竹类植物SSR引物开发策略及应用

微卫星(SSR)指的是以核苷酸为单位,串联重复的DNA序列,分布于真核生物的整个基因组中。SSR标记是基于DNA长度多态性的分子标记技术,广泛应用于群体遗传结构分析、构建遗传图谱、基因定位、亲缘关系等领域。本文综述了竹类植物中的SSR引物开发方法及应用,旨在为SSR分子标记在竹类植物中的应用提供参考。     

水杉基因组微卫星分析及标记开发

微卫星(microsatellite)又称简单重复序列(simple sequence repeat,SSR),是指以少数几个核苷酸为单位,多次串联重复的DNA序列,其普遍存在于真核生物及一些原核生物基因组中.基因组序列中微卫星重复序列变异最快,在群体间和不同个体间通常表现出很高的序列多态性,且呈共显性遗传.由于重复单元重复次数的高度可变性及其侧翼序列的相对保守性,微卫星作为一种分子标记被广泛应用于物种的指纹鉴定、亲子谱系分析、群体遗传结构分析、遗传图谱构建、比较基因组及分子标记辅助育种等诸多研究领域(李淑娴等,2010).     

磁珠富集法快速制备油茶基因组微卫星标记

利用磁珠富集高效微卫星分离法,设计生物素标记的寡核苷酸（AG）15与（AC）15作为探针,快速分离油茶微卫星序列并建立其SSR分子标记体系。从获得的52份具微卫星序列的克隆测序结果中,成功开发40对油茶SSR引物,序列开发引物成功率在76.9%;对扩增结果进行比较分析后,共得到14对具有清晰扩增条带的SSR引物,占总引物的35%;进一步利用18个油茶无性系开展引物多态性检测,显示6对SSR引物具良好的多态性。研究结果可为油茶遗传学研究提供新的分子标记工具,同时为山茶属其他重要经济树种的相关研究提供很好的借鉴。     

SSR标记技术在杨属植物研究中的应用

SSR标记具共显性和多态性等特点,是一种很有价值的分子标记,微卫星在林木基因组中广泛存在。本文综合国内外SSR标记在杨属植物研究中的应用,并探讨了该技术存在的问题及发展趋势。     

分子标记SRAP及其在林木研究中的应用

分子标记SRAP是近年来发展起来的新型分子标记系统, 具有简单、高效、稳定、部分共显性、扩增片段易测序等优点。它可检测基因的可读框(ORFs)区域, 揭示DNA序列的多态性。介绍了SRAP标记的基本原理与流程, 综述了该标记目前在遗传图谱构建、遗传多样性分析、QTL定位、基因组图谱比较、转录图谱绘制、基因克隆等方面的研究进展。尽管SRAP标记在林木研究中的应用刚刚开始, 但已显示出十分广阔的应用前景。     

新型分子标记SRAP及其在植物中的应用

相关序列扩增多态性(SRAP)是一项基于PCR技术的新型分子标记技术,由于它具有操作简便、结果稳定、高共显性、重复性、易于分离条带及测序等优点,被广泛地应用到植物的研究中。通过查阅大量文献,阐述了SRAP分子标记的设计原理与特点,以及SRAP标记技术在植物应用中的进展。     

分子标记及其在杨树研究中的应用

分子标记是以DNA分子多态性为基础的遗传标记,即在生物的基因组内或各染色体上提供基因的准确位置,为研究基因的结构、序列、功能及其遗传和变异规律提供基础资料。该文介绍了分子标记的种类、特征,及其在杨树种质资源和遗传研究的应用情况。     

杉木叶绿体微卫星及其单倍型变异分析

杉木是我国南方重要的用材林树种,但其分子标记开发滞后于其他树种。文章利用种（属、科）间扩增法,从来源于黑松、日本柳杉等的21个叶绿体微卫星（SSR）位点中为杉木筛选适合的标记。结果表明:候选标记位点中有10个能够成功扩增,其中2个位点（CJCP1m₀04和CJCP2m₀02）具有多态性,其单倍型数量（A）分别为2和6,多样性指数（H）为0.233和0.733。多态性位点的单倍型序列分析结果表明,源于日本柳杉的CJCP2m₀02在杉木中属高变异位点,其SSR重复单元类型为（AT）n··（T）n,不同于来源物种的重复单元类型（AT）n。筛选得到的叶绿体微卫星（SSR）标记在杉木分子遗传学研究中具有重要用途。     

马尾松生长和产脂性状在SSR和ESTP标记不同基因型间的变异研究

对广东省4个试验点内拥有共同母本的马尾松7个全同胞家系和1个自由授粉家系5 a生试验林进行了调查,采用微卫星（SSR）和表达序列标签多态性（ESTP）的分子标记对360个单株进行了检测,筛选得到有多态性的SSR标记4个,ESTP标记15个,位点共21个,其中ESTP标记est8704不同基因型间的产脂量有显著差异,可作为马尾松辅助产脂量选择的候选标记.     

