玉米幼胚培养能力性状QTL分析

以18-599（红）和R15组配的F₂群体,构建了含88对SSR标记的玉米遗传连锁图谱,覆盖基因组1 636.6 cM,标记间平均距离为18.6 cM。结合幼胚组织培养试验将幼胚发生胚性愈伤组织诱导率和胚性愈伤组织绿苗再分化数作为反映玉米培养过程中胚性愈伤组织诱导力和胚性愈伤组织绿苗再分化力的性状指标,以此调查玉米幼胚培养能力。利用复合区间作图法进行QTL分析,共检测到5个与胚性愈伤组织诱导率有关的QTL,位于第1、3、7和8染色体上,可解释5.25%～23.4%的表型变异;检测到1个与胚性愈伤组织绿苗发生数有关的QTL,位于第3染色体上,可解释表型变异率为13.42%。     

杂交棉‘冀1518’纤维品质性状的QTL定位及遗传分析

‘冀1518’是以优质品种‘冀228’为母本,丰产品系‘冀567’为父本配制的适机采杂交棉新品种,为挖掘‘冀1518’的优异纤维品质相关分子标记,本研究利用杂交棉‘冀1518’的亲本构建了F_2、F_(2:3)和F_(2:9)(重组近交系)(recombinant inbred lines, RILs)三个世代的分离群体,并利用SSR分子标记分别以F_2群体和RIL(F_(2:9))群体构建遗传连锁图谱,并对纤维品质性状进行定位。结果表明,F_2作图群体共有15个标记位点连锁,包含4个连锁群,全长覆盖237.10 cM,RIL (F_(2:9))作图群体共有45个标记位点连锁,包含11个连锁群,全长覆盖554.42 cM。利用QTL IciMapping 4.1对F_2、F_(2:3)和RIL (F_(2:9))群体的纤维品质性状进行复合区间作图法分析,在F_2及F_(2:3)分离群体能同时检测到15个与纤维品质相关的QTLs,其中,与马克隆值相关的QTL位点q FM-4-2解释表型变异率最高,为21.10%,显性或超显性效应的QTLs占总数的66.7%,表明显性基因是‘冀1518’纤维品质杂种优势的主要来源。在RIL (F_(2:9))群体定位到6个与纤维品质性状相关的QTLs,解释表型变异率在5.10%～10.26%之间。F_2、F_(2:3)和RIL (F_(2:9))群体均能在HAU2349附近(F_(2:9)作图, 0.31 cM)检测到与断裂比强度和马克隆值相关的QTL位点,在HAU2710附近(F_(2:9)作图, 0.84 cM)检测到与整齐度相关的QTL位点,且上述两标记连锁,连锁区段被定位在A6染色体上。本研究获得在多世代中稳定表达的QTLs,有望用于纤维品质分子标记辅助选择,提高育种效率。     

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。     

超级杂交稻协优9308重组自交系的分子遗传图谱构建

用超级杂交稻协优9308的母本协青早A的保持系协青早B和父本恢复系中恢9308杂交,以单粒传方法建立含281个株系的重组自交系（RIL）群体。选用695对简单重复序列（SS鼬引物进行亲本多态性筛选,共有186对检测到多态性,频率为26．8％。构建成的水稻分子遗传图谱共包含163个标记座位,总图距约1578．9cM,覆盖整个基因组的87．5％,标记间平均图距为9．69cM。群体和标记中母本等位基因频率平均为0．52,群体中标记偏分离情况较严重。该图谱的构建为研究超级杂交稻协优9308各种性状的遗传规律及QTL定位打下了基础。     

以性状和分子标记为基础的水稻近等基因系的分离

以珍汕97/明恢63的一个含234个重组自交系的F6：7群体为材料, 通过以性状和分子标记为基础的方法在该群体中分离了每穗实粒数和千粒重这两个性状的近等基因系及对这两个性状有效应的QTL标记位点和两两互作位点的近等基因系。 在重组自交系RIL65和RIL197家系内分别分离了每穗实粒数和千粒重的近等基因系。 在重组自交系RIL54     

