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 F1 generations produced from the cross between the inbred line Zheng 58 and the inbred line W499 belonging to the Reid subgroup. Using the MaizeSNP50 BeadChip, 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 ReidxSipingtou in China through a marker-assisted selection approach.

Genetics and Molecular Mapping of a High-Temperature Resistance Gene to Stripe Rust in Seeding-Stage in Winter Wheat Cultivar Lantian 1

Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici （Pst）, is a severe foliar disease of common wheat （Triticum aestivum L.） in the world. Resistance is the best approach to control the disease. The winter wheat cultivar Lantian 1 has high-temperature resistance to stripe rust. To determing the gene（s） for the stripe rust resistance, Lantian 1 was crossed with Mingxian 169 （M169）. Seedlings of the parents, and F 1 , F 2 and F 2-3 progenies were tested with races CYR32 of Pst under controlled greenhouse conditions. Lantian 1 has a single partially dominant gene conferred resistance to race CYR32, designated as YrLT1. Simple sequence repeat （SSR） techniques were used to identify molecular markers linked to YrLT1. A linkage group of five SSR markers was constructed for YrLT1 using 166 F 2 plants. Based on the SSR marker consensus map and the position on wheat chromosome, the resistance gene was assigned on chromosome 2DL. Amplification of a set of nulli-tetrasomic Chinese Spring lines with SSR marker Xwmc797 confirmed that the resistance gene was located on the long arm of chromosome 2D. Because of its chromosomal location and the high-temperature resistance, this gene is different from previously described genes. The molecular map spanned 29.9 cM, and the genetic distance of two close markers Xbarc228 and Xcfd16 to resistance gene locus was 4.0 and 5.7 cM, respectively. The polymorphism rates of the flanking markers in 46 wheat lines were 2.1 and 2.1%, respectively; and the two markers in combination could distinguish the alleles at the resistance locus in 97.9% of tested genotypes. This new gene and flanking markers should be useful in developing wheat cultivars with high level and possible durable resistance to stripe rust.

Mapping novel genetic loci associated with female liver weight variations using Collaborative Cross mice

Background: Liver weight is a complex trait, controlled by polygenic factors and differs within populations. Dissecting the genetic architecture underlying these variations will facilitate the search for key role candidate genes involved directly in the hepatomegaly process and indirectly involved in related diseases etiology.Methods: Liver weight of 506 mice generated from 39 different Collaborative Cross(CC) lines with both sexes at age 20 weeks old was determined using an electronic balance. Genomic DNA of the CC lines was genotyped with high-density single nucleotide polymorphic markers.Results: Statistical analysis revealed a significant(P < 0.05) variation of liver weight between the CC lines, with broad sense heritability(H^2) of 0.32 and genetic coefficient of variation(CV_G) of 0.28. Subsequently, quantitative trait locus(QTL) mapping was performed, and results showed a significant QTL only for females on chromosome 8 at genomic interval 88.61-93.38 Mb(4.77 Mb). Three suggestive QTL were mapped at chromosomes 4, 12 and 13. The four QTL were designated as LWL1-LWL4 referring to liver weight loci 1-4 on chromosomes 8, 4, 12 and 13,respectively.Conclusion: To our knowledge, this report presents, for the first time, the utilization of the CC for mapping QTL associated with baseline liver weight in mice. Our findings demonstrate that liver weight is a complex trait controlled by multiple genetic factors that differ significantly between sexes.

Rapid Construction of a High-Density Rice Linkage Map by High Efficiency Genome Scanning (HEGS) System

High-density linkage maps are essential tools for genome analysis of various biological traits. Our developed compact multi-gel system, HEGS （high efficiency genome scanning） is a high-throughput and high-cost-performance electrophoresis apparatus. Using this system, a high-density （average interval 2.3 cM） map with 1 065 AFLP and 63 SSR markers was constructed from recombinant inbred lines of a japonica and indica hybrid in just two months of electrophoreses by a single person. More than 50% of the mapped AFLP markers were commonly polymorphic for several combinations between japonica and indica rice and 15% were applicable for genetically closer crosses between upland and lowland types of japonica rice. This system can be used for rapid analyses of all kinds of markers.

