Chelex100法提取甘薯小象甲DNA及云南地区甘薯小象甲的分子鉴定

甘薯小象甲是国内外重要的检疫性害虫,除本身为害薯块外,引起的伤口还会诱致病菌侵入,使受害薯块发生恶臭和苦味无法食用。准确鉴定云南地区的甘薯小象甲,特别是研究其遗传变异可为检疫提供依据。本研究采集了云南元谋县甘薯小象甲,采用Chelex-100法快速提取甘薯小象甲基因组DNA,分别对雌雄成虫rDNA ITS-1序列进行系统发育分析,首次发现云南元谋县的甘薯小象甲属于东亚分支的东南亚亚支,与我国之前报道的甘薯小象甲属于东亚分支的东北亚亚支不同,说明云南元谋县的甘薯小象甲种群来源与中国广东、福建、浙江和重庆的种群来源不同。     

鲤多拷贝基因Apo-14kDa和ApoE的系统学分析和其在胚胎发育中的功能探索

本研究首次从鲤(Cyprinus carpio)中得到2种形式的14 kD载脂蛋白(Apo-14kD)和4种形式的载脂蛋白E(ApoE),分别为Apo-14kDa-a和Apo-14kDa-b(同源性为79%)、ApoE-a1和ApoE-a2(同源性为91%)以及ApoE-b1和ApoE-b2(同源性为90%)。系统学分析表明,Apo-14kDa-a与多数硬骨鱼的Apo-14kDa同源性高于与Apo-14kDa-b的同源性,而Apo-14kDa-b与草鱼(Ctenopharyngodon idellus)的Apo-14kDa同源性较高,提示二者在鲤科鱼类中的分化时间较早;ApoE-a和ApoE-b的分化时间也应该处于鲤科鱼类分化的早期阶段,随后进一步分化出4个同源基因。半定量RT-PCR结果显示Apo-14kDa-a基因在肝、头肾中大量表达,肠中微弱表达,其他组织无表达,Apo-14kDa-b基因只在肝表达;ApoE-a1基因和ApoE-a2基因只在肠表达;而ApoE-b1基因和ApoE-b2基因均在脑、皮肤、鳃、肝、精巢、肠、心脏、肌肉、体肾、头肾中表达,但在脾和卵巢发生表达分化。进一步的qRT-PCR检测发现6个基因在不同胚胎发育时期的表达模式也有较大不同,且在不同时期的表达均存在阶段差异性。另外,qRT-PCR分析证实Apo-14kDa基因和ApoE基因均有可能在鲤胚胎发育过程中发挥着重要且显著不同的作用。     

禾本科植物叶绿体基因组结构的系统进化研究

为了探讨叶绿体基因组结构变化与系统发生的关系,以烟草为参照,系统比较了禾本科植物叶绿体基因组结构的进化。结果发现：（1）大单拷贝序列上产生3个倒置;（2）3个基因accD、ycf1、ycf2退化;（3）clpP、rpoC1内含子序列丢失;（4）IR与SC的边界变化大都发生于科的水平,但也存在一定的层次性。结构变化的系统发生与叶绿体基因内含子构建的系统进化树相一致。叶绿体基因组的结构变化可以用于构建相关植物的系统发生。     

基于线粒体COI基因序列的挂墩稻弄蝶分类地位研究

对稻弄蝶属Parnara4种20个样本的线粒体COI基因序列(1380 bp)的特征、遗传距离进行了分析,并以2种谷弄蝶Pelopidas为外群,采用最大简约法(MP)和贝叶斯法(BI)构建系统树.结果表明:种间最小序列差异为3.3%,种内个体间最大序列差异为0.9%;系统树显示挂墩稻弄蝶Parnara batta与直纹稻弄蝶Parnara guttata是2个明显不同的分支;其种间的平均遗传距离为3.5%.综合地理分布与形态差异,挂墩稻弄蝶应该是一个独立的种.     

