国内外甜高粱种质遗传多样性的SSR分析

用24对扩增带型稳定的SSR引物,研究了206份国内外甜高粱种质资源的遗传变异,共检测出220个等位基因,每对引物检测出2～19个等位基因。引物位点的多态信息含量指数(PIC)变幅在0.50～0.87。利用220个多态性标记计算206份甜高粱品种之间的遗传相似系数(GS),范围在0.32～0.96之间。利用SSR标记遗传相似系数矩阵,按UPGMA方法对206份甜高粱品种进行聚类分析,将其分为A、B两大组,B组只包含3个品种,与其他品种遗传关系较远,A组进一步被分成15个类群,农艺性状近似的聚在同一类群。     

桃花粉育性与花药颜色的关系及其SSR分子标记

以李属桃亚属的637份桃品种种质和栽培种瑞光19×Summergrand杂交的138株F1群体为试材,对桃花粉育性与花药颜色的关系及其SSR分子标记进行研究。结果表明:在所有品种中,橘红花药最多,占总份数的91.2%,其中绝大部分花粉可育;橘黄和黄色花药的种质数量次之;白色和浅褐花药的种质最少,且均表现为花粉不稔;整体表现为红色和黄色花药与花粉可育具有较强的正相关性。本试验从122对SSR引物中筛选出2对与花粉育性性状连锁的标记CPDCT013和CP-SCT012,根据这2个标记参考整合参考图谱的位置,将控制花粉育性的基因定位在桃第6条染色体上端。对已经报道的2个桃花粉育性标记CPPCT004和NNJ-I以及第6条连锁群的其他SSR位点在花粉育性不同的24个品种上验证,结果表明只有UDP96-001(125bp)可以用于桃花粉育性的分子标记辅助育种。     

Mapping of qGL7-2,a grain length QTL on chromosome 7 of rice

A residual heterozygous line(RHL)carrying a heterozygous segment between two SSR loci RM11 and RM134 on the rice chromosome 7 was selected from a set of recombinant inbred lines from the cross D50(javanica)/HB277(indica).The former parent produces much longer grains than the latter.Selfed progenies of this selection were analyzed genotypically(SSRs)and phenotypically(grain length).Grain length was discontinuously variable in the mapping populations,allowing for the placement of this QTL qGL7-2 within a～4.8 cM interval defined by RM351 and RM234.A set of new markers within this region were developed,which narrowed the QTL to a 278 kb region defined by the markers Indel1 and RM21945.This region contains 49 predicted genes.The results also suggest that the novel allele for grain length will be used for the application of marker assisted selection for the improvement of grain length.     

The linkage maps of Dendrobium species based on RAPD and SRAP markers

Dendrobium plants are used commonly as tonic herbs and health food in many Asian countries,especially in China.Here we report the genetic map construction of two Dendrobium species with a double pseudo-testcross strategy using random amplified polymorphic DNA (RAPD) and sequence-related amplified polymorphism (SRAP) markers.A F1 mapping population of 90 individuals was developed from a cross between D.officinale and D.hercoglossum.A total of 307 markers,including 209 RAPD and 98 SRAP,were identified and used for genetic linkage group (LG) analysis.The D.officinale linkage map consisted of 11 major linkage groups and 3 doublets,which covered 629.4 cM by a total of 62 markers with an average locus distance of 11.2 cM between two adjacent markers.The D.hercoglossum linkage map contained 112 markers mapped on 15 major and 4 minor linkage groups,spanning a total length of 1,304.6 cM with an average distance of 11.6 cM between two adjacent markers.The maps constructed in this study covered 92.7% and 82.7% of the D.hercoglossum and D.officinale genomes respectively,providing an important basis for the mapping of horticultural and medicinal traits and for the application of marker-assisted selection in Dendrobium breeding program.     

A novel marker for the platyfish （Xiphophorus maculatus） W chromosome is derived from a Polinton transposon

A consensus sequence,encoding a putative DNA polymerase type B derived from a Polinton transposon,was assembled from the sex determination region of Xiphophorus maculatus.This predicted protein,which is 1,158 as in length,contains a DNA_pol_B_2 domain and a DTDS motif.The DNA polymerase type B gene has about 10 copies in the haploid X.maculatus genome with one Y-specific copy.Interestingly,it has specific copies on the W chromosome in the X.maculatus Usumacinta strain (sex determination with female heterogamety),which represent new markers for this type of sex chromosome in platyfish.This marker with W-and Y-specific copies suggests relationship between different types of gonosomes and allows comparing male and female heterogameties in the platyfish.Further molecular analysis of the DNA polymerase type B gene in X.maculatus will shed new light on the evolution of sex chromosomes in platyfish.     

