大麦重组自交系千粒重性状的QTL定位

本研究以二棱春性大麦(Hordeum vulgare L.)Prisma和Apex为亲本所建立的94个重组自交系为材料,采用复合区间作图法对三个氮素水平下大麦重组自交系千粒重进行QTL定位分析,在三个氮素环境中同时检测到的QTLs为q TWG6-2,定位在第6染色体的标记区间E38M54-307-E45M58-676,为进一步QTL精细定位和克隆创造条件。     

首个韩国人基因组图谱绘制成功

据韩国联合通讯报道,韩国研究机构日前宣布．第一个完整的韩国人基因组图谱已经绘制成功。这是人类染色体碱基序列第四次被完整破译,这项成果是由韩国嘉泉医科大学和韩国生命工程研究院的两个研究团队通过共同研究取得的。研究的目的是建立韩国人标准染色体数据库。研究人员期待,在染色体碱基序列图谱基础上进一步分析韩国人特有的遗传特性．有助于探明韩国人种发病率较高的遗传性疾病的病因,找到后基因时代的解决办法。研究还发现,金圣镇的染色体具有323万个单核苷酸多态性位点．     

水稻同源四倍体杂种优势利用技术新体系的研究

运用遗传育种、细胞工程及分子生物学等技术手段对同源四倍体水稻开展了多方面的研究。取得成果如下:创制了同源四倍体水稻材料近1000份。选育出同源四倍体水稻雄性不育系6份、不育系材料46份;保持系22份、保持系材料100多份;恢复系28份、恢复系材料500多份;成功地实现了四倍体水稻杂种优势利用三系配套。培育出T462A×T4509等四倍体杂交稻新组合。三系及杂种的细胞学研究表明,其染色体数为48条,为二倍体水稻染色体数的2倍,证明是同源四倍体。并初步开展了分子生物学的研究。     

北京基因组所合作完成鲤鱼基因组序列图谱绘制

<正>中科院北京基因组所于军研究组与其合作者完成了鲤鱼全基因组序列图谱绘制,这也是国际上首个完成全面解析的异源四倍体硬骨鱼类基因组图谱。该研究团队完成了雌核发育鲤鱼的基因组深度测序、精细图谱绘制和基因组注释。在遗传图谱信息的基础上,科研人员利用基因组组装结果,将鲤鱼基因组定位到染色体上,得到了较完整的鲤鱼精细图谱。其基因组由16.9亿碱基组成,含有52610个功     

科技动态

我国科学家分离出控制水稻产量基因《自然—遗传学》网络版发表了中科院院士、华中农业大学教授张启发团队的研究论文,报道了他们首次发现并成功克隆的一个同时控制水稻株高、抽穗期和每穗粒数的QTL     

水稻抗褐飞虱与白背飞虱基因定位研究进展

褐飞虱(BPH,Nilaparvata lugens)与白背飞虱(WBPH,Sogatellafurcifera)是水稻的两种重要害虫,培育抗虫品种是防治这两种飞虱的有效途经.近年水稻抗褐飞虱与白背飞虱资源发掘与利用研究取得长足进展,迄今已经在水稻上鉴定或定位了许多抗稻飞虱基因,这些基因来源于水稻的栽培种和野生种.本文就近年来水稻抗褐飞虱与白背飞虱主基因定位和QTL分析研究进展进行阐述.并简要回顾分子标记辅助选择在抗飞虱育种上的应用概况,对当前基因定位研究中存在的问题及其应用前景作了探讨.     

多角度解释生命的复杂性

2002年1月4日,美国《科学》杂志发表了日本理化学研究所染色体组科学综合研究中心的研究小组在世界上首次绘制成功的黑猩猩的染色体组图谱。黑猩猩的染色体与人的染色体差异精确到只有1.23％。该研究小组把黑猩猩的染色体组分成约6.4万个片断,以几百个为一组,然后分别读取基因片断两端的碱基对序列,再把它们同已完成的人类染     

科学历程

正2001年2月12日——首次公布人类基因组图谱2001年,由中、美、英、法、德、日6国科学家共同参与的国际人类基因组计划公布了人类基因组图谱及初步分析结果。6国先后参加人类基因组对23对染色体DNA大规模测序的国际合作,最终绘制了一张类似化学元素周期表的人类基因组精确图谱。科学家经过初步解读,发现人类基因组中包含3万多     

