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CIMMYT牧草与普通玉米杂交后植物学形态变异研究 总被引：1，自引：0，他引：1
[研究目的]为发掘利用CIMMYT牧草生长繁茂和抗逆能力强等优良遗传特性,改良普通玉米材料的抗逆性和创制新型饲草材料.[方法]以CIMMYT牧草和4个普通玉米自交系为遗传交配材料,比较研究了CIMMYT牧草和4个杂交(回交)后代材料的植物学形态特征及其与普通玉米的差异.[结果]CIMMYT牧草能将其生长繁茂、分蘖力强、生物产量高的特性遗传给杂交后代材料,并有较强的世代传递能力;该牧草幼苗、植株及其生长习性、花器官、种子特征等与普通玉米差异明显,其与普通玉米的杂交后代基本保持了它的生长发育特性,但花器官和种子特征更偏向于普通玉米;回交后代除保持了一定的分蘖特性、明显的多穗和返祖现象外,其余特征特性与普通玉米基本没有区别.[结论] CIMMYT牧草生长繁茂和生物产量高的特性能遗传给杂交后代,世代传递能力较强,通过遗传改良途径,能将CIM-MYT牧草的优良特性转育到普通玉米中,培育出饲草玉米育种新材料. 相似文献
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玉米杂交组合的产量高低，与玉米穗粒和植株部位的各种性状有着极密切的关系。但是，穗粒性状和植株性状的遗传极为复杂，不仅与杂交组合的环境条件有密切关系，而且与生育期长短也有密切的关系。在近几年玉米早熟种的选育中，体会到它与中晚熟种有许多不尽相同的地方。例如，早熟种对温度的反应极为敏感，不同试验地点的温度差异，对生育期的变化影响极大。百粒重的变化也与不同地理位置有明显关系。因此，有必要深入研究早熟种玉米选育时的主要农艺性状指标。1供试材料1996年利用一批早熟优良自交系，组配成111个杂交组合。2试验地点试验… 相似文献
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从小麦×玉米诱导小麦单倍体技术的机理及技术特点及双单倍体（DH）的遗传分析与研究，针对不同的小麦玉米杂交组合，对其杂交后代进行单倍体鉴定是必要的。这些研究有助于将玉米有益基因导入小麦基因组，从而利于对普通小麦种质进行遗传改良和遗传创新。 相似文献
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CIMMYT玉米自交系在广西具有较好的适应性，目前利用CIMMYT和广西玉米自交系杂交已成功选育出许多适合广西种植的玉米新品种。为了解CIMMYT和广西玉米自交系间的杂种优势关系，本研究以20份CIMMYT自交系和169份广西自交系为供试材料，以5份中国骨干自交系和4份广西骨干自交系作为参照系，利用10K玉米SNP芯片进行全基因组扫描，开展遗传相似性、系统进化树和主成分分析，划分参试材料的杂种优势群。研究结果表明，189份玉米自交系绝大多数杂合率均小于10%，纯合度较高。CIMMYT自交系相互间遗传相似性较高，与广西玉米自交系间遗传相似度较低。进化树和主成分分析将189份自交系分为PB群、SPT群、‘桂单162-0810’母本群、‘桂单162’父本群、‘桂单0810’父本群和其他类群，其中大部分CIMMYT玉米自交系属于SPT群，大部分广西玉米自交系属于‘桂单162-0810’母本群、‘桂单0810’父本群和其他类群。可见，CIMMYT与广西玉米自交系间遗传差异较大，大多属于不同杂种优势群，两类自交系进行杂交能够较大概率获得优良玉米品种。 相似文献
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爆裂玉米膨爆特性的遗传及杂交种选育研究进展 总被引：25，自引：5，他引：25
综述了爆裂玉米膨爆特性的遗传及其与穗粒性状的相关性、爆裂玉米的育种方法等方面的国内外研究进展。爆裂玉米的膨爆特性是由多基因控制的数量性状，与籽粒产量及大多数穗粒性状呈显著负相关。通过不同爆裂玉米间相互杂交及其与普通玉米杂交、回交或长期的轮回选择，可有效地聚集分散在不同材料、不同个体中的优良性状和有利基因，显著提高育种效果。 相似文献
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玉米生理成熟后子粒脱水速率的配合力分析 总被引：4，自引：1，他引：4
选用10个熟期相近而子粒脱水速率差异较大的玉米自交系为试验材料，采用完全双列杂交设计配制杂交组合，对玉米生理成熟后子粒脱水速率进行配合力分析。结果表明，供试10份玉米自交系生理成熟后子粒脱水速率一般配合力方差达到极显著水平，5份自交系表现为正效应。90个杂交组合的特殊配合力方差达到极显著水平，玉米生理成熟后子粒脱水速率正反交效应存在极显著差异。遗传参数估计表明，玉米生理成熟后子粒脱水速率的广义遗传力和狭义遗传力均较高，分别达到81．45％和61．71％，在后代的遗传中加性基因占主导地位。 相似文献
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12个外来玉米群体与我国主要种质配合力效应和杂种优势分析 总被引：3，自引：0，他引：3
国际玉米小麦改良中心(CIMMYT)和美国玉米带种质含有丰富的遗传变异, 是拓展我国玉米种质基础的重要来源。本文采用NCII遗传交配设计, 以中综5号、中综6号和中综7号综合种为测验种, 与12个外来群体配制36个组合。以郑单958为对照, 2009—2010年分别在北京顺义、山东济南和河南新乡进行产量及相关性状测定。利用Miranda Filho-Geraldi模型, 评价外来群体主要性状配合力效应及杂种优势表现。结果表明, Pob43、La Posta、Pob21、Pob32、Pob49、Pob501等群体的产量及相关性状GCA表现优良。群体Pob49、Pob501与我国PA种质, Pob32、BS29与我国PB种质, Pob43、La posta与我国D群四平头种质的遗传关系较近。因此, 在改良外来群体适应性的基础上, 可以我国A、B和D类群种质为核心, 将群体Pob21、Pob49、Pob501与A群种质, Pob32与B群种质, Pob43、La Posta与D群的四平头种质构建复合种质并进行改良, 逐步拓宽我国主要种质类群的遗传基础。 相似文献
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Zea mays ssp. mexicana, an annual wild relative of maize, has many desirable characteristics for maize improvement. To transfer alien genetic germplasm
into maize background, F1 hybrids were generated by using Z. mays ssp. mexicana as the female parent and cultivated maize inbred line Ye515 as the male parent. Alien introgression lines, with a large range
of genetic diversity, were produced by backcross and successive self-pollinations. A number of alien introgression lines with
the predominant traits of cultivated maize were selected. Genomic in situ hybridization (GISH) proved that small chromosome
segments of Z. mays ssp. mexicana had been integrated into the maize genome. Some outstanding alien introgression lines were evaluated in performance trials
which showed 54.6% hybrids had grain yield greater than that of hybrid check Yedan12 which possessed 50% Ye515 parentage,
and 17.1, 9.9% hybrids had grain yield competitive or greater than those of Nongda108 and Zheng958, which were elite commercial
