大豆产量和产量构成因子及倒伏性的QTL分析

随机选取中豆29×中豆32重组自交系群体中165个家系作为2年田间试验材料,分析大豆单株产量、产量构成因子及倒伏性等性状的相关性和遗传效应,并检测各性状QTL。结果表明,38个与产量、产量构成因子及倒伏性状等有关的QTL,主要集中在C2、F和I连锁群。表型相关分析结果与QTL定位结果一致。在F连锁群上,2年均检测到倒伏QTL qLD-15-1,解释的表型变异超过20%,与百粒重和分枝荚数QTL分别位于相同和相邻标记区间,表明产量相关性状与倒伏性存在一定的关联。在I连锁群上,每荚粒数QTL和二、三、四粒荚数QTL不仅于同一位置,解释的表型变异为32%~65%,并且2个年份均重复出现,每荚粒数和四粒荚数QTL与二、三粒荚数QTL的增效基因分别来自不同的亲本。这4个粒荚性状QTL的共位性与表型相关分析结果一致,证实每荚粒数和四粒荚数与二、三粒荚数分别由不同的机制调控,对于育种上探讨以改良大豆粒荚性状为途径提高大豆产量,提供了重要依据。     

大豆产量及主要农艺性状QTL的上位性互作和环境互作分析

以栽培大豆晋豆23为母本,半野生大豆灰布支黑豆ZDD2315为父本杂交衍生的F2:15和F2:16的447个RIL家系为遗传群体,绘制SSR遗传图谱,采用混合线性模型方法,对2年大豆小区产量及主要农艺性状进行加性QTL、加性×加性上位互作及环境互作分析。结果检测到9个与小区产量、茎粗、有效分枝、主茎节数、株高、结荚高度相关的QTL,分别位于J_2、I、M连锁群上,其中小区产量、茎粗、株高、有效分枝和主茎节数QTL的加性效应为正值,说明增加这些性状的等位基因来源于母本晋豆23。同时,检测到7对影响小区产量、茎粗、株高和结荚高度的加性×加性上位互作效应及环境互作效应的QTL,共发现14个与环境存在互作的QTL。上位效应和QE互作效应对大豆小区产量及主要农艺性状的遗传影响较大。大豆分子标记辅助育种中,既要考虑起主要作用的QTL,又要注重上位性QTL,才有利于性状的稳定表达和遗传。     

开花后不同光周期条件下大豆农艺性状和品质性状的QTL分析

以开花期相近的181个大豆重组自交系(RIL)为材料,研究开花后不同光照长度对大豆主要农艺性状的影响,并在利用SSR标记构建大豆遗传图谱的基础上,分别在长日(16 h)和短日(12 h)条件下检测与主要农艺性状及其光周期敏感度(PS)相关的QTL。结果表明,开花后光照处理对大豆农艺性状和品质性状有较大影响,不同性状的光周期敏感度差异明显,株高＞主茎节数＞蛋白质含量、脂肪含量＞百粒重＞单株荚数＞蛋白质和脂肪总量。利用复合区间作图法检测到12个与株高、主茎节数、单株荚数、百粒重、蛋白质和脂肪总量等性状及各性状对开花后光周期处理的敏感度相关的QTL,分别定位于A1、A2、B1、B2、C1、D1a、F、L等8个连锁群上。其中,在短日条件下检测到4个QTL,可解释的遗传变异范围在11.37%~26.63%之间;在长日条件下检测到3个QTL,可解释的遗传变异范围在11.84%~27.85%之间;检测到5个与不同性状光周期敏感度有关的QTL,可解释相对应性状表型变异的范围在6.15%~21.44%之间。针对同一性状,未检测到在长日和短日条件下均起作用的主效QTL, 说明开花后光周期对大豆产量和品质性状相关基因的表达有较大影响。     

