石刁柏雄性连锁的AFLP及SCAR标记的建立

目的:对石刁柏雌雄株基因组差异进行分析,筛选雄性或雌性连锁的分子标记.方法:利用限制性片段长度多态性技术,设计了多个引物组合,分别对石刁柏雌雄株基因组进行扩增.结果:在使用的72个引物组合中,引物组合E-AAG+M-CAT从雄性基因组中扩增出了一个雄性连锁的标记(MLDA555),该序列长度为555bp,AT含量为59%.Blast检索未发现相似序列.根据该片段序列设计的引物将该标记转化为雄性连锁的大小为523bp的稳定的SCAR标记,经过不同基因型雄性个体的验证证明该标记广泛存在于不同基因型石刁柏雄性个体中.结论:通过AFLP扩增筛选得到了石刁柏雄性连锁的AFLP和SCAR标记,为石刁柏性别决定机制的理解及石刁柏的分子标记辅助育种提供理论资料和技术支持.     

高粱抗丝黑穗病SCAR标记的建立

选用高粱丝黑穗病感病恢复系矮四、抗病恢复系2381R以及二者F2代抗感个体为试验试材,采用CTAB法提取高粱基因组DNA,并应用RAPD筛选技术对高粱基因进行分子标记,选取了100对RAPD随机引物对其进行扩增,有88对引物扩增出条带。分析结果表明:88对引物中S_(405)在抗感品种间扩增出差异谱带。进一步对抗感群体进行分离分析,得出抗丝黑穗病基因重组率为11.7%。将S_(405)扩增出的差异片段进行克隆测序,差异谱带的片段长度为320bp。根据差异谱带的碱基排列顺序,设计特异性引物,然后进行序列扩增,将RAPD分子标记转化为SCAR分子标记,并将该标记命名为S_(405-320),为高粱优良品种的筛选和培育奠定一定的基础。     

青海芥菜型油菜多室基因Bjln2连锁标记的SCAR转化

为了提高多室油菜分子标记辅助选择育种的效率,以青海芥菜型多室油菜与新芥为亲本构建的BC4分离群体为试验材料,将前人测序的11个与Bjln2连锁的AFLP标记的特异性片段序列信息作为研究基础,根据测序信息设计了12对SCAR引物,将复杂的AFLP标记转化为操作简便的SCAR标记。结果表明:设计的12对SCAR引物中,AFLP组合SA09MG08和SA10MC16被成功转化,多态性良好。由于该标记在BC4分离群体中得到验证,可利用该SCAR标记苗期对多室与二室进行鉴定,有效提高育种效率。     

与银杏性别相关的RAPD标记

应用Random Amplified Polymorphic DNA (RAPD)技术,筛选与银杏性别相关的分子标记,应用150个10bp随机单引物及110对随机引物组合,检测了雌雄银杏的基因组DNA,获得1个与雄性相关的RAPD标记,该标记的获得,可望进一步转化为Sequence Characterized Amplification Region(SCAR)标记或PCR标记,用于银杏早期的性别鉴定,同时该标记的获得为进一步克隆与其性别相关的基因奠定了基础。     

青鳉DMY基因的克隆及其在性别鉴定中的应用

提取雄性青鳉成鱼基因组DNA为模板,利用特异性引物,聚合酶链式反应(polymerase chain reaction,PCR)扩增获得1 908 bp的特异性条带.经测序证明为DMY基因片段,其核苷酸序列由3个外显子和2个内含子组成,可连续编码150个氨基酸.建立准确而有效的鉴定任意发育阶段青鳉个体雌雄性别基因型的方法,即利用管家基因——肌动蛋白基因PCR扩增条带的有无验证DNA样本提取和PCR扩增的有效性,同时利用雄性DMY基因的PCR扩增条带的有无鉴定青鳉个体的雌雄性别.对随机选取的成鱼和新生鱼卵样本,应用该方法可成功地鉴定出青鳉个体的雌雄性别.     

