不同磷素条件下玉米产量构成因子一致性图谱构建

以玉米高密度遗传连锁图谱IBM2 2008 Neighbors为参考图谱,收集来自不同磷素条件下定位的307个玉米产量构成因子的数量性状位点(quantitative trait locus,QTL),利用Bio Mercator 2.1软件在10条染色体上发掘出36个不同磷素条件下产量构成因子"一致性"QTL(MQTL)区间。图距范围在0.73~7.44 c M之间。通过MQTL两端标记在玉米物理图谱Ref Gen_v2上的位置,将MQTL进行物理图谱定位。MQTL在物理图谱上的图距范围在0.5~10.6 Mb之间。结果表明MQTL位点为今后发掘玉米耐低磷产量构成因子的候选基因提供了基础,为深入理解磷素产量构成因子遗传控制机制和分子设计育种提供科学依据。     

基于元分析和生物信息学分析的玉米抗旱相关性状QTL一致性区间定位

定位玉米基因组中一致的抗旱性区段是玉米抗旱分子育种的重要基础。本研究对至今发表的在干旱条件下定位的相关性状QTL信息搜集整理,以IBM2 2008 Neighbors为参考图谱,利用overview分析和元分析方法进行Meta-QTL (MQTL)检测,共发掘79个MQTL,生物信息学分析结果显示,有43个区间内包含抗旱相关基因信息,占检出MQTL总数的54.43%。基于MaizeGDB网站的Genome Browser中的遗传图谱与物理图谱的整合信息,进行MQTL物理距离的估算,根据maizesequence网站的玉米基因组序列信息,进行初步的抗旱基因预测表明,这些区段中包含丰富的MYB、bZIP以及DREB转录因子序列信息以及大量的LEA基因家族成员。     

大豆重组自交系群体NJRIKY遗传图谱的加密及其应用效果

作物基因组研究,包括基因或数量性状位点(QTL)定位、图位克隆以及物理图谱构建等,首先必须建立具有丰富标记信息的高密度遗传连锁图谱。由科丰1号和南农1138-2杂交组合衍生的重组自交系群体NJRIKY已经构建了4张大豆遗传连锁图谱,但由于遗传信息和标记数目不够充分,在基因和QTL作图时仍然存在精确度和准确度问题。为增加NJRIKY图谱密度,本研究在967对SSR引物中获得了401个多态性SSR标记。结合其他分子数据,使用作图软件Mapmaker/Exp3.0b,获得一张含有553个遗传标记,25个连锁群,总长2071.6cM,平均图距3.70cM的新遗传连锁图谱,其中SSR标记316个,RFLP标记197个,EST标记39个,形态标记1个。连锁群上大于20cM的标记间隔由原来42个减少到2个。原图谱的3个SMV抗性基因定位于D1b连锁群末端的开放区间上且仅与一个RFLP标记连锁,利用加密图谱对Rsc-3、Rsc-7、Rsc-9、Rsc-13、Rsa、Rn1和Rn3等7个SMV抗性基因重定位,全部位于D1b连锁群,与相邻分子标记距离均小于6cM,其中Rsc-9、Rn1、Rsa的距离小于1cM,Rsc-13与EST标记GMKF168a共分离。对本群体农艺性状进行QTL重定位,获得8个性状相关的42个主效QTL,其中20个QTL遗传贡献率大于10%,与原图谱比较,新定位的各QTL的标记区间明显缩短,与相邻标记的连锁更加紧密。     

玉米苗期在盐胁迫下耐盐相关QTL分析

通过对玉米耐盐性状基因的QTL定位,找到耐盐性状控制位点在染色体上的位置,来帮助耐盐玉米品种的选育和基因的克隆。本研究选用耐盐自交系8723和盐敏感自交系P138为材料构建的F2群体,通过Jionmap 4.0软件对F2群体构建分子遗传连锁图谱。构建了一个包含有174个SSR标记位点的分子遗传连锁图谱,平均分布在玉米的10条染色体上共2 764.3 cM,标记区间平均间距为15.88 cM。通过对表型数据的分析,对玉米的4个植株性状进行了QTL定位。结果共检测到8个与玉米苗期耐盐性状相关的QTLs,分别位于2号、4号、6号、9号染色体上。本研究结果为幼苗在盐碱地正常生长提供科学依据。     

