利用黄褐棉染色体片段导入系定位产量和纤维品质性状QTL

陆地棉的遗传基础狭窄,阻碍了棉花的遗传改良进程。为有效拓宽陆地棉的遗传基础,本试验利用野生种黄褐棉(AD4)为供体亲本,以综合性状优良的B0011品系为受体亲本(国审棉华杂棉H318的亲本之一),构建了含71个株系的导入系BC5S5群体。基于SLAF-seq的基因分型和多年多点田间试验的综合分析表明,该导入系在产量和纤维性状方面具有很大的变异,共检测到48个QTL,其中包含19个产量和29个纤维构成因素相关的QTL。在At亚组检测到9个性状的32个QTL,在Dt亚组为16个。进一步对QTL加性效应方向分析显示,其中有30个QTL的加性效应为正,18个QTL的加性效应为负。本研究结果为利用黄褐棉重要农艺性状有利等位基因改良陆地棉产量和品质奠定了基础。     

陆地棉遗传图谱构建及产量和纤维品质性状QTL定位

利用3 458对SSR引物筛选陆地棉中棉所35和渝棉1号间的多态性引物, 获得173对。以多态性引物检测(渝棉1号×中棉所35)F₂群体180个单株的标记基因型, 共获得178个标记位点。构建的遗传连锁图谱包括148个标记, 36个连锁群, 总长1 309.2 cM, 标记间平均距离8.8 cM, 覆盖棉花基因组的29.5%。36个连锁群中的28个分别被定位于20条染色体, 8个连锁群未定位于染色体。以渝棉1号×中棉所35的F₂、F_2:3群体的产量、纤维品质性状鉴定结果, 利用区间作图方法, 检测到4个产量性状QTL, 即2个衣分(LP)、1个铃重(BW)、1个籽指(SD); 5个纤维品质性状QTL, 即1个纤维长度(FL)、2个纤维比强度(FS)和2个纤维细度(FF)。LP1、BW、SD、FL和FS1被定位于第7染色体, LP2、FS2、FF1和FF2被分别位于第15、21、9和20染色体。5个纤维品质QTL的有利等位基因均来源于渝棉1号。     

陆地棉高品质品系纤维品质性状QTL的分子标记及定位

为进一步挖掘利用高品质品系NM03102的优异纤维品质性状的基因,利用陆地棉鲁棉研21作为母本、NM03102为父本构建了F2和F2∶3分离群体。通过7892对SSR引物对亲本进行筛选,获得222对多态性引物,进一步对195个F2群体单株分析得到242个标记位点。其中,182个标记位点连锁构建37个连锁群,共覆盖1661.6 cM,每个连锁群平均包含4.9个标记位点,标记间平均相距9.1 cM,其中35个连锁群被定位到了20条染色体上。利用F2和F2∶3纤维品质数据,通过复合区间作图法,共检测到20个纤维品质性状QTL。其中,1个纤维强度的QTL和1个纤维整齐度的QTL与已有的报道一致,1个纤维强度的QTL和1个麦克隆值的QTL在两世代中稳定存在,这为标记辅助选择奠定了基础。     

基于陆地棉背景的海岛棉染色体片段导入系产量性状QTL定位

棉花产量分为籽棉产量和皮棉产量,其中高皮棉产量总是育种的首要目标。皮棉产量由单株铃数、衣分、单铃重等因素组成。其中衣分在各因素中的遗传率最高,同时也是产量育种中重要的选择指标。育种中利用分离群体对单株铃数、铃重等产量性状选择受环境影响较大。利用染色体片段导入系进行铃数、铃重等产量性状的定位,定向改良产量性状,是棉花分子设计育种的有效方法。本研究利用陆地棉TM-1为轮回亲本和海岛棉海7124为非轮回亲本构建了一套陆地棉背景的染色体片段导入系,并在7个环境的田间试验下,鉴定了它们的产量表现,定位了28个与单株铃数、铃重、衣分和籽指相关的QTL。其中,在Dt亚组染色体上鉴定出的产量性状QTL多于在At亚组染色体上鉴定出的。28个QTL中,加性效应为正的16个,加性效应为负的12个,表明海岛棉不同的导入片段效应不同,有的片段可以提高陆地棉产量,有的则降低陆地棉产量。在6个环境下,导入系IL008(特征标记NAU2573和NAU3576)的衣分均显著高于轮回亲本TM-1,因此IL008可以应用于棉花分子育种,定向改良陆地棉的衣分。     