利用AFLP技术筛选与银杏性别相关的分析标记

利用amplified fragment length polymorphism(AFLP)技术,应用48个引物组合,检测了雌雄银杏基因组DNA的多态性,筛选与银可性别相关的分子标记,其中3个引物组合各提供了1个与雌性相关的分子标记。经Southern点杂交证实有两个标记为银杏雌性基因组所特有。这些分子标记的获得,为寻找性别特异的探针或PCR引物,用于银杏的性别鉴定奠定了基础。     

废水处理系统中功能菌株特异分子标记

用40条10碱基随机引物对油脂化工废水处理系统中分离到的降解脂肪酸和脂肪胺功能菌株FA-2。FA-3及对照菌株进行RAPD分析。筛选出长度为700bp的FA-2的特异性片段,并克隆到pMD 18-T载体上．根据测序结果,设计了1对SCAR(sequence characterized anlplfied region)引物,通过SCAR-PCR反应,获得SCAR标记,并通过对20个培养样品进行PCR扩增,验证了标记特异性．结果表明该标记可作为特异的分子标记用于污水处理系统中功能菌株FA-2的监测．     

普通小麦Brock中一个抗白粉病新基因AFLP标记P13/M13250的筛选

用225对AFLP引物组合，对白粉病敏感小麦品种京411，抗病品种Brock和以京411为轮回亲本、Brock为抗源供体育成的近等基因系（NILs）进行分子标记筛选，其中，引物组合P13／M13能在抗、感材料间稳定产生P13／M13-250bp的多态性片段．用Brock与京411杂交R代抗、感分离单株，对P13／M13 250进行了初步连锁性鉴定，该标记对小麦植物抗病育种分子标记辅助选择有一定用处．     

黄鳝性别决定与SRY基因不相关

以人和鼠的SRY片断为探针与黄鳝基因组DNA进行杂交,发现雌雄黄鳝中均有相同的杂交带.用一对SRY基因保守区HMGbox的引物,在雌雄黄鳝的基因组DNA中均扩增出约200bp片段.将此片断克隆测序后发现雌雄个体中此片断仅相差1个bp,且与人的SRY基因HMG盒基因极相似.以该片段与雌雄个体的RNA进行Northern杂交未能检测到杂交带,RT-PCR反应扩增出一条微弱的200bp片段.以上结果表明:在雌雄黄鳝的基因组DNA中均存在SRY同源片断;黄鳝中的SRY同源片断可能与其性别无直接关系,而是具备其他功能,由此推测低等脊椎动物的性别决定可能由其他基因控制.     

松属树种种苗鉴定中AFLP指纹技术的研究

AFLP(扩增片段长度多态性)标记技术是高效而可靠的标记技术之一，特别对于那些基因组序列信息很少的物种更为有效。笔对基因组较大的松属树种的AFLP实验程序进行了优化，提供了松树树种AFLP分析中DNA酶切、引物连接、预扩增及选择性扩增的优化实验程序。结果显示．预扩增反应中利用选择碱基数不同的预扩增引物(E/M 1，E／M-2)制备的模板对后续的选择性扩增结果没有显影响；在选择性扩增反应中，对碱基数目选择进行了细致的优化．分别测试了15个E-3M-3引物组合，6个E 4/M 3引物组合及15个E 3/M 4引物组合。对于有相同选择碱基数的引物．扩增结果随选择碱基的组合不同而有较大差异。据总的扩增结果发现，选择碱基增加时．扩增谱带数明显减少，谱带清晰度增加，即当选择碱基增加到E引物末端时(M十4／E 3)，大多数引物组合的扩增谱带数要比选择碱基增加到M引物末端(E 3/M 4)的引物组合扩出的谱带数少且带型清晰。总体来看，E 4/M 3的引物组合比较适合于松属树种的AFLP分析。笔还利用单株树种子的胚乳组织对AFLP标记的遗传方式进行了研究，在所用的两个引物组合获得的标记中，约有30％左右的分离标记．分离标记中偏分离比例约为6％。另外．选用3个松属树种对选出的14个AFLP引物组合进行的验证显示，这些组合在不同种间均获得了较好的扩增结果．说明在不同松属树种中筛选出的引物组合可以为其它松属树种AFLP分析引物组合的选择提供借鉴。     

