青海大黄油菜粒色性状分子标记的开发和图谱整合

利用青海大黄油菜和褐籽白菜型油菜09A-126构建BC₄和F₂分离群体, 结合AFLP与群体分离分析法(bulked segregant analysis, BSA)筛选引物, 获得5个与黄籽基因Brsc1紧密连锁的分子标记Y11~Y15。5个AFLP特异片段的序列, 均与白菜型油菜的A9染色体部分序列表现同源。将5个AFLP标记成功转化为5个SCAR标记(SC11~SC15)。利用目标基因所在染色体区段序列筛选到7个与目标基因紧密连锁的SSR标记(BrID10607、KS10760、B089L03-3和A1~A4)。利用SCAR和SSR标记扫描F₂群体中部分单株, 发现SC14和A1为共显性标记。用BC₄群体将Brsc1定位在标记Y06和A4之间1.7 Mb的区间内, 遗传距离分别为0.115 cM和0.98 cM。标记Y05和Y12与Brsc1共分离。本研究为黄籽油菜分子标记辅助选择育种体系的建立及目标基因的进一步精细定位和图位克隆奠定了基础。     

小麦花粉致死基因Ki的SSR标记分析

小麦雄性不育主要是通过花粉的败育表现,其不育材料对小麦杂种优势的利用研究具有重要意义和价值,国外研究表明,某些特定普通小麦品种间杂交F₁表现的花粉部分不育现象,受控于核基因组花粉致死基因Ki,为了筛选小麦花粉致死基因Ki的连锁标记,利用现代分子生物学技术通过定位该基因,克隆出花粉致死基因连锁标记片段,为小麦雄性不育种质材料的转育提供有效的选择标记。对小麦花粉致死基因Ki进行了分子标记定位,以‘中国春’和澳大利亚春小麦品种的BC₁F₁代作为定位群体,利用分离群体分组分析法(BSA)对位于小麦6B染色体上85对SSR引物进行多态性筛选,具有多态性的引物再通过BC₁F₁定位群体进行验证,从中筛选出与目的基因连锁的2个SSR标记Xgwm626和Xgpw4138。运用Mapmaker 3.0软件进行连锁分析。结果表明,Xgwm626和Xgpw4138与Ki基因的遗传距离分别为9.2 cM和6.9 cM,且2个SSR标记位于目的基因两侧,并将Ki定位于小麦6BL染色体上。研究结果为Ki基因的分子标记辅助选择和进一步精细定位奠定了基础。     

大豆质核互作雄性不育系NJCMS3A双亲雄性育性基因的SSR标记

利用大豆质核互作雄性不育系NJMCS3A的质、核供体亲本N21566和N21249构建F₂和BC₁F₁育性分离群体进行雄性育性的遗传分析与基因定位。结果表明, F₁正反交可育,F₂和BC₁F₁的可育株与不育株分离比例经χ²测验分别符合3∶1和1∶1,表明NJCMS3A供体亲本雄性育性由一对基因控制,可育等位基因为显性。该基因可能是NJCMS3A的一个恢复基因。选用793对SSR引物对F₂和BC₁F₁群体分别进行育性基因定位,发现该育性基因位于O连锁群上,在Satt331和Satt477标记之间,与Satt331、CSSR133和Satt477标记距离的次序一致,分别为8.1~10.4 cM、11.4~16.4 cM、13.3~19.2 cM。     

控制白菜叶片紫色的pur基因初步定位

为了定位控制白菜叶片紫色的pur基因,选用大白菜自交系09-680和紫色小白菜09N-742进行杂交构建了一个由307个单株组成的F2群体,采用群体分离分析法(Bulked segregant analysis,BSA)构建紫色和绿色池,对分布在白菜基因组10个连锁群上的125个InDel标记和100个SSR标记进行多态筛选,其中位于A3连锁群末端的2个In-Del标记BrID10999和BrID10399与紫色性状表现连锁.连锁分析发现,2个标记与pur基因的遗传距离分别为7.3,5.7 cM,位于pur基因的同侧.在此基础上,根据这些标记所在区域的BAC序列设计了23对SSR引物,其中来源于KBrH005 P10的SSR标记BVRCP10-6位于pur基因的另一侧,距离pur基因仅1.9 cM.这些标记可有效用于白菜紫色性状的分子标记辅助育种,也为进一步精细定位和克隆pur基因奠定了基础.     

