大铃棉中棉所48主要经济性状的QTL定位分析

利用4961对SSR引物对中棉所48的2个亲本进行多态性筛选,结果筛选到71对条带清晰、稳定性好的多态性引物,利用这些引物对261个F2群体进行扩增构建连锁图,获得了包含有49个标记位点的14个连锁群,共覆盖498.7cM,约占棉花总基因组10.0％的遗传图谱.采用WinQTL Cartographer 2.5的复合区间作图法(CIM),对F2群体的铃重、衣分及纤维品质进行分析,共检测到l1个稳定的QTLs,其中铃重2个、表分4个、纤维整齐度2个、纤维细度2个、纤维伸长率1个.这些稳定表达的QTLs能解释较大的表型变异,可用于纤维品质及产量性状的标记辅助选择,也可为大铃、优质棉的分子标记辅助选择,改良、提高大铃基因的选择效率,提供理论依据.     

陆地棉产量性状QTLs的分子标记及定位

用我国的高产栽培品种泗棉3号和美国栽培品种TM-1为材料,构建F₂和F_2∶3作图群体,应用301对SSR引物和1040个RAPD引物,对产量性状QTLs进行了分子标记筛选,结果共筛选出了37对SSR多态性引物和10个RAPD多态性引物的49个位点,鉴定出了控制产量性状变异的主效QTLs。定位于第9染色体的连锁群,分别具有控制铃重、衣分和籽指的主效QTLs,铃重的2个QTLs分别解释F_2∶3群体表型变异的18.2%和21.0%;在F₂群体检测到的1个衣分QTL解释表型变异的25%,另一个衣分QTL在F₂群体和F_2∶3群体都检测到,解释F₂群体衣分的24.9%的表型变异,解释F_2∶3群体衣分的5.9%的表型变异;在F_2∶3群体铃重的一个QTL的同一位置同时检测到一个籽指QTL,它解释15.6%的表型变异,是一因多效或是紧密连锁的两个QTLs,有待进一步研究。本研究标记的产量性状主效QTLs可用于棉花产量性状的标记辅助选择。     

利用置换系检测棉花第16染色体的产量、纤维品质QTLs

陆地棉(Gossypium hirsutum L.)和海岛棉(Gossypium barbadense L.)是两个栽培四倍体棉种.前者产量高、适应性广,后者纤维品质优良.置换了海岛棉一对染色体的陆地棉置换系是研究海陆杂种此对染色体上基因互作的优异材料.在对第16染色体的置换系(简称Sub 16)进行遗传评价的基础上,利用(TM-1×Sub 16)F2∶3家系对位于第16染色体上的重要农艺性状进行遗传分析,发现第16染色体上有铃重、衣分、衣指、纤维长度、第一果枝节位的QTLs 各2个,纤维伸长率、开花天数的QTL各 1个,没有检测到子指、纤维强度、麦克隆值的QTL.在构建第16染色体的RAPD、SSR分子标记连锁图基础上,利用分子标记对相应重要农艺性状进行区间作图,检测到铃重、开花天数、纤维长度、纤维伸长率的QTL各1个,在F2∶3株系群体中能解释的表型变异分别为15.2%、12.1%、19.7%和11.7%;检测到2个衣指QTLs,在F2∶3株系群体中能解释的表型变异分别为11.6%和41.9%;检测到3个衣分QTLs,在F2∶3株系群体中能解释的表型变异分别为8.7%、9.6%和29.2%.单标记检测到铃重、开花天数的QTL各1个,在F2∶3株系群体中能解释的表型变异分别为1.60%和4.63%.证明了第16染色体与铃重、衣分、衣指、纤维长度、纤维伸长率、开花天数等性状的关系.     

