小麦雄性不育系AL18A育性恢复基因的QTL定位

为加快AL型杂交小麦的发展,以不育系AL18A、恢复系99AR144-1及二者杂交F2代群体为材料,选用SSR标记和分离群体分组分析法进行育性恢复基因的QTL定位。结果表明,育性恢复由主效和微效基因共同控制,采用复合区间作图法分析,在1B染色体上检测到了1个主效恢复基因QTLqRf-1B-1,在5AL染色体上检测到了1个微效QTLqRf-5A-1。qRf-1B-1位于SSR标记Xbarc8与Xgwm413之间,与两标记的遗传距离分别为0.85cM和2.00cM,LOD值为14.06,加性效应为18.87,可解释22.43%的表型变异;qRf-5A-1位于SSR标记Xgwm595与Xgwm410之间,与两标记的遗传距离分别为10.00cM和0.10cM,LOD值为3.18,加性效应为12.32,可解释5.44%的表型变异。     

小麦穗部性状和株高的QTL定位及T6VS·6AL易位效应分析

为了发掘新的穗部性状和株高QTL,利用扬麦17与扬麦18杂交后代206个单株组成的F2群体,构建了一个由141个SSR标记组成的全长1005.1cM的遗传图谱。该图谱包括26个连锁群,覆盖15条染色体,标记间平均距离为7.03cM。结合F2和F2:3群体的表型数据,对穗部性状和株高进行QTL分析,利用复合区间作图法检测出15个QTL,分布在2B、2D、4B、5A、5B和7A染色体上,其中4个QTL能够同时在两个世代被检测到,表型变异解释率为1.93%~20.78%,穗长QTLQSl-YY-2D、QSl-YY-5A和株高QTLQPh-YY-4B的贡献率超过10%。根据6VS特异性标记鉴定和表型调查结果,推测扬麦18的6VS上携带有增加穗长和穗粒数的基因,且为部分显性。2B染色体上总小穗数和5B染色体上穗粒数、穗基部结实粒数的QTL增效等位基因及2D、4B染色体上降低株高的QTL增效等位基因均来自扬麦18,表明该品种可作为具有高产潜力的小麦育种材料加以利用。     

Molecular genetic mapping of quantitative trait loci associated with loaf volume in hexaploid wheat (Triticum aestivum)

Major efforts in wheat research are being made to improve the yield and quality of wheat. Loaf volume (Lv) is the main quality parameter deciding the bread making potential of wheat. To genetically dissect quantitative trait loci (QTLs) for Lv, a Recombinant Inbred Line (RIL) population (F₈) was developed from a cross between two Indian wheat varieties “HI 977” and “HD 2329”. A total of 914 SSR and 100 ISSR primers were used for molecular analysis and the genetic map comprising 19 chromosomes was constructed with 202 SSR markers and 2 HMW glutenin subunit loci: Glu-B1 and Glu-D1. The phenotypic data were collected from six environments including three different agro-climatic zones for 2 consecutive years. Dissection of Lv through AMMI model revealed significant G×E variance for the trait. QTL analysis was performed using composite interval mapping. A total of 30 QTLs for Lv were detected and significant QTLs were identified on 6B and 6D chromosomes; 1B, 1D, 2A, 3A, 5B and 5D also contributed genetically to Lv. Association between 6B and 6D QTLs and variable expression of gliadins on group 6 chromosomes were discussed. QTLs detected in this study were compared with other QTL analysis in wheat.     

大麦籽粒苯丙氨酸含量QTL初步定位分析

为挖掘控制大麦籽粒苯丙基酸含量的QTL,以紫光芒裸二棱和Schooner构建的包含193个家系的重组自交系(RIL)为材料,测定RIL群体及亲本籽粒苯丙氨酸含量,并结合SSR标记和完备区间作图法构建遗传连锁图谱,对大麦籽粒苯丙氨酸含量进行QTL定位.结果 表明,紫光芒裸二棱籽粒苯丙氨酸含量为1.23 mg· g-1,S...     

