美国白蛾种群的遗传多样性与遗传分化

采用微卫星技术对入侵中国的5个美国白蛾种群进行遗传多样性和遗传分化及影响因素的研究.用10对微卫星引物对300个样品DNA进行PCR扩增,并进行聚丙烯酰胺凝胶电泳分析.5个美国白蛾种群的多态位点百分率P=98.36%;多态位点百分率的大小顺序为:沧州种群、烟台种群、秦皇岛种群、丹东种群、石家庄种群;美国白蛾整个群体的遗传分化:34.38%的变异存在于种群间,65.62%的变异存在于种群内,遗传距离变化范围为0.138 6～0.322 4.用UPGMA法对Nei's遗传距离作聚类分析的结果表明:种群的分化程度与分化时间和入侵来源密切相关.影响美国白蛾种群遗传多样性与遗传分化的主要因素是经度、平原比率、年降水量、纬度、入侵时间.美国白蛾种群现有遗传结构的形成与其生活史特性及入侵生态学特性有关.     

分子标记技术及其在林木遗传改良研究中的应用

分子标记是继形态标记、细胞标记和生化标记之后发展起来的一种新的较为理想的遗传标记形式,近年来发展非常迅速.本文对DNA限制性片段长度多态性(RFLP)及随机扩增多态性DNA(RAPD)遗传标记技术的基本原理与特点进行了简要介绍.全面阐述了DNA分子标记技术在林木遗传连锁图谱构建、林木遗传资源研究、数量性状位点定位与分子标记辅助育种、目的基因追踪等研究方面的应用及前景.     

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为7.5、2.36,平均观察杂合度、平均期望杂合度和平均多态信息含量分别为0.577、0.634和0.580。研究结果表明成都麻羊种群遗传多样性较高,具有较高的保种潜力。     

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。     

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.     

黄心夜合的遗传多样性研究

运用随机扩增多态DNA（RAPD）技术,对黄心夜合[Michelia martinii（Levl.）Levl.]自然分布区的6个自然种群遗传多样性进行了研究。从100个随机引物中筛选出能产生清晰、稳定的多态性标记引物18个,共检测出110个位点,其中多态性位点为96个,占87.27%;在物种水平上,有效等位基因数目（Ne）,Nei’s基因多样性系数（He）和Shannon表型多样性指数（I）分别为1.735 2,0.416 3和0.597 1;总的遗传变异量（Ht）为0.339 8,其中居群内遗传变异量（Hs）为0.258 7,各居群间的遗传分化系数（Gst）达到0.323 1.应用UPGMA法对遗传距离进行聚类分析并构建树系图,结果表明：黄心夜合自然种群具有较高的遗传多样性,其种群间的遗传差异与其地理分布有关。     

云南特有濒危植物馨香木兰的遗传多样性研究

为研究云南特有濒危植物馨香木兰的遗传多样性水平,采用随机扩增多态DNA技术（ RAPD）,对云南省馨香木兰4个居群,即文山州广南县、西畴县新街、西畴县亚坪等3个天然居群及昆明树木园1个人工居群,进行遗传多样性分析。随机筛选出重复性好的8条随机引物,对70个样品的基因组DNA进行扩增,建立RAPD分析图谱。扩增结果为,共检测出84个多态位点。遗传多态位点百分率为61.90％（文山广南）、76.19％（西畴新街）、71.43％（昆明树木园）和66.67％（西畴亚坪）。遗传多样性Shannon指数为0.5686,其中30.55％来自种群间,69.45％来自种群内; Nei’s指数为0.3903,种群间的遗传分化系数（GST）为0.2216。文山广南和西畴亚坪之间的遗传距离最大,昆明树木园与西畴亚坪之间的遗传距离最小。结果显示,与木兰科等其他濒危植物相比较,馨香木兰遗传多样性相对较高。根据各种群遗传背景研究结果,提出了该物种迁地保护种群遗传资源管理建议。     

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).     