hybrids in China, respectively. The results indicated that some of the introgression lines had excellent agronomic traits
and combining ability for maize cultivar, and demonstrated that Z. mays ssp. mexicana was a valuable source for maize breeding, and could be used to broaden and enrich the maize germplasm. 相似文献
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M. Meeks S. C. Murray S. Hague D. Hays A. M. H. Ibrahim 《Journal of Agronomy and Crop Science》2012,198(3):161-172
Drought stress is thought to promote epicuticular wax accumulation on maize leaves, which reduces plant water loss. We evaluated 62 maize inbred lines and their hybrid testcross progeny for epicuticular wax accumulation on flag leaves at flowering under full and limited irrigation regimes. Extracted wax was measured as a percentage of wax weight to leaf weight (WLW) and leaf area (WLA). Eleven genotypes had above average WLW as both inbred lines and hybrid testcrosses. Thirteen genotypes had above average WLA as either inbred lines or hybrid testcrosses. The drought treatment did not significantly alter WLW or WLA. Heritability of WLW was 0.17 (inbred lines) and 0.58 (hybrid testcrosses). Heritability of WLA was 0.41 (inbred lines) and 0.59 (hybrid testcrosses), suggesting it is a better trait than WLW for epicuticular wax screening. Correlations (r) between inbred lines and their testcross progeny were 0.44 and 0.18, for WLW and WLA, respectively. Heritability of grain weight per ear and plot yield was highest in hybrid testcrosses, with no correlation between inbred and hybrid germplasm. It is not warranted to evaluate epicuticular wax accumulation as the sole drought tolerance mechanism. However, it may be a good secondary trait to observe in relation to grain yield production in hybrids tested under water‐limiting conditions. 相似文献
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Amplified fragment length polymorphisms (AFLPs) were used to follow the possible introgression of maize DNA into haploids of wheat as a side‐effect of exploiting wheat x maize hybridization for haploid production. AFLPs were generated with 64 MseI/ EcoRI and 64 MseI/ PstI primer combinations, and the AFLP profiles of haploids were tested against those of maize and of the regular wheat varieties involved in the crosses. On average, 45.1 and 110.7 fragments were produced per assay with the MseI/EcoRI and MseI/PstI combinations, respectively. Different numbers of fragments were produced for wheat and maize: an average of 81 in the haploid, 80 in the wheat parent, and only 67.1 in maize. No evidence was found for introgression of maize into the wheat genome. Three unique AFLP fragments were detected in haploids, which were not present in the parental wheat genotypes. These ‘novel’ AFLP bands in the haploids could be caused by nucleo‐cytoplasmic interaction in the hybrid zygote. Such instability in the wheat genome is defined as temporal, as it was not detected in further generations when colchicine‐doubled progeny of the haploids was tested for the presence of polymorphic fragments. 相似文献
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Paul C. Mangelsdorf 《Euphytica》1961,10(2):157-168