A major QTL for gluten strength in durum wheat (Triticum turgidum L. var. durum)

Gluten strength is an important characteristic, determining the end product quality of durum wheat semolina. To identify the genetic basis of gluten strength in North Dakota durum cultivars, a doubled haploid population was developed from the cross of a weak gluten cultivar ‘Rugby’ and a strong gluten cultivar ‘Maier’. A framework linkage map consisting of 228 markers was constructed and used with phenotypic data on gluten strength (measured by sedimentation volume) to conduct single- and two-locus QTL analyses. Only one consistent QTL (QGs.ndsu-1B) contributing up to 90% of the phenotypic or 93% of the genotypic variation was detected on 1BS. No QTL × QTL or QTL × environment interactions were observed. The QGs.ndsu-1B was flanked by two DArT markers which were converted to STS markers and used along with SSR and EST-SSRs to develop a map of 1BS. QTL analysis delineated QGs.ndsu-1B in a 7.3 cM region flanked by an STS marker (STS-wPt2395) and a SSR marker (wmc85). The adapted background of this material and availability of PCR-based markers closely associated with this locus represent invaluable resources for marker-assisted introgression of gluten strength into other durum wheat varieties. A single QTL segregating in this population also makes it an ideal target for map-based cloning.     

地方小麦品种贵协3号赤霉病抗性QTL的定位与效应鉴定

为明确抗填料霉病地方小麦品种贵协3号的赤霉病抗性遗传基础,利用感赤霉病品种绵麦96-5及其构建的含有196个株系的双单倍体(doubled haploid,DH)群体为材料,于2018和2019年分别在江苏南京和四川绵阳对赤霉病严重度进行调查,并利用55K DArT基因芯片技术构建的遗传图谱进行QTL定位。结果表明,所构建的遗传图谱覆盖小麦全基因组,图谱全长15 195.8 cM,平均图距10.6 cM。利用复合区间作图法共检测到3个抗赤霉病QTL（QTL-FHB.GX-2B、QTL-FHB.GX-5B和QTL-FHB.GX-7A）,分布在2B、5B和7A染色体上,抗性等位基因均来自于抗病亲本贵协3号,可解释1.2%~1.5%的表型变异,说明贵协3号的赤霉病抗性是多个微效基因/QTLs的累加效应。     

利用三倍体胚乳遗传模型定位爆裂玉米子粒蛋白含量QTL

在两种环境条件下种植以普通玉米自交系丹232和爆裂玉米自交系N04为亲本构建的259个F23∶家系群体,采用SSR标记构建了包含183个标记的爆裂玉米遗传连锁图谱,覆盖玉米基因组1762.2cM,标记间平均距离为9.6cM。利用三倍体胚乳遗传模型和区间作图方法对子粒蛋白含量进行了QTL定位和效应分析。在春、夏播条件下均检测到6个QTL,分别位于第1、3、4、6、7和第8染色体上,其中春、夏播条件下都检测到的QTL有3个,可解释的表型总变异分别为42.85%和53.19%,单个QTL可解释的表型变异为4.50%～17.70%。表现为加性、部分显性、显性和超显性的QTL数目分别为2、2、2和6。3个QTL的增效基因均来自丹232,其余QTL的增效基因均来自N04。     

QTL underlying plant and first branch height in cassava (Manihot esculenta Crantz)