水稻稻瘟病抗性基因定位与候选基因辅助选育

本试验研究了304个来源于中156／谷梅2号的重组自交系（RIL）和80个来源于Vandana／Moroberekan的高世代回交群体（BC3B和BC3F4）。在RIL中，利用RFLP，RAPD，SSLP，RGA和候选基因标记定位了一个对菲律宾稻瘟病菌株Ca89（谱系4）的抗性主基因，该基因来源于谷梅2号，暂定名为Pi-26（t），位于第6染色体上的两个RGA标记之间，距离标记RGA24a为4．9cM，距离RGA6a为8．4cM。同时，定位了对浙江稻瘟病菌株92-183的两个抗性基因，其中一个基因来自于中156，     

玉米抗甘蔗花叶病毒QTL的初步研究

以黄早四(抗)×掖107(感)的F2分离群体(184个单株)为作图群体, 构建了具有65个SSR标记位点的遗传连锁图谱, 覆盖玉米基因组1333.3 cM, 标记间平均距离20.5 cM. 通过人工接种鉴定评价184个F3家系对SCMV引起的玉米矮花叶病的抗性反应. 采用复合区间作图法对抗病数量性状位点(QTL)进行定位及遗传效应分析, 结果共检测到3个QTLs,     

山农01-35×藁城9411重组自交系遗传图谱构建及粒重QTL分析

为利用分子遗传图谱进行小麦产量数量性状位点定位分析,以大粒高产小麦品系山农01-35和强筋小麦藁城9411为亲本,衍生了含182个家系的重组自交系(RIL)F₈群体,用442个DArT标记、59个SSR标记和1个TaGW2-CAPS标记,构建了包括29个连锁群的分子遗传图谱,总遗传长度为4 084.5 cM,标记间平均距离为8.13 cM。定位了54个新标记位点,包括44个DArT和10个SSR标记,分布于除4D、6B、7B外的其他18条染色体上。用该分子遗传图谱和4个环境粒重表型值,共检测到7个影响粒重的加性QTL,分别位于1B、4B、5B、6A染色体,其中QGW4B-7、QGW5B-20和QGW6A-29在单环境分别定位和4个环境共同定位两种方法中均能检测到。QGW4B-7、QGW5B-12和QGW6A-29对粒重的贡献率均超过10%,为主效QTL。本研究结果可为小麦高产优质性状的QTL分析及分子标记辅助选择提供参考。     

不同世代小麦花药培养的遗传效应分析

实验用4个小麦杂交组合的6个不同世代群体为材料分别进行花药培养,对各材料出愈率、绿苗率、白苗率和白苗/绿苗比4个性状的世代平均值进行多元回归分析。结果表明:各组合出愈率存在明显的显性效应和显性×显性互作;绿苗率以加性效应和显性效应为主;白苗率则主要受上位性效应的影响.从而提出在小麦花药培养中注意利用杂种优势可以提高出愈率和绿苗率;选择一般配合力高的亲本杂交可以提高绿苗率,但对白苗率无多大影响。本文对同一性状不同组合、同一组合不同性状的遗传构成以及遗传因素对花粉白苗的影响等问题进行了讨论。     

花生SSR标记与品质性状的相关分析

为了研究花生SSR分子标记与品质性状之间的关系,本研究以农家品种四粒红和冀农黑3号杂交产生的251个重组自交系(RIL)群体为材料,运用SPSS17.0软件分析花生RIL群体品质性状与SSR分子标记的相关性。结果表明多数品质性状间有极显著或显著相关的关系。棕榈酸和油酸的相关系数最高为(r=-0.887),其次为硬脂酸和油酸(r=-0.753)。Pearson’s相关分析表明77个分子标记与8个品质性状存在着显著相关性。运用多元回归分析得到45个与8个品质性状相关的标记,解释的表型总变异的范围为8.1%~28.5%。上述结果为利用分子标记辅助选择改良花生的品质性状提供了参考。     

利用重组自交系定位棉花第22染色体短臂的纤维品质性状的QTL

 以TM-1的染色体片段代换系CSB22sh和TM-1杂交,构建了包含104个家系的重组自交系（RILs）群体。利用74对具有多态性位点的引物进行检测,构建了包含61个多态性位点,长度为76.93 cM的遗传图谱,平均标记间距离1.26 cM。利用此遗传图谱结合重组自交系群体4个环境下的5个纤维品质性状进行QTL定位,共定位出12个QTLs,解释性状表型变异的2.45%～21.11%;在1,2,3,4个环境中同时检测到的QTLs分别有9,1,1,1个。而利用4个环境平均值进行联合分析定位出个4个QTLs,纤维长度和纤维整齐度的QTLs均为2个,解释性状表型变异的14.37%～19.97%,并且纤维长度和整齐度的QTL在相同的位置。多环境下检测到的QTL可能对标记辅助选择有实际应用价值。     