陆地棉低世代群体纤维品质QTL定位及候选基因功能注释

【目的】通过对纤维品质数量性状位点(Quantitative trait loci,QTLs)定位及其基因功能注释,为分子标记辅助育种提供理论依据。【方法】以2个纤维品质有差异的陆地棉品种(系)中棉所49和396289为亲本构建F2群体,以高密度遗传图谱为基础,对3个环境的F2:3家系做包括细度和成熟度等在内的7个纤维品质性状QTLs定位,利用直系同源基因簇(Clusters of orthologous groups,COG)、基因本体(Gene ontology,GO)和京都基因与基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)等数据库对QTLs做基因功能注释。【结果】获得157个与纤维品质有关的QTLs,分布于20条染色体上,A03、A04、D02、A11和D07等有较多性状的QTLs聚集,可能是控制纤维品质性状的关键染色体。共获得13个稳定QTLs,其中qFL-A03-1和qFin-A11-4在3个环境中重复出现,另有9个QTLs则在2个环境中重复出现。通过COG、GO和KEGG对QTLs进行基因功能注释,共获得4 763个候选基因,3个数据库分别注释到2 416、4 188和2 512个基因,在稳定QTLs中共注释到429个基因,其中一些基因可能与纤维品质关系密切。【结论】利用高通量测序获得的高密度遗传图谱有助于获得较多QTLs,有利于纤维品质相关候选基因的筛选及性状的改良,提高育种效率。     

利用陆地棉置换系进行海岛棉主要性状基因的染色体定位

 利用海岛棉染色体置换陆地棉一对染色体或染色体臂的置换系,进行主要农艺性状、抗黄萎病性和纤维品质基因染色体定位。结果表明,海岛棉1号染色体可以增加株高;16、17、18、4号染色体携带降低铃数基因;22Lo、22Sh、16、11Sh、26Lo号染色体可以提高衣分;大部分染色体降低铃重。16、26Lo染色体可以增强抗黄萎病性。对纤维品质性状分析表明,14Sh、26Lo号染色体可以提高纤维长度;14Sh、15Sh号染色体可以提高强度;4号染色体可以降低麦克隆值;22Sh、16、22Lo、11Sh号染色体可以提高伸长率。推测这些染色体上可能具有对应性状的基因。     

利用东乡普通野生稻染色体片段置换系定位产量相关性状QTL

以东乡普通野生稻和日本晴为亲本构建的染色体片段置换系为研究材料, 2019年分别在北京、山东临沂和江西南昌对分蘖数、穗粒数和粒形等11个产量相关性状进行多环境鉴定,结合染色体片段置换系基因型数据定位水稻产量相关性状QTL。3个环境共检测到68个QTL,包括株高4个、穗长5个、分蘖数2个、一次枝梗数7个、一次枝梗粒数8个、二次枝梗数8个、二次枝梗粒数10个、每穗粒数6个、千粒重7个、粒长8个和粒宽3个; LOD值介于2.50～12.66之间,贡献率变幅为4.67%～27.79%,15个QTL的贡献率大于15%;24个QTL与已报道位点/基因位置重叠,44个QTL为新发现位点; 6个QTL在2个环境能被检测到, 1个QTL qTGW2能在3个环境检测到,且是还未报道的新位点。最后,利用BSA法验证了qPH7、qPBPP8-2和qGW10三个QTL的可靠性。本研究将为后续产量相关性状基因克隆以及进一步解析其遗传基础和分子调控机制奠定基础。     

转基因抗虫棉产量相关性状QTL的分子标记及定位

 采用亚洲棉渐渗的纤维强度突出的陆地棉优质新品系0-153与陆地棉转基因抗虫新品系sGK9708为亲本,构建了F₂及F_2∶3分离群体。利用3869对SSR引物筛选亲本,得到125对多态性引物。进一步对183个F₂群体单株分析得到150个多态性标记位点,其中100个标记位点连锁,构建20个连锁群,共覆盖660 cM,占棉花总基因组的14.67%,每个连锁群平均包含5个标记位点,标记间平均相距6.6 cM,其中13个连锁群确定了对应的染色体。利用F₂和F_2:3数据,通过复合区间作图,共检测到28个产量及相关因素的QTLs。这些控制产量性状的QTLs只存在于5个连锁群上,成簇分布。与皮棉产量性状有关的2个QTLs,均与其它多个产量相关性状的QTLs在同一个连锁区段内,增效基因遗传效应方向一致,有必要研究其在标记辅助选择中的效果。本研究没有检测到在多世代表现稳定的QTL。因此,需要培育重组自交系,进一步明确产量性状有关QTL的遗传效应。     

海岛棉主要纤维品质性状的分离及相关性分析

以海岛棉新海3号×吉扎82的190个F2：3家系为材料,对海岛棉主要纤维品质性状在后代群体中的分离规律及性状间的相关性进行了研究。结果表明,海岛棉主要纤维品质性状均是由微效多基因控制,符合正态分布,表现为数量性状遗传方式。相关分析表明,纤维上半部平均长度与断裂比强度、整齐度呈极显著正相关,与短绒指数呈极显著负相关,马克隆值与断裂比强度和整齐度呈显著正相关。     