Cassava, Manihot esculenta Crantz subsp. Esculenta was a major food crop across Asia and Africa. The crop was a highly heterozygous perennial woody shrub cultivated from stem cuttings. Cassava improvement for starchy tuberous roots requires about 5-6 years from F₁ hybrid seed germination to the selection of superior genotypes. Early selection with DNA markers could increase the number of elite genotypes identified. The aim here was to identify DNA markers associated with loci underlying plant and first branch height. In this study, 640 SSR primer pairs were used to screen for polymorphisms in two parental lines, cv. ‘Huaybong60’ (female) and cv. ‘Hanatee’ (male). There were 235 informative polymorphic markers used to genotype 100 individuals of an F₁ mapping population. Genotype data was analyzed by JoinMap^® version 3.0 software in order to construct a genetic linkage map. The map consisted of 156 linked SSR markers distributed across 25 linkage groups. The total length of the map was 845.2 cM (Kosambi cM) with 6.2 loci per linkage group, and an average distance between markers of 7.9 cM. Plant and first branch height of stem cuttings from the F₁ mapping population were collected from individual lines planted in 2007-2009. Quantitative Trait Loci (QTL) underlying these traits were identified using mapQTL^®/version 4.0. A total of seven QTL placed on four linkage groups were found for plant height. Of these, one major QTL was discovered on linkage group 2 near the marker SSRY155 with 17.9% of phenotypic variation explained (PVE). For first branch height, five QTL located on five linkage groups were identified. The two major QTL were located on linkage groups 2, and 20 at the loci SSRY323 and SSRY236 with 23.5% and 22.6% PVE, respectively. The QTL for plant and first branch height will serve as useful molecular markers in a cassava breeding program and may allow identification of the underlying genes in future.     

小麦品种潍麦8号2AS染色体上的抗叶锈病QTL定位

为了解小麦品种潍麦8号抗叶锈基因在染色体上的位置,利用EST标记对潍麦8号2AS染色体上的抗叶锈病QTL进行检测和分子作图。2011-2013年,对抗病品种潍麦8号×感病品种郑州5389杂交得到的179个F2:3家系及其亲本进行成株期抗叶锈病鉴定,得到表型数据。前期研究已利用SSR标记在潍麦8号2AS染色体上检测到一个主效QTL,为了寻找与该QTL距离更近的标记,本试验通过35个位于2AS染色体上的EST标记检测亲本及其F2:3家系,结果表明,4个EST标记与抗叶锈病QTL连锁,该QTL位点被定位在BE444541和CD452782之间,区间距离为11.3cM,3年解释的遗传变异分别为63.59%、62.48%和62.43%。     

Genetic Analysis and QTL Mapping of Large Flag Leaf Angle Trait in Japonica Rice

Genetic segregation analysis for flag leaf angle was conducted using six generations of P1,P2,F1,B1,B2 and F2 derived from a cross of 863B(a maintainer line of japonica rice) and A7444(a germplasm with large flag leaf angle).Genotypes and phenotypes of flag leaf angle were investigated in 863B(P1),A7444(P2) and 141 plants in BC1F1(863B/A7444$$$$863B) population.An SSR genetic linkage map was constructed and QTLs for flag leaf angle were detected.The genetic map containing 79 information loci was constructed,which covers a total distance of 441.6 cM,averaging 5.6 cM between two neighboring loci.Results showed that the trait was controlled by two major genes plus polygene and the major genes were more important.Fifteen markers showed highly significant correlations with flag leaf angle based on single marker regression analysis.Two QTLs(qFLA2 and qFLA8) for flag leaf angle were detected by both composite interval method in software WinQTLCart 2.5 and composite interval method based on mixed linear model in QTL Network 2.0.The qFLA2 explained 10.50% and 13.28% of phenotypic variation,respectively,and was located at the interval of RM300 and RM145 on the short arm of chromosome 2.The qFLA8 explained 9.59% and 7.64% of phenotypic variation,respectively,and was located at the interval flanking RM6215 and RM8265 on the long arm of chromosome 8.The positive alleles at the two QTLs were both contributed from A7444.     

小麦旗叶宽主效QTLQFlw-5B遗传效应解析

为了明确位于小麦5B染色体上的一个旗叶宽主效QTL QFlw-5B的遗传效应,对5B染色体进一步加密,从而缩小靶区段的范围,在加密图谱的基础上,利用衍生自科农9204×京411的188个重组自交系群体(KJ-RIL),对8个环境下旗叶宽做进一步的定位分析,将 QFlw-5B定位于AX-110978403～AX-111671812的61.22～68.60 cM遗传距离范围内,能够解释9.40%～19.76%的旗叶宽表型变异,来自科农9204的等位基因增加旗叶宽0.04～0.07 cm。利用与 QFlw-5B紧密连锁标记AX-108884656对188个KJ-RIL家系进行遗传分析,结果表明, QFlw-5B优异等位基因在8个环境下均能增加穗粒数,在6个环境下能增加千粒重和单株产量,而对单株穗数有一定的负效应。利用310份育成品种(系)对 QFlw-5B优异单倍型的应用情况进行分析,结果表明, QFlw-5B优异单倍型虽然已经被育种家选择,但还有较大的遗传改良空间。     

