水稻米粒延伸性的遗传剖析

以籼稻ZYQ8与粳稻JX17为亲本的DH群体作为研究材料,考察DH群体及双亲的米粒延伸率相关性状,并使用该群体的分子连锁图谱进行QTL分析.共检测到14个与稻米延伸性有关的QTL,包括2个粒长QTL、7个饭粒长QTL和5个米粒延伸率QTL,分别位于第1、2、3、5、6、7、10、11和12染色体.所有QTL的LOD值介于2.26～9.25,分别解释性状变异的5.31%～17.21%.在第3染色体上的G249～G164、第6染色体上的G30～RZ516和第10染色体上的G1082～GA223区间同时检测到控制饭粒长和米粒延伸率的QTL.米粒延伸性受多基因控制,Wx基因与位于第6染色体上的qCRE-6的G30～RZ516区间相近,对米饭的延伸性具重要影响.     

水稻纹枯病抗性QTL分析

对灿稻窄叶青8号（ZYQ8）和粳稻京系17（JX17）以及由它们构建的加倍单倍体（DH）群体,分别在杭州和海南岛,采用注射器接种法进行纹枯病抗性鉴定,并使用该群体的分子链锁图谱进行数量性状座位（QTL）分析。共检测到4个抗纹枯病的QTL（qSBR-2、qSBR-3、qSBR-7和qSBR-11）,分别位于第2、第3、第7和第11染色体。其中qSBR-2、qSBR-3、qSBR-7的抗性基因由抗病亲本ZYQ8贡献,而qSBR-11的抗性基因来自感病亲本JX17。qSBR-2、qSBR-3、qSBR-7在杭州和海南岛都能检测到,而qSBR-11只在杭州检测到。在杭州的实验中,纹枯病病级与秆长和抽穗期呈显著负相关;在控制秆长和抽穗期的QTL中,控制秆长的qCL-3与qSBR-3位于同一染色体区域,其余QTL与抗纹枯病的QTL之间无连锁关系。     

水稻苗期耐旱性基因位点及其互作的分析

随着全球水资源的日益贫乏和旱灾的日趋严重,水稻耐旱性的研究越来越重要,对籼稻窄叶青8号（ZYQ8）和粳稻京系17（JX17）以及由它们构建的加倍单倍体（DH）群体,参照国际水稻研究所的耐旱鉴定方法,在苗期进行断水,调查期耐旱性,利用该群体的分子连锁图谱进行数量性状座位（QTL）区间作图分析,共检测到2个耐旱的QTL（qDT-5和qDT-12),分别位于第5染色体的GA41-GA257之间的和第12染色体的RG457-Y12817R之间,这两个QTL的加性效应均来自ZYQ8的等位基因,用Epistat软件检测到2个单位点,即GA257和Y12817R,与区间作图分析的结果一致,Epistat还检测到与GA257互作的3个位点（RG541、G318和G192,分别位于第1、4和8染色体上）和与Y12817R互作的1个位点（CT234,位于第3染色体上）。     

水稻柱头外露率的QTL分析

利用高柱头外露率的籼稻窄叶青8号(ZYQ8)和极低外露率的粳稻京系17(JX17)以及由它们构建的加倍单倍体(DH)群体,在海南对各DH株系的柱头外露率进行调查,并使用该群体的分子连锁图谱进行数量性状座位(QTL)分析。共检测到2个控制水稻柱头外露率的QTL(qPES-2,qPES-3),分别位于第2、第3染色体;并发现控制柱头单边外露率的QTL与柱头外露率完全一致,而控制柱头双边外露率的QTL在第2染色体上检测到;其增效基因均来源于ZYQ8。同时定位的控制穗粒数的QTL位于第6染色体和第8染色体上,与柱头外露率之间没有连锁关系。     

Mapping quantitative trait loci associated with arsenic accumulation in rice (Oryza sativa)