新疆棉花纤维品质性状的QTL分析

 以自育高品质中长绒棉品种（新陆中9号提高系）9-1696为母本,与主栽品种中棉所35为父本配置单交组合,筛选出12对SSR引物在F₂群体和B1群体进行纤维长度、整齐度、比强度和伸长率4个纤维品质性状的QTL分析,采用区间作图法（LOD>2.0）,在F₂群体中检测到6个与纤维品质性状连锁的QTL位点。其中,检测到纤维长度、纤维整齐度、伸长率各1个QTL位点,比强度检测到3个QTL。在B₁群体中检测到2个QTL,分别与比强度和纤维长度连锁。     

QTL Mapping for Yield and Fiber Quality Traits in Double-Cross Population of Chromosome Segment Introgression Lines from Gossypium hirsutum×Gossypium barbadense

[Objective] The aim of this study was to map quantitative traits loci (QTLs) for yield and fiber quality traits in chromosome segment introgression lines (CSILs) from Gossypium hirsutum×Gossypium barbadense. [Method] Four CSILs, MBI 7115, MBI 7412, MBI 7153 and MBI 7346, which were obtained by advanced backcrossing and continuous inbreeding from upland cotton variety CCRI 45 and sea-island cotton variety Hai 1, were used to construct double-cross segregating populations F1 and F1:2 through the following crosses: [(MBI 7115×MBI 7412)×(MBI 7153×MBI 7346)]. Simple sequence repeat (SSR) molecular markers were used to evaluate the genotyes of parents. The F1 and F1:2 populations were used to map QTLs for yield and fiber quality-related traits. [Result] The recovery rates of the recurrent parent CCRI 45 in the four CSILs were all above 97%. Forty-one QTLs, which were distributed across 11 chromosomes, were detected using the two segregating populations. There were 30 QTLs controlling fiber quality with phenotypic variations ranging from 1.11% to 11.80% and 11 QTLs controlling yield-related traits with 1.09%–13.57% phenotypic variations. [Conclusion] Five QTLs for fiber quality were consistently detected in two populations and they were all newly discovered QTLs. This study provides an important theoretical basis for fine mapping of these QTLs and molecular marker-assisted breeding for excellent fiber quality.     

Mapping QTL of Fiber Yield and Quality Traits in F2 Populations of Chromosome Segment Substitution Lines from Gossypium hirsutum × Gossypium barbadense

In this study, F₂ populations from two chromosome segment substitution lines MBI7455 and MBI7358, were quantified using SSR to evaluate the parents' genotype and detect QTL related to fiber quality plus yield traits of cotton. Results show that the recurrent parent (CCRI45) hosted 96.70% and 95.60% of chromosome segment substitution in MBI7455 with 12 chromosome segments and in MBI7358 with 16 chromosome substitution segments of Gossypium barbadense, respectively. In the F₂ population, the average rate of chromosome substitution of the recurrent parent (CCRI45) was 96.44%, and the average segments of chromosome substitution of Gossypium barbadense was 13.42, with an average segments of homozygous donor chromosome value of 3.90. Analysis showed 19 fiber quality-related QTL with a phenotypic variance of between 2.52%-13.11% and seven yield traits-related QTL with a range of 2.93%-11.40% phenotypic variance, resulting in a total of 26 QTL. The CSSLs could be used to detect QTL for fiber yield and quality traits, which offer an important foundation for the cotton molecular-assisted breeding.     

Evaluation of Chromosome Segment Substitution Lines Related to Fiber Yield and Quality Traits from Gossypium hirsutum×Gossypium barbadense

Three generations of chromosome segment substitution lines lines (BC₄F₃, BC₄F_3:4, and BC₄F_3:5, Anyang, Korla) were used to evaluate phenotypic traits related to fiber yield and quality. The average performance of the traits in the population was near to the control, CCRI45, in the four populations. Seventy-eight percent of the lines showed longer and stronger fibers than the recurrent parent, and 22.59%～53.61% of lines had bigger bolls and higher lint percentages than the recurrent parent. Correlation analysis showed that the yield and fiber quality traits were positively correlated among the four populations. These results indicated that most of the genetic background in the substitution lines has been restored to the recurrent parent with abundant genetic variations. In addition, most of substitution lines had good yield and fiber quality. This study provided a large amount of basic research materials for cotton quantity genetics, gene pyramiding, and gene function analysis, and provided parent materials and new strains that can directly applied for cotton breeding.     

