玉米株高和穗位高的QTL定位

摘要: 用玉米自交系掖478和丹340构建了397个F_2:3家系群体, 利用双亲间多态的150个共显性SSR标记绘制分子连锁图谱, 图谱总长度1 478.7 cM, 标记间平均距离10.0 cM。在5种环境下对株高和穗位高性状进行鉴定, 复合区间作图法检测到21个株高QTL和25个穗位高QTL。于第1和5染色体的umc2025－umc1035及umc1822－bnlg1118区域检测到平均贡献率分别为12.2%和14.9%的株高QTL。于第3和5染色体的phi029－umc1102及phi109188－bnlg1118区域检测到平均贡献率达到10.2%和22.8%的穗位高QTL。第5染色体的Bin5.05－5.07区域可能存在控制株高和穗位高的主效QTL。株高和穗位高的基因作用方式主要是加性和部分显性效应。文章还分析了群体大小及试验环境对株高和穗位高QTL定位结果的影响     

水稻叶绿素含量的QTL定位

利用由两个籼稻品种Acc8558和H359杂交构建的一个包含131个株系(F19)的重组自交系群体,及其相应的包含147个RFLP和78个AFLP标记的遗传图谱,采用多性状复合区间定位方法,对控制水稻叶绿素含量的QTL进行了定位分析。对叶绿素a和叶绿素b含量各检测到6个QTL,其中5个QTL在两性状问是相同的。这些QTL主要分布在第1和第4染色体上,因此这两条染色体对叶绿素含量是重要的。QTL qChlAlc／qChlBlb(二者位置相同)在4个观测时期均表现较大效应,且在最后的剑叶期贡献最大,因此对叶绿素含量最为重要。另两个QTL(qCh-LA4a／qChlB4a和qChlA4b／qChlB4b)只在第2次观测时期效应显著,表明它们只在特定发育阶段发挥作用。     

玉米抗南方锈病基因的QTL定位

为发掘新的抗南方锈病基因资源,本研究以感病自交系黄早四为母本、抗病自交系W456为父本,构建F2群体并开展抗病基因定位研究。采用人工接种鉴定的方法对两个亲本、F1、F2群体及对照材料进行表型鉴定和遗传分析。利用均匀覆盖10条染色体的200个SSR标记,分析240个F2单株的基因型并构建含有200个SSR位点的遗传连锁图,连锁图总长度3331 cM,标记间平均距离16.6 cM。使用QTL IciMapping V4.1软件中的完备区间作图法对抗病QTL进行分析,共检测到6个控制南方锈病的QTL:qSCR3、qSCR7、qSCR8-1、qSCR8-2、qSCR9和qSCR10,邻近标记分别为umc2105和umc1729、umc1066和bnlg2271、umc1904和umc1984、umc1984和bnlg1651、umc1957和bnlg1401、umc2034和umc1291,分别位于3、7、8、9和10号染色体上,其中8号染色体上有两个位点,标记区间长度在5～19 cM之间。单个QTL的表型贡献率在2.61%～24.19%之间,可以解释表型总变异的62.3%,其中3个QTL贡献率大于10%,位于10号染色体上的qSCR10贡献率最大,可解释表型变异的24.19%。通过对目标区间标记加密,将该位点的定位区间进一步缩小到2.51 cM内,与两侧标记的距离分别是2.15 cM和0.36 cM。初步定位得到10号染色体上存在抗南方锈病的主效QTL,可为抗病品种的培育提供参考。     

水稻光合功能相关性状QTL分析

利用粳稻Kinmaze／籼稻DV85杂交后代单粒传衍生的81个F11家系所组成的重组自交系（Recombinant Inbred Lines,RILs）群体,研究水稻光合功能相关性状的数量性状基因座（QTL）。在水稻抽穗后7d测定叶片全氮含量（TLN）、叶绿素a／b比值（Chl．a：b）和叶绿素含量（Chl）。共检测到6个QTL,各QTL的LOD值为2．66～4．81,贡献率为11．2％-29．6％,其中,在第1、2和11染色体上检测到3个与全氮含量相关的QTL,相应贡献率为17．3％、15．3％、13．7％;在第3和4染色体检测到2个与叶绿素a／b比值相关的QTL,贡献率为13．8％和29．6％;在第1染色体检测到1个与叶绿素含量相关的QTL,贡献率为11．2％。4个QTL为本研究新检测的基因座。有趣的是,控制叶绿素含量的qCC-1位于第1染色体上RFLP标记C122附近,与已报道的NADH-谷氨酸合成酶基因位置一致,而叶绿素合成始于谷氨酸,暗示该基因座与水稻光合功能关系极为密切。然而,对抽穗后30d叶绿素含量进行QTL分析,结果未检测到与其相关的QTL,表明控制叶绿素含量qCC-1效应随水稻叶片的衰老而降低。     