大豆幼苗根系性状的QTL分析

为研究大豆幼苗期根系性状的遗传规律,以中豆29和中豆32构建的RIL群体为材料,在V2期测定水培幼苗根系性状(主根长、侧根数、根重、根体积和根冠比等)及相关性状(株重、茎叶重和下胚轴重等),以方差分析方法估算遗传参数,并采用复合区间作图法对大豆幼苗期根系等性状进行QTL定位。结果表明,在8个染色体上检测到20个根系及相关性状QTL,其中9个主效QTL位于第11和第14染色体,表型贡献率在10.5%~26.1%之间。在第11和第14染色体上,部分根系性状QTL与地上部性状QTL处于同一位置,其QTL的共位性与形态性状表型相关分析结果一致,反映了根系性状与地上部性状存在一定的关联。     

大豆耐旱选择群体QTL定位

以红丰11为轮回亲本、Clark为供体亲本构建回交群体进行耐旱性鉴定,对获得选择群体进行全基因组SSR标记扫描,计算供体基因型导入频率,利用卡方测验检测偏分离SSR位点,并结合GGT软件对各连锁群分析, 对5个耐旱相关性状进行QTL定位。以卡方测验检测到23个SSR偏分离位点(超导入),分布于10条连锁群。方差分析表明,8个叶片持水能力QTL分布于A₁、B₁、C₂、E、L和N连锁群;9个根长QTL分布于C₂、F、G和I连锁群;11个根干重QTL分布于A₂、B₁、B₂、E、F、K、L、M和O连锁群;12个产量QTL分布于B₁、D₁a、E、F、G、I、L、M和O连锁群;7个生物量QTL分布于E、F、G、K、L和N连锁群。在E连锁群的Sat_136位点,对于叶片持水能力、根干重、产量和生物量具有一致性;在F连锁群的GMRUBP位点,对于根干重和生物量具有一致性,Satt586位点,对于根长、根干重和产量具有一致性;在K连锁群的Satt167位点,对于根干重和生物量具有一致性,SOYPRP1位点,对于根长和生物量具有一致性;在L连锁群的Satt398位点,对于根长和产量具有一致性,Satt694位点对于叶片持水能力和生物量具有一致性;在M连锁群的GMSL514位点,对于根干重和产量具有一致性;以上位点均与卡方测验检测到的“超导入”位点具有一致性。经过供体等位基因卡方测验和耐旱QTL定位,共检测到33个QTL,其中有17个同时被检测到。这些位点可能是控制大豆耐旱性的重要位点。     

利用大豆四向重组自交系群体定位产量相关性状QTL

为探明大豆产量与株高、主茎节数、单株荚数、单株粒数、百粒质量等产量构成因素间的相关性,定位控制这些性状的QTL进而提高大豆产量,以4个产量相关性状差异较大的大豆亲本配制双交组合(垦丰14×垦丰15)×(黑农48×垦丰19)衍生的包含160个株系的四向重组自交系群体(FW-RIL)为材料,在哈尔滨(2013-2015年)和克山(2013,2015年)种植,获得的株高、主茎节数、单株荚数、单株粒数、百粒质量的表型数据,结合已经构建的包含275个SSR标记的大豆遗传图谱对产量相关性状QTL进行定位。结果表明:在多个环境下重复稳定检测到产量相关性状的QTL 28个,其中10个株高QTL可解释表型变异率在3.20%～11.72%,3个主茎节数QTL可解释表型变异率分别为6.55%,5.70%,3.77%,9个单株荚数QTL可解释表型变异率在2.60%～11.25%,4个百粒质量QTL可解释表型变异率在3.83%～9.35%,2个单株粒数QTL可解释表型变异率分别为8.58%,7.52%;28个多环境重复检测到的产量性状QTL,其中16个QTL是本研究新检测到的,12个与国内外报道过的产量相关性状QTL位点一致,说明QTL检测准确率较高。利用分子标记遗传图谱,定位控制产量相关性状的QTL,为利用分子标记改良大豆产量潜力提供了有力手段。     