低成本手持式稠密点云采集系统

针对现有室内外场景无法使用低成本便携式LiDAR很好地采集高稠密度点云数据的问题,本文研究设计了一种对低成本LiDAR和IMU传感器在硬件层面进行组合的低成本手持式稠密点云采集系统。采用简化残差计算量后的Faster-LIO当作里程计,通过传感器紧耦合的方式,将LiDAR和IMU之间的外参矩阵作为优化量,在采集的过程中进行实时优化以获得准确的相对位姿,从而得到满足精度要求的稠密点云。本文方法与经典的基于LOAM特征的LiDAR里程计及RTK里程计进行对比,试验结果表明,本文方法是有效的,手持式旋转激光雷达扩增了LiDAR的视野,而且对采用的里程计算法进行了改进,在减少算力要求降低成本的同时,大幅度降低了LiDAR和IMU等设备安装时无法避免的相互扰动问题,能较好地完成对场景稠密点云的采集及初步重建。

基于高密度遗传图谱定位水稻籽粒性状QTL

籽粒性状直接影响水稻的产量和品质,因此,解析水稻籽粒性状的遗传机制对提高水稻产量和品质至关重要。本研究以籽粒性状差异较大的穞稻和广百香占为亲本构建定位群体,利用水稻1 K mGPS SNP芯片对定位群体进行基因分型,构建了包含770个Bin标记的高密度遗传图谱,通过QTL定位分析,最终鉴定出17个调控籽粒性状的QTLs,其中粒长QTL 4个,粒宽QTL 3个,粒厚QTL 3个,长宽比QTL 2个,千粒重QTL 5个,LOD值介于2.55~42.44之间,表型贡献率介于4.73%~29.63%之间。在这17个QTLs中,9个为已知粒型基因位点,8个可能是新鉴定位点,分别为粒长qGL6,粒宽qGW5、qGW10和qGW12,粒厚qGT10,长宽比qGLWR5-2,千粒重qTGW10和qTGW11。根据新发现粒宽QTL(qGW5)定位区间内的基因注释、与拟南芥的同源基因比对、时空表达分析、激素响应分析和序列分析,最终筛选到1个编码CCCH类锌指蛋白的调控水稻粒宽的候选基因Os05g0195101。本研究为进一步开展水稻籽粒性状基因的克隆和遗传调控的解析奠定了基础。

利用高密度遗传图谱定位两种不同环境的水稻剑叶形态性状QTL差异

水稻剑叶形态性状是构成理想株型的重要因素之一,发掘新的控制剑叶形态性状的基因资源是提高水稻产量的重要途经。本研究利用高密度遗传图谱对在杭州和海南陵水种植的印度粳稻品种M494和中国籼稻品种中9B(Z9B)杂交衍生的重组自交系(recombinant inbred lines,RIL)群体剑叶长、剑叶宽、剑叶面积和剑叶长宽比进行数量性状位点(Quantitative trait locus,QTL)定位检测。研究共检测到10个QTL,包括1个剑叶长QTL、4个剑叶宽QTL、4个剑叶面积QTL和1个剑叶长宽比QTL,分布于第4、第7、第8、第9和第10号染色体,贡献率介于6.47%~13.28%之间;鉴定到2个多效性QTL区间,其中在第4号染色体Block536~Block544区间检测到同时控制剑叶宽和剑叶面积的QTL,在第10号染色体Block942~Block961区间检测到同时控制剑叶宽和剑叶长宽比的QTL,其贡献率分别为8.82%、13.28%、12.28%和12.60%。两地间QTL差异较大,仅在Block536~Block544区间同时定位到控制剑叶宽及剑叶面积的QTL及在Block942~Block961区间同时定位到控制剑叶宽及剑叶长宽比的QTL。

