辣椒遗传图谱的构建与QTL定位研究进展

对近十年来构建的辣椒遗传图谱和相关性状的QTL定位研究进展进行了总结分析,包括辣椒种内遗传图谱、种间遗传图谱和整合图谱的构建,以及抗病虫性状和细胞雄性不育恢复性等主要农艺性状的QTLs定位,并对相关研究中存在的问题进行了讨论,以期为辣椒分子标记辅助选择育种提供理论参考。     

玉米秃尖的研究

本试验以８个在杂交后代表现出不同秃尖程度的自交系及其组配的一套８×８的双列杂交组合为材料，对其决小花数、退化花数和未受精花数进行分析研究表明，各组合总小花数目的多少是由基因型决定的，Ｆ１代的多花优势与双亲的多花性呈高度的正相关。雌穗上的小花能否发育有成有效花，组合间有差异。一般在果穗的顶部出现退化花和未受精花，是影响有效花数目最直接的因素，雌穗上退化花和未受精花数目的多少主要受环境的影响。     

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。     

玉米生育期相关性状QTL定位

生育期是玉米重要的性状之一,其中抽穗期、散粉期和吐丝期是3个最重要的指标.以玉米自交系LDC-1和YS501构建的186个重组自交系为材料,在2个大田种植环境下对抽穗期、散粉期和吐丝期3个生育期相关性状进行QTL解析.基于Maize10k芯片数据构建总长为2569.89 cM的高密度遗传图谱,共包含2624个bin,相...     

陆地棉高密度遗传图谱的构建及产量相关性状的QTL定位

【目的】通过构建高密度SNP遗传图谱,开展棉花多群体产量相关性状的QTL定位,获得稳定性好、精确度高的QTL,为产量性状调控基因的挖掘和有效分子标记的开发提供依据。【方法】以高稳产冀丰1271为母本、优质自交系冀丰173为父本,构建包含200个单株的F₂群体,利用测序基因分型(genotyping by sequencing,GBS)技术开发群体的SNP标记并构建高密度遗传图谱,对F₂、F_2:3、F_2:4群体的衣分、子指和单铃重进行QTL定位,注释主效和稳定QTL位点内的基因并分析基因在不同组织的表达模式,筛选候选基因。【结果】通过简化基因组测序,共获得383.07 Gb数据,包括母本冀丰1271的26.93 Gb、父本冀丰173的27.30 Gb和F₂群体的328.84 Gb,Q30值分别为90.55%、89.95%和95.77%。在F₂群体中开发了1 305 642个SNP标记,其中,用于构建遗传图谱的aa?bb型SNP为410 726个。构建了一张包...     

基于高密度遗传图谱定位水稻籽粒长宽比QTL

挖掘水稻籽粒长宽比相关的QTL可为水稻粒型的遗传机制研究提供理论基础.以特大粒水稻TD70和小粒籼稻Kasalath构建的重组自交系群体为研究材料,2019、2020年连续2年考察各株系的籽粒长宽比,利用群体重测序构建的高密度遗传图谱对控制水稻籽粒长宽比相关QTL进行分析.结果显示,在重组自交系群体中籽粒长宽比呈连续变异,有明显的超亲分离现象.2019、2020年2年共检测到11个QTLs,分别位于2、3、4、5、6、7、9号染色体上.QTL的LOD值介于3.74～31.41之间,单个QTL可解释2.48％～24.67％的表型变异,2年重复检测到的QTL位点共有4个.进一步分析发现,qLWR2-2、qLWR3-1、qLWR3-2、qLWR4、qLWR5、qLWR6-2及qLWR7共7个位点所在区间与前人的报道相同或相似.qLWR2-1、qLWR6-1、qLWR9-1和qLWR9-2可能是新发现的QTL位点.本研究结果可用于下一步QTL的克隆及分子标记辅助选择育种.     

