枫香优良观赏种质的遗传多样性分析

利用ISSR标记技术对12份枫香观赏种质进行遗传多样性分析,通过正交实验优化枫香的ISSR-PCR扩增体系,即在20μL体系中加入PCR反应缓冲液2μL、镁离子1.5 mmol.L-1、Taq DNA聚合酶0.75 U、dNTP 0.15 mmol.L-1、引物0.4mmol.L-1、DNA模板80 ng。筛选出的19条ISSR引物共得到131条扩增带,其中多态性条带为94条,多态性条带比率为71.75%。12份种质的有效等位基因数是1.482,基因多样性0.3012,Shannon信息指数0.4674,表明遗传多样性水平相对较高。进一步的聚类将这些种质分成3类,其中4号样本和11号样本的遗传相似度最高。     

Estimating genetic relationships among historical sources of alfalfa germplasm and selected cultivars with sequence related amplified polymorphisms

Fifteen alfalfa populations consisting of six public cultivars and nine historically recognized sources of alfalfa germplasm in North American cultivars were examined using sequence related amplified polymorphisms (SRAPs). Three bulk DNA samples from each population were evaluated with fourteen different SRAP primer pairs. This resulted in 249 different amplicons, of which over 90% were polymorphic. A dendrogram from the analysis suggests that the public cultivars are quite diverse from all the historical sources of germplasm. The highest mean genetic similarity among the nine original sources of Medicago germplasm was 0.85 between PI 536535 (Peruvian) and 536536 (Indian), while the lowest (0.47) was between PI 560333 (M. falcata) and 536539 (African). The highest mean genetic similarity among the nine original sources of Medicago germplasm and the public alfalfa cultivars was 0.78 between PI 536532 (Ladak) and Vernal, while the lowest (0.59) was between PI 536539 (African) and Oneida. Relationships based on SRAP analysis appear to generally concur with expected relationships based on fall dormancy. This report demonstrates that SRAPs are a promising marker system for detecting polymorphisms in alfalfa.     

2014年-2016年广西地区猪繁殖与呼吸综合征病毒Nsp2和ORF5基因的遗传多样性分析

为了解广西地区猪繁殖与呼吸综合征病毒(PRRSV)流行毒株的遗传进化情况,对2014年-2016年来自广西各地的部分PRRSV阳性病料进行Nsp2和ORF5基因的扩增和测序分析.结果获得34个Nsp2基因序列和45个ORF5基因序列,均属于美洲型毒株.Nsp2基因间核苷酸序列的同源性为91.8％~100％,与PRRSV美洲型毒株VR-2332、CH-1a、JXA1及NADC30株核苷酸序列的同源性分别为81.3％~84.3％、88.9％~92.1％、94.3％~99.3％和73.5％~75.1％,而与PRRSV欧洲型毒株LV株核苷酸序列的同源性为51.5％~53.2％.ORF5基因间核苷酸序列的同源性为82.8％~100％,与PRRSV美洲型毒株VR-2332、CH-1a、JXA1及NADC30株核苷酸序列的同源性分别为83.7％~99.5％、85％~95％、83.8％~99.7％和83.2％~86.4％,而与PRRSV欧洲型毒株LV株核苷酸序列的同源性为62.4％~64.5％.基于Nsp2和ORF5基因推导的氨基酸序列绘制的遗传进化树中,广西地区的毒株主要分布在以JXA1为代表的Ⅳ亚群.表明当前广西PRRSV流行毒株以JXA1株为代表的高致病性美洲型毒株为主,各毒株Nsp2和ORF5基因序列存在一定的差异,尚未发现欧洲型毒株和美洲型NADC30类毒株.     

江苏省4个太湖新银鱼种群遗传多样性和遗传结构分析

太湖新银鱼(Neosalanx taihuensis)是我国特有的银鱼种类,主要分布在长江和淮河中下游及其附属湖泊,近年来其资源量呈明显下降趋势。为了解太湖新银鱼遗传背景,本研究采用线粒体细胞色素b (Cytochrome b, Cyt b)基因序列,分析了江苏省太湖、高邮湖、洪泽湖和骆马湖4个太湖新银鱼野生群体共144尾样本的遗传多样性及遗传结构。结果显示,太湖新银鱼Cyt b基因序列共发现29个变异位点,定义25个单倍型;平均单倍型多样性(Hd)为0.682±0.037,核苷酸多样性(π)为0.00231±0.00021;4个群体中,高邮湖群体的遗传多样性最高(Hd: 0.609±0.078; π: 0.00094± 0.00027),太湖群体的遗传多样性最低(Hd: 0.343±0.107; π: 0.00075±0.00033)。分子方差分析(AMOVA)显示,太湖新银鱼群体间遗传差异(71.53%)大于群体内遗传差异(28.47%),遗传变异主要来自于群体间。遗传分化指数Fst值统计检验表明,骆马湖群体与太湖、高邮湖和洪泽湖群体之间有显著性差异。分子系统树和单倍型网络进化图分析显示,25个单倍型形成2个明显的地理分支,一支由太湖群体、高邮湖群体和洪泽湖群体组成,另一支由骆马湖群体组成。中性检验和错配分布图分析表明,太湖新银鱼历史上发生过群体扩张。整体来看,太湖新银鱼野生种群遗传多样性较低,应加强种质资源保护。建议将太湖、高邮湖群体和洪泽湖群体作为整体进行管理和保护,骆马湖群体单独管理和保护。     