利用棉花优质渐渗系进行纤维品质性状和衣分的QTL定位

纤维品质和衣分是棉花育种改良的主要目标性状。为充分挖掘与纤维品质和衣分相关的优异基因资源,利用海岛棉优异纤维渐渗系Sealand(Se)和高产抗逆的陆地棉品种鲁棉研37号(L37)为亲本,构建了包含372个单株的F2群体,进行遗传图谱的构建和QTL定位的研究。从9628对引物中筛选到320对在亲本中具有多态的标记,多态率约为3.32%;连锁分析表明(LOD=6.5),有248个标记位点进入连锁群,分布在26条染色体上,覆盖区间为2347.63 cM,约占棉花基因组的52.76%,平均每条染色体9.54个标记,标记间平均间距为9.50 cM;利用F2群体的棉花纤维品质和衣分数据,共定位到20个与纤维品质性状和衣分相关的QTLs,其中纤维上半部平均长度和整齐度指数各2个,断裂比强度5个,马克隆值和伸长率各4个,衣分3个,贡献率为3.50%～16.82%;与纤维上半部平均长度、断裂比强度和伸长率相关的11个QTLs,增效基因均来自亲本Se,与马克隆值、整齐度指数和衣分相关的9个QTLs,增效基因均来自亲本L37。在D6染色体上鉴定到一个含有纤维上半部平均长度、断裂比强度和马克隆值的QTL簇,该区间包含有148个基因,通过GO富集分析和KEGG富集分析,并结合TM-1的转录组数据,获得了3个可能与纤维发育相关的基因:Gh_D06G0039、Gh_D06G0142和Gh_D06G0145。本研究为棉花纤维品质和衣分性状QTL的精细定位及相关候选基因的筛选奠定了基础。     

三色堇与角堇种间遗传连锁图谱构建

该研究以二倍体三色堇和角堇为亲本杂交产生的66株F2代分离群体为作图群体,采用SRAP标记技术进行基因分型,利用JoinMap4.0软件构建了首张三色堇与角堇的种间遗传连锁图谱。结果表明:(1)从256对SRAP引物组合中筛选获得50对多态性好、标记位点清晰且稳定的引物组合。(2)通过对三色堇F2代群体的PCR扩增,共获得118个SRAP多态性标记位点,其中偏分离标记率为24.6%,符合遗传作图需要。(3)成功构建了三色堇和角堇的种间分子遗传连锁图谱,该图谱有15个连锁群,67个SRAP标记,连锁群长度范围1.6~52.2 cM,覆盖基因组总长度327.9 cM,标记间平均图距为4.9 cM。研究结果为三色堇和角堇高密度遗传图谱构建和重要性状的基因定位及分子标记辅助选择育种奠定了基础。     

基于SRAP分子标记的冰草遗传连锁图谱构建

构建高密度遗传连锁图谱是冰草抗性、品质、产量等重要性状QTL精细定位及标记辅助育种研究的基础。该试验以四倍体杂交冰草F2群体的202个分离单株及其亲本为材料,利用SRAP分子标记技术和Join Map 4.0作图软件对冰草的遗传连锁图谱进行了构建。结果表明:(1)共筛选出22对多态性好、标记位点清晰稳定的SRAP适宜引物,对冰草杂种F2分离单株的基因组DNA进行PCR扩增,共获得510个SRAP多态性标记位点,其比率占88.2%。(2)偏分离分析表明,偏分离标记比率仅为14.12%,符合遗传作图的要求。(3)成功构建了冰草的SRAP分子标记遗传连锁图谱,该图谱有14个连锁群、510个标记,连锁群间长度范围86.4～179.0cM,覆盖基因组总长度1 912.9cM,标记间平均间距3.75cM,为高密度遗传图谱。     

棉花高品质纤维性状QTLs的分子标记筛选及其定位

利用7235、TM-1亲本(P1、P2),以及(7235×TM-1)F1、F2(南京和美国2个环境)与F23(南京和海南2个环境)家系群体,根据F2与F23的纤维品质性状表现,构建了纤维强度、细度与长度的极值DNA混合池,通过221对SSR引物、1840个RAPD引物对亲本和极值DNA混合池筛选,共得到了13个多态性标记,其中8个标记可能与高强有关,1个标记与低强有关;3个标记与麦克隆值有关;1个与绒长有关.进一步通过F2分离群体检测,连锁分析表明与高强有关的8个标记(2个SSR标记和6个RAPD标记)紧密连锁,覆盖15.5cM.这一高强纤维的QTL,4个环境中均以FSR1933为最近,相距不超过0.6cM,能解释35%的F2变异,53.8%的F23的表型变异,是目前纤维强度单个QTL效应最大的,多个环境下稳定,可以直接用于标记辅助育种.单体测验表明,该在棉花的第10染色体上.麦克隆值的一个主效QTL标记FMR1603,在F2中能解释7.8%的变异,在F23中能解释25.4%的变异,同样表现环境稳定.纤维长度的一个标记FLR11550,在3个环境中预测到,最大能解释9.5%     