兰科植物遗传图谱与QTL定位研究进展

兰科植物俗称兰花,是最重要的观赏花卉,构建遗传图谱,特别是高密度遗传图谱有助于提高育种水平,本研究主要对兰科植物遗传图谱与重要性状的QTL定位进行了综述。结果表明:1)2007年报道出兰科石斛属第一张遗传图谱以来,累计发表了13张兰科植物遗传连锁图谱。2)从图谱类型来看,5张为品种间图谱,8张为种间图谱;从图谱用途来分,7张可以用于QTL定位,3张可用于精细定位或基因克隆,另3张为基础参考图谱。3)从已构建的兰科植物遗传图谱看,总图距越来越高且平均图距越来越小,为图谱的实际应用奠定了基础,但作图群体较小始终是个问题。4)虽然在蝴蝶兰叶片、花色,石斛兰萼片大小及石斛茎及多糖含量等相关性状上进行了QTL定位,但在花朵大小、花朵数、花香、花型、花斑和植株抗性等方面均未涉及。因此,构建遗传图谱,特别是高密度遗传图谱能够为兰花的生物学研究及分子标记辅助育种提供参考依据。     

基于高密度遗传图谱的水稻穗长QTL定位与分析

【目的】深入挖掘与穗长相关的新基因,为水稻穗长调控的遗传机理研究及分子育种提供依据。【方法】以2个优良亲本‘ZP37’和‘R8605’及其杂交衍生的208个高世代重组自交系(Recombinant inbred lines,RILs)为作图群体,利用全基因组重测序高密度连锁图谱对3个不同环境下的穗长数量性状座位(Quantitative trait locus,QTL)进行定位,同时分析它们的聚合效应。【结果】共检测到11个穗长QTL,分别分布在第3、4、7、8、9和12号染色体上,其似然函数比对数值(Log of odds,LOD)介于3.07～12.87之间,贡献率在2.17%～10.94%之间,有7个QTL是新位点,其余4个QTL位点与已报道的穗长基因和QTL位置重叠或相近。在2个不同环境下重复检测到4个稳定的QTL位点;对聚合了不同数量穗长QTL株系的分析结果表明,穗长QTL表现出累加效应,QTL数量的增加能显著增加水稻穗长。【结论】本研究结果为水稻穗长QTL的克隆和功能解析奠定坚实的基础,为水稻高产育种提供理论依据和遗传资源。     

苹果遗传图谱的构建与QTL定位研究进展

对近年来构建的苹果遗传连锁图谱和相关重要性状的QTL定位研究进展进行了总结分析,主要包括苹果单一群体遗传连锁图谱、多个群体遗传连锁图谱、物理图谱的构建,以及抗病性状和主要农艺性状的QTLs定位,并讨论了相关研究中目前存在的问题及对遗传连锁图谱后期的展望,为苹果育种者在分子标记辅助育种方面提供参考。     

玉米秃尖的原因分析及预防措施

本文就造成玉米秃尖的原因及防止途径做简单论述。     

团头鲂高密度遗传连锁图谱的建立及性别QTL定位

以团头鲂自交197个F1个体为作图群体,通过RAD-Seq测序挖掘SNP分子标记,构建团头鲂最新一代高质量、高密度的遗传连锁图谱,并对性别相关QTL进行定位.结果显示,该遗传连锁图谱包括10795个SNP标记,24个连锁群,图谱全长为2578.54 cM,平均标记间隔为0.24 cM.使用MapQTL6.0软件的多QT...     

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.     

Construction of high-density SNP genetic maps and QTL mapping for dwarf-related traits in Litchi chinensis Sonn