Seed proteins of the wild and the cultivated Amaranthus species

The 13–21% variation in seed protein content was observed in wild and cultivated forms of amaranth. Seed proteins of amaranth are highly nutritive and composed presumably of easily digestable albumins and globulins (over 50% of total protein); of 20.8% alkali-soluble proteins-glutelins with similar nutritive value and only of 12% alcohol-soluble proteins-prolamins which are lacking in essential amino acids. The results of polyacrylamide gel electrophoresis (buffer pH being 3.2) indicate that seed proteins of amaranth are heterogeneous and compose of 38 bands which, by their electrophoretic mobility, can be tentatively assigned to four zones: A, B, C and D. By their protein patterns all Amaranthus species were assigned to 7 biotypes. The cytogenetic and electrophoretic comparison enabled us to determine the degree of diversity among amaranth forms studied. The phylogenetic relationship between A. paniculatus L. and A. hybridus L. was confirmed. A relationship was also supposed between these two species and A. lividus L. and between A. powellis L. and A. deflexus L. which by their electrophoretic patterns belong to the same biotype. A taxonomic classification of 5 samples whose classification has not been done yet was performed, as well as of cultivars Elbrus and Progress which were assigned to specious A. edulis L. It was confirmed that the method of electrophoretic analysis of seed storage proteins is very promising for detecting the phylogenetic relationship between Amaranthus species. This revised version was published online in July 2006 with corrections to the Cover Date.     

Impact of variation in length of individual testing periods on estimation of (co)variance components of a random regression model for feed intake of growing pigs

A simulation study was conducted to assess the influence of differences in the length of individual testing periods on estimates of (co)variance components of a random regression model for daily feed intake of growing pigs performance tested between 30 and 100 kg live weight. A quadratic polynomial in days on test with fixed regressions for sex, random regressions for additive genetic and permanent environmental effects and a constant residual variance was used for a bivariate simulation of feed intake and daily gain. (Co)variance components were estimated for feed intake only by means of a Bayesian analysis using Gibbs sampling and restricted maximum likelihood (REML). A single trait random regression model analogous to the one used for data simulation was used to analyse two versions of the data: full data sets with 18 weekly means of feed intake per animal and reduced data sets with the individual length of testing periods determined when tested animals reached 100 kg live weight. Only one significant difference between estimates from full and reduced data (REML estimate of genetic covariance between linear and quadratic regression parameters) and two significant differences from expected values (Gibbs estimates of permanent environmental variance of quadratic regression parameters) occurred. These differences are believed to be negligible, as the number lies within the expected range of type I error when testing at the 5% level. The course of test day variances calculated from estimates of additive genetic and permanent environmental covariance matrices also supports the conclusion that no bias in estimates of (co)variance components occurs due to the individual length of testing periods of performance‐tested growing pigs. A lower number of records per tested animal only results in more variation among estimates of (co)variance components from reduced compared with full data sets. Compared with the full data, the effective sample size of Gibbs samples from the reduced data decreased to 18% for residual variance and increased up to five times for other (co)variances. The data structure seems to influence the mixing of Gibbs chains.     

海南桑树青枯病病原菌鉴定及其分子鉴定

桑树青枯病是由青枯雷尔氏菌引起的细菌性病害,热带、亚热带地区发病严重,严重影响蚕桑产业的可持续发展。雷尔氏菌不同种间致病力和宿主各不相同,其防治策略也相应不同,准确地分离鉴定病原菌是青枯病有效防控的先决条件。本研究采集、分离了海南省琼中县桑青枯病发病桑园（‘桂桑优62’）桑树根部、茎部病原菌,并通过致病性、生理小种、生化变种测定,结合16S rDNA、特异性引物、复合PCR检测体系、序列变种等分子鉴定方法初步确定了病原菌的种类和分类地位。结果表明,引发海南省琼中县桑青枯病的病原菌属于青枯雷尔氏菌（Ralstonia solanacearum）、生理小种5（race 5）、生化变种Ⅴ（biovar Ⅴ）,病原菌遗传进化分析结果显示病原菌属演化型Ⅰ（phylotype Ⅰ）即亚洲分支菌株,序列变种12（sequevar 12）。这些结果将为海南桑青枯病的有效防控奠定基础。     