舞毒蛾不同地理种群基于AFLP分子标记的遗传分析

舞毒蛾是一种食性很广、危害很大的世界性林木害虫,根据其地理分布和生活特性,现在被分为亚洲型和欧洲型2种。对来自俄罗斯远东地区、蒙古、日本、美国和中国5个地理种群,共26份舞毒蛾样品进行AFLP分子标记研究。成功建立并优化舞毒蛾AFLP分析体系,从16对引物组合中筛选出3对扩增条带多、多态检出率高的荧光标记引物组合,利用CEQ-8000遗传分析仪进行毛细管电泳及数据分析,共检测到507个多态性位点。通过PAUP软件对AFLP数据进行UPGM和NJ树的聚类分析以及遗传距离分析,结果表明:5个地理种群舞毒蛾明显分成欧洲型(美国种群)和亚洲型,其中亚洲型又可分成俄罗斯、日本、中国及蒙古3个类群。美国种群间遗传变异比其他种群较大,中国种群与美国种群遗传距离最大,而与蒙古种群遗传分化最小。从分子水平上研究舞毒蛾不同种群的遗传分类情况,揭示利用AFLP分子标记技术可以区分舞毒蛾不同地理种群的基因型,为研究舞毒蛾的起源、入侵与扩散、遗传与变异以及检疫措施的制定等方面提供科学依据。     

白桦种群间木材纤维性状的表型变异与分子标记的遗传多态性

以东北地区的5个白桦天然种群为研究材料,在木材纤维形态性状测定的基础上,采用ISSR、RAPD分子标记研究了5个种群的遗传变异以及种群间纤维形态性状与DNA分子标记的相关性.结果表明:白桦天然林成熟材(18～31年生)的木材纤维长度在种群间差异不显著,纤维宽度和长宽比差异显著,帽儿山种群的木材纤维形态性状最好,汪清最差;利用ISSR和RAPD 2种标记检测5个白桦种群的遗传多样性,所得的研究结果基本一致,多态位点比率最高的为辽宁新宾种群,其次是帽儿山和汪清,而塔河和金山屯最低;ISSR标记的AMOVA分析表明白桦种群间的遗传变异占总遗传变异的10.82%;RAPD标记的AMOVA分析表明白桦种群间的遗传变异占总遗传变异的12.94%,研究结果均显示白桦的遗传变异主要发生在种群内部.利用2种标记技术的种群聚类结果基本一致,这一结果与基于木材纤维性状的表型聚类基本一致, 而且种群间遗传距离和地理距离之间存在一定的相关性.     

Genetic diversity and differentiation of fall webworm (Hyphantria cunea Drury) populations

The molecular variation and genetic relationships among five populations of the fall webworm (Hyphantria cunea Drury) in China were assessed using microsatellite technology. Ten microsatellite primers, producing polymorphic bands, were used across 300 samples. The percentage of polymorphic loci (PPB) was 98.36%; the percentage of polymorphic loci in five populations ranged from high to low in the following order: Cangzhou population, Yantai population, Qinhuangdao population, Dandong population, and Shijiazhuang population. The results showed that 34.38% of the total genetic variation of the fall webworm (GST) occurs among populations, while most variation (65.62%) exists within populations. Nei’s genetic distances ranged from 0.1386 to 0.3224. Using the unweighted pair group method with arithmetic mean (UPGMA), Nei’s genetic distances were analyzed by a clustering technique and the dendrogram shows that population differentiation is closely related to the time and geographic origin of the invasion. The major factors impacting genetic diversity of fall webworm populations are longitude, the plain area ratio, annual precipitation, latitude and time of invasion. The formation of genetic structure is correlated with characteristics of the life history and invasion ecology of the species.     

Risks involved in fecal DNA-based genotyping of microsatellite loci in the Amur tiger Panthera tigris altaica: a pilot study

In modern wildlife ecological research,feces is the most common non-invasive source of DNA obtained in the field and polymerase chain reaction(PCR) technology based on microsatellite markers is used to mine genetic information contained within.This is especially the case for endangered species.However,there are risks associated with this genotyping method because of the poor quality of fecal DNA.In this study,we assessed genotyping risk across 12 microsatellite loci commonly used in previous tiger studies using blood and fecal DNA from captive Amur tigers(Panthera tigris altaica).To begin,we developed an index termed the accumulated matching rate of genotypes(R_m)between positive DNA(blood samples) and fecal DNA to explore the correct genotyping probability of a certain microsatellite locus.We found that different microsatelliteloci had different genotyping risks and required different PCR amplification protocols.The genotyping errors we detected altered population genetic parameters and potentially impact subsequent analyses.Based on these findings,we recommend that:(1) four loci(E7,Fca094,Pti007 and Pti010) of 12 loci are not suitable for Amur tiger genetic research because of a low R_mand difficulty reaching a stable status;(2) the R_mof the 12 microsatellite loci plateaued differently,and considering limited budgets,amplification times of some loci could be increased when using fecal samples; and(3) future genetic analysis of wild Amur tigers should be corrected by genotyping error rates(1-R_m).     