Litchi chinensis Sonn is widely cultivated in subtropical regions and has an important economic value. A high-density genetic map is a valuable tool for mapping quantitative trait loci (QTL) and marker-assisted breeding programs. In this study, a single nucleotide polymorphism (SNP)-based high-density linkage map was constructed by a genotyping-by-sequencing (GBS) protocol using an F₁ population of 178 progenies between two commercial litchi cultivars, ‘Ziniangxi’ (dwarf) and ‘Feizixiao’ (vigorous). The genetic map consisted of 3027 SNP markers with a total length of 1711.97 cM in 15 linkage groups (LGs) and an average marker distance of 0.57 cM. Based on this high-density linkage map and three years of phenotyping, a total of 37 QTLs were detected for eight dwarf-related traits, including length of new branch (LNB), diameter of new branch (DNB), length of common petiole (LCP), diameter of common petiole (DCP), length of internode (LI), length of single leaf (LSL), width of single leaf (WSL), and plant height (PH). These QTLs could explain 8.0 to 14.7% (mean=9.7%) of the phenotypic variation. Among them, several QTL clusters were observed, particularly on LG04 and LG11, which might show enrichment for genes regulating the dwarf-related traits in litchi. There were 126 candidate genes identified within the QTL regions, 55 of which are differentially expressed genes by RNA-seq analysis between ‘Ziniangxi’ and ‘Feizixiao’. These DEGs were found to participate in the regulation of cell development, material transportation, signal transduction, and plant morphogenesis, so they might play important roles in regulating plant dwarf-related traits. The high-density genetic map and QTLs identification related to dwarf traits can provide a valuable genetic resource and a basis for marker-assisted selection and genomic studies of litchi.     

Identification of a major QTL for flag leaf glaucousness using a high-density SNP marker genetic map in hexaploid wheat

Cuticular wax plays an important role in protecting land plant against biotic and abiotic stresses. Cuticular wax production on plant surface is often visualized by a characteristic glaucous appearance. This study identified quantitative trait loci(QTLs) for wheat(Triticum aestivum L.) flag leaf glaucousness(FLG) using a high-density genetic linkage map developed from a recombinant inbred line(RIL) population derived from the cross Heyne×Lakin by single-seed descent. The map consisted of 2 068 single nucleotide polymorphism(SNP) markers and 157 simple sequence repeat(SSR) markers on all 21 wheat chromosomes and covered a genetic distance of 2 381.19 c M,with an average marker interval of 1.07 c M. Two additive QTLs for FLG were identified on chromosomes 3AL and 2DS with the increasing FLG allele contributed from Lakin. The major QTL on 3AL,QFlg.hwwgr-3AL,explained 17.5–37.8% of the phenotypic variation in different environments. QFlg.hwwgr-3AL was located in a 4.4-c M interval on chromosome 3AL that was flanked by two markers IWA1831 and IWA8374. Another QTL for FLG on 2DS,designated as QFlg.hwwgr-2DS which was identified only in Yangling in 2014(YL14),was flanked by IWA1939 and Xgwm261 and accounted for 11.3% of the phenotypic variation for FLG. QFlg.hwwgr-3AL and QFlg.hwwgr-2DS showed Additive×Environment(AE) interactions,explaining 3.5 and 4.4% of the phenotypic variance,respectively. Our results indicated that different genes/QTLs may contribute different scores of FLG in a cultivar and that the environment may play a role in FLG.     

番茄AFLP遗传连锁图谱的构建及耐冷性状的QTL定位

[目的]构建冷敏感和抗冷番茄的F2代分离群体,对番茄耐冷抗性基因进行QTL定位.[方法]通过将番茄耐冷品种O-33-1与冷敏感品种耐运2000杂交,得到的F1代番茄自交获得用于构建图谱的F2分离群体.测定O-33-1、耐运2000以及F2代番茄分离群体的生理指标,确定其抗寒性;利用AFLP技术构建连锁遗传图谱,对番茄耐冷性基因进行QTL定位.[结果]番茄耐冷品种O-33-1的抗寒性显著高于冷敏感品种耐运2000,F2代分离群体的抗寒性高于耐运2000而低于O-33-1,介于两亲本之间.本试验构建的番茄遗传图谱共包括连锁群16个,共包含155个标记,整个图谱总的长度为686 cM,标记间平均图距为4.42 cM.平均间距最小的连锁群为16,为1.75cM.并且检测到1个抗冷性的QTL位点.[结论]通过对番茄耐冷性状QTL分析发现了1个QTL,被定位于连锁群4上11E/M619和9E/M330之间.     