Genetic diversity of livestock-associated MRSA isolates obtained from piglets from farrowing until slaughter age on four farrow-to-finish farms

During a previous longitudinal study, performed on four farrow-to-finish farms (A to D), samples were taken from twelve sows, their offspring, and the environment on various occasions over six months to study the MRSA presence. During the present study, a selection of the obtained MRSA isolates were typed by multiple-locus variable-number tandem-repeat analysis (MLVA), Pulsed Field Gel Electrophoresis (PFGE), spa typing, and SCCmec typing to study the genetic diversity of LA-MRSA isolates and to determine possible MRSA sources for pig(let)s. PFGE, spa typing, and SCCmec typing revealed the presence of one or few dominant genotype(s) per farm. In contrast, 212 MLVA types were detected on the four farms, forming one cluster on farm A, three on farm B, four on farm C and two on farm D. The genotype, found on farm A was unique for this farm. Farms B, C and D shared one cluster. In general, MLVA types from these clusters were isolated from piglets, sows, and the environment on various sampling events. Piglets carried MLVA types both related and unrelated to their mother sows’ MLVA types at farrowing and onwards. In conclusion, molecular typing revealed that within a farm one or a few dominant strain(s) are widespread. Potential MRSA sources for piglets were mother sows, the environment and other piglets.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-014-0089-4) contains supplementary material, which is available to authorized users.     

广东南岭自然保护区翼手类物种资源调查

2009年9月,对南岭自然保护区翼手类物种多样性进行了调查。采集蝙蝠标本9种36号,其中西南鼠耳蝠和中管鼻蝠为广东省蝙蝠新纪录。结合以往调查资料,得出该保护区共有翼手类25种,隶属5科12属,其物种多样性十分丰富。     

马鹿的起源进化与遗传多样性研究进展

马鹿是非常重要的物种资源,由于栖息地的流失和人为干扰进行近亲繁殖等导致野生马鹿数量急剧减少,而家养马鹿多经过改良,因此马鹿的纯种数量锐减。对马鹿进行分子遗传学研究不仅可以加深人们对马鹿起源和物种形成的认识,还能帮助开展遗传多样性保护研究。随着高通量测序技术、分子生物学和生物信息学的迅速发展,马鹿的起源进化研究已发展到全基因组水平,并取得了一定的成果。马鹿的起源进化研究从最初对体态外貌和染色体核型的研究逐渐发展到对DNA序列与生理指标的研究。文章回顾了近年来国内外对马鹿起源进化和遗传多样性方面的研究,从起源时间、起源地和迁徙路线等方面揭示了马鹿的演化历史,介绍了父系、母系和常染色体研究方面分析了马鹿遗传多样性选取的不同分子标记,为进一步揭示马鹿种群的遗传变异、分化情况、迁徙路线和系统发育关系等提供基础信息,同时为马鹿遗传资源的利用和保护以及马鹿产业的良性发展提供重要的借鉴与参考。     

不结球白菜形态性状及SSR遗传多样性关联分析

分析不结球白菜遗传多样性,筛选与形态性状相关联且具有多态性的标记位点,为不结球白菜的分子辅助育种选择、种质资源的利用和新品种选育提供依据.本研究以类型差异大、有南方特色的54份种质资源为材料,对其6个质量性状和5个数量性状进行3次田间调查,从40对引物中筛选出25对SSR引物进行遗传多样性分析,结合形态性状对54份不结...     

普通豇豆应用核心种质的SSR指纹图谱构建及多样性分析

不同种质资源群体的多样性及遗传背景分析可为种质资源收集保存及创新利用提供有效信息。对不同来源的88份普通豇豆应用核心种质资源进行了14个SSR位点的指纹图谱构建及多样性分析,共检测到39个等位变异,每对引物检测到2~5个,平均为2.79。多态信息含量（PIC）变幅为0.25~0.72,平均为0.58。UPGMA聚类结果显示,除了3对种质外,39个等位变异可将其他材料有效区分,且在遗传相似系数为0.63时,88份种质可分为4个类群,地理来源相同的材料有聚在一起的趋势。     

芜湖市公园绿地植物群落基本类型及其物种多样性研究

公园是城市园林绿地系统的主体,也是植物群落及其物种多样性最丰富的地方,研究公园植物多样性可为城市生物多样性保护提供基础数据。根据对芜湖市6个公园绿地的调查,分析和总结了芜湖市公园绿地植物群落组成和基本类型,论述了公园绿地物种多样性特征,并对芜湖市的园林绿化提出了一些可行性建议。