基于QTL定位的蓖麻株高性状遗传解析

用YC2(高杆)×YF1(矮杆)和YC1(高杆)×YF1(矮杆)组合衍生的2个F₂代群体, 对蓖麻株高性状进行相关、回归和QTL定位分析。结果表明, 株高与主穗位高、主茎节长和主茎茎粗之间显著正相关, 但与主茎节数不相关;主穗位高与主茎节数、主茎节长和主茎茎粗之间显著正相关;主茎节数与主茎节长之间显著负相关。利用QTLNetwork 2.0软件在YC2×YF1的F₂群体中检测到株高、主穗位高、主茎节数、主茎节长和主茎茎粗的5、4、6、3和2个QTL, 分别解释了45.9%、45.3%、66.1%、55.4%和12.6%的总变异。在YC1×YF1的F₂群体中检测到3、4、5、1和2个上述5性状的QTL, 分别解释了26.0%、25.5%、35.4%、37.4%和7.6%的总变异。证明QTL间的“一因多效”和连锁是株高、主穗位高和主茎节长之间高度相关的遗传基础, 加性效应是株高、主穗位高和主茎节长的主要遗传组分, 互作效应是主茎节数和主茎茎粗的主要遗传组分。建议育种上将主穗位高和主茎节长作为株高早期选择和预测的间接指标,并将多节数和短节间作为高产育种的主攻方向。     

黄淮夏大豆形态性状的遗传研究

本文以黄淮地区6个夏大豆品种(系)通过双列杂交保留下来的F_3代材料,研究大豆6个形态性状的遗传特性.结果表明,株高、有效分枝数、主茎节数、主茎荚丛数和茎粗5个性状均符合加性—显性模型.而底荚高则存在非等位基因之间的互作效应.株高、有效分枝数、主茎节数和主茎荚丛数为部分显性,茎粗存在超显性现象.主茎节数和主茎荚丛数可能有相似的遗传特点.豫豆8号大豆带有较多的控制株高的显性基因,油84-30大豆带有较多的控制分枝和茎粗的显性基因,而尖顶大白角大豆控制主茎节数和美丛数的显性基因较多.     

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。     

大豆抗倒伏性的评价指标及其QTL分析

倒伏性的鉴定通常采用倒伏程度分级法, 但其表现依赖于田间实时环境, 分级较粗放。育种实践需要一种不依赖于实时环境的倒伏潜势评价方法。本研究利用表型差异大的32个大豆品种和1个重组自交系(RIL)群体NJRIKY, 研究了鲜重力矩(株高×鲜重, PF)、干重力矩(株高×干重, PD)、单位抗折力鲜重力矩(株高×鲜重/抗折力, PFS)和单位抗折力干重力矩(株高×干重/抗折力, PDS)等4种倒伏性评价指标与倒伏程度的关系, 从中遴选出PF与倒伏程度的相关系数高、物理意义明确、测度简便、环境稳定性高, 与倒伏程度共同QTL多, 综合表现最优, 反映了倒伏势。在A2、C2、D2和G连锁群上, 共检测到7个倒伏程度相关的QTL, 分别解释表型变异的6%~12%, 2年未检测到相同的QTL; 在B1、C2和O连锁群共检测到7个倒伏势有关的QTL, 分别解释表型变异的5%~12%, 其中qPFC2-2, 2年均能稳定表达, 贡献值较大; 倒伏程度和倒伏势共有的QTL区间有GMKF059a~satt319和satt286~A63_1T两个; 抗倒伏性等位基因来自亲本科丰1号。     

Quantitative trait loci analysis of stem strength and related traits in soybean

Stem strength is one of the major influencing factors of lodging in soybean [Glycine max (L.) Merr.] as well as other crops. To identify quantitative trait loci (QTL) associated with stem strength and related traits in soybean, a recombinant inbred line (RIL) population consisting of 165 lines derived from Zhongdou No. 29 × Zhongdou No. 32 was used in 3 years. Significant positive correlations were found among the four traits (stem strength, stem diameter, number of nodes, root dry weight). A linkage map spanning 1,240.7 cM was constructed using 245 SSR (simple sequence repeat) markers and a phenotypic marker (leaflet shape). By composite interval mapping and two-round strategy of QTL meta-analysis, 32 consensus QTL and 19 unique QTL were identified, respectively. Of eight pleiotropic unique QTL, two QTL (uq.A2-2 and uq.A2-3) located at the intervals of 23.2–26.8 and 38.5–42.4 cM on linkage group A2, respectively, were associated with all the four traits. Additive × environment (ae) interaction effects, epistasis (aa) and epistasis × environment (aae) interaction effects of QTL were detected as well. The results provide useful information for further genetic studies on stem strength of soybean.     

