北方早熟玉米抗病自交系的选育及改良

试验设在黑龙江省农科院试验农场玉米连作10年以上的病圃内,并连年用丝黑穗病菌土盖种和对植株进行人工接种大、小斑病菌。材料和方法以自育稳定自交系和国内外引入的优良稳定系2000余份,作为筛选抗源和高抗玉米大斑病及丝黑穗病的鉴定材料;用自选低代系和引入的非稳定     

玉米自交系中7490的选育

为了解决玉米选系材料遗传基础狭窄的问题,我国从70年代末期开始,通过群体改良和导入热带玉米种质等途径,进行玉米育种素材的改良创新研究,已取得了一定进展。 本文前名作者,1978～1980年在阿拉伯也门共和国白脱纳(BAITNA)农业试验中心工作期间,利     

改进玉米自交系常规选育技术的探讨

本文从玉米自交系的选育目标、基础材料的组建、自交系常规选育的技术路线和选育方法等方面，阐述了如何改进玉米自交系常规选育技术。提出了在自交系选育时要适当的近交和回交、注重从原有材料中选自然变异株和把目标性状逐步整合组装等技术路线。     

玉米自交系快速选育新技术

优良自交系的选育是玉米育种工作的基础。目前，玉米育种仍主要采用传统的方法。传统育种方法选育一个自交系至少需5～7年，育种周期长、工作量大，特别是在一年一季的北方，育种进程更加缓慢。各个育种单位都采取南繁加代来加快玉米品种选育进程。但是，南繁加代要耗费大量的人力物力。随着现代生物技术的发展，玉米育种技术研究已取得了一些新的进展，为加速玉米育种进程带来了新的曙光。     

玉米自交系选育方法

简要介绍了自交系选育的多种方法与途径,并对各种方法进行了评述。以期为广大育种者尤其是初学者提供借鉴。     

玉米自交系JTR411选育与应用

阐述了玉米新自交系JTR 411的选育经过和配合力表现,综述了其特征特性、繁殖制种及高产栽培要点等,以期为玉米的育种研究和应用提供参考.     

浅谈玉米自交系的选育

随着种子体制改革及现代种业的迅速发展,玉米育种呈现出了“百花齐放,百家争鸣”的新局面。玉米自交系是玉米育种的基础,一个优良自交系可以育成一批优良品种。因此,玉米自交系的水平决定了杂交种的水平,玉米自交系的选育是玉米育种的前提。     

黄改玉米自交系嫩H75121的选育及应用

摘要：嫩H75121是黑龙江省农业科学院齐齐哈尔分院玉米遗传育种研究室以黄早四和丹705二环系自交选育的黄改玉米自交系,具有适应性强、配合力高、株型紧凑、生育期短、灌浆速度快、耐旱、耐高温等特征特性。利用嫩H75121成功选育优质、高抗、宜机收玉米品种嫩单23,适合黑龙江省第二积温带种植。     

玉米自交系若干性遗传改良趋势的初步研究

选择不同年代育成的１１个玉米自交系为代表，对株型和产量组成两类共９个性状进行了遗传改良趋势的研究。结果表明：各性状的遗传方差均达极显著水平。影响玉米自交系耐肥、抗倒状性的穗位／株高性关以及决定玉身材一的叶向值等性状的改良效果最显著。改良趋势最明显。而穗部性状的改良趋势只有穗粗比较明显。     

极早熟玉米自交系“承18”的选育及其特点

针对我国高寒山区积温少、无霜期短,无杂交玉米,从搜集超早熟玉米种质资源入手,利用超早熟、抗寒冷玉米珍贵种质资源“坝上火玉米”,导入高配合力、优良农艺性状遗传基因,选育出极早熟优良自交系“承18”,总结出选育一环系和二环系相结合的顶交玉米育种的新途径,并分析该系的特点和育成经验,可为今后选育极早熟玉米自交系提供借鉴.     

玉米自交系新01A3及其改良系的选育及应用

玉米种质资源的改良和创新是选育优良玉米杂交种的关键。根据黄淮海地区杂种优势模式,选育和改良唐四平头类自交系,对黄淮海玉米杂交种的选育至关重要。通过研究玉米自交系新01A3及其改良系的选育过程,进而探讨了新01A3及其改良系作为亲本组配出的杂交种在生产上的应用。     

利用孤雌生殖诱导系诱导单倍体技术在玉米自交系选育中的应用

由于单倍体只具有每一对同源染色体及等位基因中的一个,遗传基础单一,单倍体染色体的加倍,相当于同质结合,可得到遗传上稳定、纯合,性状不分离的二倍体纯系。玉米单倍体育种技术能有效地提高选育效率,加快育种进程。与其他玉米常规育种选系技术相比,在自交系纯化方面具有不可替代的优越性。本文简要介绍该项技术在玉米自交系选育中的应用过程,为进一步科学有效地利用提供操作依据。     