玉米雄穗颜色QTL分析

雄穗是玉米的重要生殖器官,不同品种间玉米的雄穗外观差异明显。对玉米雄穗的颜色进行遗传分析和QTL定位,筛选与雄穗颜色紧密连锁的分子标记,可以作为玉米的品种保护和品种鉴别的有用工具。同时,紫色雄穗中花色苷类色素含量较高,与玉米雄穗的抗虫性密切相关。本研究利用一个黑玉米自交系SDM为共同父本,分别与白玉米自交系木6和黄玉米自交系Mo17杂交,构建2个相关F2∶3群体,分别命名为MuS(木6×SDM)和MoS(Mo17×SDM),在云南和重庆两个不同的环境中种植,对玉米花药颜色(COAn)和花药护颖颜色(COCa)2个性状进行QTL定位。结果表明:玉米花药和花药护颖的颜色均为数量性状,受主效基因和微效基因共同控制。2个群体在2个环境中共检测到7个与花药颜色相关的QTL,位于第2、3、6和10染色体上,其中位于第10染色体标记区间umc1196a-IDP8526内的QTL在重庆和云南同时表达,对表型的贡献率分别为23.17%和19.98%;2个群体在2个环境中共检测到9个与花药护颖颜色相关的QTL,位于第3、6、9和10染色体上,其中3个QTL为环境钝感QTL(在2个环境中均表达,且至少在1个环境中贡献率大于10%),分别位于第6染色体标记区间umc1979-umc1796、mmc0523-umc2006内和第10染色体标记区间umc1196a-umc2043内,对表型的贡献率为10.69%～59.30%。2个群体检测到的主效QTL的位置和效应高度一致,且控制花药颜色和花药护颖颜色2个性状的主效QTL有连锁分布的现象,主要表现在bins 6.04处的标记mmc0523和bins 10.04处的标记IDP8526附近。位于第6和第10染色体上的在不同环境和遗传背景下稳定的QTL可以作为进一步精细定位的靶位点,也可以为玉米雄穗颜色的分子标记辅助选择提供有价值的参考。     

玉米种质资源H21和Mo17抗亚洲玉米螟的QTL分析

本研究以H2 1×Mo17的F2 :3 群体 (12 0个家系 )为作图材料 ,利用SSR和AFLP标记对玉米资源H2 1的亚洲玉米螟抗性进行了数量性状位点 (QTL)分析。结果表明 ,基于叶片侵食度性状 ,检测到 3个QTL ,分别位于染色体 1、5、8上 ;基于茎秆虫孔数性状 ,检测到 3个QTL ,分别位于染色体 4和 10 (2个 )上 ;基于茎秆隧道长度性状 ,检测到 2个QTL ,位于染色体 4和 8上 ;以隧道长度 /虫孔数为鉴定性状 ,检测到 1个QTL ,位于染色体 4上。这些QTL所能解释的表型变异在 7 7%～5 1 8%之间。超显性是QTL作用的主要方式。     

玉米优异早熟种质单330开花相关性状的QTL分析

玉米开花相关性状与玉米的成熟期和产量有密切的联系。通过对玉米CN165×单330(早熟种质)群体的130个F2:3家系开花相关性状在3个环境下进行分子鉴定和数量性状位点(QTL)分析,结果表明,在3个环境中检测到控制抽雄天数的10个QTL,分别位于第2、3、4、5、7、8染色体上,在第8染色体上同一区域在3种环境下都检测到了QTL;检测到控制散粉天数的10个QTL,分别位于第1、2、3、5、7、8染色体上,在第8染色体上同一区域在2种环境下都检测到了QTL;检测到控制吐丝天数的4个QTL,分别位于第4、5、8染色体上,在第8染色体不同环境下都检测到了2个QTL;仅仅在一个环境中检测到控制ASI的2个QTL,分别位于第6、9染色体上。这些QTL的基因效应以部分显性和超显性为主。研究表明,第8染色体上ph i060-um c2401区域(8.03~8.04)是一个研究开花相关性状的重要基因组区段,涉及到的标记可以作为分子标记辅助选择的重要候选标记。     