Discovery of a male-biased mutant family and identification of a male-specific SCAR marker in gynogenetic gibel carp Carassius auratus gibelio

Gibel carp (Carassius auratus gibelio) is a uniquely gynogenetic species with a minor ratio of males in natural habitats, but its male origin and sex determination mechanisms have been unknown. In this study, a male-biased mutant family was discovered from the gynogenetic gibel carp, and a male-specific SCAR marker was identified from the mutant family. Normal spermatogenesis was observed in the male testes by immunofluorescence histochemistry. Nearly identical AFLP profiles were observed between males and females, but a male-specific 86 bp AFLP fragment was screened by sex-pool bulked segregant analysis and individual screening. Based on the male-specific AFLP fragment, a total of 579 bp sequences were cloned by genome walking. Subsequently, a male-specific SCAR marker was designed, and the male-specific DNA fragment was confirmed to be steadily transmitted to the next generation and consistently detected only in males.     

Construction of AFLP-based genetic linkage maps for the Chinese shrimp Fenneropaeneus chinensis

Fenneropaeneus chinensis is an important species in marine fishery resources and aquaculture in China. A genetic linkage map is essential for improving the efficiency of its breeding by marker-as- sisted selection and identifying commercially important genes. Linkage maps of F. chinensis were constructed with an F2 mapping population (110 progenies) using amplified fragment length polymor- phic (AFLP) marker in this study. Fifty-five AFLP primer combinations produced 532 AFLP markers fitting for map strategy in mapping family. The markers with 3:1 segregating ratios were analyzed using F2 intercross model for the common linkage map, while the markers with 1:1 ratio were analyzed using the pseudo-testcross strategy. The maps of male, female and common were constructed. The female map included 103 markers that formed 28 linkage groups, covering a total length of 1090 cM. All mark- ers were linked with the linkage groups. Segregation distortion was observed for 6 of 103 markers in the female map. The average distance between markers was 14.53 cM and ranged from 4.4 to 24.8 cM. The male map included 144 markers that formed 35 linkage groups. Ten markers remained unlinked in male map. Segregation distortion was observed for 7 of 144 markers in the male map. The total dis- tance of male map covered 1617 cM. The average distance between markers was 16.36 cM. The male map was 32.6% longer than the female map, which may reflect sex-specific recombination rates in Chinese shrimp. The common map was composed of 216 markers, including in 44 linkage groups covering a total distance of 1772.1 cM. Two markers remained unlinked. No distorted markers of 216 markers were shown in the common map. The distance between markers was 10.42 cM. An average estimated genome size for the Chinese shrimp was 2420 cM, which was consistent with the relative size of the Penaeid genome. The distribution of AFLP markers was relatively even in chromosomes of Chi- nese shrimp maps. The linkage analysis presented in this work provided some insight into the level of polymorphism and genetic variation of Chinese shrimp.     

黄瓜全雌性状相关的RAPD分子标记筛选

用CTAB法提取黄瓜总基因组DNA，采用RAPD技术探寻与黄瓜全雌性相关的分子标记.共筛选39条随机引物，其中有12条引物显示多态性.进一步筛选表明：S10引物能在全雌系黄瓜中扩增出一条约2000 bp的稳定、清晰的特异条带，而在雌雄同株的单株中不存在.经回收、克隆并测序，获得全长2003 bp的序列.在NCBI上进行Blast分析，表明为新发现序列，含有编码62个氨基酸的开放阅读框.其编码短肽的功能尚不确定.     