基于Meta分析构建抗玉米粗缩病的染色体单片段代换系

为发掘玉米粗缩病抗性基因,解析其遗传规律。借助IBM2 2008 Neighbors遗传图谱,整合已报道的92个抗玉米粗缩病QTLs(Quantitative trait locus),通过Meta分析获得24个"一致性"抗病区间。利用生物信息分析,确定抗病区段的物理位置信息,在相关区段对郑58和齐319的全基因组重测序序列分析鉴定出7 142个InDel位点,其中546个含有InDel位点的序列可用于引物开发,进一步通过试验筛选出在郑58和齐319第2,4,5,6,7,8,10号染色体上的多态InDel位点158个。以抗粗缩病玉米自交系齐319为供体亲本,感病优良自交系郑58为受体亲本,利用上述InDel标记辅助选择构建整套染色体单片段代换系材料。为抗玉米粗缩病QTL位点的精细定位提供了可能,也为抗病育种提供新的种质资源。     

玉米抗矮花叶病QTL定位

利用玉米自交系X178（抗）和B73（感）组配的F2群体（234个单株）,构建了包含249个SSR和AFLP标记位点的遗传连锁图谱,图谱全长1 659.3 cM,平均图距6.58 cM。采用人工接种法对216个F3家系在苗期、拔节期和抽雄期分别进行玉米矮花叶病的抗性鉴定。应用复合区间作图法分析抗病QTL与基因效应。结果表明,在3个发育阶段检测到的     

玉米抗病基因一致性图谱的构建

发掘和精细定位玉米抗病基因是构建玉米抗病分子育种技术体系的重要基础。利用生物信息学手段,整理文献和玉米基因组数据库中已有的抗病基因定位的信息,借助高密度玉米分子标记连锁图谱IBM2 2005 neighbors,通过染色体映射的方法,绘制了玉米抗病基因的一致性图谱。结果显示,在试验涉及到的14种主要玉米病害的78个抗病主基因或QTL之中,抗病基因在各条染色体上呈不均匀分布,第3、第6、第10染色体上的主效抗病基因较多,第5和第7染色体上的抗病基因较少,且抗病基因呈簇集分布。研究结果为进一步发掘和鉴定玉米抗病基因和建立玉米抗病分子标记辅助育种技术体系奠定了基础。     

猪肉嫩度相关QTL整合定位与基因关联分析研究

为了优化猪肉嫩度相关数量性状位点(quantitative trait loci,QTL),为基因的精细定位和克隆奠定基础。通过Meta分析,利用数学模型整合猪肉嫩度相关QTL,分析已知候选基因与“真实”QTL的关联性。收集猪肉嫩度相关QTL,将其逐一映射到美国肉畜研究中心(USDA-MARC 2.0)公布的猪遗传连锁图谱,构建整合图谱。进行Meta分析,得到精确性更高的“真实”QTL,并将已知候选基因映射到整合图谱,比较候选基因与各“真实”QTL的关联性。研究表明：99个猪肉嫩度相关QTL映射到参考图谱,构建成新的整合图谱。通过Meta分析,定位了16个“真实”QTL,图距2.42~25.18 cM,比较原始QTL缩短29.21%~93.18%。值得一提的是MQTL1和MQTL2,图距仅为2.42 cM和3.22 cM,且分别由9个和20个原始QTL聚合而成,有较高的研究价值。将FABP3、MYPN和ANK1基因映射到整合图谱,分别定位在MQTL5、MQTL12和MQTL16区间内,距离中心位置5.70 cM、3.67 cM和2.49 cM,可将这些区间作为关键区域,开展基因精细定位和挖掘工作。     