玉米籽粒重金属铅(Pb2+)含量的QTL定位

铅(Pb²⁺)是现存环境最大量的有毒重金属污染元素,在我国特别是西南地区种植的玉米受重金属Pb²⁺污染日益严重,已严重影响到食物安全。文章利用玉米籽粒Pb²⁺低富集自交系178和籽粒Pb²⁺高富集自交系9782杂交衍生的重组自交系群体为作图群体,利用165对SSR多态性标记,构建了总长度为1499.85 cM、标记间平均距离为9.07 cM的分子遗传图谱,对玉米籽粒Pb²⁺含量性状进行了QTL定位分析,以期为选育籽粒低富集Pb²⁺的玉米新品种提供参考。结果表明,在Pb²⁺浓度为333.32 mg/kg胁迫下,共检测到2个与籽粒Pb²⁺含量相关的QTL,分别位于玉米第1、第4号染色体,其中qPC1位于标记区间umc1661~phi002h之间,表型贡献率为11.13%,加性效应为0.062;qPC4位于umc1117~nc005之间,表型贡献率为5.55%,加性效应为-0.044。性状相关分析结果表明,籽粒中Pb²⁺含量与穗长、穗粗、行粒数、穗重和百粒重等产量性状间均未达到显著水平,表明选育玉米籽粒Pb²⁺低富集的新自交系或杂交种不一定会影响到产量性状,而且籽粒Pb²⁺含量是一个相对独立的遗传性状。     

水稻幼苗特性与籽粒大小关系的分子检测

水稻( Oryza sativa L.)幼苗特性如叶的发生、叶绿素含量、植株高度等对早期生长是重要的,与籽粒大小相联系.以水稻珍汕97A和明恢63组合的重组自交系群体为材料,对5个幼苗特性性状和籽粒大小进行了数量性状基因定位(QTL),目的在于从遗传水平探求幼苗特性与籽粒大小的内在关系.对叶绿素a、总叶绿素含量、第二片叶长、第三片叶长、幼苗高度、粒重分别检测到2、1、5、4、4、9个QTLs.结果揭示4个幼苗特性性状的QTL和4个籽粒大小的QTL位点分别定位在4个相似区域 (G359-RG532、C567-RG236、RZ403-R19和C371-C405a),表明幼苗特性性状与籽粒大小间的紧密关系,也显示控制籽粒大小的几个染色体区域对幼苗特性性状没有影响,这意味着通过标记辅助选择改良幼苗活力但并不增加粒重是可能的.     

苹果叶片相关性状的QTL定位及其遗传效应分析

利用苹果栽培品种‘红富士’和新疆野苹果优系‘红肉苹果’杂交的110个F1株系为作图群体,构建了苹果的分子遗传图谱,采用区间作图法对苹果9个叶片相关性状(叶片长度、叶片宽度、叶片厚度、叶柄长度、叶片面积、总叶绿素含量、叶绿素a含量、叶绿素b含量和类胡萝卜素含量)进行了QTL定位分析。结果显示:从110个F1株系中共检测到20个控制叶片相关性状的QTL位点,分布在第1、2、3、4、5、7、8、10、11、12、16、17连锁群上;各QTL位点的LOD值在2.58~3.55之间,其中主效QTL位点2个(LOD≥3.5),可解释11.63%~16.36%的表型变异。获得紧密连锁的特异标记(CH05d11-435m、CH04c06-201m)为进一步进行QTL精细定位提供了参考。     

Mapping QTLs for root system architecture of maize (Zea mays L.) in the field at different developmental stages

Root system architecture (RSA) is seldom considered as a selection criterion to improve yield in maize breeding, mainly because of the practical difficulties with their evaluation under field conditions. In the present study, phenotypic profiling of 187 advanced-backcross BC(4)F(3) maize lines (Ye478?×?Wu312) was conducted at different developmental stages under field conditions at two locations (Dongbeiwang in 2007 and Shangzhuang in 2008) for five quantitative root traits. The aims were to (1) understand the genetic basis of root growth in the field; (2) investigate the contribution of root traits to grain yield (GY); and (3) detect QTLs controlling root traits at the seedling (I), silking (II) and maturation (III) stages. Axial root (AR)-related traits showed higher heritability than lateral root (LR)-related traits, which indicated stronger environmental effects on LR growth. Among the three developmental stages, root establishment at stage I showed the closest relationship with GY (r?=?0.33-0.43, P?相似文献   