QTL mapping of phosphorus deficiency tolerance in soybean (Glycine max L. Merr.)

Phosphorus (P) deficiency is a major abiotic stress that limits plant growth and crop productivity throughout the world. In the present study, 184 recombinant inbred line (RIL) families developed from soybean varieties Kefeng No. 1 and Nanong 1138-2 were used to identify quantitative trait loci (QTL) associated with P deficiency tolerance. Seven traits of plant height (HT), weight of fresh shoot (FSW), weight of fresh root (FRW), weight of dry root (DRW), length of main root (RL), phosphorus content in leaf (LP), phosphorus content in root (RP), were used as parameters to assess the phosphorus deficiency tolerance. The QTL mapping for the seven traits was performed using the program WinQTLCart. Seven QTLs were detected and mapped on two linkage groups for three traits of weight of fresh shoot, phosphorus contents in leaf and in root. The QTLs that had LOD scores more than three were detected for all of the three traits above. Most of the QTLs explained more than 10% of the total variation. The two QTLs for phosphorus content in leaf explained more than 20% of the total variation, respectively. Five QTLs were mapped on linkage group F2, and two on linkage F1. It was suggested that the genes related to phosphorus deficiency tolerance located on linkage group F in soybean.Contributed equally to this work.     

Development of linkage map and mapping of QTLs for oil content and yield attributes in linseed (<Emphasis Type="Italic">Linum usitatissimum</Emphasis> L.)

Linseed (Linum usitatissimum L.) is an important oilseed as well as stem fiber crop and rich source of omega-3 fatty acid. The present study aims to develop linkage map based on Indian genotypes and utilize it for mapping QTLs for important agronomic traits. Two diverse parental genotypes (KL-213 and RKY-14) of linseed showed wide range of variability for oil content and yield attributes. These parental genotypes also showed reasonable level of SSR polymorphism (~ 9.0%). The mapping population showed normal distribution of phenotypic traits. One hundred forty-six SSR markers were mapped on 15 linkage groups with marker density ranging from 3 to 18 markers per linkage group at average distance of 14.2 cM. A total of 11 QTLs were identified for six quantitative traits. Three QTLs for capsules/plant, 2 QTLs each for plant height, seeds/capsule and oil content and 1 QTL each for branches/plant and seed weight/plant were detected. Phenotypic variability explained by these QTLs varied from 1 to 15.23%. This study provides framework linkage map of linseed using Indian genotypes, which needs to be enriched further for future application in marker assisted breeding of linseed.     

大豆苗期耐低磷性及其QTL定位

利用来自波高和南农94-156（耐低磷种质）的重组自交系群体NJ(SP)BN（151个家系）通过盆栽试验研究与耐低磷有关的性状,并进行耐低磷性状的QTL定位。初步结果表明,不施磷处理的总干重主要由单株P吸收量决定,而与磷利用效率无关;而单株P吸收量与根干重、根效率均极显著正相关,单株P吸收量变异的76.2%由根效率决定。不施磷处理的根冠比（R/S）显著增加主要是茎干重无显著变化而根干重显著增加所致。在D1b+W、F、G、N和O等5个连锁群上共检测到7个QTL与耐低磷有关。分别可解释所对应性状表型变异的4.8%~17.0%,其中5个QTL的增效基因来自亲本波高,2个QTL的增效基因来自亲本南农94-156。     

玉米抗倒伏相关性状QTL的关联和连锁分析

倒伏是影响玉米高产和机械化收获的重要因素,明确玉米抗倒伏相关性状的遗传基础,增强玉米品种抗倒伏能力,可为玉米高产宜机收育种提供理论依据。本研究以国内外收集的153份自交系为材料,利用6H90K SNP芯片检测的70,438个高质量SNP标记对地上第3节茎秆强度、株高、穗位高和穗位系数进行全基因组关联分析,分别检测到与茎秆强度、株高、穗位高和穗位系数相关位点5个、14个、16个和21个,单个关联位点最大效应值为13.24。同时以KA105/KB020的F₅群体为试验材料,采用QTL IciMapping V4.2软件的完备区间作图法进行QTL定位,检测到21个与抗倒伏相关的QTL,可解释表型变异3.86%～16.58%。结合关联分析和连锁分析结果发现, 2个QTL区间与关联分析的候选区间重合。经过候选区段的基因功能注释和文献查阅,挖掘到GRMZM2G105391、GRMZM2G014119和GRMZM2G341410等与细胞壁生物合成、细胞分裂和细胞伸长的相关基因可供进一步分析。本研究结果为进一步解析玉米抗倒伏性状的遗传基础提供参考。     