Identification of QTL for stalk sugar-related traits in a population of recombinant inbred lines of maize

Increasing sugar content in silage maize stalk improves its forage quality and palatability. The genetic mapping and characterization of quantitative trait loci (QTLs) is considered a valuable tool for trait enhancement, yet little information on QTL for stalk sugar content in maize has been reported. To this end, we investigated QTLs associated with stalk sugar traits including Brix, plant height (PHT), three ear leaves area (TELA), and days to silking (DTS) in two environments using a population of 202 recombinant inbred lines from a cross between YXD053, which has a high stalk sugar content, and Y6-1, which has a low stalk sugar content. A genetic map with 180 SSR and 10 AFLP markers was constructed, which spanned 1,648.6 cM of the maize genome with an average marker distance of 8.68 cM, and QTLs were detected using composite interval mapping. Seven QTLs controlling Brix were mapped on chromosomes 1, 2, 6 and 9 in the combined environments. These QTLs could explain 2.69–13.08 % of the phenotypic variance. One major QTL for Brix on chromosome 2 located between the markers bnlg1909 and umc1635 explained 13.08 % of the phenotypic variance. Y6-1 also contributed QTL allele for increased Brix on chromosome 6. One major QTLs controlling PHT on chromosome 1 and TELA on chromosome 4 were also identified and accounted for 13.68 and 12.49 % of the phenotypic variance, respectively. QTL alleles for increased DTS were located on chromosomes 1 and 5 of YXD053. Significant epistatic effects were identified in four traits, but no significant QTL × environment interactions were observed. The information presented here may be valuable for stalk sugar content improvement via marker-assisted selection in silage maize breeding programs.     

Identification of QTLs for rice grain size and shape of Iranian cultivars using SSR markers

Grain size is a main component of rice appearance quality. In this study, we performed the SSR mapping of quantitative trait loci (QTLs) controlling grain size (grain length and breadth) and shape (length/breadth ratio) using an F₂ population of a cross between two Iranian cultivars, Domsephid and Gerdeh, comprising of 192 individuals. A linkage map with 88 markers was constructed, which covered 1367.9 cM of the rice genome with an average distance of 18 cM between markers. Interval mapping procedure was used to identify the QTLs controlling three grain traits, and QTLs detected were further confirmed using composite interval mapping. A total of 11 intervals carrying 18 QTLs for three traits were identifed, that included five QTLs for grain length, seven QTLs for grain breadth, and six QTLs for grain shape. A major QTL for grain length was detected on chromosome 3, that explained 19.3% of the phenotypic variation. Two major QTLs for grain breadth were mapped on chromosomes 3 and 8, which explained 34.1% and 20% of the phenotypic variation, respectively. Another two major QTLs were identified for grain shape on chromosomes 3 and 8, which accounted for 27.1% and 20.5% of the phenotypic variance, respectively. The two QTLs that were mapped for grain shape coincided with the major QTLs detected for grain length and grain breadth. Intrestingly, gs2 QTL specific to grain shape was detected on chromosome 2 that explained 15% of the phenotypic variation.     

Molecular mapping of quantitative trait loci for domestication traits and β-glucan content in a wheat recombinant inbred line population

Genetic maps are useful for analysis of quantitative trait loci (QTLs) and for marker-assisted selection (MAS) in breeding. A simple sequence repeat (SSR) marker linkage map of common wheat was constructed based on recombination inbred lines (RILs) derived from a cross between Chinese Spring and spelt wheat. The map included 264 loci on all wheat chromosomes covering 2,345.2 cM with 962, 794.6, and 588.6 cM for the A, B, and D genomes, respectively. Using the RILs and the map, we detected 42 putative QTLs on 15 chromosomes for ear length, spikelet number, spike compactness, kernel length, kernel width, kernel height and β-glucan content. Each QTL explained 4–45% of the phenotypic variation. Five QTL cluster regions were detected on chromosomes 1A, 5AL, 2B, 2D, and 4D. The first QTLs for β-glucan content in wheat were identified on chromosomes 3A, 1B, 5B, and 6D.     