The principal characteristics of maize and its two relatives, teosinte and Tripsacum are described. The manifestations of the introgression of teosinte into maize determined from experimental cultures can be recognized in prehistoric maize from Guatemala, Mexico, and the southwestern United States. This introgression, which began at least 2,000 years ago, is still proceeding in Mexico where maize and teosinte commonly grow in the same fields and hybridize frequently. Evidence is presented of the direct introgression of Tripsacum in several races of maize of South America. The introgression of teosinte and Tripsacum has contributed to the evolution of maize through gene recombination, mutagenic effects, and various types of heterotic phenomena. The role of introgression in the improvement of maize is discussed.Presented at a conference entitled The role of introgressive hybridization in the evolution of crop plants and their wild relatives, held at Versailles on 4th January, 1961 by the Section Wild Species and Primitive Forms of Eucarpia (European Association for Research on Plant Breeding).The research reported in this paper was supported in part by a grant from the Rockefeller Foundation and the publication expenses were borne in part by the Maria Moors Cabot Foundation for Botanical Research. I am indebted to Dr. W. C. Galinat for several drawings and to Mr. S. M. Sehgal for the photographs in figure 14. 相似文献
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杂种优势已广泛应用于玉米育种, 在提高玉米产量、品质以及增强抗逆性等方面起到了重要的作用, 然而杂种优势的分子机制尚不清楚。植物miRNA主要在转录和转录后水平调节基因的表达。为阐明miRNA是否及如何对玉米雌穗发育杂种优势产生影响, 本研究对玉米杂交种郑单958及其亲本自交系(昌7-2和郑58)进行了高通量miRNA测序和降解组测序。取玉米雌穗花序分生组织(IM)发育为成对小穗分生组织(SPM), 进而产生小穗分生组织(SM), 及小花分生组织(FM)将3个不同时期的雌穗样品用于miRNA建库测序, 鉴定出16个miRNA家族中的81个保守miRNA为非加性表达, 认为是与雌穗发育杂种优势形成相关的miRNA; 3个阶段中分别检测到80.30%、56.06%和48.10%的非加性表达的miRNA被显性或超显性抑制。鉴定出8种新的miRNA, 属于7个miRNA家族。通过雌穗降解组测序, 发现在郑单958及其亲本自交系中共同检测到的miRNA靶向42个基因的82个转录本。根据测序结果构建了miRNA参与玉米雌穗杂种优势的模型, 并推测在雌穗发育早期阶段杂交种雌穗的miRNA的普遍抑制导致其靶基因上调表达, 随着发育进程miRNA逐步解除抑制, 带来其靶基因表达量的逐步减少, 这种miRNA与其靶基因的拮抗关系也许与玉米雌穗发育杂种优势形成有关。 相似文献
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John E. Bradshaw 《Euphytica》2017,213(3):60
Plant breeders can help farmers increase food production by breeding new cultivars better adapted to their chosen farming systems, but these must be capable of providing the necessary plant inputs for the required levels of crop production in 2050. Until 200 years ago the farmers themselves were the plant selectors. Plant domestications, extensive crop dispersions and farmers’ selections produced thousands of locally adapted landraces of cultivated plants. During the twentieth century these were largely replaced by relatively few high yielding cultivars and the natural habitats of many of their wild relatives became endangered. Hence in situ and ex situ conservation, and evaluation and use of plant genetic resources is vital for future plant breeding. The development of scientific breeding from the beginning of the twentieth century was based on understanding the mechanism of inheritance and the mating systems of crop plants. The types of genetically uniform, high yielding cultivars that have been bred from genetically heterogeneous landraces were determined by the mode of reproduction and mating system of the cultivated plant species: inbred line (wheat) and hybrid (rice) cultivars for inbreeding species, hybrid (maize) cultivars for outbreeding species, and clonal (potato) cultivars for vegetatively propagated species. When genetically heterogeneous crops are desired, mixtures of cultivars and synthetic cultivars can be produced. Future progress in crop improvement will come from three complementary approaches: use of hybridization and selection in further conventional breeding, base broadening and introgression; mutation breeding, cisgenesis and gene editing; and genetically modified crops. 相似文献
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为鉴定和筛选出适于黄淮海地区种植的抗粗缩病的玉米新品种,采用田间自然感病鉴定的方法,对295份玉米自交系和10个用其组配的高产杂交组合进行粗缩病抗性鉴定。鉴定出高抗玉米自交系12份、抗性玉米自交系32份、中抗玉米自交系69份、感病玉米自交系71份和高感玉米自交系115份以及3个抗粗缩病的玉米杂交组合。其中,12份高抗玉米自交系可以直接用于抗粗缩病玉米新品种的选育。在选育抗粗缩病玉米新品种的初期,必须确保玉米杂交组合的母本和父本均达到中抗以上水平,或者其父本或母本之一必须为高抗粗缩病的自交系。 相似文献