利用“永久F2”群体进行小麦幼苗根系性状QTL分析

为了研究小麦苗期根系性状的遗传,以小麦品种花培3号和豫麦57的杂交DH群体组配了一套含168个杂交组合的“永久F₂”群体。利用WinRHIZO根系分析系统测定四叶一心期小麦水培幼苗根系总长度、直径、表面积、体积、根尖数、最大根长、茎叶干重、根干重及根茎干重比9个性状。采用复合区间作图法分析幼苗根系8个性状的QTL,定位了7个加性效应QTL和12对上位性互作QTL,包括加性效应、显性效应,加加互作、加显互作和显显互作,分布在1A、1D、2A、2B、2D、3A、3B、5D、6D和7D染色体上,单个QTL可解释0.01%~11.91%的遗传变异。在染色体2D上XWMC41至XBARC349.2区间检测到同时控制总根长和根干重的一个QTL。上位性对苗期根系生长发育有重要作用。试验结果表明,苗期根系性状的遗传机制较复杂, 因此在育种中要综合考虑根系各性状之间的关系,保证根系协调统一、发达健壮。     

Identification of drought responsive QTLs during vegetative growth stage of rice using a saturated GBS-based SNP linkage map

Drought is a major abiotic constraint for rice production worldwide. The quantitative trait loci (QTLs) for drought tolerance traits identified in earlier studies have large confidence intervals due to low density linkage maps. Further, these studies largely focused on the above ground traits. Therefore, this study aims to identify QTLs for root and shoot traits at the vegetative growth stage using a genotyping by sequencing (GBS) based saturated SNP linkage map. A recombinant inbred line (RIL) population from a cross between Cocodrie and N-22 was evaluated for eight morphological traits under drought stress. Drought was imposed to plants grown in 75 cm long plastic pots at the vegetative growth stage. Using a saturated SNP linkage map, 14 additive QTLs were identified for root length, shoot length, fresh root mass, fresh shoot mass, number of tillers, dry root mass, dry shoot mass, and root-shoot ratio. Majority of the drought responsive QTLs were located on chromosome 1. The expression of QTLs varied under stress and irrigated condition. Shoot length QTLs qSL1.38 and qSL1.11 were congruent to dry shoot mass QTL qDSM1.38 and dry root mass QTL qDRM1.11, respectively. Analysis of genes present within QTL confidence intervals revealed many potential candidate genes such as laccase, Calvin cycle protein, serine threonine protein kinase, heat shock protein, and WRKY protein. Another important gene, Brevis radix, present in the root length QTL region, was known to modulate root growth through cell proliferation and elongation. The candidate genes and the QTL information will be helpful for marker-assisted pyramiding to improve drought tolerance in rice.     

烤烟6个农艺性状的QTL定位

由于烟草的分子标记开发和遗传图谱构建十分困难,迄今烟草中有关数量性状基因座(QTL)的定位研究仍非常有限。本研究利用一个由207个株系组成的烤烟DH群体及基于该群体所构建的含有24个连锁群、611个SSR标记,总长为1 882.1 cM的遗传图谱,采用复合区间作图方法,对株高(PH)、茎围(SG)、节距(IL)、叶片数(LN)、最大腰叶长(LWL)和最大腰叶宽(WWL) 6个与叶片产量有关的农艺性状进行QTL定位分析。共检测到69个QTL,大部分QTL的效应值较小,仅有4个具有较大的效应值,可解释大约15%~20%的表型变异。6个性状之间大多彼此相关。与此相符,在基因组中发现存在许多小区域,每个区域包含两个或两个以上紧密连锁的不同性状的QTL。