萝卜细胞质雄性不育恢复基因的RAPD标记

以萝卜恢复系9802和不育系9802A配制杂交组合,并以174株个体组成的F2分离群体作为恢复基因的标记群体.以分离群体的不育株和可育株分别建立不育池和恢复池,利用100个RAPD引物对两池间的多态性进行研究.分析表明引物OPC6在两池间扩增出稳定的多态性差异.经连锁分析,证明标记OPC61900与萝卜细胞质雄性不育恢复基因连锁,遗传距离为11.6cM(Centimorgan).这个标记可应用于对育性恢复基因的标记辅助选择.     

海岛棉产量和早熟性相关性状的QTLs定位

对海岛棉产量和早熟性状进行QTL初步定位,为分子标记辅助育种提供依据。利用5200多对SSR引物筛选海岛棉品种新海3号和Giza82间的多态性引物,获得107对。以多态性引物检测新海3号×Giza82的190个F2:3家系,获得120个多态性位点。利用JoinMap3.0分析软件构建了一个包含22个连锁群,74个标记,标记间平均距离12.06 cM,全长893 cM,覆盖海岛棉基因组20.12%的分子标记遗传连锁图谱。采用复合区间作图法检测到21个与海岛棉产量性状和早熟性状有关的QTL,其中早熟性状检测到12个QTL,分别位于1、3、5、6、11、17、22共7个连锁群上;产量性状检测到9个QTL,分别位于1、4、5、6、7、16、22共7个连锁群上。研究结果为海岛棉产量性状和早熟性状的分子设计育种提供了有用的信息。     

利用重组自交系进行陆地棉产量及产量构成因子性状的QTL定位

以高产陆地棉栽培品种中棉所12和8891的杂交组合湘杂棉2号为材料,采用单粒传法构建了含有180个家系的重组自交系(RILs)群体。本研究的目的是分析产量及其构成因子的相互关系并进行相应的QTL定位。重组自交系群体、两亲本和F1于2002年、2003年分别种植于南京农业大学江浦实验农场和江苏省灌云棉花基地。收获每行中间五株的籽棉并考察产量及产量构成因子性状。调查的产量及产量构成因子性状包括单株籽棉产量、单株皮棉产量、单株铃数、铃重、衣分、衣指和籽指。筛选了4,106对SSR引物和384个AFLP引物组合,分别得到127和18个多态位点;此外,2个RAPD引物、1个SRAP引物组合以及来自亲本8891的显性黄花药基因P1也被用来作为标记检测群体基因型。最终共获得149个多态位点,其中132个位点分布于26个染色体/连锁群,覆盖865.20cM,约占棉花基因组的18.57%,标记间平均距离6.55cM。利用此遗传图谱结合重组自交系群体3个环境下的产量及产量构成因子性状,应用QTLCartographer2.0的复合区间作图法进行单位点QTL定位。对各环境资料的分离分析共定位出34个QTL,而利用三环境平均值的联合分析定位出15个QTL。本研究定位的QTL可为棉花产量育种提供信息,其中衣分QTLqLP-A10-1在联合分析及分离分析下的两个环境都能检测到,可能对标记辅助选择有实际应用价值。通径分析结果表明,各产量构成因子中,铃数对皮棉产量贡献最大,这与产量构成因素性状在F1的杂种优势表现一致;因此,在棉花育种上,可优先考虑单株铃数并结合其它产量构成因素进行品种选育和杂交组合选配。     

