籼稻不同定位群体的抽穗期和株高QTL比较研究

 【目的】通过分析控制不同定位群体水稻抽穗期、株高和产量性状表现的QTL，挖掘同时控制株高与产量性状且对抽穗期影响小的QTL区间，为水稻高产育种提供参考。【方法】以杂交稻恢复系密阳46作为共同父本，分别与保持系协青早B和珍汕97B配组，构建2个籼籼交重组自交系群体，在同一地点多年种植，对不同群体抽穗期和株高相关的QTL定位结果进行比较。【结果】共定位到12个抽穗期QTL和11个株高QTL，其中2个抽穗期QTL在2个群体中都能检测到，分别位于第6染色体短臂和第7染色体长臂近着丝粒区域。通过与前期相同群体产量性状QTL定位结果比较，发现6个多效性区间，其中，1个同时控制抽穗期、株高和产量性状，3个同时控制抽穗期和产量性状，2个同时控制株高和产量性状。【结论】相对于共同的父本密阳46，水稻矮败型保持系协青早B与野败型保持系珍汕97B对抽穗期和株高的遗传控制存在较大差异，并以株高更为明显。第2染色体长臂RM6—RM240的QTL作用较稳定，对株高和产量性状作用方向一致，且对抽穗期无显著影响，对于通过“矮中求高”实现水稻高产育种具有重要的应用价值。     

水稻叶绿素含量的动态QTL剖析

为剖析水稻叶绿素不同时期的发育动态规律及其遗传机制,以沈农265和丽江新团黑谷的粳-粳交重组自交系为材料,对水稻分蘖期、抽穗期和成熟期的叶绿素含量进行动态QTL分析.共检测22个条件QTL和14个非条件 QTL,分布在第5条染色体以外的11条染色体上.控制分蘖期、抽穗期和成熟期叶绿素含量的条件QTL分别有5个、7个和10个;控制分蘖期-抽穗期和抽穗期-成熟期叶绿素含量的非条件QTL各有7个.进一步分析表明,在叶绿素含量动态发育的不同阶段,控制叶绿素含量QTLs的数目、效应及作用方式不同,反映出叶绿素生物合成过程的复杂性.与其他研究比较发现,定位在第1染色体 RM428-RM580区段、第3染色体RM426-RM514区段、第4染色体RM470-RM559区段、第8染色体RM408-RM25区段和第9染色体RM566-RM242区段的位点可以在不同群体和不同环境下稳定表达.其中,第3染色体上 qCT3a、qCH3、qCM3以及第9染色体qCT9、qCH9b和qCH9等区域是提高叶绿素含量的重要功能区.对这些区域开发稳定并易于检测的分子标记,可用于培育高产新品种     

利用水稻F_2群体对其抽穗期和株高的QTL定位

利用遗传作图群体对水稻抽穗期和株高进行QTL定位,以明确控制性状的基因,揭示性状的遗传机制。将粳型品种月之光与籼型品种明恢63杂交(月之光×明恢63),获得一个含189个家系的F2遗传作图群体;利用该群体建立含127个SSR标记的遗传连锁图谱,图谱覆盖12条染色体,连锁群总长度2 123cM,标记间平均距离16.7cM。F2群体抽穗期和株高均表现为连续的数量变异,呈正态分布,且出现明显的双向超亲分离,抽穗期和株高之间呈现极显著的正相关。以QTL作图软件Cartgrapher 2.5对F2群体抽穗期和株高性状进行了QTL定位分析,共定位到4个与抽穗期相关的QTLs,分别分布于第1、6、8、12号染色体上,第8号染色体上的qHD8 LOD值为10.70,贡献率达48.0%,是主效基因,与已克隆的DTH8在相近位置,可能是DTH8。定位到4个与株高相关的QTLs,分别位于第1、3、8、12号染色体上,表型贡献率为6.3%～21.1%,第1号染色体上检测到的qPH1能解析21.1%的表型变异,是主效基因,位于矮秆基因sd1附近,可能是sd1。定位到的这些QTLs是进行分子标记辅助选择改良相应性状的候选基因位点。     