海岛棉CSSLs分子评价及纤维品质、产量性状QTL定位

本课题组前期以陆地棉中棉所8号(CCRI8)为轮回亲本, 海岛棉Pima 90-53为供体亲本培育了一套陆地棉中棉所8号为背景的海岛棉染色体片段置换系(CSSLs), 本研究利用SSR标记对该置换系群体BC₃F₅进行基因型检测, 在3个不同环境下(河北保定、青县和新疆轮台)鉴定其纤维品质和产量相关性状并进行QTL定位。该置换系群体包含182个家系, 置换片段数在1~15个之间, 平均为6.6个; 导入片段长度在0.7~83.2 cM之间, 平均长度为16.8 cM; 置换片段总长度20 249.6 cM; 背景回复率在92.3%~99.6%之间, 平均为96.2%。共检测出59个相关的QTL, 其中与纤维品质性状相关的41个, 单个QTL的贡献率为1.27%~26.66%; 与产量性状相关的18个, 单个QTL的贡献率为2.03%~19.38%; 检测到14个稳定的QTL, 其中4个马克隆值和2个纤维伸长率相关的稳定QTL增效基因均来自高值亲本海岛棉Pima 90-53, 2个铃重相关的稳定QTL增效基因来自高值亲本陆地棉中棉所8号。研究结果为深入开展纤维品质和产量性状的QTL精细定位、QTL间互作和分子育种提供了理论依据。     

向日葵高密度遗传连锁图谱构建及两种水分条件下芽期性状的QTL分析

干旱胁迫对向日葵发芽出苗有重要影响。以K55×K58组合衍生的187个F6重组自交系为材料,利用SSR、SRAP、AFLP标记构建向日葵高密度遗传连锁图谱,设置正常水分(CK)和模拟干旱(18%聚乙二醇PEG-6000)两种水分条件,调查9个芽期数量性状,PCR扩增株系,构建一张包含17个连锁群、1105个标记(368个SSR、368个SRAP和369个AFLP)的高密度遗传连锁图谱。该图谱覆盖基因组长度3846.0 c M,平均图距3.48 c M,连锁群长度147.6~295.5 c M,每个连锁群标记数10~165个。两种条件下检测到33个QTL,其中干旱条件下检测到发芽指数、发芽率、胚芽长、胚根长、胚芽鲜重和胚根鲜重6个性状的14个QTL,可解释6.1%~14.0%的表型变异;正常水分(CK)条件下检测到发芽势、胚根长、胚芽鲜重、胚根鲜重、胚根干重和胚芽干重6个性状的19个QTL,可解释6.1%~25.8%的表型变异。两种水分条件下检测到Qefw5-1、Qefw5-2、Qefw5-4、Qrfw5、Qrfw10和Qrl9共6个QTL的遗传贡献率超过10%,此外,还检测到9个影响干旱胁迫与正常水分条件下性状差值的QTL,可能对抗旱性有直接贡献。这些QTL可为向日葵芽期抗旱分子设计育种研究提供重要参考。     

栽培种花生荚果大小相关性状QTL定位

以远杂9102为母本,徐州68-4为父本杂交衍生的F5和F6共188个家系,构建了一张包含365个标记,总长度713.07 c M,标记间平均距离1.96 c M的栽培种花生遗传图谱。图谱包含22个连锁群,各连锁群平均长度12.37~81.39 c M,连锁群上标记数量3~46个。结合2013和2014年采集的荚果表型数据,采用Win QTLcart 2.5软件的复合区间作图法(composite interval mapping,CIM)进行QTL定位和效应估计。2个环境下共检测到41个QTL,其中与荚果长、宽、厚和百果重相关的QTL分别为13、7、13和8个,表型变异解释率为3.14%~18.27%。有6个QTL在2种环境下被重复检测到,其中百果重相关的2个(q HPWLG13.1、q HPWLG14.1),分布在LG13和LG14连锁群,遗传贡献率为6.95%~14.60%;与荚果长相关的3个(q LPLG2.2、q LPLG13.1、q LPLG14.1),分布在LG2、LG13和LG14连锁群,遗传贡献率为3.14%~18.27%;与荚果厚相关的1个(q TPLG3.4),分布在LG3连锁群,遗传贡献率为8.24%~9.24%。本研究涉及性状存在9个QTL热点区,每个热点区涉及2~3个性状,表型贡献率为3.57%~18.27%。     