遮光处理对不同生育期小麦生物量分配和叶片叶绿素含量的影响

以普通小麦'扬麦12号'(Triticum aestivum 'Yangmai 12') 为实验材料,研究了遮光处理对不同生育期小麦生物量分配和叶片叶绿素含量的影响.结果显示,从拔节期到完熟期,在不同遮光条件下(对照:相对透光率为100%;T1:相对透光率约为80%;T2:相对透光率约为60%;T3:相对透光率约为20%),小麦地上部分、地下部分及全株干质量随着发育期的延续总体呈增加趋势.遮光处理使小麦地上部分和地下部分干质量较对照不同程度降低,其中遮光对地上部分干质量的影响大于地下部分,并且根冠比随遮光程度的增加而增大.从开花期开始,各个生育期T3处理组小麦的根冠比均为最大,对照组小麦的根冠比均为最小.'扬麦12号'地上部分和地下部分异速生长关系为简单的线性异速生长模型,遮光后小麦的异速性减小,按小麦地上部分和地下部分间的异速性由大至小依次排序为对照组、T1处理组、T2处理组、T3处理组.从抽穗期到乳熟期,对照及各处理组小麦叶片的叶绿素a、叶绿素b及总叶绿素含量在灌浆期(或乳熟期)最高;在不同的生育期,不同遮光处理对小麦叶片中叶绿素a、叶绿素b及总叶绿素含量的影响不同,随着遮光程度的增加,各遮光处理组小麦的叶绿素a/b均不同程度低于对照.     

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.     

两种供氮水平下水稻生长后期相关性状的QTL定位

以特青为母本与Lemont杂交,然后用特青为轮回亲本回交,建立特青背景下的染色体片段置换系（CSSL）群体。在正常和低氮条件下分别在生长后期对株高（PH）、单株穗数（PN）、叶绿素含量（CC）、地上部干物重（SDW）和单株籽粒产量（YD）等性状进行了QTL分析,共检测到31个QTL。其中在正常供氮水平下控制PH、PN、CC、SDW和YD的QTL数目均为3个;在低氮水平下检测到5、4、5和2个影响PH、PN、CC和SDW的QTL,在低氮水平下没有检测到控制YD的位点。大部分QTL集中在第2、3、7、11和12染色体上,影响不同性状或在两种供氮水平下影响同一性状的QTL在染色体上成串或成簇分布。其中RM30-RM439、RM18-RM478、RM309-RM270、RM235-RM17等区域同时检测到控制两个以上性状的QTL,表现出明显的一因多效现象。推测仅在低氮水平下检测到的QTL可能跟水稻对低氮胁迫耐性有一定的关联。     

Identification of Related QTLs at Late Developmental Stage in Rice (Oryza sativa L.) Under Two Nitrogen Levels

QTL underlying related traits at the late developmental stage under two different nitrogen levels were investigated in rice using a population of chromosome segment substitution lines (CSSL) derived from a cross between Teqing and Lemont. A total of 31 QTLs referring 5 traits, that is, plant height (PH), panicle number per plant (PN), chlorophyll content (CC), shoot dry weight (SDW) and grain yield per plant (YD), were detected. Under normal N level, 3 QTLs were detected for each trait, while under low N level, 5,4, 5 and 2 QTLs were detected for PH, PN, CC and SDW respectively. Most of the QTLs were located on chromosome 2, 3, 7, 11 and 12. QTLs controlling different traits or the same trait under different N levels were mapped on the same or adjacent intervals, forming several clusters in rice chromosomes. More than two traits were controlled by QTLs on one of four intervals (RM30-RM439, RM18-RM478, RM309-RM270, and RM235-RM17), suggesting that there were some pleiotropic effects. It was supposed that some QTLs only detected at low N level might be associated with the ability to tolerate the low N stress in rice.     

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)× 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 underlying chlorophyll a/b ratio were mapped on chromosomes 6 and 11. The intrinsic relationship among the four traits and the practical implication in rice breeding are discussed. __________ Translated from Journal of Wuhan University (Science Edition), 2006, 52(6): 751–756 [译自: 武汉大学学报(理学版)]     

小麦幼苗耐热性的QTL定位分析

以小麦DH群体(‘旱选10号’ב鲁麦14’)为材料,在高温(热胁迫)及常温(对照)两种条件下考察小麦幼苗的根干重、苗干重、幼苗生物量、叶片叶绿素含量、叶绿素荧光参数及其耐热指数,并应用基于混合线性模型的复合区间作图法分析幼苗性状及其耐热指数QTL的数量、染色体分布及表达情况,以及QTL与环境的互作效应。结果显示:(1)亲本‘旱选10号’的耐热性明显优于‘鲁麦14’,且杂交后代的耐热性出现超亲分离。(2)控制幼苗耐热相关性状的QTL位点在染色体2D、6B、3A、4A、5A和7A上分布较多,而控制幼苗性状耐热指数的QTL在染色体6A、6B、3A、2D、5A和7A上分布较多,QTL位点在染色体上的分布有区域化的趋势。(3)控制幼苗性状的单个加性QTL和上位性QTL解释的表型变异分别平均为2.48%和2.65%;而控制耐热指数的单个加性QTL和上位性QTL解释的表型变异分别平均为8.84%和1.98%。(4)在热胁迫和对照条件下共检测到与幼苗性状及其耐热指数有关的加性效应QTL 13个和上位性效应QTL 28对,分布在除4D和6D以外的19条染色体上。研究表明,控制幼苗性状的QTL以上位性效应为主,而其耐热指数的QTL以加性效应为主。     