The quantitative trait loci (QTLs) associated with arsenic (As) accumulation in rice were mapped using a doubled haploid population established by anther culture of F1 plants from a cross between a Japonica cultivar CJ06 and an Indica cultivar TN1 (Oryza sativa). Four QTLs for arsenic (As) concentrations were detected in the map. At the seedling stage, one QTL was mapped on chromosome 2 for As concentrations in shoots with 24.4% phenotypic variance and one QTL for As concentrations in roots was detected on chromosome 3. At maturity, two QTLs for As concentrations in grains were found on chromosomes 6 and 8, with 26.3 and 35.2% phenotypic variance, respectively. No common loci were detected among these three traits. Interestingly, the QTL on chromosome 8 was found to be colocated for As concentrations in grain at maturity and shoot phosphorus (P) concentrations at seedling stage. These results provide an insight into the genetic basis of As uptake and accumulation in rice, and will be useful in identifying genes associated with As accumulation.     

应用二种定位法比较不同世代水稻产量性状QTL的检测结果

应用珍汕97B／密阳46的F2和重组自交系（RIL）群体,建立RFLP连锁图,检测控制稻谷产量及其5个构成因子的QTL。结果表明,具有较大加性效应者,能同时在F2和RIL群体中检测到。而且,在重组自交系群体中,发现设重复的表型鉴定与基于单株的表型鉴定,对效应较高的QTL的检测影响不大。     

Quantitative trait loci for glucosinolate accumulation in Brassica rapa leaves

Glucosinolates and their breakdown products have been recognized for their effects on plant defense, human health, flavor and taste of cruciferous vegetables. Despite this importance, little is known about the regulation of the biosynthesis and degradation in Brassica rapa. Here, the identification of quantitative trait loci (QTL) for glucosinolate accumulation in B. rapa leaves in two novel segregating double haploid (DH) populations is reported: DH38, derived from a cross between yellow sarson R500 and pak choi variety HK Naibaicai; and DH30, from a cross between yellow sarson R500 and Kairyou Hakata, a Japanese vegetable turnip variety. An integrated map of 1068 cM with 10 linkage groups, assigned to the international agreed nomenclature, is developed based on the two individual DH maps with the common parent using amplified fragment length polymorphism (AFLP) and single sequence repeat (SSR) markers. Eight different glucosinolate compounds were detected in parents and F(1)s of the DH populations and found to segregate quantitatively in the DH populations. QTL analysis identified 16 loci controlling aliphatic glucosinolate accumulation, three loci controlling total indolic glucosinolate concentration and three loci regulating aromatic glucosinolate concentrations. Both comparative genomic analyses based on Arabidopsis-Brassica rapa synteny and mapping of candidate orthologous genes in B. rapa allowed the selection of genes involved in the glucosinolate biosynthesis pathway that may account for the identified QTL.     

玉米5个农艺性状的QTL定位

利用“豫玉22”构建的266个玉米F2：3家系为材料,通过一年两点的随机区组田间试验和分子标记分析,研究了玉米穗位高、雄穗分支数、茎粗、抽雄期、吐丝期5个重要农艺性状。相关分析表明,穗位高、雄穗分支数、茎粗与单株产量显著正相关,抽雄期与吐丝期高度正相关,雄穗分支数与茎粗显著正相关。采用复合区间作图法,通过500次排列测验分别确定各性状的LOD阈值,在武汉和襄樊两地共定位了7个穗位高QTL、9个雄穗分支数QTL、8个茎粗QTL、9个抽雄期QTL和7个吐丝期QTL;这些QTL在染色体上分布不均匀,具有集中分布的特点。研究表明,数量性状间的表型相关可能源于控制数量性状的QTL位点间的相关。     

Mapping QTLs with epistatic effects and QTL×environment interactions for plant height using a doubled haploid population in cultivated wheat