基于高密度遗传图谱的水稻萌发耐淹性QTL定位

通过对水稻萌发耐淹性进行QTL定位和稳定位点的聚合效应分析,可以为萌发耐淹性基因的精细定位及后续分子辅助育种奠定基础。本研究利用一个包含144份家系的强萌发耐淹性粳型杂草稻WR-4与籼稻品种广百香占的F2:3定位群体,基于1K m GPS SNP芯片构建了一个包含825个Bin标记的高密度遗传图谱,利用完备区间作图法共检测到10个萌发耐淹性QTL,分布于水稻第3、4、7、8、9和10染色体上,LOD值介于3.6~21.3之间,可解释3.0%~21.1%的表型变异。其中,具有较高LOD值和贡献率的2个主效QTL(q GS4-1和q GS7-1)能够被重复检测到,是后续基因克隆的候选位点。根据Bin标记分型结果将不同子代在两个稳定QTL区间内分为WR型和广百香占型,在F2:3群体中进行聚合效应分析,发现聚合增效等位基因数量越多的家系,其淹水条件下的胚芽鞘越长,这些携带多个耐性QTL的株系可为分子育种培育耐低氧萌发水稻新品种提供亲本资源。

利用高密度遗传图谱挖掘水稻芽期耐盐QTL

【目的】挖掘水稻芽期耐盐新位点,为进一步开展基因功能分析和盐渍土直播生产提供理论依据。【方法】以耐盐品种‘龙稻133’和盐敏品种‘彩稻’衍生的169个RIL群体为试验材料,利用包含1107个高质量多态性Bin标记的高密度遗传连锁图谱,对对照和0.5%NaCl胁迫下的胚芽鞘长、胚根数、胚根长以及相对胚芽鞘长、相对胚根数和相对胚根长共9个性状进行QTL定位分析。【结果】高密度遗传连锁图谱共覆盖水稻基因组2957.35 cM,标记间的平均距离为2.67 cM。12条染色体含有的平均标记数为92.25个。描述性统计分析表明,亲本‘龙稻133’的耐盐性显著高于‘彩稻’,亲本的性状表型值位于RIL群体的极值之间,群体表现出超亲分离现象。盐胁迫严重抑制RIL群体的胚芽鞘长、胚根数和胚根长,且不同株系受胁迫影响差异较大,各性状基本符合正态分布,具有数量性状的遗传特性。连锁分析共鉴定到19个QTL,贡献率为2.58%~14.83%,发现2个QTL区间内存在已克隆的耐盐相关基因,其中qTCL3区间内包含DST,qRRN10区间内包含OsMSRA4.1。此外,发现控制盐胁迫下胚芽鞘长的qTCL10、控制相对胚芽鞘长的qRCL10以及控制相对胚根长的qRRL10均位于同一QTL区间内;控制盐胁迫下胚根长的qTRL7和控制相对胚根长的qRRL7也位于同一QTL区间内。2个共定位区间内的25个候选基因qRT-PCR分析结果显示,盐处理后,LOC_Os07g44210、LOC_Os07g44240、LOC_Os07g44250、LOC_Os07g44350、LOC_Os10g42940和LOC_Os10g43060在‘彩稻’或‘龙稻133’均显著上调表达。其中,LOC_Os07g44350在盐处理后的‘龙稻133’胚芽鞘和胚根内均极显著上调表达。【结论】发掘19个与水稻芽期耐盐相关QTL,其中包含2个共定位位点qTRL7和qTCL10,2个共定位区间内共有25个候选基因。通过qRT-PCR分析发现6个在盐处理后表达量上调的基因,其中LOC_Os07g44350是芽期耐盐的重要候选基因。

高密度场景下基于改进A^(*)算法的无人机路径规划

针对无人机在高密度障碍物的城市环境飞行中路径规划实时性难以满足的问题,在A^(*)算法基础上结合跳点搜索(Jump Point Search, JPS)策略,提出一种Jump A^(*)(JA^(*))算法。将A^(*)算法进行三维扩展,并提出了一种三维对角距离精确表示了实际路径代价,缩短了搜索时间。在二维JPS策略的基础上拓展得到了三维JPS策略,代替了A^(*)算法中的几何邻居扩展,大大减少了扩展结点数。对障碍物密度0.1~0.4的复杂三维栅格地图进行了路径规划仿真。仿真结果表明,JA^(*)算法相较于A^(*)算法,在高密度多障碍物的近地城市环境下,路径长度几乎不变,评估节点数大幅度减小,搜索速度具有显著提升。