玉米产量相关性状QTL通用图谱的构建及功能候选基因的开发

通过生物信息学手段,收集整理玉米基因组数据库中产量相关性状的QTL信息,借助高密度玉米遗传连锁图谱IBM 2005 Neighbors和临近分子标记,建立了涵盖干物质和淀粉产量、籽粒相关性状、粒重相关性状以及穗部相关性状四大类共计18个指标的QTL通用图谱。并将位于QTL分布密集区域的基因,与水稻基因序列进行比对,找到了与水稻木质素合成有关的gh2具有高同源性的基因AY109876,同时改进了利用生物信息学手段筛选功能候选基因的路线图。     

大豆主茎节数数量性状座定位及遗传效应分析

为了定位控制主茎节数的QTL并明确其遗传效应,利用100对SSR引物,并采用Mapmaker Exp 3.0和复合区间法,研究构建了一张包括3个连锁群的连锁图谱。以‘黑农37’（栽培大豆）×ZYD581（野生大豆）组合的亲本、F₂、F₃为试材,分别在chr1连锁群上定位了一个影响大豆主茎节数的QTL,2007年QTL位于Satt238—Satt242这个区间内,与Satt238的遗传距离是0.01 cM,与Satt242的遗传距离是24.69 cM,其遗传贡献率为17.22%,加性效应为-3.2608;2008年QTL位于Satt238—Satt240之间,与Satt238的遗传距离为0.59 cM,与Satt240的遗传距离为6.01 cM,其遗传贡献率为6.68%,加性效应为-1.4965。2年大豆主茎节数QTL分析表明,在chr1连锁群上Satt238附近确定了1个控制大豆主茎节数QTL位点。     

干旱和灌溉两种处理条件下玉米株高、产量的QTL分析

为了对玉米的抗旱遗传学研究以及开展抗旱分子标记辅助育种提供有力支撑,利用SSR分子标记技术,构建了玉米基于RIL6群体的遗传连锁图谱,包含101个位点,覆盖玉米基因组1 395.2 cM,标记间平均距离为13.81 cM。在灌溉与干旱两种环境下,对该RIL家系的株高、产量进行QTL初级定位,在灌溉条件下,检测到3个控制株高和3个控制产量的QTL,在干旱条件下,检测到5个控制株高和3个控制产量的QTL,两种水分条件下检测出的QTL不同,并找到1个相对稳定的QTL。     

玉米产量性状“一致性QTL”分析

在构建含221个玉米产量性状QTL整合图谱的基础上,采用元分析方法,当LOD值≥4.0时,在第2染色体上确定了1个控制粒重和穗数的“一致性QTL”,介于标记Sdg107和Isu2117b之间,间距30.99 cM;同样,在第3和第4染色体上发掘了2个控制穗数和粒重的“一致性QTL”,分别由标记ucsd72d和IDP37...     

QTL mapping of maize (Zea mays) stay-green traits and their relationship to yield

A maize genetic linkage map derived from 115 simple sequence repeat (SSR) markers was constructed from an F₂ population. The F₂ was generated from a cross between a stay-green inbred line (Q319) and a normal inbred line (Mo17). The map resolved 10 linkage groups and spanned 1431.0 cM in length with an average genetic distance of 12.44 cM between two neighbouring loci. A total of 14 quantitative trait loci (QTL) were detected for stay-green traits at different postflowering time intervals and identified by composite interval mapping. The respective QTL contribution to phenotypic variance ranged from 5.40% to 11.49%, with trait synergistic action from Q319. Moreover, maize stay-green traits were closely correlated to grain yield. Additional QTL analyses indicated that multiple intervals of stay-green QTL overlapped with yield QTL.     