甜菜遗传连锁图谱初步构建

以甜菜高产低糖型JV34-2和低产高糖型2B023两材料杂交, 构建了200个单株的F₂作图群体, 利用所筛选出的56对SRAP引物组合和20对SSR引物, 对F₂作图群体进行PCR扩增和遗传连锁分析, 初步构建了一张包含9个连锁群、141个(123个SRAP和18个SSR)标记位点的甜菜遗传连锁图谱。该图谱覆盖长度为1399.88 cM, 平均图距9.92 cM。未进入连锁群的有4个标记。9个连锁群包含3~26个标记不等, 连锁群遗传距离15.69~237.21 cM。连锁群上有20.56%的标记出现偏分离, 主要集中在Ch3连锁群上, 其余分散在Ch1、Ch2、Ch8和Ch9中。该图谱是我国甜菜领域利用SRAP和SSR相结合方法, 构建的第一个较精密的分子遗传图谱, 为重要性状的基因定位和优良基因的克隆奠定了基础。     

甘蓝型油菜花叶性状的遗传及基因定位

为明确甘蓝型油菜花叶性状的遗传特点,开发与花叶性状连锁的分子标记。以甘蓝型油菜品系2205(圆叶)、1423(花叶)为亲本,构建了3个世代群体:F1、BC1和F2,探讨花叶性状的遗传规律;利用分子标记技术对花叶基因进行定位。结果表明,F1植株叶形表现为花叶,BC1(F1×2205)和F2中花叶与圆叶的植株分离比分别符合1∶1和3∶1,说明甘蓝型油菜的花叶性状受1对不完全显性基因控制。利用集团分离法(BSA)筛选637对SSR引物,共筛选到了3个与花叶基因紧密连锁的SSR标记:CB10079、BNGMS114和BNGMS385。连锁分析发现,这3个连锁标记均位于花叶基因的一侧,其中BNGMS114与花叶基因的遗传距离最近,其遗传距离为2.5 c M。将这3个连锁标记的序列与白菜基因组的序列进行比对,结果发现它们与白菜A10染色体的序列共线性较好,花叶基因位于A10染色体的15.70 Mb下游区段。上述标记的获得为油菜花叶性状的分子标记辅助选择育种以及花叶基因的克隆奠定理论基础。     

陆地棉亚红株突变体基因的初步定位

陆地棉亚红株突变体PD-17与GK19杂交F₁代表现出良好的光合作用效率,具有较高的超亲优势,是潜在的优良种质资源。寻找与该突变基因Rs连锁的分子标记并进行染色体定位,对于该基因的进一步精细定位或克隆具有重要的意义。以亚红株突变体PD-17与GK19配置的BC1群体为作图群体,选用覆盖棉花所有已鉴定染色体及大多数连锁群的419对SSR引物,利用BSA（bulked segregation analysis）法筛选有多态性差异引物,然后根据群体单株基因型进行作图分析。结果显示,位于第7条染色体上的5个分子标记与Rs基因相连锁,SSR标记BNL2634与Rs基因的遗传距离较小,约为10.3 cM,SSR标记CIR393位于Rs基因另一侧,与Rs基因的遗传距离约为29.1 cM,由此,可将Rs基因定位于第7染色体上。     

烟草抗TMV基因连锁分子标记的筛选及在抗病资源筛选中的应用

以抗TMV品种Coker176和感TMV品种K326为亲本,经杂交、自交获得F2作图群体.通过SRAP、SSR、N基因特异引物等分子标记分析结合田间TMV抗性鉴定,将TMV抗性基因定位于LG1连锁群上.TMV抗性基因位点位于标记N2和XSRP1x26之间,遗传距离分别是4.3 cM和9.6 cM.利用N2标记对84份烤...     