陆地棉纤维品质性状关联分析及优异等位基因挖掘

本研究检测了214个陆地棉材料在多环境下的纤维品质指标(上半部平均长度、断裂比强度、马克隆值、伸长率和整齐度),选用在棉花基因组上均匀分布多态性较好的259个SSR标记对供试群体进行基因型检测,利用Tassel软件中的GLM(Q)方法挖掘与纤维品质指标相关的QTLs,依据表型效应值鉴别优异等位变异位点及典型材料。结果显示:同一纤维品质性状在3个地点2~3年内变化趋势相对稳定,纤维上半部平均长度、断裂比强度和整齐度三者之间呈正相关(P<0.01),纤维上半部平均长度/断裂比强度均和马克隆值/伸长率负相关。259个SSR标记共检测到309个等位基因,涉及774个基因型,多态性信息含量(PIC,polymorphic information content)平均为0.2688,基因多样性指数平均为0.2239。按照基因型数据可将该群体划分为2个亚群。通过关联分析获得与纤维品质相关的等位变异位点134个(P<0.01),在3个及以上环境中均可检测到的位点有30个,有3个位点(NAU6177、DPL0886、NAU3607)在7个环境中分别与断裂比强度、马克隆值、伸长率显著关联(P<0.01),最高表型变异解释率分别为11.14%、5.74%和13.99%。31个位点同时与2个及以上纤维品质指标相关,其中,NAU 6177与5个纤维品质指标均显著关联(P<0.01)。与已发表结果比对,17个QTL已被报道与纤维品质性状相关,10个QTL与前人关联指标相同。分析多环境纤维品质关联位点的表型效应,获得72个等位变异位点,5份携带优异等位基因载体材料。本研究在多环境下挖掘与陆地棉纤维品质指标关联的分子标记,同时鉴别携带优异等位变异基因的典型载体材料,为棉花纤维品质分子标记辅助选择及目标基因定位提供有益信息。     

Identification of cotton fiber quality quantitative trait loci using intraspecific crosses derived from two near-isogenic lines differing in fiber bundle strength

Cotton fiber properties are very important to the yarn quality. Modern high-speed textile operations around the world require long, strong and fine cotton fibers. The objective of this research was to identify stable fiber quantitative trait loci (QTLs) that could be used in cotton breeding through marker-assisted selection (MAS). Two cotton lines, MD90ne and MD52ne, are near-isogenic with significant differences in fiber properties, especially strength. Fiber samples from 734 progeny plants of two F2 populations (A and B) derived from crosses between MD90ne and MD52ne were collected at Stoneville, MS, USA in 2012. Fiber quality attributes were measured using a High Volume Instrument 1000. A simple sequence repeat (SSR) genetic linkage map with 165 loci covering 632.53 cM was constructed using population A, consisting of 356 F2 individuals and used for identifying QTLs related to fiber bundle strength (FBS), short fiber index (SFI) and upper-half mean fiber length (UHML). One QTL for FBS originating from the stronger fiber parent MD52ne was identified on chromosome (Chr.) 3. Three QTLs each for SFI and UHML were identified on Chrs. 3, 4 and 14 and Chrs. 3, 11 and 24, respectively. Population B, consisting of 378 F2 progeny, was used to confirm these QTLs by analyzing 57 SSR markers mapped on Chrs. 3, 14 and 24. Three QTLs—qFBS-c3, qSFI-c14 and qUHML-c24—were confirmed and appeared stable. These three QTLs could potentially be used in breeding to improve cotton fiber quality through a MAS strategy.     

玉米株高和穗位高遗传基础的QTL剖析

利用玉米强优势组合(Mo17×黄早四)自交衍生的191个F2单株构建了由SSR和AFLP标记组成的分子连锁图谱.F2进一步自交产生的184个F2:3家系用于调查株高和穗位高的表型值.采用基于混合线性模型的复合区间作图法和相应的作图软件QTLmapper/V2.0,分别定位了7个株高和6个穗位高QTL;检测到18对控制株高和13对控制穗位高的上位性效应位点;同时发现了与环境存在显著互作的6个株高和8个穗位高单位点标记区域以及4对株高和4对穗位高上位性效应区域.分析了各种遗传因素在株高和穗位高遗传基础中的相对作用大小,指出了加性、显性和上位性是玉米株高和穗位高的重要遗传基础.并对所定位的QTL的真实性、株高和穗位高的关系以及研究结果对分子育种的启示予以讨论.     