改造枯草芽孢杆菌底盘细胞高效生产乙偶姻

以实验室前期保藏的经代谢工程改造的枯草芽孢杆菌(Bacillus subtilis)QRC-1为出发菌株,其在5 L发酵罐平均发酵生产乙偶姻的产量达到50.7 g/L。然而,枯草芽孢杆菌存在的自溶与生长速率较慢的问题限制了其在发酵过程中的生物量增长,同时发酵产泡多的特点也影响了该菌在放大培养过程中的实时调控。因此本实验基于生理特性对枯草芽孢杆菌QRC-1进行优化改造,利用分子遗传技术开发一种新的策略,达到提高生物量和乙偶姻产量的目标。最终获得的菌株RKCR-8,比生长速率比原菌提高了30%,生物量增加了1.36倍,乙偶姻产量达到72.3 g/L。使用本研究构建的重组枯草芽孢杆菌生产乙偶姻具有更强的生产效率和工业稳定性。这一结果不仅为乙偶姻的生产提供更多参考价值,也为未来工业微生物底盘的构建提供了一种新的思路。

鄱阳湖湖滨多宝沙山成因机制

鄱阳湖地区属于亚热带季风性湿润气候带,湖滨却多处发育沙漠。多宝沙山是湖滨面积最大的沙漠,给当地环境造成了非常严重的危害。前人多认为多宝沙山是风成的;然而,沙山多处沿岸露头的地层层理均表现为水成特征。为进一步明确多宝沙山成因,本研究进行了物探(高密度电阻率法和瞬变电磁法)和野外地质露头调查,发现第四系除风成特征外,还具有水成的厚度分布及层序地层特征。本研究认为多宝沙山是风力搬运和水下沉积共同作用的结果,其形成与湖平面多次起伏、彭蠡泽南扩、湖底平坦的地形、三角洲快速沉积、断块差异运动、强劲的冬季风等多重因素在时间和空间上的耦合相关。多宝沙山形成于全新世时期,位于古赣江三角洲前缘亚相,后期发生构造抬升,多宝沙山被强风改造,风沙覆盖了除西山、笔架山之外的古构造高地,最终形成了现今的多宝沙山。

基于多尺度特征聚合和密集连接的人群计数网络

人群计数任务处理的图像受到遮挡、视角变化和透视效应、背景成像干扰等多方面的挑战。针对复杂场景中人群计数任务存在的尺度变化、图片噪声等问题,设计一种基于多尺度特征聚合和密集连接的人群计数网络模型。模型的一个重要组成部分是密集连接而成的多尺度特征聚合模块,它通过不同卷积核提取多尺度特征并聚合其跨尺度的信息进行更准确的估计。该网络模型在三个公开数据集Shanghai Tech、UCF_QNRF、UCF_CC_50上进行测试,实验结果表明,该模型相比目前先进算法CSRNet在平均绝对误差(MAE)、均方误差(MSE)均有不同程度的减少,模型精度更好。与其他模型相比,该模型更充分地利用多尺度特征信息,提高了人群计数任务的精度。

高密度城市中心区气候图研究——以深圳龙华区为例

城市化进程加速催生了许多高密度城市及建筑群,对城市气候造成了许多如热岛效应和城市洪涝灾害等不利影响。面对日益严重的城市气候问题,科学、准确地评估城市气候影响因素并提出相应的规划改善对策,对促进可持续城市发展至关重要。本文选择具有高密度特征的深圳龙华区,基于ArcGIS空间分析方法,整合现状气候信息展开研究。以城市热岛及通风问题,将热负荷因子和通风潜力因子空间叠加构建城市气候图。报告发现龙华区气候状况亟待改善,并根据影响程度按1~7级分类,提出“三区两廊多核心”的气候规划优化结构。此外,从绿地系统、开敞空间及水系规划中提出具体规划建议。本文从城市规划视角分析了龙华区热岛效应和通风问题的成因,给出相应的保护和规划对策,具有一定的实践意义。为龙华区以及其他高密度建成区提供气候规划参照,对创造良好的人居环境、促进城市可持续发展具有重要意义。

Theoretical strategies for high-resolution mapping of complex genetic disorders in humans

Positional cloning of gene(s) underlying a complex disease trait poses requirement of a highresolution linkage map between the disease locus and genetic marker loci. Recent researches have shown that this may be achieved through appropriately modeling and screening linkage disequilibrium between the candidate marker locus and the major trait locus. However, these models were restricted to the circumstances where genotyping at the disease locus was feasible. The major limitations of pedigree-based linkage analyses were addressed in the light of positional cloning and positional candidate gene identification in humans. It summarizes the recent efforts in developing theories for fine-scale mapping of genes underlying complex genetic variations where the one-to-one relationship no longer exists between phenotype of the genetic disorders and the corresponding genotype.