AFLP,SSR在黄瓜黑星病抗感材料上的多态性比较

用AFLP和SSR 2种分子标记技术对黄瓜抗感黑星病材料Q6和Q12,及其F2极性集团和F2群体进行了分析,比较了它们的多态性。结果表明,AFLP和SSR 2种分子标记的多态性比率分别为36.5%,9.6%;阳性比率分别为22%,0。在F2群体中找到了1个AFLP标记E20/M64,与目的基因的遗传距离是4.83 cM;1个SSR标记CSWCT02B,与目的基因的遗传距离是28.7 cM。AFLP的多态性比率要比SSR的多态性比率高。分析探讨了2种分子标记技术的优缺点及其在目的基因连锁标记筛选、基因定位等研究中的应用。     

利用抗、染根肿病F_2群体构建大白菜AFLP遗传连锁图谱

以易感染根肿病的大白菜(Brassica campestris ssp.pekinensis)自交系94SK和抗根肿病的CR Shinki DH系为亲本,通过杂交获得F1,并选择一株F1植株进行自交,构建了F2作图群体.利用扩增出与根肿病抗性基因CRb连锁标记的17对AFLP引物组合Pst+GNN/Mse+CNN构建大白菜遗传连锁图谱.这些AFLP引物组合共扩增出322个亲本间表现出多态性的AFLP标记.应用其中6个与CRb基因紧密连锁的AFLP标记转化成的SCAR标记和清晰可见的大于100 bp的211个AFLP标记构建了一张包含179个标记位点、10个连锁群、覆盖长度为576 cM,平均图距3.3 cM的遗传图谱.抗根肿病基因CRb定位在第一条连锁群9 cM的范围内.研究表明,利用Pst/Mse Ⅰ和EcoR Ⅰ/Mse Ⅰ引物组合以及其他分子标记类型构建遗传连锁图谱,并有效减少遗传图谱中聚集和间隙现象的产生提供了一定的科学依据.同时,该图谱的构建对在基因组范围内通过分子标记辅助选择选育大白菜根肿病抗性品种奠定了基础.     

青海大黄油菜Brsc1基因的精细定位及图谱整合

大黄油菜是源于青海湟源的地方品种,种皮颜色鲜黄,其大黄油菜的黄籽性状受1对隐性基因(Brsc1)控制,该基因被定位于白菜A9染色体上一段1.7 Mb的区间内。为了更好地利用这一黄籽资源,对Brsc1基因进一步精细定位。利用青海大黄油菜和褐籽白菜型油菜09A-126构建BC4及F2分离群体。利用白菜同源区段内已公布的SSR标记,同时利用该区段序列信息开发新的SSR引物,共获得6个与目标基因紧密连锁的标记(Br ID10711、Br A5~Br A9),其中Br A5与目标基因共分离,Br A9为一侧最近标记,它与目标基因之间的遗传图距为0.69 c M。至此,Brsc1基因进一步被限定于标记Y06和Br A9之间约1.2 Mb的区间内。利用本研究中获得的标记检测F2群体中3种类型单株,鉴定出一个共显性标记Br A8。将本研究中获得的SSR标记与前人研究结果进行整合,加密了Brsc1基因所在区间的标记密度。同时,特异片段与拟南芥基因组进行序列比对的结果表明,共有5个标记与拟南芥的第1染色体有较好的共线性关系,暗示Brsc1基因的同源基因可能位于拟南芥的第1染色体上。本研究中获得的标记将为Brsc1基因的克隆及利用Brsc1基因进行黄籽油菜的分子辅助育种提供有利条件。     

芥菜型油菜黄籽性状的遗传、基因定位和起源探讨

油菜种皮颜色既是一个形态指示性状, 又与种子休眠和品质有关。以芥菜型油菜种皮颜色分离的2个BC₆F₂群体为作图群体,用微卫星(SSR)等标记进行连锁定位, 并用定位标记对22份材料进行关联分析, 通过反转录-聚合酶链反应(RT-PCR)分析12份材料种皮中4-二氢黄酮醇还原酶(DFR)、花色素合酶(ANS)和花色素还原酶(ANR)基因的表达, 对6份黄籽材料的种皮颜色基因等位性进行测定, 结果将芥菜型油菜控制种皮颜色的2个基因位点分别定位到A9和B3连锁群, 并找到其两侧紧密连锁标记, 发现黄籽材料种皮颜色基因位点附近0.9 cM和1.5 cM区域高度保守, 所有黑色种皮中DFR、ANS和ANR基因均表达, 所有黄色种皮中DFR和ANS均不表达,但ANR基因表达或不表达,黄籽材料的种皮颜色基因等位。根据这些结果结合前人研究, 认为芥菜型油菜种皮颜色基因是调控基因,黄籽为单一起源。     