QTL mapping in A-genome diploid Asiatic cotton and their congruence analysis with AD-genome tetraploid cotton in genus Gossypium

Asiatic cotton(Gossypium arboreum L.) is an Old World cultivated cotton species.The sinense race was planted extensively in China.Due to the advances in spinning technology during the last century,the species was replaced by the New World allotetraploid cotton G.hirsutum L.Gossypium arboreum is still grown in India and Pakistan and also used as an elite in current cotton breeding programs.In addition,G.arboreum serves as a model for genomic research in Gossypium.In the present study,we generated an A-genome diploid cotton intraspecific genetic map including 264 SSR loci with three morphological markers mapped to 1 3 linkage groups.The map spans 2,508.71 cM with an average distance of 9.4 cM between adjacent loci.A population containing 1 76 F2:3 families was used to perform quantitative trait loci(QTL)mapping for 17 phenotypes using Multiple QTL Model(MQM)of MapQTL ver 5.0.Overall,108 QTLs were detected on 13 chromosomes.Thirty-one QTLs for yield and its components were detected in the F2 population.Forty-one QTLs for yield and its components were detected in the F2:3 families with a total of 43 QTLs for fiber qualities.Two QTLs for seed cotton weight/plant and lint index and three QTLs for seed index were consistently detected both in F2 and F2:3.Most QTLs for fiber qualities and yields were located at the same interval or neighboring intervals.These results indicated that the negative correlation between fiber qualities and yield traits may result from either pleiotropic effect of one gene or linkage effects of multiple closely linked genes.     

Genetic dissection of the introgressive genomic components from Gossypium barbadense L. that contribute to improved fiber quality in Gossypium hirsutum L.

We crossed Luyuan343, containing the Gossypium barbadense (GB) genomic component, with Lumianyan22, a high-yielding Gossypium hirsutum (GH) variety, to evaluate the introgressive exogenous genomic components that contribute to fiber quality in upland cotton. A total of 158 of 334 mapping simple sequence repeats (SSR) loci screened from 18,467 SSR primer pairs were identified as putative GB introgression loci. Twenty-four quantitative trait loci (QTLs) for fiber quality and lint percentage were detected by WinQTLCart 2.5 based on three phenotypic datasets collected over 2 years in two different locations. Of these QTLs, 20 were mapped in the introgression chromosomal regions; the GB alleles contributed to improved fiber quality at eight loci, which were located in the introgression segments of chromosome (Chr.) 3, Chr.7 and Chr.25. A total of eight digenic epistasis and nine significant QTL × environment (QE) interactions were identified by QTLNetwork-2.2. Fiber elongation was found to be most easily influenced by environment since all QTLs for this trait showed significant QE interaction with large effects. Fiber length, fiber strength, and lint percentage were scarcely affected by environment as no or minor QE interaction effects for these traits were detected. Genome-wide identification of the introgressive GB components and mapping of the fiber-related QTLs indentified in this study will be beneficial for the simultaneous marker-assistant selection of improved fiber quality and lint yield in upland cotton breeding.     

Molecular mapping of QTLs for fiber qualities in three diverse lines in Upland cotton using SSR markers

The improvement of cotton fiber quality is extremely important because of changes in spinning technology. The identification of the stable QTLs affecting fiber traits across different generations will be greatly helpful to be used effectively in molecular marker-assisted selection to improve fiber quality of cotton cultivars in the future. Using three elite fiber lines of Upland cotton (Gossypium hirsutum L.) as parents, three linkage maps were constructed to tag QTLs for fiber qualities using SSR markers. There were 39 QTLs, 17 significant QTLs, LOD 3.0 and 22 suggestive QTLs, 3.0 > LOD 2.0, detected by composite interval mapping for fiber traits, in which 11 QTLs were for fiber length, 10 for fiber strength, 9 for micronaire and 9 for fiber elongation. Out of 17 significant QTLs, 5 QTLs with high logarithm of odds (LOD) score value and stable effect could be found in both F₂ and F_2:3 segregating populations, showing a great potential for molecular-assisted selection in improving fiber quality. At least three common QTLs could be identified in two populations. These common QTLs detected in different populations suggested that there existed elite fiber genes and possibly of the same origin. In addition, we found three pairs of putative homoeologous QTLs, qFL-7-1c and qFL-16-1c, qFS-D03-1a, qFS-A02-1b and qFS-A02-1c, and qFE–D03-1a and qFE-A02-1c. Our results provided a better understanding of the genetic factors of fiber traits in AD tetraploid cottons.     