重要农艺性状的全基因组关联分析取得进展

北京基因组所／上海生科院植生生态所韩斌课题组,通过与中国水稻所、中科院遗传与发育所等单位的研究人员合作,结合第二代测序技术和自主开发的基因型分析方法。对517份中国水稻地方品种材料进行测序,构建了高密度的水稻单体型图谱（HapMap）,并对籼稻品种的14个重要农艺性状进行全基因组关联分析,     

水稻第四号染色体精确测序完成

水稻是最重要的粮食作物之一,是世界约一半以上人口的主要口粮。水稻作为禾本科植物基因组研究的模式作物,具有十分重要的意义。中国科学院国家基因研究中心率先完成了国际水稻基因组计划的第4号染色体全长序列的精确测序,该成果已在英国的《自然》杂志发表。本文简要报告水稻基因组测序的意义和目前我国在这一领域已取得的进展,并着重介绍水稻基因组4号染色体精确测序和分析的成果。     

杂交稻中共显性RAPD标记及产量性状基因的检测

ＲＡＰＤ标记是利用含有１０（或９）个碱基的随机引物（单引物）,通过聚合酶链式反应（ＰＣＲ）对模板ＤＮＡ进行随机扩增,比较不同基因组ＤＮＡ的差异,ＲＡＰＤ标记具有样品用量少,灵敏度高,检测容易等优点,因而比ＲＦＬＰ更易于应用,但ＲＡＰＤ是显性标记,在分离群体中不能区别纯合显性和杂合显性个体。     

Pleiotropic effects of the sdw1 locus in barley populations representing different rounds of recombination

BackgroundIn the present study populations, representing different rounds of recombination were used for the analysis of phenotypic effects associated with the sdw1/denso locus. Other studies have mostly focused only on one type of population. Many different QTLs mapped at the same position as the sdw1/denso locus may indicate a pleiotropy of this gene or a tight linkage between genes conditioning quantitative traits. To date, results of studies have not unequivocally proven either of these two phenomena.ResultsBoth breeding and molecular mapping experiments were undertaken to examine 200 single seed descent (SSD) and 60 doubled haploid (DH) lines obtained from the Maresi (with a semi-dwarfing gene) and Pomo cross combination. They were evaluated for the type of juvenile growth habit and certain agronomic traits were measured after harvesting. The estimates of mean values, standard errors and significance of effects were analyzed. In terms of the analyzed characteristics, the greatest variability was obtained for genotypes with the prostrate growth habit. Microsatellite markers (SSR) were also used to identify co-segregation with the sdw1/denso locus and Bmag0013, Bmag0877, Bmag0306b markers were linked the closest. A partial linkage map of chromosome 3H with the sdw1/denso semi-dwarfing gene was constructed and QTLs were identified.ConclusionsOur experiments confirmed the impact of the semi-dwarfing gene on plant height, heading and flowering date both in SSD and DH populations, which may indicate pleiotropy. Moreover, a partial linkage between sdw1/denso locus and grain weight per spike and 1000-grain weight was found in the SSD population.     

基于水足迹视角的中国北方10省三大粮食作物种植结构优化

水资源短缺与水-土-粮系统不协调是制约中国粮食生产可持续发展的重要因素,种植结构优化作为农业结构型节水的重要举措,对保障中国水资源安全与粮食安全具有重要意义。本文聚焦中国北方10省,揭示水足迹视角下水资源压力与三大粮食作物种植结构的关系,探讨不同目标权重情景下三大粮食作物种植结构的优化趋势,并通过构建多目标种植结构优化模型,得出不同节水情景下北方10省三大粮食作物种植结构优化方案。研究表明：①中国北方10省中粮食种植规模较大的地区水资源压力指数普遍偏高,水资源约束呈趋紧态势;②当使用熵权法对经济收益、蓝水（灌溉水）消耗和绿水（雨水）利用目标客观赋权时,北方10省将增加高收益高耗水的水稻种植。随着蓝水消耗最小化目标的权重逐渐加大,水稻种植面积和蓝水耗水量会逐步减少;③在15%节水情景中,山东、山西、内蒙古、陕西、甘肃、青海应调增玉米种植面积而减少水稻和小麦的种植面积,宁夏和新疆应调增小麦种植面积而调减水稻和玉米的种植面积,河南应调增水稻和玉米的种植面积而减少小麦的种植面积;④在节水5%、10%和15%情景中,优化的种植结构能够使北方10省三大粮食作物生产的蓝水足迹总量较2019年分别减少38亿m³、51亿m³和64亿m³,平均单位蓝水足迹的现金收益提升4%、3%和2%。本文结果对保障中国粮食安全,实现农业可持续发展具有重要的政策启示。     