Quantitative trait loci for yellow pigment concentration and individual carotenoid compounds in durum wheat

A defining factor for the commercial value of durum wheat pasta is its amber colour, which depends on the semolina yellow pigment concentration and on the oxidative enzymatic activity. Among carotenoids controlling yellow colour, the presence of β-carotene is also important as precursors of vitamin A. The aim of the present study was to detect quantitative trait loci (QTL) for yellow pigment concentration, yellow index and individual carotenoid compounds (lutein, zeaxanthin, β-cryptoxanthin, α-carotene and β-carotene) in a durum segregant population. Total carotenoid concentration amounted to 37% of the yellow pigments, indicating unknown colour-producing compounds in the durum extracts. Lutein was the most abundant carotenoid, followed by zeaxanthin, α-carotene and β-carotene, while β-cryptoxanthin was a minor component. Phytoene synthase marker Psy-A1, 150 SSR and EST-SSR markers, and 345 DArT^® markers, were used to construct the linkage map for subsequent QTL analysis. Clusters of QTL for total and/or one or more carotenoid compounds were detected on the same chromosome regions (2A, 3B, 5A and 7A) where QTL for yellow pigment concentration and yellow index were identified. The molecular markers associated to major QTL would be useful for marker-assisted selection programs to facilitate high carotenoid concentration with high nutritional carotenoid compounds in wheat grain.     

普通小麦穗部性状QTL分析

为给小麦穗部性状标记辅助选择提供可供选择的分子标记,并进一步对小麦穗部相关性状QTL进行精细定位及相关基因克隆,利用普通小麦Heyne×Lakin杂交F2代单粒传获得的145个F6代重组自交系(recombinant inbred line,RIL)群体,构建了含有2 210个标记(2 068个SNP标记和142个SSR标记)的总长度为2 139.35cM的遗传连锁图谱,并利用该图谱对小麦穗部性状(穗长、小穗数、穗密度)进行了QTL分析。结果表明,共检测出16个加性QTL,其中,与穗长相关的QTL有6个,分布在2A、2D、3B、4D、5A和7D染色体上,可解释表型变异7.58%~15.94%;与小穗数相关的QTL有4个,分布在1A、4A和7D染色体上,可解释表型变异7.28%~14.78%;与穗密度相关的QTL有6个,位于4D、5A和6B染色体上,可解释表型变异5.60%~20.06%。     

利用SNP标记和宁7840×Clark重组自交系(RIL)群体检测小麦染色体偏分离区域

为给小麦偏分离规律研究及小麦农艺性状的QTL定位研究提供相关信息,以普通小麦(Triticum aestivum L.)宁7840和Clark杂交得到的F12重组自交系(RIL)为试验材料,利用筛选出的2 404个单核苷酸多态性SNP标记和291个SSR标记对该群体进行遗传分析。结果表明,共有494个标记位点表现偏分离,占总标记数的18.3%,其中有429个标记偏向父本Clark,占偏分离标记数的86.8%,65个标记偏向母本宁7840,占偏分离标记数的13.2%。大多数偏分离标记在连锁图谱上成簇分布,形成偏分离区域(Segregation distortion region,SDR),共检测到33个SDR,分别位于1A、1B、2A、2B、3A、4B、5A、6A、6B、7A、7B和7D染色体上,其中有6个SDR偏向母本宁7840,27个SDR偏向父本Clark。杂合致死基因Ne2、导致偏分离的QSd.ksu-7D、核质互作增强子基因scs所在染色体区间分别与SDR-2B.1、SDR-7D.1、SDR-1A.2存在部分重合,这3个SDR中可能存在上述基因或其同源基因,在合子体选择和配子体选择共同作用下造成偏分离,形成SDR。     