利用重组自交系群体在长日照和短日照条件下进行水稻抽穗期QTL分析

在海南岛冬季短日照条件下,分2次种植珍汕97和明恢63构建的重组自交系群体,利用超高密度SNP遗传连锁图检测抽穗期QTL,将结果与武汉夏季长日照条件下7组抽穗期QTL定位结果进行比较,探究长日照和短日照条件下QTL的差异。两地结果的主要差别在于:武汉长日照条件下抽穗期的主效QTL定位在第7染色体着丝粒附近,但该QTL在海南短日照条件下无显著效应;在海南条件下检测到第6染色体物理位置9.12~9.65 Mb处一个效应很大的QTL,在武汉条件下效应不显著。本研究结果进一步完善了该群体抽穗期的遗传研究,增进了对水稻长短日照条件下抽穗期遗传基础的理解。     

利用染色体片段代换系定位水稻主效抽穗期QTL

从日本晴/明恢63染色体片段代换系中筛选到1个抽穗期分离家系BC3F2,调查该家系327个单株,发现单株抽穗期呈明显双峰分布,晚抽穗和早抽穗单株比例符合3∶1的分离比,表明抽穗期受1个主效QTL qHd-3控制.利用极端集团混合法筛选到标记RM416在2个DNA混合池中有多态性,单因子方差分析证明了标记RM416和qHd-3连锁.在引物RM416附近20 cM继续筛选多态性标记,对BC3F2群体进行基因型分析,构建局部连锁图.通过QTL分析,qHd-3被定位在IDL01-RM5995,与2个标记的遗传距离分别为5.3 cM 和1.5 cM,它可以解释表型变异的62.9%.在同一区间内还检测到控制每穗颖花数微效QTL qSpp-3和分蘖数微效QTL qTn-3.     

利用岗46B/A232重组自交系群体分析叶绿素含量相关QTL

【目的】本文剖析了水稻叶绿素在不同时期的表达规律。【方法】利用由2个籼稻品种岗46B和A232杂交构建的包含173个株系(F10)的重组自交系群体,其相应的包含130个SSR标记的遗传图谱,采用完备区间作图法,检测2年2个生长阶段(分蘖期和抽穗期)控制顶三叶叶绿素含量的QTL。【结果】2年共检测到30个QTL,分布在第1、2、3、4、5和7染色体上的16个标记区间上,单个QTL对表型的贡献率为5. 91%～38. 69%。位于第3染色体RM231～RM3392区间,2年中共有8次被检测到,说明该区间上的QTLs受环境影响较小,且在不同生长阶段也能稳定表达,有利于提高叶片叶绿素含量,增强光合作用。与其他研究比较发现,定位在第3染色体RM5625～RM1350区段和RM231～RM3392区段、第4染色体RM280～RM1113区段和RM5473～RM303区段和第7染色体RM21253-RM248区段的位点可以在不同群体和不同环境下稳定表达。【结论】这些QTL将为进一步了解水稻叶绿素含量的遗传机制提供理论依据,可用于水稻分子标记辅助育种。     

水稻DH群体苗期耐低氮能力QTL定位分析

利用云南元江普通野生稻与优良籼稻品种"特青"构建的DH群体的139个家系,采用单标记分析法对DH群体中与耐低氮能力相关的QTL进行分析.以株高、鲜重和干重的平均抑制率作为指标,检测到7个与耐低氮相关的QTL,分别位于第4、5、7、10染色体上,在"特青"中定位到1个耐低氮QTL,在野生稻中定位到6个耐低氮QTL.其中,位于第4染色体RM307、RM335和RM303,第5染色体RM440,以及第7染色体RM481和RM172附近的QTL位点,来源于野生稻的等位基因表现为耐低氮胁迫;位于第10染色体RM222附近的QTL位点,来源于栽培稻"特青"的等位基因表现为耐低氮胁迫.检测到的QTL的贡献率均较小,没有定位到主效QTL.     

