QTL mapping of general combining abilities of four traits in maize using a high-density genetic map

General combining abilities(GCAs) are very important in utilization of heterosis in maize breeding. However, its genetic basis is unclear. In the present study, a set of 118 doubled haploid(DH) lines were induced from F_1 generations produced from the cross between the inbred line Zheng 58 and the inbred line W499 belonging to the Reid subgroup. Using the Maize SNP50 Bead Chip, a high-density genetic map was constructed based on the DH population which included 1 147 bin markers with an average interval length of 2.00 cM. Meanwhile, the DH population was crossed with three testers including W16-5, HD568, and W556, which belong to the Sipingtou subgroup. The GCAs of the ear height(EH), the kernel moisture content(KMC), the kernel ratio(KR), and the yield per plant(YPP) were estimated using these hybrids in three environments. Combining the high-density genetic map and the GCAs, a total of 14 QTLs were detected for the GCAs of the four traits. Especially, one pleiotropic QTL was identified on chromosome 1 between the SNP SYN16067 and the SNP PZE-101169244 which was simultaneously associated with the GCAs of the EH, the KR, and the YPP. These QTLs pave the way for further dissecting the genetic architecture underlying GCAs of the traits, and they may be used to enhance GCAs of inbred lines under the fixed heterotic pattern Reid×Sipingtou in China through a marker-assisted selection approach.     

重组自交系稻米品质性状的相关性分析及QTL定位

[目的]分析重组自交系稻米品质性状的相关性,并对其进行数量性状座位(QTL)定位,为水稻品质性状遗传改良提供理论依据.[方法]以珍汕97B、柳沙油占202及二者杂交构建的174个重组自交系群体为材料,对12个稻米品质性状进行相关性分析和QTL定位.[结果]3个稻米碾磨品质性状(出糙率、精米率和整精米率)间均呈极显著正相关(P<0.01,下同).6个稻米外观品质性状中,除粒长与垩白率、垩白度和透明度间无显著相关性(P>0.05)外,其他性状间均呈极显著正或负相关.3个稻米蒸煮食味品质性状中,胶稠度与直链淀粉含量和碱消值呈极显著负相关.碾磨品质性状、外观品质性状和蒸煮食味品质性状间也存在不同程度相关性,如垩白粒率和垩白度与除粒长外的其他9个性状呈显著(P<0.05,下同)或极显著相关等.在第5和第6染色体上共检测出出糙率、精米率、粒宽、长宽比、垩白率、垩白度、直链淀粉含量、胶稠度和碱消值9个性状的11个QTL,其中9个QTL的表型变异贡献率大于10%,为主效QTL,且显著或极显著相关性状的QTL定位区域存在趋同现象.[结论]重组自交系群体12个稻米品质性状存在互作效应,与QTL定位结果相互印证.鉴定所得主效QTL可用于水稻稻米品质相关性状的遗传改良.     

水稻遗传图谱构建及粒形相关性状的QTL定位

[目的]构建水稻遗传连锁图谱,并对水稻粒形相关性状进行QTL分析,为水稻高效育种提供理论依据和育种材料.[方法]对具有极端粒形差异的两份水稻材料K1561和G1025进行杂交、自交获得F2分离群体,通过软件Map-maker/Exp 3.0构建水稻遗传连锁图谱,并利用软件QTLNetwork-2.0对2011年F2群体、2012年F2∶3家系群体的粒形相关性状数据进行相关性状的QTL定位.[结果]两个亲本的粒形性状指标差异明显,以千粒重相差最大;F2、F2∶3两个群体的相关粒形指标基本上呈连续分布状态且分布频率范围广.与F2单株相比,F2∶3家系的千粒重、粒长和粒宽的平均值更偏向于大粒亲本K1561.构建了含161对SSR标记的水稻遗传连锁图谱;共检测到18个粒形相关性状的QTL,分别分布于第1、2、3、7、9和12染色体上.其中,控制千粒重、粒长、粒宽和长宽比的QTL分别有7、5、5和1个,除qGL/GW12外,其他增效等位基因均来源于大粒亲本K1561.两个群体均能检测到的QTL有8个,分别为qTGW3、qTGW7、qTGW9.2、qTGW12、qG L1、qGL9、qGW12和qGL/GW12,其平均加性遗传力为6.04％、12.59％、6.29％、22.08％、4.86％、15.39％、22.12％和10.83％.[结论]定位获得3个效应值较大的新QTL位点qTGW12、qGL9和qGW12,为进一步定位并克隆这些粒形相关基因、阐明水稻产量和品质的控制机理提供了较好的遗传材料.     

QTL mapping of grain appearance quality traits and grain weight using a recombinant inbred population in rice(Oryza sativa L.)