Identification of maize brace-root quantitative trait loci in a recombinant inbred line population

Brace roots are vital constituents of the root system in maize. Their contribution to plant development is affected by brace-root traits (BRTs) including tier number (TN), root number (RN) and radius of the brace root (RBR). However, the genetic control of BRTs still remains elusive. Here, we have identified quantitative trait loci (QTLs) from 207 recombinant inbred lines of BY815/K22 grown in three environments to dissect the genetic architecture of BRTs in maize. All three of BRTs were highly heritable and were affected by genotype, environment and the interaction between them. RBR was positively correlated with both RN and TN. Eight QTLs were identified, 3 for TN, 3 for RN and 2 for RBR, and located on chromosome 1, 2, 9 and 10. They together explained 26.4% (TN), 21.5% (RN) and 13.4% (RBR) of phenotypic variation. Sixty of annotated genes were identified from the narrower QTLs by the bin-map method, including genes for signal transduction, gene expression regulation, and metabolism and related processes. The results also show that the interaction may occur between QTLs for BRTs. Our results can help to further study the genetic basis of BRTs and improve the approaches to control maize brace-root system through SNP marker-assisted selection.     

玉米自交系大黄132雌穗发育异常及其防治措施

大黄 132玉米自交系,由贵州盘县种子公司于 1982年从当地农家品种普古大黄中经 6代连续自交选育而成. 1992年冬季在三亚市崖城繁殖 100亩,出现雌穗发育异常现象,空秆率达 80%,减产 85%左右; 2002年冬季在海南省乐东县九所镇三脚村以大黄 132为母本,苏 37 2为父本制种,结果早播的 50亩大黄 132和第一批父本也出现不同程度的雌穗发育异常现象.这种现象在温带和亚热带种质中少有报道,本文就这一现象进行初步探讨.     

玉米胞质不育系C齐319的选育和利用

杂种优势的应用使玉米产量有了大幅度的提高,但是配制杂交种需要人工去雄,不仅增加了劳动强度,提高了生产成本,而且会因去雄不及时、不彻底而影响杂交种的质量。据调查,近年来全国大多数玉米杂交种的自交株率较高,致使杂交     

Genetic dissection of seed vigour under artificial ageing conditions using two joined maize recombinant inbred line populations

Seed vigour plays an important role in agricultural production, and seeds with high sowing quality are necessary for improving agriculture production. In our study, two connected maize recombinant inbred line (RIL) populations derived from Yu82 × Shen137 and Yu537A × Shen137 crosses were evaluated for the mean germination time (MGT) and other related traits under three artificial ageing treatments. We used meta‐analysis to integrate genetic maps and identify quantitative trait loci (QTLs) across the two populations. In total, 74 QTLs and 20 meta‐QTLs (mQTLs) were identified. Four key mQTLs, mQTL2‐2, mQTL5‐4, mQTL6 and mQTL8, which contained initial QTLs with R² values >10% and included 5–9 initial QTLs, may be hot spots of important QTLs for the associated traits. Twenty‐two key candidate genes associated with four seed vigour‐related traits mapped to 14 mQTLs. In particular, the GRMZM2G163749, GRMZM2G122172/GRMZM2G554885/GRMZM2G122871 and GRMZM2G150367 genes mapped within the important mQTL5–4, mQTL6 and mQTL8 regions, respectively. Fine mapping for the genetic regions of these three mQTLs merits further study and could be utilized for marker‐assisted breeding.     

Discriminating maize inbred lines using molecular and DUS data

Growing numbers of candidate varieties, decrease of their variability for morphological traits, and internationalization of the national list all contribute to excessive increase of the trial costs, thus creating the need for the improvement of current variety evaluation procedures, especially regards their distinctness, Uniformity, and Stability (DUS) component. Due to rapid advancement in molecular techniques, the use of molecular markers in DUS testing as a complement to, or replacement of, morphological observations became the subject of great interest in scientific studies, and consequently topic for discussion within International Union for the Protection of New Varieties of Plants (UPOV). In order to explore the potential of simple sequence repeat (SSR) markers for distinctness tests, present study involved set of 41 maize inbred lines that were scored for 32 DUS characters prescribed by UPOV and genotyped at 28 SSR loci. Results were largely in favor of the use of molecular markers, revealing or confirming their already known advantages over morphological markers like better consistency with the pedigree, and relatively higher discriminative power. However, their integration into DUS testing protocols still depends upon resolving of several important issues.