Suwan种质的特点及在玉米育种中的利用

Suwan种质包括Suwan－1群体及含有其基础种质的改良群体、自交系等玉米种质资源．具有适应性好、抗逆性强、配合力高、品质优良等特点,热带、亚热带的许多国家和地区在玉米生产和育种上广泛利用,有合成群体、选育品种间杂交种、改良温带种质等。     

甘肃玉米种质资源创新问题探析

引证有关文献,对甘肃玉米种质资源储备不足、种质创新缺乏动力,制约玉米产业的发展,以及对当前种质创新技术、机制及法规体系方面存在的问题和影响进行分析,并对种质资源创新方法、提高甘肃省在玉米种质资源创新研究的投入效率和对创新种质的有效保护问题提出了建议。     

Suwan种质在玉米育种中的利用

Ｓｕｗａｎ种质在玉米育种中的利用任洪，郑常祥，杨斌，陈泽辉（贵州省农科院旱粮所）Ｓｕｗａｎ种质包括Ｓｕｗａｎ－１群体及含有其基础种质的改良群体、自交系等玉米种质资源。Ｓｕｗａｎ种质具有适应性好、抗逆性强、配合力高、品质优良等特点，在热带、亚热带许多国...     

我国玉米种质资源创新的现状

介绍近年来我国玉米种质资源研究和创新的现状,并针对我国玉米种质基础狭窄的状况提出其相应的种质创新途径和方法。     

玉米抗低温灌浆种质的创新及其育种利用

用超低温处理浸泡6h的特早熟玉米F1种子15min,后代出现了3.3%～10.0%的变异。通过育种选择获得了抗低温高灌浆速率自交系99-3,在16.3℃低温下灌浆速率为4.6mg /(粒·d),比一般玉米材料平均高82 5%,能充分利用自然能量,延长灌浆期。用其组配的特早熟单交种极早单2号在16.3℃低温下灌浆速率比对照冀承单3号高67.9%,比晋单43号高97.6%,区试增产20.5%。     

浙江省玉米种质资源现状与利用

玉米种质资源是选育优良品种的遗传物质基础，收集原始素材，拓宽种质基础，开展种质鉴定、创新和利用，在玉米品种改良工作中始终占有重要地位。从全球范围来看，大约有300个玉米地方种族，但广泛开发利用的只有5～6个。种质资源狭窄也是当前我国玉米育种和生产的突出矛盾，杂交玉米育种中每一次突破性品种的诞生，总是以突破性的基础材料和自交系为前提。为了扩大玉米遗传育种的种质基础，自20世纪80年代以来，我国育种家对热带。     

玉米特异性种质资源的创新与利用

根据国内外的研究进展和我国市场需要,就目前我国尚未开发利用的饲用糯玉米、高油糯玉米、高直链淀粉玉米、低植酸玉米、氮(磷、钾)高效玉米等特异型玉米种质的创新与开发利用做了简要阐述.     

玉米种质创新与自交系培育

培育自交系是玉米杂交育种的物质基础。优异自交系及其组合选配可以促进突破性新品种的诞生。２０世纪７０～９０年代，中国玉米育种家采取多种途径，拓展玉米种质基础，成功地培育出许多综合性状或特异性状优良以及高配合力的自交系，为选育高产优质玉米杂交种创造了条件。１抗病性改良玉米抗病性的垂直抗性是指寄主对病原菌的某一个或多个小种是抵抗或免疫的，而对另一些小种是感病或高感的；水平抗性是指对病原菌的全部小种具有同等水平或同样有效的抵抗能力。例如玉米品种对大斑病具有水平抗性，虽总体感病，但并不严重。自从发现了显性…     

浅谈美国玉米种质在我国玉米育种中的作用

农业作为推动我国国民经济的重要组成部分之一,对我国社会经济的建设和发展有较大的帮助作用。虽然当前我国农业不断改革,对于先进技术的应用力度也比较广泛,但是要想进一步推动我国农业的稳步前进,就要注重结合我国国情,加强对先进科技品种的应用。基于此,简要分析了美国玉米种质应用到我国玉米育种当中的作用。     

Properties of maternal haploid maize plants and potential application to maize breeding

Summary Presented are the results of a two-year study of haploid maize plants in the field. The haploids were produced with the aid of inducer line ZMS. In total, 604 and 1030 haploids were obtained and studied in the first and second years, respectively. Tassels of haploid plants were found to be almost completley sterile. Fertility of ears was studied by pollinating them with the pollen from diploid inbred lines, the cross resulting in almost all of the haploid ears carrying kernels. On average 27.4 kernels per ear of haploid plant were obtained in the first year of study and 26.3 in the second. These gave rise to normal diploid plants. This property allows genotypes selected at the level of haploid plants to be involved in breeding process. Unusual plants were found among haploids, phenotypically resembling homozygous lines. It was assumed that the plants had resulted from spontaneous chromosome doubling in haploids. The results of comparative studies of progenies of unusual plants and inbred lines derived from the same synthetic population are presented.     