不同密度下玉米DH群体果穗性状的QTL定位分析

试验利用由79个DH系组成的‘农单5号’DH群体,分别在6万株/hm2和13.5万株/hm22个密度、2次重复条件下,调查了玉米穗长、秃尖长、穗粗、穗行数、行粒数、粒长、粒宽和粒厚等穗部性状,利用在双亲间存在差异且均匀分布于玉米10条染色体上的160对SSR标记对该群体进行遗传作图,并采用复合区间作图法对上述性状进行QTL分析。结果表明:在2个密度条件下共检测出30个QTL位点,单个QTL所解释的表型变异在3.26%~31.59%之间,QTL与环境之间存在复杂的互作关系。在2个密度水平下分别检测到的qEL2a(umc1165-umc1261)与qEL2b(umc1165-umc1261)可能是同一位点,qRN4a(umc2135-bnlg292a)、qRN4b(bn-lg292a-bnlg292b)和qED4(bnlg292a-bnlg292b)也很可能是同一位点。在4.08 bin区间存在着控制穗粗或穗行数的重要基因,而该基因位于umc2135-bnlg292b标记区间。     

Construction of a high-density adzuki bean genetic map and evaluation of its utility based on a QTL analysis of seed size

Adzuki bean(Vigna angularis(Willd.) Ohwi Ohashi) is an annual cultivated leguminous crop commonly grown in Asia and consumed worldwide. However, there has been limited research regarding adzuki bean genetics, which has prevented the efficient application of genes during breeding. In the present study, we constructed a high-density genetic map based on whole genome re-sequencing technology and validated its utility by mining QTLs related to seed size. Moreover, we analyzed the sequences flanking insertions/deletions(In Dels) to develop a set of PCR-based markers useful for characterizing adzuki bean genetics. A total of 2 904 markers were mapped to 11 linkage groups(LGs). The total length of the map was 1 365.0 cM, with an average distance between markers of 0.47 cM. Among the LGs, the number of markers ranged from 208(LG7) to 397(LG1) and the total distance ranged from 97.4 cM(LG9) to 155.6 cM(LG1). Twelve QTLs related to seed size were identified using the constructed map. The two major QTLs in LG2 and LG9 explained 22.1 and 18.8% of the total phenotypic variation, respectively. Ten minor QTLs in LG4, LG5 and LG6 explained 3.0–10.4% of the total phenotypic variation. A total of 9 718 primer pairs were designed based on the sequences flanking In Dels. Among the 200 selected primer pairs, 75 revealed polymorphisms in 24 adzuki bean germplasms. The genetic map constructed in this study will be useful for screening genes related to other traits. Furthermore, the QTL analysis of seed size and the novel markers described herein may be relevant for future molecular investigations of adzuki bean and will be useful for exploiting the mechanisms underlying legume seed development.     

甜瓜遗传连锁图谱构建及果实相关性状QTL定位

试验以厚皮甜瓜品系M4-5为母本材料,薄皮甜瓜品系M1-15为父本材料,配制杂交组合获得F1、F2代,研究甜瓜果实相关性状遗传规律。对M4-5和M1-15两亲本间存在SNP突变位点序列作CAPS检测,共设计CAPS标记523对,筛选出在亲本间有多态性的CAPS标记223对,多态率43.8%。利用多态性引物标记F2代群体,构建甜瓜遗传连锁图谱,该图谱包含195个标记,12个连锁群,覆盖基因组长度1 702.55 c M,标记间平均距离8.78 c M。检测到果实相关位点共计28个,贡献率介于3.4974%~17.9684%。其中与果实形状相关位点14个,与产量相关位点9个,与可溶性固形物含量相关位点5个。     

玉米抗矮花叶病毒B株系的QTL定位

为明确玉米对矮花叶病的抗病机制,以代表国内外两大玉米杂种优势类群的优良自交系黄早4和Mo 17为亲本,构建了含239个重组自交系的F9代分离群体,并利用该群体构建了包含101个SSR标记的遗传连锁图谱,图谱全长1422.7 cM,标记间的平均图距为15.6 cM。通过人工接种病毒鉴定,评价了亲本及群体对玉米矮花叶病毒B株系的抗性反应。采用复合区间作图法对玉米矮花叶病抗性QTL进行了定位及其遗传效应分析,在第5、6染色体上,各定位了控制发病率的1个微效QTL和1个主效QTL,分别与标记Bnlg602和Bnlg161连锁,其遗传效应能分别解释表型方差的2.3%和33.8%。