Characterization and molecular marker screening of a rice bacteria-resistant gene Xa-min(t)

To test the resistant spectrum of the Xa-min(t) gene introgressed from Oryza minuta, thirty-four isolates of different bacterial blight pathogen, Xanthomonas oryzae pv. oryzae (Xoo), from 11 countries were used to inoculate the Xa-min(t) introgression line 78-15. Four rice cultivars, IR24, C64 (IRBB21), Nipponbare and Zhonghua 11 were used as controls. The results showed that the Xa-min(t) gene was broad-spectrum and highly resistant to diverse Xoo isolates. The methods of bulk segregant analysis (BSA), randomly amplified polymorphic DNA (RAPD) and sequence characterized amplified regions (SCAR) were used to analyze F2 individuals of the hybrid IR24×78-15 and molecular genetic markers linked to Xa-min(t) gene were identified. A total of 800 arbitrary decamer oligonucleotide primers were used for RAPD analysis. Two RAPD markers, BE05300 and BE061400, produced by primers BE05 and BE06 respectively, were closely linked to the Xa-min(t) gene. Based on the sequences of these two markers, sequence specific primers were designed and used to screen all F2 plants. One RAPD marker, BE05300, was converted into a stable SCAR marker (ScBE05300). Linkage analysis was carried out using markers ScBE05300 and BE061400 on 948 and 719 F2 individuals of the hybrid IR24×78-15. Our results indicate that the genetic distances from Xa-min(t) to ScBE05300 and BE061400 are 2.2 cM and 3.7 cM respectively on the same side. This study may facilitate the construction of the fine physical map of the Xa-min(t) gene.     

应用RAPD和AFLP标记的方法对甜(辣)椒和番茄品种的多态性分析

应用RAPD和AFLP的DNA指纹图谱方法分析25个甜(辣)椒和22个番茄品种的真实性,并进一步比较RAPD和AFLP的DNA指纹图谱在鉴定亲缘关系较近的品种之间的真实性时的有效性。对于甜(辣)椒品种,AFLP方法中,2个引物组合扩增反应的多态性片段即能将25个品种完全分开。虽然,每个样品的AFLP的扩增产物中多态性片段的百分率为9％,低于RAPD的35％多态性片段的百分率。但是,AFLP的信息量远远大于RAPD的信息量,它的每对引物组合扩增的平均多态标记为5．1,而RAPD仅为2．2。所以,在甜(辣)椒的指纹图谱中,AFLP的有效率是RAPD的2倍。对于番茄品种,每个样品的AFLP的扩增产物中多态性片段的百分率为5．5％,大大低于RAPD的单引物61％多态性片段和双引物58％多态性片段的百分率。它的每对引物组合扩增反应的平均多态标记为2．6,而RAPD中,单引物扩增的平均多态标记为4．2,双引物扩增的平均多态标记为4．4。一个单引物和一个双引物的RAPD扩增反应的多态性片段即能将22个番茄品种中的21个完全分开。所以,在番茄的指纹图谱中,RAPD的有效率是AFLP的2倍。因此,在应用分子标记辅助鉴定品种的真实性时,不同的作物所适用的方法是不同的。     

AFLP分子标记在鉴定海滨锦葵杂交后代上的应用

海滨锦葵是较好的食用和工业利用的盐生经济植物。用 AFLP分子标记对海滨锦葵两对杂交亲本的36个F1 代个体的真伪进行了鉴定。18个AFLP引物对在亲本Hy103×Hh182间扩增出1 100条AFLP带,其中108条是多态带(多态率为9.82%);在亲本Slhy353×Blho301间扩增出1 181个AFLP条带,其中148条是多态带(多态率为12.51%)。实验结果表明:(1)引物对E AAC / M CTC在亲本Hy103×Hh182间扩增出5条父本特征带:401 bp,390 bp,156 bp,137 bp和108 bp,引物对 E AAG/M CTG则产生了7条:457 bp,356 bp,312 bp,251 bp,240 bp,190 bp和76 bp。父本特征带从Hy103×Hh182的8个F1 代个体均扩增出,表明其为真杂种;(2)引物对E AAC/M CTT在亲本 Slhy353×Blho301 间扩增出 5 条父本特征带:440 bp,393 bp,289 bp,162 bp和67 bp,引物对 E ACA/M CAT 则产生了 4 条: 448 bp, 360 bp, 217 bp和 145 bp;父本特征带从Slhy353×Blho301 28个F1 代个体中的26个个体上扩增出,表明其为真杂种,另外2个为假杂种。     