茶藨生柱锈菌(Cronartium ribicola)研究进展

由茶藨生柱锈菌引起的红松疱锈病和华山松疱锈病,严重危害着红松、华山松等树种,为此,对茶藨生柱锈菌的分类地位、转主寄主以及遗传关系、防治措施等方面进行介绍,以期为有效防治该病菌提供理论依据,同时,为进一步深入研究该病菌指明方向。     

荞麦不同种间BW10KD过敏蛋白基因序列比较

荞麦过敏蛋白(BW10KD)与变应原病人的血清免疫球蛋白(immunoglobulin E,IgE)有强烈反应.通过对属于8个养麦种和1个变种的58个收集系中的BW10KD过敏蛋白基因保守片段进行差异分析与系统进化关系研究,为探讨BW10KD基因的结构功能及其在不同种间的进化奠定了基础,并为发生在物种基因DNA水平的微尺度的变异与进化研究中提供新的分析方法.用设计的特异引物进行扩增,所得序列与已报道过敏蛋白编码基因序列相似性达99％.各收集系间进行序列比对,得到307个排列位点(不含缺失位点),其中单型不变位点150个,多态位点S为157个(含简约信息位点数101个和单型可变位点56个).整个序列突变位点Eta为201个.选择特定分类群内变异小、分类群间变异大的19个位点进行系统聚类分析得到清晰的种系关系图.金荞、细柄野荞、硬枝万年荞聚在一起,暗示其具有较保守的BW10KD过敏蛋白基因序列;栽培甜荞与野甜荞亲缘关系近,其次与左贡野荞较近缘;毛野荞与大野荞彼此较近缘;栽培苦荞与野苦荞亲缘关系最近,与毛野荞和大野荞亲缘关系次之.     

基于线粒体基因的新疆三种野兔分类及遗传多样性

旨在利用分子遗传学方法探讨新疆3种野兔的系统发育关系和遗传多样性,以期明确其亲缘关系和分类地位,并评估其遗传多样性水平,为后续新疆野兔乃至中国野兔的保护遗传学等研究提供基础数据。本研究选用线粒体DNA的COI、ND4、16S rRNA 3个基因为分子标记,通过PCR扩增及测序技术分别测定采自新疆8个地区、4个地理组群共计57例野兔组织样本的3个基因序列,将序列校正拼接后用MEGA 7、DNAsp 6、Arlequin 3.1、MrBayes 3.2等软件进行数据分析。结果表明,将57例野兔样本的3个基因序列合并后共检测到43种单倍型,系统发育和中介网络图将相同及相邻地区的野兔划分为5个支系（Clade A-E）3大枝,且3大枝之间的遗传距离（4.21%~9.09%）均达到种间距离水平;其中,第3大枝中来自中部地区的野兔（Clade D）和新疆北部野兔（Clade E）的亲缘关系较近,二者之间的遗传距离≤2.26%,未达到种间遗传距离水平。新疆3种野兔中塔里木兔、藏兔帕米尔亚种和托氏兔西域亚种的单倍型多样性（h）较高,分别为0.979±0.014、0.972±0.064和0.972±0.064,而托氏兔西域亚种和中亚亚种的核苷酸多样性（π）较高,分别为0.033±0.018和0.023±0.015。基于线粒体3个基因的综合分析结果,结合已报道文献,本研究认为来自新疆西南部帕米尔高原的野兔应属于藏兔帕米尔亚种,支持将来自新疆北部阿勒泰及中部达坂城和托克逊地区的野兔分别划分为托氏兔西域亚种和托氏兔中亚亚种。新疆3种野兔具有丰富的遗传多样性和较明显的系统地理分布格局。