Quantitative trait loci (QTLs) for plant height in wheat (Triticum aestivum L.) were studied using a set of 168 doubled haploid (DH) lines, which were derived from the cross Huapei 3/Yumai 57. A genetic linkage map was constructed using 283 SSR and 22 EST-SSR markers. The DH population and the parents were evaluated for wheat plant height in 2005 and 2006 in Tai’an and 2006 in Suzhou. QTL analyses were performed using the software of QTLNetwork version 2.0 based on the mixed linear model. Four additive QTLs and five pairs of epistatic effects were detected, which were distributed on chromosomes 3A, 4B, 4D, 5A, 6A, 7B, and 7D. Among them, three additive QTLs and three pairs of epistatic QTLs showed QTL×environment interactions (QEs). Two major QTLs, Qph4B and Qph4D, which accounted for 14.51% and 20.22% of the phenotypic variation, were located similar to the reported locations of the dwarfing genes Rht1 and Rht2, respectively. The Qph3A-2 with additive effect was not reported in previous linkage mapping studies. The total QTL effects detected for the plant height explained 85.04% of the phenotypic variation, with additive effects 46.07%, epistatic effects 19.89%, and QEs 19.09%. The results showed that both additive effects and epistatic effects were important genetic bases of wheat plant height, which were subjected to environmental modifications, and caused dramatic changes in phenotypic effects. The information obtained in this study will be useful for manipulating the QTLs for wheat plant height by molecular marker-assisted selection (MAS).     

栽培稻旱胁迫叶片相关性状的遗传解析

利用籼稻窄叶青8号(ZYQ8)和粳稻京系17(JX17)衍生的加倍单倍体(DH)群体127个株系,2002年在杭州采用田间断水法栽培,在水分胁迫下,对叶片的卷叶、相对含水量和电导率3个性状进行了评价和QTL分析。结果表明,3个性状在DH群体中均存在双向超亲分离,接近正态分布,受数量性状基因的控制;检测到影响这些性状的6个QTL,其中卷叶3个(qLR—1,qLR—5和qLR—11)、相对含水量2个(qRWC—1和qRWC—6和电导率1个(qERC—6）。旱胁迫时,目测卷叶方便易行,适于对大批品种或资源筛选,对抗旱栽培稻品种的筛选和利用具有一定的指导意义。     

水稻籽粒VB6含量的调控位点挖掘及分析

维生素B6(vitamin B6,VB6)作为参与动植物多项生命活动的重要组成成分,体现了水稻等粮食经济作物的营养品质。目前对于控制水稻籽粒VB6含量的相关基因的挖掘较少且不深入。本研究以‘华占(HZ)’和‘热研2号(Nekken2)’为亲本所构建的重组自交系为材料,在数量性状基因座(quantitative trait loci,QTL)定位的基础上进行候选基因初步筛选,共获得10个候选基因,其中LOC_Os01g52450、LOC_Os01g52500、LOC_Os05g09500、LOC_Os05g09440、LOC_Os05g20570和LOC_Os05g36270基因的表达量在双亲间差异显著。结合基因表达量和亲本VB6含量数据,推测LOC_Os05g09500是影响水稻籽粒VB6含量的关键基因,其高表达显著影响水稻籽粒VB6含量。本研究填补了水稻籽粒VB6性状QTL定位研究的空白,为进一步阐明水稻VB6合成的分子遗传机理、克隆相关基因提供了理论支持,在鉴定、筛选和培育高VB6含量的水稻新品种方面具有一定意义。     

Mapping QTLs with epistatic effects and QTL×environment interactions for plant height using a doubled haploid population in cultivated wheat

Quantitative trait loci (QTLs) for plant height in wheat (Triticum aestivum L.) were studied using a set of 168 doubled haploid (DH) lines, which were derived from the cross Huapei 3/Yumai 57. A genetic linkage map was constructed using 283 SSR and 22 EST-SSR markers. The DH population and the parents were evaluated for wheat plant height in 2005 and 2006 in Tai'an and 2006 in Suzhou. QTL analyses were performed using the software of QTLNetwork version 2.0 based on the mixed linear model. Four additive QTLs and five pairs of epistatic effects were detected, which were distributed on chromosomes 3A, 4B, 4D, 5A, 6A, 7B, and 7D. Among them, three additive QTLs and three pairs of epistatic QTLs showed QTLxenvironment interactions (QEs). Two major QTLs, QphAB and Qph4D, which accounted for 14.51 % and 20.22% of the phenotypic variation, were located similar to the reported locations of the dwarfing genes Rhtl and Rht2, respectively. The Qph3A-2 with additive effect was not reported in previous linkage mapping studies. The total QTL ef fects detected for the plant height explained 85.04% of the phenotypic variation, with additive effects 46.07%, epistatic effects 19.89%, and QEs 19.09%. The results showed that both additive effects and epistatic effects were important genetic bases of wheat plant height, which were subjected to environmental modifications, and caused dramatic changes in phenotypic effects. The information obtained in this study will be useful for manipulating the QTLs for wheat plant height by molecular marker-assisted selection (MAS).     