国际粮食价格对中国粮食价格的非对称性影响研究

随着经济全球化与中国粮食市场开放程度的不断提高,国内外粮食价格的关联性日益增强,然而国际粮食价格的上涨和下跌对国内粮食价格的影响作用机制存在差异。本文基于时变概率马尔科夫区制转移（MS-TVTP）模型,实证分析在粮食市场的不同运行阶段下,中国的合成粮食价格以及小麦、大米、大豆、玉米四类粮食价格受到国际价格的非对称性影响及其差异性。研究发现国际粮食价格通过贸易途径对国内粮食价格的影响存在非对称性效应,国内粮食价格倾向于对国际粮食价格上涨时的波动产生过度反应,而对国际粮食价格下跌时的波动反应不足。大豆受到国际价格影响最为显著,其正向影响作用在国内大豆价格上涨阶段大于下跌阶段;小麦、大米、玉米受到的非对称性影响形式因贸易形势、自给率等决定的价格传递形式不同而呈现差异。大豆低自给率和较高外贸依存度要求政府需健全大豆市场的政策保障,合理利用国际大豆价格的影响,规避国际市场异常波动对国内市场价格的冲击。     

土地细碎化视角下种粮目的对稻农生物农药施用行为的影响

在不同土地细碎化条件下,厘清影响稻农生物农药施用行为的关键因素,对实现农药减量、保障农产品质量安全具有重要现实意义。基于2017年湖北省765份农户实地调研问卷,从追求风险最小化、利润最大化以及食品安全3个方面构建稻农生物农药施用行为多目标效用模型,实证检验不同土地细碎化条件下种粮目的对稻农生物农药施用行为的异质性影响。结果显示：①以自留口粮占比表征的种粮目的,越趋向于满足自家消费需要,稻农施用生物农药的可能性越大,且自留口粮占比每提高1%,施用生物农药的可能性会提高10.56%;②对于土地细碎化程度低（平均地块面积大于0.133 hm ²）的稻农而言,种粮目的对其生物农药施用行为产生负向影响,而对于土地细碎化程度高（平均地块面积小于0.133 hm ²）的稻农而言,种粮目的表现为正向影响;③稻农生物农药施用行为也会受到农药残留意识、绿色农产品重要性认知、市场风险感知以及健康水平的正向影响,以及市场风险感知的负向影响。根据研究结论提出政策建议：加快农田标准化建设,实现同质化生产,同时加快普及新型农业技术和农业发展形势,从生产源头和市场建设双管齐下。     

Molecular characterization and genetic diversity of different genotypes of Oryza sativa and Oryza glaberrima

BackgroundAvailability of related rice species is critical for rice breeding and improvement. Two distinct species of domesticated rice exist in the genus Oryza: Oryza sativa (Asian rice) and Oryza glaberrima (African rice). New rice for Africa (NERICA) is derived from interspecific crosses between these two species. Molecular profiling of these germplasms is important for both genetics and breeding studies. We used 30 polymorphic SSR markers to assess the genetic diversity and molecular fingerprints of 53 rice genotypes of O. sativa, O. glaberrima, and NERICA.ResultsIn total, 180 alleles were detected. Average polymorphism information content and Shannon's information index were 0.638 and 1.390, respectively. Population structure and neighbor-joining phylogenetic tree revealed that 53 genotypes grouped into three distinct subpopulations conforming to the original three groups, except three varieties (IR66417, WAB450-4, MZCD74), and that NERICA showed a smaller genetic distance from O. sativa genotypes (0.774) than from O. glaberrima genotypes (0.889). A molecular fingerprint map of the 53 accessions was constructed with a novel encoding method based on the SSR polymorphic alleles. Ten specific SSR markers displayed different allelic profiles between the O. glaberrima and O. sativa genotypes.ConclusionsGenetic diversity studies revealed that 50 rice types were clustered into different subpopulations whereas three genotypes were admixtures. Molecular fingerprinting and 10 specific markers were obtained to identify the 53 rice genotypes. These results can facilitate the potential utilization of sibling species in rice breeding and molecular classification of O. sativa and O. glaberrima germplasms.     