利用水稻近等基因系群体进行Ghd7和Qph1上位性分析

应用珍汕97/P0kkali的BC<,3> F<,2>群体,在第1染色体sd-1附近定位1个主效株高QTL Qph1,它同时对每穗粒数也有较大效应.构建Ghd7和Qph1两个QTL同时分离的近等基因系群体,发现P0kkali在Ghd7和Qph1位点均携带增效等位基因,Ghd7和Qph1的上位性影响了株高.进一步剖分互作...     

水稻株高QTL Qph1的精细定位

利用珍汕97B与南阳占的重组自交系(recombinant inbred line,RILs)构建了以珍汕97B为背景的近等基因系(near isogenic line,NILs)BC3F2,通过对其320株随机分离小群体的研究,发现Qph1同时具有加性效应和显性效应,其可解释的遗传变异达71.28%,局部QTL连锁分析把该QTL定位于2.1cM、180.2kb的RM6333-RM11961区间内;进一步发展6 000株大群体,筛选出230株极端隐性重组单株,利用重叠作图法将Qph1进一步精细定位于距离约为90kb的SSR标记SHL4和InDel(Insertl Deletion)标记HL13间,通过与已克隆的sd1基因比较,发现二者并不在同一个区域,这为进一步克隆该QTL和分子标记辅助选择培育矮秆水稻新品种奠定了基础。     

TD70/Kasalath RIL群体定位水稻穗部主要性状的QTL(英文)

利用穗部性状存在明显差异的粳稻TD70和籼稻品种Kasalath杂交,经单粒传法获得的240个重组自交系(RIL)为作图群体,分别于2010和2011年对穗长每穗总粒数和着粒密度进行鉴定,用完备区间作图法,以均匀分布于12条染色体的141个SSR标记对粒型性状进行QTL检测结果表明,共检测到3个性状的QTL23个,其中控制穗长的5个QTL每穗总粒数的8个QTL着粒密度的10个QTL,分布在第2、3、4、6、7、8、9和10染色体上,LOD值范围为2.5~9.3,单个QTL的贡献率介于4.0%~20.8%之间第2染色体的RM5699-RM424第3染色体的RM489-RM1278第4染色体的RM3367-RM1018和第6染色体的RM3343-RM412区间,都检测到同时影响每穗总粒数着粒密度的QTL,2年均被检测到的QTL共有6个QTL,分别是控制穗长的qPL3每穗总粒数的qTSP4、qTSP6-2、qTSP7着粒密度的qGD3-2、qGD7其中qPL3qTSP6-2qGD3-2和qGD7为主效QTL除穗长性状5个位点均有报道外,其余2个性状中均发现新的位点,共有16个QTL可能是新的位点,单个QTL贡献率为4.0%~9.5%本研究为进一步精细定位或克隆这些粒型QTL奠定了基础。     

Quantitative Trait Loci for Panicle Size and Grain Yield Detected in Interval RM111-RM19 784 on the Short Arm of Rice Chromosome 6

A rice residual heterozygous line （RHL） carrying a heterozygous segment extending from RM111 to RM19784 on the short arm of rice chromosome 6 was selected from a RHL-derived population used previously. The resultant F2：3 population was used to detect quantitative trait loci （QTLs） for three yield traits, the number of spikelets per panicle （NSP）, the number of grains per panicle （NGP） and grain yield per plant （GY）. Two QTLs for NSP, one QTL for NGP and one QTL for GY were detected, all of which were partially dominant and had the enhancing alleles from the maternal line Zhenshan 97B. Analysis based on the genotypic groups of the markers closely linked to the two QTLs for NSP indicated that they did not interact with each other. Two F2 populations and two near isogenic line （NIL） sets segregating in two sub-regions of interval RM111-RM19784 were developed. The two QTLs for NSP were validated, of which one had major effect and was co-segregated with heading date gene Hdl, and the other had smaller effect and was located in an upper region linked to Hdl. The two regions also showed significant effects on the number of filled grain and grain yield, although the effect on the number of filled grain was less consistent.     