水稻种子活力QTL定位及上位性分析

利用1个粳／籼交来源(Lemont／Teqing)、包含264个重组自交系的作图群体,采用纸卷法在18℃培养箱中进行2次重复的发芽实验,考察了种子发芽7d、9d和1ld的发芽率,种子发芽15d后的芽长及干重等种子活力的相关性状。结合一张含有198个DNA标记的连锁图谱,用作图软件QTLMapper1．0定位与种子活力相关的QTL。共检测到13个主效应QTL,这些QTL对性状的贡献率为2．9％～12．7％,平均贡献率为6．2％。同时检测到18对贡献率≥5％的互作位点,其贡献率为5．1％～11．8％,平均贡献率为6．9％,比检测到的主效应QTL的平均贡献率稍大。种子活力相关性状的大多数主效应和互作QTL成串分布于少数几个染色体区段(Chromosome Regions,CRs),并且成串分布在同一染色体区段的QTL效应的方向总是一致,该结果与这些性状在表型上的正相关相一致。若将成串分布有3个及3个以上种子活力相关性状QTL的CRs视为与种子活力高度相关的CRs,则共检测到7个上述与种子活力高度相关的CRs,分别分布在水稻12条染色体中的7条染色体上。根据所含QTL的种类(主效应QTL或／和上位性QTL)可将这些CRs分成以下3种：1)M-CRs：只含有主效应QTL,如CR^sv-7;2)E-CRs：所含位点没有主效应,但与其他位点发生互作,如CR^sv-1、CR^sv-6和CR^sv-12;3)ME-CRs：既含有主效应QTL、也含有与其他位点产生互作的互作位点,如CR^sv-2、CR^sv-5和CR^sv-8。另外还发现,有的CR上的位点同时与多个不同CR上的位点互作,影响种子活力的相关性状。与前入的研究结果相比较,发现有些与种子活力高度相关的CR可在不同研究者所用的不同定位群体中被检测到,而有的CR只在特定的定位群体中被检测到。由此表明,水稻种子活力具有丰富的遗传多样性和复杂的遗传基础,其主效QTL和互作位点可能基于遗传背景的不同而相互转化。     

Analysis of quantitative trait loci underlying the traits related to chlorophyll content of the flag leaf in rice

A population of 117 doubled haploid (DH) lines derived from the cross of Zhaiyeqing 8 (indica) x Jingxi 17 (japonica) was employed to map quantitative trait loci (QTL) underlying four physiological traits related to chlorophyll contents of the flag leaf. There were significantly positive correlations among chlorophyll a, chlorophyll b and chlorophyll a+ b content. Chlorophyll a/b ratio was significantly negatively correlated with chlorophyll b content. These four traits were normally distributed with transgressive segregation, suggesting that they were controlled by multiple minor genes. A total of 11 QTLs were detected for the four traits and they lay on six chromosomes. Each of them explained 9.2%-19.6% of the phenotypic variations, respectively. Of these, two QTLs controlling chlorophyll a content were mapped on chromosomes 2 and 5; four QTLs underlying chlorophyll b content were mapped on chromosomes 2, 3, 5 and 9; three QTLs underlying chlorophyll a+b amount were mapped on chromosomes 3, 5 and 9; two QTLs under-lying chlorophyll a/b ratio were mapped on chromosomes 6 and 1 1. The intrinsic relationship among the four traits and the practical implication in rice breeding are discussed.