玉米自交系繁育体系的研究及应用

1玉米自交系繁育体系现状我国从事玉米种子生产经营的公司或企业的玉米自交系生产,基本以外引(调)后隔离繁殖,严格去杂为主,即"省提、市繁、县制"的繁育体系.这种繁育体系是计划经济体制的产物,与市场经济格格不入.随着市场经济的发展,只有少数专业化程度较高的大型种子公司建立了独立的玉米自交系繁育体系.这种繁育体系是以"循环选择法"、"重复繁殖法"、"株系循环法"等为原则指导生产玉米自交系.     

玉米转基因育种技术环节思考

转基因技术自产生以来因为生物安全而被关注。本文对转基因的育种过程的回交转育、选择、标记辅助选择、资源保护、生物安全、育种者责任、法律规定和未来发展方向等各个环节进行了分析、概括和总结。希望育种者能够在进行转基因过程中明确自身责任,按照法规行事,提高育种技巧,更好更安全地利用转基因为生产服务。     

我国玉米地方种质资源在育种中的应用

近20年来,我国生产上大面积应用的玉米杂交种的亲本自交系,主要集中在唐四平头、旅大红骨、lan-caster和ReidYellowDent等四大种质类群上,玉米育种的种质基础狭窄和遗传脆弱性已成为人们十分担心的问题,为了开发新的种质资源,扩大玉米遗传育种的种质基础,自20世纪80年代以来,我国育种家对热带、亚热带及美国等外来种质产生了浓厚兴趣,通过引进、改良驯化和导入利用等大量研究,取得了一定成效。然而我国十分丰富的地方种质资源,其优良种质虽然在玉米育种史上发挥过重要作用,但目前利用较少。充分开发地方种质资源、进行种质扩增和杂交种选…     

姊妹交在玉米育种中的研究进展

早代分离的优良姊妹系间相互杂交可提高姊妹交种产量30%以上.分离早代用姊妹交代替自交选育自交系,不但能将双亲的优良性状有机地结合起来,选育出产量和配合力较高的自交系,而且可以避免种质资源的大量流失.     

转基因玉米育种的研究进展与展望

<正>转基因玉米的研究从20世纪80年代中期开始到现在的短短十几年时间得到了迅速的发展,整个里程大致分为3个阶段:1988年以前是转化方法的探索阶段;1989-1994年是直接遗产转化方法的研究与发展     

甘肃省玉米育种问题与对策探讨

分析了甘肃玉米育种的现状和存在的问题。种质创新能力不足、育种技术、育种方法、抗逆性育种重视不够,是目前品种产量潜力不大、适应性和抗逆性不强的主要原因。提出了加强协作攻关、调整育种目标、提高适应性,加强种质扩增、改良和创新,改进育种选择方式,推进新技术应用,密切新品种与栽培技术相结合等对策。育种思路以增强玉米品种适应性和高产优质为目标,以本土化的种质为基础,构建杂种优势群为核心,强化逆境人工选择、采用密植育种策略,探索高配合力的玉米生理生态育种技术。     

Participatory maize breeding for low nitrogen tolerance

The local maize variety Sol da Manhã has a broad genetic background. It was identified in 1985 in a participatory evaluation trial as being suitable for cultivation under low soil fertility conditions in Sol da Manhã, situated in Seropédica, State of Rio de Janeiro, Brazil. The variety was then improved for 6 selection cycles by the formal breeding sector at the experimental station of Embrapa Agrobiologia. There were three cycles of mass selection, one selection cycle between and within half-sib families, one selection cycle within full-sib families, and one selection cycle between and within S₁ families. Thereafter, the variety was improved in collaboration with the informal sector, viz. a group of farmers of the agricultural community of Sol da Manhã for 6 cycles of mass selection. The variety was evaluated in 1994 in field trials for grain yield and nitrogen use efficiency. Sol da Manhã can be characterised as efficient in nitrogen use, under both favourable and unfavourable growing conditions.     

Choice of shrinkage parameter and prediction of genomic breeding values in elite maize breeding populations

Genomic selection (GS) is a promising alternative to marker‐assisted selection particularly for quantitative traits. In this study, we examined the prediction accuracy of genomic breeding values by using ridge regression best linear unbiased prediction in combination with fivefold cross‐validation based on empirical data of a commercial maize breeding programme. The empirical data is composed of 930 testcross progenies derived from 11 segregating families evaluated at six environments for grain yield and grain moisture. Accuracy to predict genomic breeding values was affected by the choice of the shrinkage parameter λ², by unbalanced family size, by size of the training population and to a lower extent by the number of markers. Accuracy of genomic breeding values was high suggesting that the selection gain can be improved implementing GS in elite maize breeding programmes.     

玉米单倍体在育种中的应用进展

介绍了玉米单倍体的研究概况,单倍体的染色体加倍问题以及双单倍体在玉米育种中的应用。