Mapping quantitative trait loci for oil,starch, and protein concentrations in grain with high-oil maize by SSR markers

The objective of this investigation was to map QTL controlling oil, protein, and starch concentrations in maize grain and to evaluate their genetic effects. The mapping population included 298 F_2:3 family lines containing Beijing high-oil (BHO) maize germplasm. F₂ individuals were genotyped with 183 SSR markers to construct a genetic linkage map, which spanned 1,605.7 cM, with an average interval of 8.77 cM. Oil, protein, and starch concentrations in grain among F_2:3 families were measured by near-infrared (NIR) analyzer. Using QTL Cartographer, we mapped six QTL associated with oil in grain, six associated with protein, and five associated with starch concentrations. The proportion of phenotypic variation explained by single QTL ranged from 4.34 to 13.13% for oil, from 5.19 to 6.66% for protein, and from 4.14 to 7.85% for starch concentrations. QTL for oil, protein, or starch concentrations were often detected in identical intervals and the direction of their effects were consistent with the sign of their phenotypic correlation. They were considered as common QTL for chemical compositions in maize grain. In this study, we identified three QTL for oil in grain, two QTL for protein, and three QTL for starch concentrations, which were on identical or similar chromosomal locations to those previously mapped with Illinois high-oil (IHO) maize germplasm. These suggests that more diverse germplasm should be necessary to detect additional QTL and to discover more favorable alleles for chemical composition of maize grain.     

QTL mapping of a partial resistance to the corn delphacid‐transmitted viruses in Lepidopteran‐resistant maize line Mp705

A partial resistance to maize mosaic virus (MMV) and maize stripe virus (MStV) was mapped in a RILs population derived from a cross between lines MP705 (resistant) and B73 (susceptible). A genetic map constructed from 131 SSR markers spanned 1399 cM with an average distance of 9.6 cM. A total of 10 QTL were detected for resistance to MMV and MStV, using composite interval mapping. A major QTL explaining 34–41% of the phenotypic variance for early resistance to MMV was detected on chromosome 1. Another major QTL explaining up to 30% of the phenotypic variation for all traits of resistance to MStV was detected in the centromeric region of chromosome 3 (3.05 bin). After adding supplementary SSR markers, this region was found to correspond well to the one where a QTL of resistance to MStV already was located in a previous mapping study using an F₂ population derived from a cross between Rev81 and B73. These results suggested that these QTL of resistance to MStV detected on chromosome 3 could be allelic in maize genome.     

玉米抗丝黑穗病QTL分析

以Mo17（抗）×黄早四（感）的F₂分离群体（191个单株）为作图群体,构建了含有84个SSR位点和48个AFLP位点的遗传连锁图谱,全长1 542.9 cM,平均图距11.7 cM。在吉林省公主岭和黑龙江省哈尔滨2个地点通过人工接种方法对184个相应的F₃家系（缺失7个）进行抗病鉴定。采用复合区间作图法对抗丝黑穗病数量性状位点（QTL）进行定位及遗传效应分析。在吉林公主岭地区检测到5个QTL,分别位于第1、2、3、8、9染色体上,解释的表型方差为10.0%~16.3%。在黑龙江哈尔滨地区也检测到5个QTL,分别位于第1、2、3、4、7染色体上,解释的表型方差为4.6%~13.4%。比较分析发现,两地一致在第2、3染色体上各检测到1个QTL,其中第2染色体上的表现为超显性效应,第3染色体上的表现为加性效应。研究结果为玉米抗丝黑穗病种质改良提供了重要信息。     

玉米SSR连锁图谱构建与株高及穗位高QTL定位

用玉米自交系组合R15×掖478的F₂群体构建连锁图谱,并通过1年2点随机区组试验设计,考察玉米229个F_2:4家系成株期的株高和穗位高。所建连锁图谱上共拟合146个SSR标记位点,覆盖基因组1 666 cM,标记间平均距离为11.4 cM。用复合区间作图法进行QTL分析,共检测到8个控制株高的QTL,分别位于第2、3、4、5和8染色体;3个控制穗位高的QTL位点,位于第4染色体。单个株高QTL的贡献率变幅为6.67%~11.59%,单个穗位高QTL贡献率变幅为10.46%~12.15%。     

QTL underlying field grain drying rate after physiological maturity in maize (<Emphasis Type="Italic">Zea Mays</Emphasis> L.)