Grain appearance quality traits,measured as grain length(GL),grain width(GW),length to width ratio(LWR),grain thickness(GT) and the percentage of grain with chalkiness(PGWC),as well as 1 000-grain weight(TGW),are very important factors that contribute to rice grain quality and yield.To detect quantitative trait loci(QTLs) affecting these traits,we developed a set of recombinant inbred lines(RILs) derived from Gang46B(G46B) and K1075,a G46 B introgression line with lower PGWC.Based on a linkage map containing 33 simple sequence repeat(SSR) markers,a total of 15 additive QTLs governing six measured traits were identified on 4 chromosomes across two environments.Of these,the five major QTLs which controlled GW,LWR,GT,PGWC,and TGW,each explaining up to 44.30,55.29,62.30,30.94,and 28.78%of the variation,respectively,were found in the same interval of RM18004-RM18068 on chromosome 5.The G46 B alleles contributed to the increase in GW,GT and PGWC at all loci,as well as the increase in TGW at its major QTL locus.Significant interactions between additive QTL and the environment were found at most loci,in which the largest,accounting for15.06%of variation,was observed between qPGWC-5 and the environment.A total of 15 epistasis QTLs were detected for all the traits,and GL,GW and PGWC had significant epistasis QTLs based on environment interactions with minor effects.These results are valuable for future map-based cloning of the QTLs and the collaborative improvement of G46 B in grain appearance quality and yield.     

玉米隐性矮秆突变体的遗传分析与初步定位

利用3个回交后代分离群体结合混合分群法,对发现的玉米矮秆平展叶突变体的遗传机理进行了初步分析.结果表明,该突变体主要是由于植株节间长缩短而导致株高降低,同时穗上叶夹角接近直角,表现为典型的一因多效作用.遗传分析结果表明,该材料的株高与叶夹角变异由1对隐性基因控制.利用SSR标记将该基因定位在玉米第3染色体的3.05 bin,位于SSR标记umc2265和umc2166之间,遗传距离分别为2.5和5.4 cM.     

邓小平思维方式特点浅析

邓小平思维方式是符合时代需要的科学的思维方式。文章从历史和现实、理论和实践结合的角度,对邓小平思维方式的形成及特点进行分析研究,这对我们形成科学的思维方法,迎接新世纪面临的挑战,具有积极的意义。     

六个玉米自交系数量性状配合力的分析

利用6个玉米自交系,按照双列杂交方法组配成15个组合,并对它们的株高、穗位高以及穗部性状进行了遗传学分析和配合力的估算,结果表明,自交系鲁原92和478的一般配合力较高,表现为综合性状较好,用它们作亲本组配杂交种,易得到较广泛的优势;而齐319和178自交系在穗重性状上的特殊配合力高,用它们作亲本会出现穗重突出的组合。     

Identification and QTL mapping of Z550, a rice backcrossed inbred line with increased grains per panicle

An elite backcrossed inbred line Z550 with increased grains per panicle was identified from advanced backcrosses between Nipponbare and Xihui 18 by simple sequence repeat (SSR) marker-assisted selection (MAS). Z550 carries 13 substitution segments distributed on chromosomes 1, 6, 7, 8, 9, 10, and 12, with an average substitution length of 1.68 Mb. Compared with the Nipponbare parental line, plant height, panicle length, spikelets per panicle, grains per panicle, and grain weight for Z550 were significantly increased. While the grain width of Z550 was significantly narrower, and the seed setting ratio (81.43%) was significantly lower than that of Nipponbare, it is still sufficient for breeding purposes. Quantitative trait loci (QTLs) mapping for important agronomic traits was conducted with the F₂ population derived from Nipponbare crossed with Z550 using the restricted maximum likelihood (REML) method. A total of 16, including 12 previously unreported QTLs were detected, with contribution rates ranging from 1.46 to 10.49%. Grains per panicle was controlled by 8 QTLs, 5 of which increased number of grains whereas 3 decreased it. qGPP-1, with the largest contribution (10.49%), was estimated to increase grains per panicle by 30.67, while qGPP-9, with the minimum contribution rate (2.47%), had an effect of increasing grains per panicle by 15.79. These results will be useful for further development of single segment substitution lines with major QTLs, and for research of their molecular functions via QTL cloning.     

水分胁迫下水稻叶片相关生理性状的QTL定位

利用籼稻品种IR64和粳稻品种Azucena杂交产生的包含96个加倍单倍体株系的群体．在分蘖期用10％PEG一6000模拟水分胁迫处理7d,测定了叶片叶绿素含量、气孔阻力、叶温和含水量,利用285个分子标记构建的遗传连锁图谱,共检测到与抗旱性相关的4个生理指标的6个加性QTL和6对上位性QTL。     

棉花数量性状的连锁作图和关联作图最新进展

现代分子生物学技术和新的统计方法,大大促进了植物数量性状基因(QTL)的解析.连锁作图和关联作图是目前植物数量性状基因解析的重要方法,两者在QTL定位的精度和广度、提供的信息量、统计分析方法等方面具有明显的互补性.连锁作图可以初步对目标性状基因进行定位,而关联作图则可快速对目标基因进行验证和精细定位,并针对特定候选基因提供大量信息,验证候选基因的功能.综述了近10年来棉花数量性状的连锁作图和关联作图最新进展,并结合两种方法对棉花的QTL研究前景进行了展望.     