Molecular dissection of complex agronomic traits of rice:a team effort by Chinese scientists in recent years

Rice is a staple food for more than half of the worldwide population and is also a model species for biological studies on monocotyledons. hrough a team efort, Chinese scientists have made rapid and important progresses in rice biology in recent years. Here, we briely review these advances, emphasizing on the regulatory mechanisms of the complex agronomic traits that afect rice yield and grain quality. Progresses in rice genome biology and genome evolution have also been summarized.     

中国主要粮食生产的化肥削减潜力及其碳减排效应

在保障中国粮食安全前提下,减少化肥不合理使用是实现农业可持续发展的重要挑战。测土配方施肥是兼顾粮食安全和生态安全的科学施肥方法,本文在中国粮食作物区域大配方施肥数据的基础上,系统测算小麦、玉米、水稻三大粮食作物化肥投入的削减潜力及其碳减排效应。结果显示,满足当前粮食产量水平下,全部采用测土配方施肥,小麦、玉米、水稻三大粮食作物主产区化肥投入可削减814.1万t/a,占主产区三大粮食作物化肥使用量的27.6%,小麦、水稻和玉米化肥使用可分别削减36.9%、28.1%和16.7%;三大粮食作物化肥使用削减可减少碳排放1 045.9万t/a。建议深入推进测土配方施肥,建立配方肥生产服务中心,出台配方肥使用补贴,创新补贴方式和推广模式,构建全国测土配方施肥大数据平台。     

Control vector optimization and genetic algorithms for mixed-integer dynamic optimization in the synthesis of rice drying processes

Rice drying synthesis is an essential operation that has to be done carefully and cost-effectively. Rice is harvested at high moisture content and hence must be dried within 24 h for safe storage. However, improper drying can cause fissuring in the rice grain, and thus greatly reduce its market value. Multi-pass drying systems are therefore used to gradually bring moisture content to desired level.The problem of rice synthesis, considered in this study, seeks the configuration of units and their corresponding operating conditions that maximize rice quality. This problem is formulated as a mixed-integer dynamic optimization problem. The integer part of the problem reflects process alternatives while the dynamic part originates from nonlinear differential-algebraic equations describing the drying behavior of a rice grain.Clearly such a formidable problem is not easy to solve. Hence, we propose an approach that makes use of two algorithms: a genetic algorithm to search for the best configuration of units and a control vector parameterization approach that optimizes the operating conditions for each configuration. We demonstrate the effectiveness of the approach on a case study.     

Disruption of MIR396e and MIR396f improves rice yield under nitrogen-deficient conditions

The microRNA miR396 directly represses GROWTH-REGULATING FACTORs (OsGRFs) and has been implicated in regulating rice yield and in nitrogen assimilation. Overexpressing the miR396 targets OsGRF4 and OsGRF6 improves rice yield via increased grain size and panicle branching, respectively. Here, we used CRISPR/Cas9 to assess the function of miR396 genes in rice. Knockout of MIR396ef (MIR396e and MIR396f), but not other isoforms, enhanced both grain size and panicle branching, resulting in increased grain yield. Importantly, under nitrogen-deficient conditions, mir396ef mutants showed an even higher relative increase in grain yield as well as elevated above-ground biomass. Furthermore, we identified OsGRF8 as a new target of miR396, in addition to the known targets OsGRF4 and OsGRF6. Disruption of the miR396-targeting site in OsGRF8 was sufficient to both enlarge grain size and elongate panicles. Our results suggest that rice-seed and panicle development are regulated by miR396ef-GRF4/6/8-GIF1/2/3 modules and that miR396ef are promising targets of genome editing for breeding environmentally friendly rice varieties that require less nitrogen fertilization.