Development of genetic maps of the citrus varieties ‘Murcott’ tangor and ‘Pêra’ sweet orange by using fluorescent AFLP markers

The progeny of 87 BC(1) hybrids of 'Murcott' tangor and 'Pera' sweet orange, genotyped with fluorescent amplified fragment length polymorphism (fAFLP) markers, was used for the construction of genetic maps for both citrus varieties. Mapping strategies, considering the progeny as a result of backcrossing and cross-pollination, were exploited in Mapmaker 2.0 (LOD score >or= 3.0 and or= 3.0 and theta 相似文献   

四倍体栽培棉种产量和纤维品质性状的QTL定位

陆地棉和海岛棉是两个不同的四倍体栽培种 ,但在生产上各有其特点 ,陆地棉丰产性强 ,海岛棉纤维品质优良 ,利用其种间杂交群体定位产量和品质性状的QTL ,对于分子标记辅助的海岛棉优质纤维向陆地棉转移很有意义。以SSR和RAPD为分子标记 ,陆地棉与海岛棉杂种 (邯郸 2 0 8×Pima90 )F2 群体为作图群体 ,构建了一张含 12 6个标记的遗传图谱 ,包括 6 8个SSR标记和 5 8个RAPD标记 ,可分为 2 9个连锁群 ,标记间平均距离为 13 7cM ,总长1717 0cM ,覆盖棉花总基因组约 34 34% ;以遗传图 12 6个标记为基础 ,对F2 :3 家系符合正态分布的 10个农艺性状及纤维品质性状进行全基因组QTL扫描 ,结果发现 2 9个QTL分别与产量和品质性状有关。其中与衣指、籽指、皮棉产量、子棉产量、衣分等产量性状相关的QTL分别有 1、3、5、6和 1个 ,与纤维长度、整齐度、强度、伸长率和马克隆值等品质性状相关的QTL分别有 2、4、2、4和 1个。各QTL解释的变异量在 12 4 2 %～ 47 0 1%之间。其中比强度有关的 2个QTL能够解释的表型变异率分别为 34 15 %和 13 86 %。     

Linkage Map Construction and Quantitative Trait Loci Analysis for Bolting Based on a Double Haploid Population of Brassica rapa

Early bolting of Chinese cabbage （Brassica rapa L.） during spring cultivation often has detrimental effects on the yield and quality of the harvested products. Breeding late bolting varieties is a major objective of Chinese cabbage breeding programs. In order to analyze the genetic basis of bolting traits, a genetic map of B. rapa was constructed based on amplified fragment-length poiymorphism （AFLP）, sequence-related amplified poiymorphism （SRAP）, simple sequence repeat （SSR）, random amplification of polymorphic DNA （RAPD）, and isozyme markers. Marker analysis was carried out on 81 double haploid （DH） lines obtained by microspore culture from F1 progeny of two homozygous parents： B. rapa L. ssp. pekinensis （BY） （an extra-early bolting Chinese cabbage line） and B. rapa L. ssp. rapifera （MM） （an extra-late bolting European turnip line）. A total of 326 markers including 130 AFLPs, 123 SRAPs, 16 SSRs, 43 RAPDs and 14 isozymes were used to construct a linkage map with 10 linkage groups covering 882 cM with an average distance of 2.71 cM between loci. The bolting trait of each DH line was evaluated by the bolting index under controlled conditions. Quantitative trait loci （QTL） analysis was conducted using multiple QTL model mapping with MapQTL5.0 software. Eight QTLs controlling bolting resistance were identified. These QTLs, accounting for 14.1% to 25.2% of the phenotypic variation with positive additive effects, were distributed into three linkage groups. These results provide useful information for molecular marker-assisted selection of late bolting traits in Chinese cabbage breeding programs.