玉米初级作图群体的籽粒性状遗传效应分析

以玉米自交系综3和衡白522的F2∶3家系为材料,通过一年两点的田间试验,研究了6个籽粒产量相关性状的遗传特点。结果表明,所调查的6个性状中,广义遗传力在两点最高的为穗行数和穗粗,其次为行粒数、穗粒重、穗重、穗长。F1代中亲优势和超亲优势的强弱依次为穗粒重、穗重、行粒数、穗长、穗行数和穗粗。F2∶3家系表现出明显的自交衰退现象。穗粒重的变异系数最高,其次分别为穗重、行粒数、穗长、穗行数和穗粗。穗粒重与穗长、穗粗、穗行数和行粒数均存在极显著正相关关系;行粒数对穗粒重的促进作用更明显。利用籽粒各性状之间的相关关系,可以为正确估算靶基因表型值、精细定位和克隆基因提供参考。     

5个含热带血缘玉米骨干自交系产量性状的杂种优势与配合力效应分析

以不同杂优类群的4个玉米自交系为父本,5个舍热带血缘的自交系为母本,按NCⅡ遗传交配设计组配成20个杂交组合,2008-2009连续2 a采用裂区设计田间试验,对穗长、穗粗等8个性状进行杂种优势和配合力效应分析.结果表明:1)组合间除穗行数超亲优势差异不显著外,其它各个性状的中亲优势与超亲优势均存在极显著差异;2)除粒...     

西镇牛微卫星DNA与生长发育性状的关联性分析

【目的】分析12个微卫星DNA与西镇牛长发育性状的关联性,为西镇牛品种资源保护和开发利用提供理论依据。【方法】测定西镇牛的体高、体长、胸围、管围、腰角宽和体质量。利用12对微卫星引物,采用PCR扩增和非变性聚丙稀酰胺凝胶电泳技术,对48头西镇牛母牛进行了遗传多样性检测,并统计分析各位点各种基因型群体与体尺性状之间的效应关系。【结果】12个微卫星位点各基因型与西镇牛生长发育性状具有关联性。IDVGA2、BM2113、DVGA55、ETH225、HEL9、ILSTS005、BM1824位点与体高,BM2113、DVGA55、ETH225、HEL9、ILSTS005、ETH10、DAVG44位点与体长,IDVGA2、DVGA55、HEL9、ILST093、IDVGA27、BM1824位点与胸围,IDVGA2、ETH225、DAVG44位点与管围,BM2113、DVGA55、ETH225、HEL9、BM1905、ILSTS005、ILST093、ETH10位点与腰角宽,IDVGA2、BM2113、DVGA55、ETH225、HEL9、ILST093、BM1824位点与体质量具有显著或极显著的效应关系。【结论】筛选出了对西镇牛生长发育性状具有正效应的等位基因45个,具有负效应的等位基因40个,可用于指导西镇牛育种实践。     

棉花分子遗传图谱构建与QTL定位研究进展

构建高密度饱和的分子遗传图谱是全面系统进行QTL定位的基础。近年来,随着分子标记技术及统计分析方法的迅速发展,许多作物已构建了较为饱和的分子遗传图谱,利用这些图谱已定位了不少重要性状QTL。棉花的分子标记及QTL定位研究较晚,但进展很快。为此,综述了近年来棉花的分子遗传图谱构建,以及重要性状,包括产量、纤维品质、抗性、形态、生理、早熟性等QTL定位的研究进展,并对当前存在的问题进行了分析和探讨。     

普通荞麦重组自交系群体F4 代主要农艺性状分析

采用方差分析、相关分析和回归分析等方法对普通荞麦构建的包括两组重组自交系(RIL)群体F4代植株的株高、结实率、单株粒重等7个农艺性状进行了统计分析。结果表明,株高、单株种子粒数、结实率、花数在双亲间存在显著或极显著差异。RIL群体各性状变异范围较大,说明其选择性也大。7个农艺性状均呈连续变异,且大多符合偏正态分布,说明为多基因控制的数量性状。单株粒重与其他农艺性状间呈现显著或极显著的相关性,且与单株种子粒数相关性最大;除千粒重外,所有性状均与株高具有显著或极显著的相关性。多元回归分析表明,株高、主茎分枝数、单株种子粒数、千粒重是影响RIL群体单株粒重的主要因素,其中单株种子粒数贡献最大。