天敌对烟粉虱捕食作用的SCAR标记检测

 以烟粉虱和捕食性天敌为研究对象，采用特征序列扩增区域（SCAR）标记法，通过对目的片段的克隆与测序设计烟粉虱特征片段扩增引物，检验该引物的种、虫态及性别特异性，并利用该引物检测捕食性天敌对棉田烟粉虱的捕食作用。研究结果表明，利用SCAR标记法获得了长度为347 bp的烟粉虱特异性片段（GenBank登录号为AY841800），根据此片段的碱基序列设计烟粉虱特异引物1对TB-F/TB-R 94585, 其扩增片段约为240 bp；种特异性检验结果表明，该引物只对烟粉虱具有扩增能力，对温室粉虱及其它相关种类不具有扩增效果；同时该引物对不同虫态、不同性别的烟粉虱具有同样的扩增效应。田间检测结果表明，同种天敌昆虫幼体捕食作用检出率高于成虫；在所检测的4类群9种捕食性天敌中，龟纹瓢虫幼虫、异色瓢虫幼虫、草蛉幼虫及东亚小花蝽成虫和蜘蛛对烟粉虱捕食作用的检出率高于50%。     

Effect of Daidzein on Ileum Microlfora Biodiversity in Hy-Line Variety Brown Layers

Daidzein is always added into poultry feed to make the production performance and immunity of poultry better. In this study, a total of 600 40-week-old Hy-Line variety brown layers were randomized into...     

亚洲百合DNA的提取及RAPD-PCR反应体系的优化

为了促进亚洲百合分子水平的研究,以亚洲百合幼嫩叶片为材料,采用改良CTAB法提取亚洲百合基因组DNA,得到的DNA质量较高,适合于RAPD-PCR分析。通过单因素优化得到在25μl反应体系中,亚洲百合RAPD分析的最佳反应体系:160μmol/LdNTPs,0.3μmol/L随机引物,TaqDNA聚合酶1.5U,Mg2 浓度2.0mmol/L。     

萝卜基因组DNA RAPD与ISSR-PCR反应体系优化

对影响PCR反应的主要因子———模板DNA、引物、dNTPs和Mg2 浓度进行优化,建立起适合于萝卜基因组DNA的RAPD和ISSR反应体系。RAPD反应体系(18μl)为随机引物0.4~0.6μmol/L,dNTPs0.15~0.2mmol/L,Mg2 2.0mmol/L,模板DNA10~40ng,TaqDNA聚合酶0.8U;ISSR反应体系(16μl)为引物0.5μmol/L,dNTPs0.16mmol/L,Mg2 2.5mmol/L,模板DNA10~40ng,TaqDNA聚合酶0.64U。对扩增程序中复性温度进行了梯度PCR试验,表明35~42℃(37℃)与52.4~58.3℃(55℃)分别适于萝卜基因组DNA的RAPD-PCR和ISSR-PCR反应;应用优化的RAPD和IS-SR反应体系对17个萝卜品种进行了鉴定分析。研究结果将为萝卜分子育种、品种鉴定与种子纯度检测提供重要的技术基础。     

Two major evolutionary lineages revealed by molecular phylogeny in the parthenogenetic collembola species Folsomia candida

In order to measure the genetic variability and determine the evolutionary relationships among strains of the parthenogenetic “standard” springtail Folsomia candida, we used Random Amplified Polymorphic DNA (RAPD-PCR) markers and determined the nucleotide sequence of the 18S and 28S rDNA genes. Both types of molecular characters were found to be polymorphic. We obtained phylogenetic trees using Direct Optimization in the dynamic homology paradigm. The trees were polarized with Isotoma viridis as an outgroup. All the trees based on one or the other type of molecular characters or based on all characters pooled together, support the hypothesis of an early divergence of two distinct lineages among the 11 strains of F. candida under study. Our results also suggest that these lineages differ in their rate of evolution and mode of diversification. The geographical origin of the studied strains was examined but we found no clear relation between the phylogenetic relationships and probable geographical origins. The early divergence of several lineages in this species should be taken into account when comparing studies on genetically different strains of this model organism. RAPD-PCR typing is an easy and efficient tool for doing such a task.     