白菜型油菜核育性相关基因片段的克隆与序列分析

通过ＲＡＰＤ标记,所获得的与育性基因紧密连锁的基因片段进行克隆与序列分析,结果表明,该育性基因片段为与油菜小孢子发育早期ＢＰ４调控基因５８％同源,并含有一ＭＡＰＤＳ盒高度同源的保邓列。Ｓｏｕｔｈｅｒｎ杂交结果表明该基因为单拷贝基因。     

Construction of AFLP-based genetic linkage maps for the Chinese shrimp Fenneropaeneus chinensis

Fenneropaeneus chinensis is an important species in marine fishery resources and aquaculture in China. A genetic linkage map is essential for improving the efficiency of its breeding by marker-assisted selection and identifying commercially important genes. Linkage maps of F. chinensis were constructed with an F2 mapping population （110 progenies） using amplified fragment length polymorphic （AFLP） marker in this study. Fifty-five AFLP primer combinations produced 532 AFLP markers fitting for map strategy in mapping family. The markers with 3：1 segregating ratios were analyzed using F2 intercross model for the common linkage map, while the markers with 1：1 ratio were analyzed using the pseudo-testcross strategy. The maps of male, female and common were constructed. The female map included 103 markers that formed 28 linkage groups, covering a total length of 1090 cM. All markers were linked with the linkage groups. Segregation distortion was observed for 6 of 103 markers in the female map. The average distance between markers was 14.53 cM and ranged from 4.4 to 24.8 cM. The male map included 144 markers that formed 35 linkage groups. Ten markers remained unlinked in male map. Segregation distortion was observed for 7 of 144 markers in the male map. The total distance of male map covered 1617 cM. The average distance between markers was 16.36 cM. The male map was 32.6% longer than the female map, which may reflect sex-specific recombination rates in Chinese shrimp. The common map was composed of 216 markers, including in 44 linkage groups covering a total distance of 1772.1 cM. Two markers remained unlinked. No distorted markers of 216 markers were shown in the common map. The distance between markers was 10.42 cM. An average estimated genome size for the Chinese shrimp was 2420 cM, which was consistent with the relative size of the Penaeid genome. The distribution of AFLP markers was relatively even in chromosomes of Chinese shrimp maps. The linkage analysis presented in this work provided some insight     

RAPD技术在罗汉松性别辨别中的应用

部分植物（包括不少濒危物种）是雌雄异株，且在非花期仅凭形态学特征难以辨别其性别；这给品种改良、植物保护工作都带来了麻烦，以罗汉松（Podocarpus macrophyllus(Thunb.)D.Don)、短叶罗汉松（Podocar、pus macrophyllus Var.maki Endl）为具体实验材料，就RAPD技术在植物性别判断方面进行了尝试，在筛选了340种随机引物后，发现其中23种引物的产物有良性的多态性；最终筛选到了可以扩增出与性别相关的特异性条带的引物P20，在这基础上对表现出多态性的RAPD产物进行了UPGMA聚类分析，观察到各样本在遗传多态性上，性别间的差异大于变种与原种间的差异，同时还对单引物、双引物的RAPD结果进行了对比。     

罗汉果性别相关的RAPD标记

应用随机扩增多态性DNA(RAPD)技术寻找与罗汉果性别相关的分子标记,筛选了130个10 bp的随机引物,发现有4个引物(S60、S90、S100、S343)能在雌、雄株DNA间扩增出5条差异性片段,大小在300~1 300 bp之间,表明这些特异带可被用来作为性别鉴别的特异性分子遗传标记。