标记信息联网技术实现病理信息规范化精细化管理

2010年6月18日,由赛默飞世尔科技提供的全球最新型组织盒书写仪（Print Mate 450）和玻片书写仪（Slide Mate）在首都医科大学附属北京安贞医院病理科安装联网成功。这两台机器与病理质控相关的资料管理网络联接后,实现了组织盒和玻片打号全流程自动化操作,不仅保持了以前型号所具有的快捷、     

省藤属11种棕榈藤亲缘关系的AFLP分析

分别对棕榈科11种省藤属植物的基因组总DNA进行EcoRⅠ+TaqⅠ与EcoRⅠ+PstⅠ限制性双酶切,采用AFLP标记技术分析其亲缘关系.用12对引物对11种棕榈藤的30个代表植株进行选择性扩增,共得到扩增谱带998条,其中多态条带981条,多态性带达98.3%.用MEGA 4.0软件中p-distance计算结果显示,11种棕榈藤30份样本间的遗传距离在0.050～0.391之间,平均为0.297;当遗传距离为0.15时,11种棕榈藤可聚为4个组;第Ⅰ组包括直立省藤、滇南省藤、杖藤、小省藤、勐腊鞭藤、长鞭藤、褐鞘省藤共7个种,第Ⅱ组仅有云南省藤1个种,第Ⅲ组由宽刺藤和泽生藤2个种构成,第Ⅳ组仅含省藤一种,可能为新种.AFLP检测结果表明,以形态特征为依据所划分的鞭轴亚属(Rhachicirrus)植物单独聚为一类;而原始省藤亚属(Protocalamus)和省藤亚属(Calamus)两个亚属的物种在整个聚类图上互相交叉渗透,各亚属植物未能独立成组;省藤亚属植物种之间遗传分化程度较高.因此,省藤属植物之间的亲缘关系和分亚属的标准、依据还需更深入地研究.     

以木糖异构酶基因为筛选标记的玉米遗传转化

利用木糖异构酶基因作为筛选标记可以在含有不同浓度木糖的培养基上筛选出玉米再生植株,其中50％-100％木糖浓度的总体筛选效果较好,但不同玉米基因型之间筛选的最佳浓度差异很大。通过DNA点杂交、PCR及PCR．Southern印记法检测表明,木糖异构酶基因已经整合到转基因植株中。以木糖作为筛选剂,可以减小潜在的生物安全隐患。     

筛选与尼罗罗非鱼性别相关的AFLP标记

尼罗罗非鱼(Tilapia)隶属于鲈形目(Perciformes)、鲈形亚目(Percoidei)、丽鱼科(Cichildae)的热带性鱼类,是联合国粮农组织向全世界推广的优良养殖鱼类,已成为世界性的主要养殖对象之一。由于繁殖快、成熟早,养殖过程中极易造成繁殖过剩,密度过大,个体过小等不利情况;另外,尼罗罗非鱼的雌雄个体之间具有明显的生长差异,从而影响产量的提高。目前解决这一问题最为理想的措施是单性养殖全雄鱼,这样既可以防止过度繁殖,又可利用雄鱼的生长优势。但是由于缺乏性别或性染色体特异的分子遗传标记,遗传性别的准确鉴定问题也一直是罗非鱼类性别控…     

黄瓜霜霉病抗病基因的RAPD及SCAR标记

以感霜霉病黄瓜L18-10-2和抗霜霉病黄瓜129为亲本构建F2代分离群体,以F3代植株霜霉病抗性鉴定表示F2代各单株抗病性并得以区分各单株杂合或纯合感病性,采用RAPD技术和转SCAR的方法筛选黄瓜抗霜霉病基因分子标记.结果显示,在318条RAPD引物中有18条引物表现出两亲本间多态性,其中引物P18的SB-SP18561扩增片段与霜霉病抗病基因之间紧密连锁,根据交换率和Kosambi函数公式计算其遗传距离为7.85 cM.回收SBSP18561片段并克隆和测序,其准确长度为561 bp.将该RAPD标记转换为SCAR标记,长度为494 bp,命名为SSBSP18494.