SSR分子标记与林木遗传育种

阐述了一种新兴的基于PCR的微卫星分子标记技术在林木遗传育种中的应用情况及发展趋势.由于微卫星位点多态性高、共显性、中性突变及遍布于整个基因组,因此使之广泛应用于遗传连锁图谱的构建与QTL定位、亲缘关系分析、遗传结构分析、基因流监测、基因突变以及系统发生等领域.文中指出SSR标记可以为林木遗传改良、种质资源保存、濒危物种保护、基因定位及分子克隆等许多应用研究领域提供理论依据,它将是一种近乎理想的新一代的分子标记.     

中国东北林蛙（Rana dybowskii）遗传多样性与分化研究

本文利用11个微卫星多态位点检测东北林蛙(Rana dybowskii)的遗传多样性和种群遗传结构。6个东北林蛙种群的75个个体分布于中国的小兴安岭和长白山地区。11个位点在所有种群中得到的等位基因数为2～10个不等,平均5.6个;平均期望杂合度(HE)为0.572,属于中度多态。基因分化系数(FST)分析表明小兴安岭和长白山地区的种群间遗传分化显著(P<0.001),基于Nei's DA遗传距离构建的UPGMA系统树和AMOVA的结果进一步验证了结论的准确性。因此, 建议将分布于小兴安岭和长白山的东北林蛙划分为两个单独的管理单元加以保护和管理。图2表7参46。     

蓝桉树木园异型杂交及花粉污染的微卫星分子标记研究

本文应用4对微卫星分子多态引物,对利用优株嫁接建立的蓝桉(E.globulus)树木园中的118个自由授粉子代的DNA微卫星指纹进行了分析.结果表明:选用的引物具有高度多态性,各个位点扩增得到的平均等位基因数为14.25,树木园中母株的异型杂交率为15%(95%,整体异型杂交率为47.9%,外源花粉污染率为17.6%.由于该树木园的异型杂交率低,其自由授粉的种子应用价值不高,因此应采用大规模人工授粉来制种或选用树木园中异型杂交率高的母株采种.     

成都麻羊种群微卫星标记遗传多样性评估

作为优良的地方山羊品种,成都麻羊对我国山羊品种的改良和新品种培育起了重要作用.畜禽遗传资源本质上是基因资源,保护畜禽遗传资源就是保护基因的多样性.为了了解成都麻羊的遗传情况,通过微卫星标记技术,选用8对中高度多态微卫星标记进行成都麻羊圈养种群的遗传多样性评估,共检测到60个等位基因,平均等位基因和平均有效等位基因数分别...     

基于微卫星DNA标记分析刺槐叶瘿蚊遗传多样性指数与样本量的相关性

[目的]探讨基于微卫星标记分析刺槐叶瘿蚊遗传多样性指数与样本量的相关关系。[方法]设置了12个样本量梯度,选取11对微卫星引物分析了我国刺槐叶瘿蚊5个种群的遗传多样性指数。[结果]表明,样本量的大小与平均等位基因数(Na)呈显著正相关,与有效等位基因数(Ne)呈中度正相关,与观测杂合度(Ho)呈负相关,而与期望杂合度(He)、Nei’s遗传多样性指数(H)和多态信息含量(PIC)没有明显相关性。此外,当样本量小于25时,随着样本量的增加,有效等位基因数增幅明显,观测杂合度起伏变化较大,但当样本量大于30时,随着样本量的增加,上述两个指数增(降)幅度平缓。[结论]在利用微卫星DNA标记对我国刺槐叶瘿蚊种群的遗传多样性研究中,选取的最适样本量应为25～30,分析的最适遗传多样性指数应为期望杂合度、Nei’s遗传多样性指数和多态信息含量。该研究结果将为我们后续研究提供科学数据,并有助于分析其他入侵昆虫种群遗传结构的研究,同时可为其他双翅目昆虫的遗传多样性研究提供样本量参考。     