Identification of QTLs for arsenic accumulation in maize (Zea mays L.) using a RIL population

The Arsenic (As) concentration in different tissues of maize was analyzed using a set of RIL populations derived from an elite hybrid, Nongda108. The results showed that the trend of As concentration in the four measured tissues was leaves>stems>bracts>kernels. Eleven QTLs for As concentration were detected in the four tissues. Three QTLs for As concentration in leaves were mapped on chromosomes 1, 5, and 8, respectively. For As concentration in the bracts, two QTLs were identified, with 9.61% and 10.03% phenotypic variance. For As concentration in the stems, three QTLs were detected with 8.24%, 14.86%, and 15.23% phenotypic variance. Three QTLs were identified for kernels on chromosomes 3, 5, and 7, respectively, with 10.73%, 8.52%, and 9.10% phenotypic variance. Only one common chromosomal region between SSR marker bnlg1811 and umc1243 was detected for QTLs qLAV1 and qSAC1. The results implied that the As accumulation in different tissues in maize was controlled by different molecular mechanism. The study demonstrated that maize could be a useful plant for phytoremediation of As-contaminated paddy soil, and the QTLs will be useful for selecting inbred lines and hybrids with low As concentration in their kernels.     

Identification of quantitative trait loci for cold-tolerance of photosynthesis in maize (Zea mays L.)

The effects of low growth temperature (15 degrees C) on the photosynthetic apparatus of maize were investigated in a set of 233 recombinant inbred lines by means of chlorophyll fluorescence, gas exchange measurements and analysis of photosynthetic pigments. A quantitative trait loci (QTL) analysis of five traits related to the functioning of the photosynthetic apparatus revealed a total of eight genomic regions that were significantly involved in the expression of the target traits. Four of these QTLs, located on chromosomes 1 (around 146 cM), 2 (around 138 cM), 3 (around 70 cM), and 9 (around 62 cM), were identified across several traits and the phenotypic correlation observed among those traits confirmed at the genetic level. The two QTLs on chromosomes 1 and 9 were also expressed in leaves developed at near-optimal temperature (25 degrees C) whilst the two QTLs on chromosomes 2 and 3 were specific to leaves developed at sub-optimal temperature. A QTL analysis conducted on traits related to the pigment composition of the leaves developed at 15 degrees C detected the QTL on chromosome 3 around 70 cM in 7 of the 11 traits analysed. This QTL accounted for up to 28% of the phenotypic variance of the quantum yield of electron transport at PSII in the fourth leaf after about 3 weeks at a sub-optimal temperature. The results presented here suggest that key gene(s) involved in the development of functional chloroplasts of maize at low temperature should be located on chromosome 3, close to the centromere.     

Mapping QTLs for root traits under different nitrate levels at the seedling stage in maize (Zea mays L.)

Nitrogen (N) loss is a worldwide problem in crop production. Apart from reasonable N fertilizer application, breeding N efficient cultivars provides an alternative way. Root architecture is an important factor determining N acquisition. However, little is known about the molecular genetic basis for root growth in relation to N supply. In the present study, an F₈ maize (Zea may L.) recombinant inbred (RI) population consisting of 94 lines was used to identify the QTLs for root traits under different nitrate levels. The lateral root length (LRL), axial root length (ARL), maximal axial root length (MARL), axial root number (ARN) and average axial root length (AARL) were evaluated under low N (LN) and high N (HN) conditions in a hydroponics system. A total of 17 QTLs were detected among which 14 loci are located on the same chromosome region as published QTLs for root traits. A major QTL on chromosome 1 (between bnlg1025 and umc2029) for the AARL under LN could explain 43.7% of the phenotypic variation. This QTL co-localizes with previously reported QTLs that associate with root traits, grain yield, and N uptake. Our results indicate that longer axial roots are important for efficient N acquisition and the major QTL for AARL may be used as a marker in breeding N efficient maize genotypes.