水稻第6染色体短臂产量性状QTL簇的分解

 【目的】将水稻第6染色体短臂上产量性状QTL分解到更小的区间中。【方法】从珍汕97B/密阳46重组自交系群体筛选到针对第6染色体短臂RM587-RM19784区间的剩余杂合体，衍生了一个由221个株系组成的F2:3群体，种植于海南和浙江两地，考察每株穗数、每穗实粒数、每穗总粒数、千粒重、结实率和单株产量，建立SSR标记连锁图，应用Windows QTL Cartographer 2.5检测QTL。【结果】在所分析的6个性状中，除穗数外在第6染色体短臂上的目标区间均检测到QTL，分别座落于目标区域中3个以上的不同区间中,单个QTL对群体性状表型变异的贡献率为6.3%～35.2%；控制产量构成因子的QTL基本以加性作用为主，但3个单株产量QTL的显性度分别为1.65、0.84和0.42。【结论】目标区间存在3个以上的产量性状QTL，且同一区间控制不同性状的QTL、不同区间控制同一个性状的QTL在遗传作用模式、效应方向和效应大小上存在一定差异。     

Characterization of the Main Effects, Epistatic Effects and Their Environmental Interactions of QTL on the Genetic Basis of Plant Height and Heading Date in Rice

Main-effect QTL, epistatic effects and their interactions with environment are important genetic components of quantitative traits. In this study, we analyzed the QTL, epistatic effects and QTL by environment interactions (QE) underlying plant height and heading date, using a doubled-haploid (DH) population consisting of 190 lines from the cross between an indica parent Zhenshan 97 and a japonica parent Wuyujing 2, and tested in two-year replicated field trials. A genetic linkage map with 179 SSR (simple sequence repeat) marker loci was constructed. A mixed linear model approach was applied to detect QTL, digenic interactions and QEs for the two traits. In total, 20 main-effect QTLs, 9 digenic interactions involving 18 loci, and 5 QTL by environment interactions were found to be responsible for the two traits. No interactions were detected between the digenic interaction and environment. The amounts of variations explained by QTLs of main effect were 53.9% for plant height and 57.8% for heading date, larger than that explained by epistasis and QEs. However,the epistasis and QE interactions sometimes accounted for a significant part of phenotypic variation and should not be disregarded.     

Dissection of QTLs for Yield Traits on the Short Arm of Rice Chromosome 6

This study was undertaken to dissect quantitative trait loci （QTLs） controlling yield traits on the short arm of rice chromosome 6. A residual heterozygous line that carries a heterozygous segment extending from RM587 to RM19784 on the short arm of rice chromosome 6 was selected from an F7 population of the indica rice cross Zhenshan 97B/Milyang 46. An F2：3 population consisting of 221 lines was derived and grown in two trial sites. Six yield traits including number of panicles per plant, number of filled grains per panicle, total number of spikelets per panicle, spikelet fertility, 1 000-grain weight, and grain yield per plant were measured. An SSR marker linkage map was constructed and employed to determine QTLs for yield traits with Windows QTL Cartographer 2.5. QTLs were detected in the target interval for all the traits analyzed except NP, with phenotypic variance explained by a single QTL ranging between 6.3% and 35.2%. Most of the QTLs for yield components acted as additive QTLs, while the three QTLs for grain yield had dominance degrees of 1.65, 0.84, and -0.42, respectively. It was indicated that three or more QTLs for yield traits were located in the target region. The genetic action mode, the direction of the QTL effect, and the magnitude of the QTL effect varied among different QTLs for a given trait, and among QTLs for different traits that were located in the same interval.     

Validation of qGSIO,a quantitative trait locus for grain size on the long arm of chromosome 10 in rice (Oryza sativa L.)