Analysis of QTL for resistance to head smut (Sporisorium reiliana) in maize

Head smut of maize, caused by the fungus Sporisorium reiliana, is an important disease in the temperate maize-growing areas worldwide. In this study, we mapped and characterized quantitative trait loci (QTL) conferring resistance to S. reiliana using a F_2:3 population of 184 families derived from a cross between Mo17 (resistant parent) and Huangzao4 (susceptible). The population was evaluated for resistance in replicated field trials with artificial inoculation of S. reiliana chlamydospores in Gongzhuling of Jilin Province and Harbin of Heilongjiang Province of China, two hot spots of head smut incidence, in 2003 and 2004. Genotypic and G × E variances for disease incidence were highly significant in the population. Heritability estimates for percentage disease incidence in the 2-location and 2-year evaluation ranged from 0.62 to 0.70. Composite interval mapping on a linkage map (1956.1 cM distance; 9.34 cM average interval) constructed with 84 SSR and 135 AFLP markers, identified five QTL, one each on chromosomes 1, 3 and 8 and two on chromosome 2, accounting for 5.0–43.7% of the phenotypic variance across four environments. One major QTL on chromosome 2 explaining up to 43.7% of the phenotypic variance can potentially be used in molecular marker-assisted selection for head smut resistance in maize.     

大麦品种扬农啤5号的黄花叶病抗性QTL定位

为分析大麦黄花叶病抗性基因的位置和效应,以高抗大麦品种扬农啤5号和感病大麦品种日引3号构建的253个RIL群体及亲本为材料,利用在双亲间具有多态性的108对SSR分子标记构建遗传群体连锁图谱,结合大麦黄花叶病抗性表型数据,采用QTL IciMapping 4.0软件进行大麦黄花叶病抗性QTL分析。结果表明,在大麦染色体1H、2H、5H和7H共检测到6个与大麦黄花叶病抗性相关的QTL,这6个QTL对大麦黄花叶病抗性的贡献率为4.39%～14.92%。其中,位于2H染色体的QTL qRYM-2Hb在3年9个时期均能检测到,介于标记区间GBM1309～EBmac0415,可解释5.70%～14.92%的表型变异,与已定位的 Rym16~(Hb)的位置相近,可能是 Rym16~(Hb)的等位基因;位于2H染色体的QTL qRYM-2Ha在2年3个时期均能检测到,介于标记区间EBmac0640～Bmag0744,可解释5.00%～10.88%的表型变异,可能是1个新的抗性位点;其他4个抗性QTL均仅在1年1个时期检测到,是否真实存在尚需进一步验证。同时,所有QTL的加性效应均为负值,表明定位的6个大麦黄花叶病抗性基因均来自母本扬农啤5号。     

QTL analysis of cold tolerance at seedling stage in rice (Oryza sativa L.) using recombination inbred lines

Cold tolerance at seedling stage of rice (Oryza sativa L.) is a favorable trait for the stable establishment in temperate and high-elevation areas. In the present study, 71 recombinant inbred lines (RIL) derived from the cross of Asominori (Japonica) and IR24 (Indica) were used to identify quantitative trait loci (QTL) affecting cold tolerance at seedling stage. The putative QTL was further confirmed using some chromosome segment substitution lines (CSSLs), in which IR24 was used as the donor parent and Asominori as the recurrent parent. The average seedling mortality was used as cold tolerance after cold treatment with 6 °C for 7 days and recovery culture with 25 °C for 4 days at three-leaf seedling stage. Three QTL affecting cold tolerance at seedling stage were detected on chromosomes 1, 5 and 6 with LOD scores ranging from 2.2 to 4.1 using composite interval mapping (CIM). Among them, qSCT-1 located in the region of XNpb87-2-C955 on chromosome 1 was a major QTL which explained 24.51% of total phenotypic variance and favorable allele came from japonica parent, Asominori. In addition, IR24 alleles at the other two loci (qSCT-5 and qSCT-6) increased cold tolerance. And these three QTL were confirmed by four lines from the IR24 CSSLs. Transferring favorable allele from japonica variety to indica background or pyramiding different QTL identified from indica is an effective way to improve cold tolerance of rice.     