Grain moisture in maize at harvest depends on the grain drying rate (GDR) after physiological maturity. The maize plants with high GDR can reduce grain moisture rapidly, which will shorten the drying time after harvest and prevent the grain to be mildew and enhance maize quality. In this study, A total of 280 recombinant inbred lines that were derived from a cross between Ji846 (high drying rate, 1.18 % day⁻¹) and Ye3189 (slow drying rate, 0.39 % day⁻¹) were used to construct genetic linkage map and identify QTL underlying GDR in different environments. A genetic linkage map was constructed containing 97 SSR and 49 AFLP markers, which covered 2356.8 cM of the maize genome, with an average distance of 16.1 cM. Composite interval mapping identified 14 QTL for GDR after physiological maturity located on chromosomes 2, 3, 5, 6 and 8. The additive effects of QTL were all from Ji846. The range of phenotypic variation explained by the QTL was 5.05–16.28 %. But only two QTL (qKdr-2-1, qKdr-3-6) were identified across both locations. qKdr-2-1 positioned between the markers phi090-umc1560 on chromosome 2 explained 15.59 % of the phenotypic variance, and the other qKdr-3-6 positioned between the markers phi046-bnlg1754 on chromosome 3 explained 10.28 % of the phenotypic variance.     

猪肉pH值相关QTL整合定位与基因关联分析

为了整合与优化猪肉pH值相关数量性状位点(quantitative trait loci,QTL),为分子标记辅助选择奠定基础。采用Meta分析,整合猪pH相关QTL,并对已知候选基因与“真实”QTL进行关联。收集猪肉pH值相关QTL,将其映射到美国肉畜研究中心(USDA-MARC 2.0)公布的猪遗传连锁图谱,构建新的整合图谱,新图谱中的QTL簇经Meta分析,聚合为“真实”QTL (MQTL)。进一步将已知候选基因映射到整合图谱,比较候选基因与各“真实”QTL的位置差异,分析其关联性。结果显示：224个原始QTL聚合成37个QTL簇,通过Meta分析,得到37个“真实”QTL。“真实”QTL的置信区间1.35~25.32 cM,相比原始QTL缩短29.20%~92.36%。其中,MQTL35、MQTL16、MQTL10、MQTL4和MQTL17的置信区间均在5 cM以内,且分别是由7、8、4、5、7个QTL聚合而成,具有较高的精确度和一致性。LYZ、RYR1、VTN、MYPN和PRKAG3基因映射到整合图谱后,分别定位在MQTL13、MQTL18、MQTL29、MQTL32和MQTL34置信区间内,可将其作为关键区域,开展深入研究工作。     

Molecular mapping of a major QTL conferring resistance to SCMV based on immortal RIL population in maize

Sugarcane mosaic virus (SCMV) is one of devastating pathogens in maize (Zea mays L.), and causes serious yield loss in susceptible cultivars. An effective solution to control the virus is utilizing resistant genes to improve the resistance of susceptible materials, whereas the basic work is to analyze the genetic basis of resistance. In this study, maize inbred lines Huangzao4 (resistant) and Mo17 (susceptible) were used to establish an F₉ immortal recombinant inbred line (RIL) population containing 239 RILs. Based on this segregation population, a genetic map was constructed with 100 simple sequence repeat (SSR) markers selected from 370 markers, and it covers 1421.5 cM of genetic distance on ten chromosomes, with an average interval length of 14.2 cM. Analysis of the genetic map and resistance by mapping software indicated that a major quantitative trait locus (QTL) was between bin6.00 and bin6.01 on chromosome 6, linked with marker Bnlg1600 (0.1 cM of interval). This QTL could account for 50.0% of phenotypic variation, and could decrease 27.9% of disease index.