AFLP-based STS markers closely linked to a fertility restoration locus (Rfm1) for cytoplasmic male sterility in barley

The Rfm1 gene restores the fertility of the msm1 and msm² male‐sterile cytoplasms in barley. Rfm1 is located on the short arm of chromosome 6H. To develop molecular markers tightly linked to Rfm1 for use in sophisticated marker‐assisted selection and map‐based cloning, an amplified fragment‐length polymorphism (AFLP) marker system with isogenic lines and a segregating BC₁F₁ population was used. Nine hundred primer combinations were screened and a linkage map was constructed around the Rfm1 locus by using 25 recombinant plants selected from 214 BC₁F₁ plants. Three AFLP markers were identified, e34m2, e46m19 and e48m17, linked to the locus. The most closely linked markers were e34m2, at 1.0 cM distally and e46m19, at 1.1 cM proximally. The two AFLP markers were converted to dominant STS markers. These markers should accelerate programmes for breeding restorer lines and will be useful for map‐based cloning.     

Identification of AFLP and SCAR markers linked to the male fertility restorer gene of <Emphasis Type="Italic">pol</Emphasis> CMS (<Emphasis Type="Italic">Brassica napus</Emphasis> L.)

The pol cytoplasmic male-sterility system has been widely used as a component for utilization of heterosis in Brassica napus and offers an attractive system for study on nuclear–mitochondrial interactions in plants. Genetic analyses have indicated that one dominant gene, Rfp, was required to achieve complete fertility restoration. As a first step toward cloning of this restorer gene, we attempted molecular mapping of the Rfp locus using the amplified fragment length polymorphism (AFLP) technique combined with bulked segregant analysis (BSA) method. A BC₁ population segregating for Rfp gene was used for tagging. From the survey of 1,024 AFLP primer combinations, 13 linked AFLP markers were obtained and five of them were successfully converted into sequence characterized amplified region (SCAR) markers. A population of 193 plants was screened using these markers and the closest AFLP markers flanking Rfp were at the distances of 2.0 and 5.3 cM away, respectively. Further the AFLP or SCAR markers linked to the Rfp gene were integrated to one doubled-haploid (DH) population derived from the cross Quantum × No.2127-17 available in our laboratory, and Rfp gene was mapped on N18, which was the same as the previous report. These molecular markers will facilitate the marker-assisted selection (MAS) of pol CMS restorer lines.     

Genetic mapping of AFLP markers in Japanese bunching onion (<Emphasis Type="Italic">Allium fistulosum</Emphasis>)

Summary The first genetic linkage map of Japanese bunching onion (Allium fistulosum) based primarily on AFLP markers was constructed using reciprocally backcrossed progenies. They were 120 plants each of (P₁)BC₁ and (P₂)BC₁ populations derived from a cross between single plants of two inbred lines: D1s-15s-22 (P₁) and J1s-14s-20 (P₂). Based on the (P₂)BC₁ population, a linkage map of P₁ was constructed. It comprises 164 markers – 149 amplified fragment length polymorphisms (AFLPs), 2 cleaved amplified polymorphic sequences (CAPSs), and 12 simple sequence repeats (SSRs) from Japanese bunching onion, and 1 SSR from bulb onion (A. cepa) – on 15 linkage groups covering 947 centiMorgans (cM). The linkage map of P₂ was constructed with the (P₁)BC₁ population and composed of 120 loci – 105 AFLPs, 1 CAPS, and 13 SSRs developed from Japanese bunching onion and 1 SSR from bulb onion – on 14 linkage groups covering 775 cM. Both maps were not saturated but were considered to cover the majority of the genome. Nine linkage groups in P₂ map were connected with their counterparts in P₁ map using co-dominant anchor markers, 13 SSRs and 1 CAPS.     