扬麦17/ 宁麦18的F2群体穗部性状QTL定位

小麦穗部性状特别是穗顶部、基部结实性对穗粒数的建成及产量具有重要影响。为给QTL精细定位、基因克隆及穗部性状分子标记的开发和辅助选择奠定基础,本研究以扬麦17与宁麦18杂交获得的310个F₂群体及其衍生的F_2:3家系为材料,构建了一个由215个SSR标记组成的全长为1 717 cM的遗传连锁图谱,共覆盖19条染色体（1D和6A未涉及）,标记间平均距离为7.99 cM,并对6个穗部性状进行QTL定位。利用复合区间作图法共检测出22个QTL,分布在1A、1B、2B、2D、3B、3D、4B、5A、5B和7A染色体上。其中,穗顶部结实粒数QTL有7个,穗基部结实粒数QTL有2个,穗长QTL有5个,总小穗数QTL有3个,不育小穗数QTL有2个,穗粒数QTL有3个,表型贡献率为2.56%～13.66%。控制穗顶部和基部结实粒数QTL的增效基因来源于宁麦18,表明该品种可作为具有高产潜力的小麦育种材料加以利用。     

波兰小麦×普通小麦品系“中13”RIL群体籽粒特性的QTL定位

小麦籽粒特性与籽粒产量和品质密切相关。本研究以波兰小麦(Tiriticum polonicum L.)×普通小麦(Triticum aestivum L.)品系"中13"杂交组合衍生的99个F8重组自交系(Recombinant inbred lines,RIL)群体为材料,利用SSR分子标记构建连锁遗传图谱。根据两年实验数据,利用复合区间作图法对粒重、粒长和粒宽3个籽粒特性相关性状进行了QTL定位分析,共检测到12个与籽粒特性相关的加性QTL位点。其中,3个粒重QTL,1个位于1A染色体上,另外2个都在2A染色体上,单个QTL可解释表型变异的13.35%～20.04%;5个粒长QTL,其中2个位于2A染色体上,其余3个分别位于3A、5A和2B染色体上,单个QTL可解释表型变异的8.53%～21.03%;4个粒宽QTL,分别位于1A、2A、3B和5B染色体上,单个QTL可解释表型变异的9.76%～40.79%。在2A染色体上共检测到5个籽粒特性相关性状的QTL,表明2A染色体与籽粒特性关系密切。     

大穗材料高麦1号/ 密小穗F2群体穗长性状的QTL初步定

为了解小麦穗长性状的遗传特性,并将其应用于分子标记辅助育种,以大穗材料高麦1号/密小穗的292个植株的F2群体为材料,利用SSR标记对穗长进行了QTL定位分析.结果表明,选用500对SSR引物对高麦1号和密小穗两个亲本进行多态性检测,共获得180对在双亲问有多态性的引物,多态性引物检出率为36.0％.利用这180对引物进一步进行F2群体筛选,有96对引物在群体中表现出多态性,占多态性标记的53.3％.利用QTL_IciMapping软件构建出小麦染色体组的8个连锁群图谱,并将96对SSR引物定位到遗传连锁图谱上.图谱全长1 383.29 cM,标记间的平均遗传距离15.37 cM.平均每个连锁群有11.25个标记,含有标记最多的是4A和6B染色体,各有17个标记,其次是3A和7B染色体,含有9～14个标记,1B和5D染色体含有的标记最少,只有5～7个.共检测出7个与穗长相关的QTL位点,包括6个加性QTL和1个加性+显性QTL.7个QTL的加性效应值均为正值,单个QTL的贡献率为2.04％～15.26％.其中3A染色体上的QTL位点距离其最近标记只有0.58 cM,为连锁最紧密的一个位点,并且其加性效应值最大,可解释表型变异的15.26％.因此,3A染色体上存在控制穗长的主效基因.