Selection of a seed orchard of Eucalyptus dunnii based on genetic diversity criteria calculated using molecular markers

A Eucalyptus dunnii Maiden breeding population of 46 accessions originated in Australia and selected for fitness to subtropical and cold environments was screened by Amplified Fragment Length Polymorphism (AFLP) and microsatellite markers to obtain quantitative estimates of genetic diversity. A randomly chosen group of AFLP primers generated 205 AFLP bands that were used to fingerprint the genotypes and to evaluate genetic relationships among accessions. Sixty-eight percent (140) of the bands were polymorphic markers. The mean diversity index (DI) was 0.33 and about 52% of the loci had values greater than 0.4. Cluster analysis derived from similarity indices (SI) revealed no particular grouping among accessions suggesting the absence of closely related genotypes, except for five pairs of genotypes. Bootstrap analysis results confirmed the suitability of AFLP to describe genetic relationships in this breeding population. In addition, four highly informative microsatellites were used to construct an identification matrix that discriminated nearly all of the genotypes. Mean values for the number of alleles per locus, DI and SI among accessions were 13, 0.78 and 0.19, respectively, indicating that the breeding population has high genetic diversity. However, several genotypes showed the presence of single microsatellite bands suggesting a putatively important degree of homozygosity. Molecular data were used to design a clonal seed orchard. To achieve this aim, the nine most divergent pairs of genotypes were chosen, thereby retaining 95.2% of the total number of alleles from the 140 polymorphic AFLP loci and the four microsatellite loci analyzed. Mean DI and SI for AFLP and microsatellites showed no significant differences between the original breeding population and the selected seed orchard, confirming that a seed orchard can be designed with a limited number of individuals, which allows similar accessions to be discarded and avoids inbreeding.     

Genetic diversity and differentiation of fall webworm (Hyphantria cunea Drury) populations

The molecular variation and genetic relationships among five populations of the fall webworm (Hyphantria cunea Drury) in China were assessed using microsatellite technology. Ten microsatellite primers, producing polymorphic bands, were used across 300 samples. The percentage of polymorphic loci (PPB) was 98.36%; the percentage of polymorphic loci in five populations ranged from high to low in the following order: Cangzhou population, Yantai population, Qinhuangdao population, Dandong population, and Shijiaz...     

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。     

我国圈养麋鹿种群发展面临的挑战及保护管理对策

目前麋鹿在迁地保护方面取得了很大成功,已在湖北石首麋鹿国家级保护区等全国50多处麋鹿饲养场所拥有圈养种群.但其种群的发展尚面临着许多挑战,如受到遗传多样性较低、目标种群数量过小、人类干扰、疾病风险、生存条件的局限、管理方式较传统等制约因素的影响,为此,提出加强种群的遗传多样性管理、强化栖息地保护管理、制定种群数量调控政策、加强安全监测、建立科学监测体系及网络、完善保护管理体系等圈养麋鹿种群的保护管理对策.     

珍稀动物麋鹿的保护研究概述

麋鹿属于国家一级保护动物,国内外学者在麋鹿种群健康繁衍和保护事业方面进行了大量的研究工作.文中介绍了麋鹿的生物学特征、种群、行为学、生境学、遗传多样性、药用价值及国外研究现状,提出国内需在分子细胞生物学层次上开展麋鹿的相关研究工作,以促进麋鹿种群的保护和健康繁衍.     

Seeding Herbs to Enhance Cervid Forage and Reforestation in Pacific Northwest Conifer Forests

Forage seeding, seeding grasses and legumes in conifer plantations, has been touted as a method of simultaneously improving elk (Cervus elaphus) and black-tailed deer (Odocoileus hemionus columbianus) nutrition and forest regeneration. When suited to local physiographical and biological conditions forage seeding may (1) increase the nutritional quality and biomass of forage preferred by cervids and (2) reduce the establishment of seral vegetation that competes with conifer seedlings. The effectiveness of forage seeding in reducing conifer browsing by cervids remains questionable. In the past, forage seeding programs have been implemented over wide geographic areas far beyond experimental study sites; many of these have had limited success. In addition, the effects of forage seeding on cervid biology and reforestation have not been rigorously tested. Thus, if forage seeding programs are implemented, it should be done so cautiously with the expectation that the outcome may differ markedly from prior experimental results. We outline criteria for selecting sites for forage seeding programs and prescribe methods for optimizing the seeding of forages. We offer guidelines for designing large-scale forage seeding research to infer treatment differences to a representative population of clearcuts with a specific set of clearly defined site conditions and management objectives. For situations where such large-scale experimentation is prohibitive, we outline research questions we believe are both important and can be answered in small-plot studies.     

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.