Identification of quantitative trait loci for seedling cold tolerance using RILs derived from a cross between japonica and tropical japonica rice cultivars

Cold tolerance at the seedling stage of rice is an important phenotypic trait that causes normal plant growth and stable rice production in temperate regions as well as tropical high-lands in Asia and Africa. In order to find quantitative trait loci (QTLs)/genes associated with cold tolerance, we constructed a linkage map using 153 recombinant inbred lines (RILs) derived from a cross between a cold-tolerant temperate japonica cultivar, Geumobyeo, and a cold-sensitive tropical japonica breeding line, IR66160-121-4-4-2. The RILs were phenotyped for cold tolerance or sensitivity based on the degrees of cold tolerance as cold tolerance indices at the seedling stage. The seedlings for cold-tolerance/-sensitive traits were scored on the 7th day of the recovery period at 25°C after cold treatment at 10°C. Two QTLs (qCTS4a and qCTS4b) associated with cold tolerance at the seedling stage were identified on the long and short arms of chromosome 4 with an LOD score of 2.89 and 2.75, respectively, using composite interval mapping. The QTLs were flanked by simple sequence repeat (SSR) markers RM3648-RM2799 and RM3375a-RM558 that explained 8.3 and 7.8% of the total phenotypic variation, respectively. Seven of the selected RILs expressed cold tolerance at both the seedling and reproductive stages. The SSR markers associated with the QTLs will be useful for tracking favorable QTLs/genes into cold-sensitive elite cultivars and may have potential for pyramiding different QTLs for the improvement of cold tolerance in rice.     

陆地棉衣分差异群体产量及产量构成因素

 以衣分差异较大的陆地棉品种为材料,构建了包含188个F₂单株的作图群体,应用6111对SSR引物对亲本进行了分子标记筛选,结果仅获得了123个多态性位点,其中88个位点构建了总长为666.7 cM、平均距离为7.57 cM的遗传图谱,覆盖棉花基因组的14.9%。通过复合区间作图法对F₂单株和F_2∶3家系进行QTL检测,共鉴定出了18个控制产量及产量构成因素变异的QTLs,包括2个衣分QTLs、4个子棉产量QTLs、4个皮棉产量QTLs、2个衣指QTLs、3个单株铃数QTLs、2个铃重QTLs和1个子指QTL。 解释的表型变异分别为\{6.9%\}～16.9%、5.6%～16.2%、4.8%～15.6%、7.7%～13.3%、8.2%～11.6%、6.1%～7%和6.6%。不同QTLs在相同染色体区段上的成簇分布表明与产量性状相关的基因可能紧密连锁或一因多效。产量及产量构成因素QTLs的遗传方式主要以显性和超显性效应为主。检测到的主效QTLs可以用于棉花产量及产量构成因素的分子标记辅助选择。     

利用永久F2群体定位小麦株高的QTL

为研究小麦株高的遗传机制,利用DH群体构建了一套包含168个杂交组合的小麦永久F₂群体, 并于2007年种植于山东泰安和山东聊城。构建了一套覆盖小麦21条染色体的遗传连锁图谱并利用该图谱的324个SSR标记对小麦株高进行QTL定位研究,使用基于混合线性模型的QTLNetwork 2.0软件进行QTL分析。在永久F₂群体中定位了7个株高QTL,包括4个加性QTL,一个显性QTL,一对上位性QTL,共解释株高变异的20%,其中位于4D染色体的qPh4D,具有最大的遗传效应,贡献率为7.5%;位于2D 染色体显性效应位点qPh2D,可解释1.6%的表型变异;位于5B~6D染色体上位效应位点,可解释1.7%的表型变异。还发现加性效应、显性效应和上位效应对小麦株高的遗传起重要作用,并且基因与环境具有互作效应,结果表明利用永久F₂群体进行QTL定位研究的方法有助于分子标记辅助育种。