Grain size is a major determinant of grain weight and a trait having important impact on grain quality in rice.The objective of this study is to detect QTLs for grain size in rice and identify important QTLs that have not been well characterized before.The QTL mapping was first performed using three recombinant inbred line populations derived from indica rice crosses Teqing/IRBB lines,Zhenshan 97/Milyang 46,Xieqingzao/Milyang 46.Fourteen QTLs for grain length and 10 QTLs for grain width were detected,including seven shared by two populations and 17 found in one population.Three of the seven common QTLs were found to coincide in position with those that have been cloned and the four others remained to be clarified.One of them,qGS10 located in the interval RM6100-RM228 on the long arm of chromosome 10,was validated using F_(2:3) populations and near isogenic lines derived from residual heterozygotes for the interval RM6100-RM228.The QTL was found to have a considerable effect on grain size and grain weight,and a small effect on grain number.This region was also previously detected for quality traits in rice in a number of studies,providing a good candidate for functional analysis and breeding utilization.     

QTL Detection and Epistasis Analysis for Heading Date Using Single Segment Substitution Lines in Rice(Oryza sativa L.)

Heading date of rice is a key agronomic trait determining cultivated areas and seasons and affecting yield. In the present study, five primary single segment substitution lines with the same genetic background were used to detect quantitative trait loci(QTLs) for heading date in rice. Two QTLs, q HD3 and q HD6 on the short arm of chromosome 3 and the short arm of chromosome 6, respectively, were identified under natural long-day(NLD). Nineteen secondary single segment substitution lines(SSSLs) and seven double segments pyramiding lines were designed to map the two QTLs and to evaluate their epistatic interaction between them. By overlapping mapping, q HD3 was mapped in a 791-kb interval between SSR markers RM3894 and RM569 and q HD6 in a 1 125-kb interval between RM587 and RM225. Results revealed the existence of epistatic interaction between q HD3 and q HD6 under natural long-day(NLD). It was also found that q HD3 and q HD6 had significant effects on plant height and yield traits, indicating that both of the QTLs have pleiotropic effects.     

水稻粒厚主效位点qGT8精细定位和候选基因分析

【目的】在已鉴定的稻谷粒长、粒宽和粒厚QTL的基础上,对控制粒厚的主效QTL进行精细定位和候选基因分析,以解析川106B(C-106B)细长粒形的遗传基础,为进一步通过分子技术改良其产量水平提供科学依据。【方法】以细长粒形的优质籼稻保持系川106B与籽粒较宽厚的籼稻保持系川345B(C-345B)杂交,构建包含182个单株的F_2群体,采用QTL Catographer v2.5软件基于复合区间作图法发掘与稻谷粒形性状相关的QTL;进一步从BC_3F_2群体筛选隐性单株(稻谷厚度较薄)对粒厚主效QTL(qGT8)进行精细定位,并对候选基因进行测序和荧光定量PCR分析。分别构建qGT8位点携带川106B等位基因的近等基因系(NIL-gt8~(C-106B))和携带川345B等位基因的近等基因系(NIL-GT8~(C-345B))并调查其稻米外观品质及产量性状。【结果】川106B和川345B的粒长、粒宽和粒厚表型存在显著差异。利用F_2群体检测到2个粒长QTL、3个粒宽QTL和3个粒厚QTL,其中,位于第7染色体区间RM21892—RM3589的粒长主效QTL(qGL7)可解释粒长变异的68.23%,川106B等位基因在该位点可增加粒长0.47 mm。控制稻谷粒宽和粒厚的主效QTL(qGW8和qGT8)位于第8染色体上相同区间RM6070—RM447,分别解释相应表型变异的26.48%和34.89%,增加粒宽或粒厚的等位基因均来自于川345B。利用1 732个BC_3F_2隐性单株,将粒厚主效位点qGT8精细定位在标记SG930和SG950间的11.2 kb区段,该区段仅包含1个注释基因LOC_os08g41940(OsSPL16)。对该基因测序分析发现,川106B和川345B在起始密码子ATG上游2 kb区段存在7个差异位点,在编码区有5个多态性位点,其中,川106B在第3外显子插入2 bp(c.1006_1007插入CT)引起移码突变,且位于qGT8的OsmiR156结合位点,推测为川106B籽粒厚度变薄、宽度变细的关键位点。实时荧光定量PCR分析发现,qGT8在幼穗中表达量较高,且在川106B和川345B中的表达方式相似,表达量在1—8 cm长幼穗发育时期随幼穗发育逐渐增加,8 cm时达到最高,之后随幼穗发育逐渐降低,但2个亲本在各时期的表达水平存在差异。近等基因系NIL-GT8~(C-345B)的粒厚、粒宽、千粒重、单株产量和垩白粒率显著高于NIL-gt8~(C-106B),而粒长、透明度、株高、单株有效穗数、穗长、每穗实粒数、结实率和播抽期与NIL-gt8~(C-106B)相当。【结论】控制粒长的主效QTL(qGL7)位于第7染色体区间RM21892—RM3589,控制粒宽和粒厚的主效QTL位于第8染色体的相同区间RM6070-RM447。粒厚主效QTL(qGT8)被精细定位在仅包含GW8的片段上,是控制粒形和产量的关键基因,但在近等基因系中高粒重与高垩白紧密连锁,表明该位点存在高产与外观品质改良的矛盾。     