Genetic diversity among Northwestern Argentinian cultivars of common bean (Phaseolus vulgaris L.) as revealed by RAPD markers

The genetic diversity of 10 commercial cultivars of common beans, developed in Northern Argentina was analyzed based on RAPD markers. Sixteen primers were assayed and among them only 4 showed polymorphisms. A similarity matrix was generated by applying three different association coefficients, Simple Matching, Jaccard and Dice. By the UPGMA method dendrograms were generated and also the principal coordinate analysis was performed. The similarity values found were higher than 40% suggesting that genetic diversity is low. Both cluster analysis and principal coordinates analysis associated commercial cultivars either to the Andean or the Mesoamerican gene pool.     

Genetic variation detected with random amplified polymorphicDNA markers among isolates of the red rot disease fungus Pythiumporphyrae isolated from Porphyra yezoensis from Koreaand Japan

ABSTRACT:   Genetic variation of the fungal parasite Pythium porphyrae ,causative organism of red rot disease of Porphyra , isolatedfrom Asan, Mokpo, Pusan and Wando in Korea, and from Aichi, Fukuokaand Miyagi in Japan was investigated by random amplified polymorphicDNA (RAPD) cluster analysis. The total 67 RAPD markers were generatedfrom 38 isolates by RAPD-polymerase chain reaction (PCR) using arbitraryprimers consisting of 10 nucleotide sequences and 33 of them indicatedpolymorphisms. The dissimilarity coefficients calculated from theRAPD banding patterns ranged from 0.0010 to 0.6983. The dendrogramgenerated by the unweighted pair-group method using arithmetic averagesshowed that the 38 isolates were classified into three clusters(Groups 1, 2 and 3). Group 1 consisting of two isolates from Miyagiwas separated from all other isolates by a genetic distance of 0.6983.Groups 2 and 3 containing the majority of the isolates were branchedon genetic distance of 0.3957. These two clusters subdivided intofour and three subclusters, respectively, which were apparentlyassociated with geographic origins of the isolates. Interestingly,the isolates from Asan of Korea were close to Japanese isolatesrather than Korean isolates on genetic diversity. In addition, thegenetic distances of intra-isolates from Japan were higher thanthose from Korea.     

八角基因组DNA的提取方法

采用4种植物基因组DNA提取方法(CTAB法、SDS法、高盐法、试剂盒法)对八角基因组DNA进行提取试验.结果表明,对传统CTAB法稍加改良可以得到较为理想的提取效果,改良的内容包括①在加入CTAB提取缓冲液之前,先用CTAB-free缓冲液抽提1～2次;②将CTAB提取缓冲液中CTAB的用量从2％提高到3％;③提取缓冲液的用量由样品干重的10倍增加到60倍.用改良CTAB法提取的DNA经RAPD-PCR扩增,条带清晰,其质量能够满足分子标记的要求.     

八角RAPD-PCR反应体系的建立及引物筛选研究

在提取高质量八角基因组DNA的基础上,通过对其RAPD反应体系的Taq DNA聚合酶、dNTPs浓度、Ｍg2+浓度、引物浓度等因子的优化,建立了稳定、重复性高的八角RAPD-PCR反应体系.研究结果表明,在25 μL PCR反应体系中,含1.0 UTaq DNA聚合酶,0.15 mmol·L-1 dNTPs,2.0mmol·L-1 Mg2+,2.0 μmol·L-1引物,20～ 80 ng模板.最佳反应程序为,94℃预变性5 min,扩增后94℃变性30 s,31 ～37℃退火30 s,72℃延伸30 s,35个循环;72℃完全延伸7 min,4℃保存.在建立RAPD-PCR反应体系的基础上,从240条RAPD引物中筛选出15条扩增条带清晰、稳定性好的引物,并通过各引物的退火温度梯度实验,确定了各引物的最适退火温度.     

不同花色铁棒锤基因组DNA提取及遗传差异分析

利用RAPD-PCR技术对不同花色的铁棒锤植物进行遗传差异分析,旨在为今后铁棒锤的引种驯化及品种选育提供参考。采用CTAB法,从铁棒锤植物不同材料提取基因组DNA,用琼脂糖凝胶电泳法和紫外分光光度法检测所得总DNA的浓度和纯度,并用20条RAPD随机引物进行PCR扩增及琼脂糖凝胶电泳分析。结果表明,CTAB法从铁棒锤的新鲜叶片及干燥种子中均可提取出基因组DNA,但前者DNA的质量好、产量高;有3条引物可以扩增出条带,其中,引物E68629的扩增产物清晰稳定,可用于铁棒锤遗传差异分析。RAPD分析结果表明,2种花色铁棒锤在分子水平上具有遗传学差异。