Genomewide identification and development of microsatellite markers for Marssonina brunnea and their applications in two populations

Marssonina brunnea is an important pathogen that causes Marssonina leaf spot disease of poplar (MLDP) in various poplar species. Resistance breeding is considered as the main method for preventing this disease and requires information on genetic diversity and population structure. However, molecular markers that may be utilized in the identification of this fungus are limited. This study investigated the distribution of microsatellites in the M. brunnea genome. A total of 15,356 microsatellite markers (excluding mononucleotide repeats) were isolated from 50.1 Mb of genomic sequence. Eight M. brunnea isolates were evaluated in terms of 102 loci, followed by the selection of markers that could be utilized in investigating the population structure of 47 M. brunnea isolates from two populations. Twenty‐four polymorphic microsatellite markers were developed for M. brunnea. The number of alleles per locus ranged from two to eight (average: 3.75). The polymorphism information content (PIC) of these loci ranged from 0.0408 to 0.6492. The average Shannon's information index of these loci in the two populations was 0.3819 and 0.5351, respectively. Using these markers, M. brunnea isolates were mainly divided into two distinct clusters based on the relatedness of the sampling sites. These results indicate that the selected markers could be effectively utilized in investigating the population genetic structure of M. brunnea. This is the first report on microsatellite markers in M. brunnea.     

Selection strategy for a seedling seed orchard design based on trait selection index and genomic analysis by molecular markers: a case study for Eucalyptus dunnii

Molecular genetic analysis was applied to 162 individuals of 37 half-sib selected families belonging to six provenances of Eucalyptus dunnii Maiden in a provenance/family trial. The individuals were selected by a trait selection index and genetic diversity criteria were later applied for designing seedling seed orchards. Genetic diversity and its distribution, as well as relationships among individuals, were assessed on the basis of nine microsatellite loci and 243 amplified fragment length polymorphism markers. High diversity was found with both kinds of markers. Clear-cut genomic patterns of identification (fingerprinting) were obtained for each individual. Genetic differentiation estimates consistently showed low differentiation among provenances (R(ST1) = 0.069, theta(P) = 0.026 and F(CT) = 0.035) and great differentiation among families (R(ST2) = 0.223, theta(S) = 0.174 and F(SC) = 0.164). A high proportion of the total variation was observed within families (around 80% by both marker analyses), suggesting that orchard design should be based on individual or family selection rather than on provenance selection, and that individual ranking by both trait selection index and molecular genetic diversity criteria should be considered. A selection procedure for a seedling seed orchard design is proposed.     

Contemporary climate influence on variability patterns of Anadenanthera colubrina var.cebil,a key species in seasonally dry tropical forests

The distribution of many plant species has been shaped by climate changes,and their current phenotypic and genetic variability reflect microclimatically suitable habi-tats.This study relates contemporary climate to variability patterns of phenotypic traits and molecular markers in the Argentinean distribution of Anadenanthera colubrina var.cebil,as well as to identify the most relevant phenotypic trait or molecular marker associated with those patterns.Individuals from four populations in both biogeographic provinces,Paranaense and Yungas,were investigated.Multivariate analyses and multiple linear regressions were carried out to determine relationships among phenotypic traits and nuclear microsatellites,respectively,to climatic variables,and to identify the phenotypic traits as well as nuclear microsatellite loci most sensitive to climate.Two and three clusters of individuals were detected based on genetic and phenotypic data,respectively.Only clusters based on genetic data reflected the biogeographic origin of individuals.Reproductive traits were the most relevant indi-cators of climatic effects.One microsatellite locus Ac41.1 appeared to be non-neutral presenting a strong correlation with climate variable temperature seasonality.Our findings show complex patterns of genetic and phenotypic variability in the Argentinean distribution of A.colubrina var.cebil related to the present or contemporary climate,and provides an example for an integrative approach to better understand climate impact on contemporary genetic and phenotypic variability in light of global climate change.     

欧洲黑杨育种基因资源SSR多态性比较研究

本研究利用13对SSR引物对120份(105份国外引进、15份我国新疆)欧洲黑杨基因资源进行了遗传多态性分析,共检测出171个等位基因,每个多态性位点检测到7～19个等位基因,平均为13.2,多态信息指数为0.396～0.909,平均为0.808;遗传距离为0～0.456 4.欧洲黑杨基因种源具有丰富的遗传多样性.通过UPGMA等类分析,将120份材料划分为8类,地理分布较近的材料基本聚在一起,表明遗传距离与地理距离相关性强.