超级杂交稻两优培九产量杂种优势标记与QTL分析

【目的】对超级杂交稻两优培九影响产量及其构成因素性状的杂种优势位点进行定位,在此基础上探讨亲本培矮64S和9311的遗传差异与水稻产量性状的杂种优势间的关系,以探明水稻产量杂种优势的分子预测途径。【方法】应用经单粒传法获得后续世代的219个培矮64S×9311 F8重组自交系(RILs)株系材料与亲本培矮64S回交,并选用151个分布于水稻基因组12条染色体上的SSR多态性标记,构建回交群体RILs BCF1;构建基因组总长为1 617.7 cM、标记间平均距离10.93 cM和含151个分子标记的遗传图谱;采用分子标记技术和自由度不等的单向分组方差两组法、三组法分析,用SAS软件ANOVA分析、混合线性模型复合区间作图等方法,对回交RILs BCF1群体的产量性状及其构成因素的F1表型值进行相关分析、优势预测与QTL定位。【结果】本回交杂种群体RILs BCF1具备多种基因型,遗传变异丰富,性状平均值均显著高于亲本群体重组自交系RILs F8,共筛选到影响RILs BCF1群体产量及其构成因素性状杂种优势的阳性、增效位点74个;其中,三组法所筛选的阳性、增效位点数高于两组法,用这些阳性、增效位点所预测的遗传距离与产量F1性状值的相关性也显著提高;三组法所筛选产量性状的增效位点与两组法所筛选的增效位点完全一致;连锁紧密的位点有成簇分布的现象,每穗空粒数、每穗实粒数、结实率有6个杂种优势位点相同,并与3个产量杂种优势位点重叠,且均处在第7染色体上;通过逐步回归建立了对4个产量性状进行预测的回归方程模型;筛选到28个杂合型的特异性标记,它们与产量性状的表型值显著相关,使用特异性标记可使遗传距离与产量F1性状值的相关系数由全部标记的0.335提高到0.617;定位到3个与产量杂种优势相关的QTL和3个影响每穗实粒数杂种优势的QTL。其中,在第7染色体上影响每穗实粒数和产量杂种优势的QTL QGpp7和QHy7与影响每穗实粒数和产量杂种优势的增效位点的结果相符。【结论】通过增加筛选产量杂种优势阳性位点或增效位点数量、筛选影响杂种优势特异性分子标记的方法,可显著提高分子标记遗传距离与产量F1性状值的相关性,有效提高用分子标记遗传距离对杂种优势预测效率。定位了3个影响产量杂种优势的QTL及3个影响每穗总粒数杂种优势的QTL,分别在第2、3、7、11和12染色体上,其中,影响产量杂种优势的数量性状位点QHy7,贡献率为7.48%,可用于杂种优势的预测和杂交组合的选配。定位于第3染色体RM293—RM468的表型贡献率为14.9%的抽穗期QTL可用于早熟高产水稻的选育。