利用高密度Bin遗传图谱定位水稻抽穗期QTL

挖掘新的控制水稻抽穗期相关位点和候选基因,对抽穗期的遗传机制研究和品种改良具有重要的意义。利用抽穗期存在明显差异的粳稻TD70和籼稻Kasalath杂交衍生的包含186个家系的重组自交系群体,构建了基于深度重测序的高密度Bin遗传图谱,图谱共包含12,328个Bin标记。RIL群体及亲本2018年和2021年正季种植于江苏省南京市江苏省农业科学院。以家系从播种到抽穗所经历的天数作为抽穗期表型值,使用IciMapping软件3.4版的完备区间作图法,对控制水稻抽穗期的QTL进行鉴定。2年共检测到15个抽穗期的QTL,分布在3号、6号、7号、8号、10号和12号染色体上,LOD值为2.58~10.68,其中7个QTL和已知抽穗期QTL的位置存在重叠或者部分重叠。共有4个QTL在2年均检测到,表现出较强的稳定性。对2年重复鉴定到的4个QTL区间进行基因功能注释和亲本间序列分析,共发现7个注释有功能,且在2个亲本间编码区存在非同义突变的基因。根据候选基因SNP的类型对RIL群体家系进行基因等位型分类和效应分析,发现4个基因其不同等位型的RIL家系在抽穗期上存在显著或者极显著差异,推测可能为候选基因,可用于后续水稻抽穗期的分子机制研究。

Mapping Glitches of Juniper Forests in Lebanon under Natural Conditions and Anthropogenic Activities

In 1965, the first forest map of Lebanon was produced. It is the oldest spatial distribution representation of junipers. Landcover maps of 2002 and 2010 are the most detailed spatial distribution that spatially shows forests. Juniper forests are found in Lebanon as mainly as clear to low density coverage. High-density juniper forests are rarely found and only on Mount-Lebanon. Juniper forests are also mixed with oaks on the Eastern flank of Mount-Lebanon. Mapping juniper forests have demonstrated high degree of complexity, especially because of their low density and being mixed. The spatial representation of juniper forests was compared between the 1965 forest map and the landcover maps of 2002 and 2010. GIS environment was used to extract juniper forests from all maps. The degree of matching between juniper forests was investigated regarding the total area and spatial overlapping. Juniper forests were examined to their spatial locations, comparing the three maps. Spatial changes and anthropogenic effect were obtained, using Google Earth facilities. Google earth had satellite images acquired since 2014. Landcover maps of 2002 and 2010 have spatially matched forest map of 1965 by about 90% and 50% respectively. Spatial coverage of juniper forests were about 12,000, 26,000 and 28,000 ha on the 1965 forest map, landcover maps of 2003 and 2010 respectively. Anti-Lebanon juniper forests were not well represented on both landcover maps. Anthropogenic activities were mainly agriculture that affected juniper forests. Cultivations have replaced about 2% of the spatial coverage of 1965 Juniper forests. Quarries and urban existed inside juniper forests but in very limited areas. Juniper forests delineation did not completely match neither between the available maps, nor to the ground. Some juniper forests were not spatially represented on all maps or existing maps represented only portion of juniper forests. Juniper forest mapping requires more consideration and field investigation. High spatial resolution satellite images are among the solutions but delimiting juniper would require extensive fieldwork and specific remote sensing treatments. Being centuries old forests and characterized by High Mountain elevations, these important conifer forests are needed to be mapped with higher accuracy for better statistics and conservation.

