity level indicates that these genotypes could be originated from the same source. AFLP analysis provides crucial information for studying genetic variation among wheat cultivars and provides important information for plant improvement.     

DNA Fingerprinting and Genetic Characterization of Anatolian Triticum spp. using AFLP Markers

In this study, genetic analysis of Triticum spp. was carried out using AFLP markers. Six AFLP selective combinations were scored as presence and absence of bands for all the individual samples obtained from a single seed of each accession (70 accessions); T. baeoticum (21), T. monococcum (5), T. urartu (16), T. araraticum (7), T. dicoccoides (16) and T. dicoccon (5), resulting in 506 polymorphic AFLP bands. The phylogenetic tree showed two major clusters; one was composed of T. monococcum (AA) and T. baeoticum (AA), and the other cluster included T. araraticum (AAGG), T. dicoccon (AABB), T. dicoccoides (AABB), and T. urartu (AA). T. urartu, although having a diploid AA genome, did not cluster with other A genome diploids such as T. monococcum and T. baeoticum; instead it clustered together with the tetraploid species, confirming that T. urartu is the A genome progenitor. The extent of variations within and among species is discussed.