Molecular mapping of a new gene for resistance to frogeye leaf spot of soya bean in 'Peking'

Amplified fragment length polymorphism (AFLP) and microsatellite (simple sequence repeat, SSR) techniques were used to map the _RGSp_eking gene, which is resistant to most isolates of Cercospora sojina in the soya bean cultivar ‘Peking’. The mapping was conducted using a defined F₂ population derived from the cross of ‘Peking’(resistant) בLee’(susceptible). Of 64 EcoRI and MseI primer combinations, 30 produced polymorphisms between the two parents. The F₂ population, consisting of 116 individuals, was screened with the 30 AFLP primer pairs and three mapped SSR markers to detect markers possibly linked to Rcs_Peking. One AFLP marker amplified by primer pair E‐AAC/M‐CTA and one SSR marker Satt244 were identified to be linked to Res_Peking. The gene was located within a 2.1‐cM interval between markers AACCTA178 and Satt244, 1.1 cM from Satt244 and 1.0 cM from AACCTA178. Since the SSR markers Satt244 and Satt431 have been mapped to molecular linkage group (LG) J of soya bean, the Res_Peking resistance gene was putatively located on the LG J. This will provide soya bean breeders an opportunity to use these markers for marker‐assisted selection for frogeye leaf spot resistance in soya bean.     

Mapping Co, a gene controlling the columnar phenotype of apple, with molecular markers

The columnar phenotype is a very valuable genetic resource for apple breeding because of its compact growth form determined by the dominant gene Co. Using bulked segregant analysis combined with several DNA molecular marker techniques to screen the F₁ progeny of Spur Fuji × Telamon (heterozygous for Co), 9 new DNA markers (6 RAPD, 1 AFLP and 2 SSRs) linked to the Co gene were identified. A total of 500 10-mer random primers, 56 pairs of selective AFLP primers and 8 SSR primer pairs were screened. One RAPD marker S1142₆₈₂, and the AFLP marker, E-ACT/M-CTA₃₄₆, were converted into SCAR markers designated SCAR₆₈₂ and SCAR₂₁₆, respectively. These markers will enable early selection in progenies where Co is difficult to identify. The Co gene was located between the SSR markers CH03d11 and COL on linkage group 10 of the apple genetic linkage map. Finally, a local genetic map of the region around the Co gene was constructed by linkage analysis of the nine new markers and three markers developed earlier.     

High-resolution mapping of the nud locus controlling the naked caryopsis in barley

The hulled or naked caryopsis character of barley is an important agronomic trait because of the direct link to its use. A single recessive gene, nud, located on the long arm of chromosome 7H, controls the naked caryopsis character. Previously, linked amplified fragment length polymorphism (AFLP) bands from bulked segregant analysis were screened, and the nud gene was mapped in a population of 151 F₂ plants. In the present study, the aim was to construct a high‐resolution map of the nud gene towards its positional cloning. Two AFLP bands were converted into sequence‐characterized amplified region (SCAR) markers (sKT5 and sKT9), and a previously reported SCAR marker sKT3 was improved for more reliable detection of polymorphism. A total of 2380 segregants derived from five cross‐combinations were analysed, and the nud gene was flanked by sKT3 and sKT9, at the 0.6‐cM proximal and the 0.06‐cM distal side, respectively. The SCAR markers developed in this study should be useful for marker‐assisted selection in naked barley breeding employing crosses between naked and hulled accessions.     

Identification of AFLP and SSR markers linked with the male fertility restorer gene of CMS 06J45 in heading Chinese cabbage (Brassica rapa L. ssp. pekinensis)

In this study, AFLP and SSR techniques were combined with the bulk segregant analysis (BSA) method to map the restorer gene BrRfp using an F₂‐segregating population comprising 258 individuals developed by crossing the polima (pol)‐like cytoplasmic male sterility (CMS) line 06J45 and the restorer line 01S325 of heading Chinese cabbage. A survey of 2048 AFLP primer pairs identified 21 polymorphic fragments, approximately half of which exhibited high similarity with the A09 chromosome sequence of Brassica rapa in the Brassica database (BRAD). Based on the genome sequence, three specific AFLP fragments linked with BrRfp were successfully converted into sequence‐characterized amplified region (SCAR) markers, named SC1233, SC2673 and SC2141. Subsequently, 178 pairs of SSR primers were redesigned for further screening, with five producing polymorphic amplification patterns. Linkage analysis showed that these markers were distributed along both sides of the BrRfp gene, with two markers, SSR03 and SSR2528, co‐segregating with the BrRfp locus in the F₂ population. These results may be valuable for marker‐assisted selection and map‐based cloning in heading Chinese cabbage.