鲁棉研15号纤维品质性状QTL定位研究

 以陆地棉（Gossypium hirsutum L.）杂交种鲁棉研15号的F₂群体为作图群体,利用SSR标记和JoinMap3.0软件构建遗传连锁图谱;利用复合区间作图法分别对随机组成的3个鲁棉研15号的F_2:3家系亚群体进行纤维品质性状QTL定位。构建的遗传连锁图谱包含116个多态位点,25个连锁群,全长892.25 cM,覆盖棉花总基因组的20.05%,平均每个连锁群4.64个标记,标记间平均距离7.76 cM;根据已有图谱的定位结果,19个连锁群与染色体建立了联系。在3个F_2:3家系亚群体中共检测到46个QTL,其中16个为纤维长度（FL）QTL、7个为纤维强度（FS）、12个为麦克隆值（FM）、6个为伸长率（FE）,5个为整齐度指数（FU）。发现在A_h05、A_h08、A_h09、D_h02染色体上QTL有成簇分布的现象,并在3个亚群体中检测到一些受环境影响较小、稳定遗传的QTL。这些QTL可以在今后应用于分子标记辅助选择。     

Improving Fiber Quality Traits of Xinluzao 45 Using Gossypium barbadense Chromosome Segment Substitution Lines

Gossypium barbadense chromosome segment substitution lines could be used as an important germplasm resource for improving fiber quality traits of upland cotton. In this study, we used TM-1 background substitution lines CSSL-122, the Xinjiang upland cotton Xinluzao 45 and hybrid, backcross progeny BC₂F₁ populations comprising 120 individual plants as test materials. Nineteen SSR markers located in Gossypium barbadense chromosomes land inked with fiber length and strength were used to screen out obvious polymorphic primers between the parents. We then traced and detected chromosome segments of Gossypium barbadense in the BC₂F₁ populations. Simultaneously, we compared fiber quality traits of positive plants that contained Gossypium barbadense chromosome segments with non-positive plants in the BC₂F₁ populations. The results showed that two markers, NAU2987 and BNL3145, which were linked with fiber length, could accurately identify the positive plants. In addition, compared with non-positive plants, the increased fiber length and strength of the positive plants were very significant (P < 0.01). Our research suggested that alien Gossypium barbadense chromosome segments significantly improved the fiber quality traits of Xinluzao 45. Thus, the Gossypium barbadense chromosome segment substitution lines will provide a vital theoretical basis and practical reference for improving Upland Cotton fiber quality traits.     

QTL Mapping of Chlorophyll Content in Gossypium hirsutum and Gossypium barbadense Backcross Inbred Lines

[Objective] The purpose of this study was to map quantitative trait loci (QTL) related to chlorophyll content based on Soil and Plant Analyzer Development (SPAD) readings in cotton. [Method] The 195 BILs (Backcross Inbred Lines) were produced by a cross between Gossypium barbadense Hai 7124 and G. hirsutum CRI 36, using CRI 36 as the recurrent parent for backcrossing with F1 to produce BC1F1, followed by seven generations of selfing. The genetic linkage map was constructed in a previous study. QTLs of chlorophyll SPAD value in the first flowering and boll development stages were identified with inclusive composite interval mapping (ICIM) method of the BIP and MET models in IciMapping 4.1 software, respectively. [Result] In total, nine chlorophyll SPAD reading QTLs were identified on 6 chromosomes. The q-SPAD-A11-1 detected at the first flowering stage overlapped with q-SPAD-A11-2 detected at the boll development stage, contributing 5.08% and 5.75% of the phenotypic variation, respectively. The q-SPAD-D08-2 physical position ranged from 48.71 to 53.65 Mb on chromosome D08, which overlapped with a chlorophyll content QTL detected in a previous study. [Conclusion] The novel stable QTLs, q-SPAD-A11-1 and q-SPAD-A11-2 detected in this study provide an important piece of information for fine mapping chlorophyll content in cotton.     

多环境下陆地棉染色体片段代换系及F_1皮棉产量与纤维品质的表型分析

以1套陆地棉染色体片段代换系为亲本材料,采用株系间随机成对杂交组配F1,在5个环境下鉴定片段代换系亲本及F1的皮棉产量与纤维品质性状表现。结果表明,与轮回亲本(中棉所36)相比,F1在铃重与皮棉产量性状上具有一定的对照优势,亲本与F1的纤维长度与比强度均表现出明显的对照优势,且环境间表现一致。F1铃重、衣分与皮棉产量在各个环境下的中亲优势均值全部为正,且相对较大。除个别环境外,纤维长度、马克隆值与比强度的中亲优势均值也全部为正,但数值相对较小。片段代换系及F1的遗传变异丰富,部分亲本与F1在多个环境下的综合表现优异,其皮棉产量与纤维品质得到同步提高,群体材料的遗传改良与杂种优势利用具有广阔前景。