基于高密度遗传图谱的芝麻籽粒品质相关性状QTL定位

芝麻是我国重要的优质油料作物,对芝麻籽粒品质性状进行数量性状位点(QTL)定位对定向培育高品质芝麻品种具有重要意义。以豫芝4号为母本、孟加拉小籽为父本,分别构建F2、F2:3、BC1和BC1F2群体,结合特异位点扩增片段(SLAF)标记和简单重复序列(SSR)标记构建F2和BC1遗传图谱,以F2:3、BC1和BC1F23个群体的表型数据为基础,进行脂肪、蛋白质、芝麻素、芝麻林素含量等4个品质性状的QTL作图分析。结果表明,在F2:3群体中共检测到16个QTL,解释表型变异的5.08%~27.12%,其中仅有1个主效QTL qOC_10-1在2个环境中被重复检测到,分别解释表型变异的9.62%和27.12%。在BC1和BC1F2群体中共检测到35个QTL,其中3个主效QTL qOC_4-1、qOC_10-2和qSmin_7-2在3个环境中被重复检测到,分别解释表型变异的8.08%~12.42%、11.95%~12.60%和4.24%~10.56%;3个主效QTL qSmin_8、qSmol_5-2和qSmol_7-2在2个环境被重复检测到,分别解释表型变异的13.36%~26.75%、11.44%~14.33%和5.77%~12.38%。经过对2个图谱进行整合和比对分析,共发现10个QTL簇,其中QTL簇loci4、loci7、loci8和loci10均与多个性状相关联,并且均至少包含1个主效QTL,其对应的最大表型变异解释率分别为12.42%、12.38%、26.75%和27.12%。

DEP1、Gn1a和qSW5组合应用调控水稻穗部性状

【目的】水稻是重要的粮食作物,为全球超过一半的人口提供主食。穗部性状是影响水稻产量的主要因素,挖掘调控穗部性状的优异基因组合,为提高水稻产量提供聚合育种策略。【方法】以弯穗型籼稻品种R99和直立穗型粳稻品种SN265构建的151个重组自交系为试材,应用Illumina测序平台对重组自交系和双亲进行全基因组重测序。结合表型数据与遗传图谱,对每穗粒数、一次枝梗着粒数、二次枝梗着粒数和粒型进行QTL分析,筛选QTL区间内的候选基因,应用基于三代测序组装的SN265和R99高质量基因组进行候选基因预测和序列比对,在重组自交系中筛选产量性状表现最好的基因组合,并在SN265遗传背景下应用CRISPR基因编辑技术对目标位点进行基因编辑。【结果】R99每穗粒数和二次枝梗着粒数显著多于SN265,SN265的一次枝梗着粒数显著高于R99,R99粒型细长,SN265粒型短圆。每个重组自交系平均测序深度为6.25×,R99和SN265的测序深度分别为30×和32×。获得1456445个高质量的SNP,利用划bin策略进行图谱构建,得到一个包含3569个bins,平均长度为58.17 kb的遗传图。QTL分析在第9染色体检测到一个同时调控每穗粒数、一次枝梗着粒数和二次枝梗着粒数的QTL,在第1染色体鉴定到一个调控每穗粒数和二次枝梗着粒数的QTL,在第5染色体鉴定到一个调控粒型的QTL。候选基因预测和序列比对发现第9染色体的DEP1同时调控水稻一次和二次枝梗着粒数,第1染色体的Gn1a主要调控水稻二次枝梗着粒数,第5染色体的qSW5主要调控粒型。在151个重组自交系中,对DEP1、Gn1a和qSW5的不同组合进行分类并调查产量构成因素,发现Gn1a^(R99)/DEP1^(SN265)/qSW5^(SN265)等位基因组合产量表现最好,Gn1a^(SN265)/DEP1^(R99)/qSW5^(R99)产量表现最差。对SN265的Gn1a位点进行分子设计育种,获得2个独立的CRISPR基因编辑株系,通过调查其产量构成因素,发现基因编辑植株穗长显著变长,每穗粒数显著增加,进而显著增加单株产量。【结论】揭示了DEP1、Gn1a和qSW5对每穗粒数和粒型的影响,明确了Gn1aSN265/DEP1R99/qSW5R99为重组自交系中最佳基因组合,通过改良SN265的Gn1a位点进一步提高了其单株产量。

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。