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从回交导入群体中筛选耐盐和抗旱水稻植株 总被引：2，自引：0，他引：2
盐害和干旱已经成为水稻产量的限制因子。培育耐盐和抗旱水稻品种的前提是高效筛选携带耐盐和抗旱基因的单株。本研究以黄华占为轮回亲本,来源于不同国家的46个品种为供体培育的BC2F2群体为材料,进行苗期耐盐和生殖生长期抗旱筛选。尽管供体和受体本身不具备耐盐性和抗旱性,但导入后代普遍出现耐盐和抗旱的超亲分离,表明供体品种普遍存在提高导入后代耐盐和抗旱的有利"隐蔽基因"。与耐盐性表现相比,导入后代出现抗旱株的组合数和每个群体中筛选出的抗旱株数均显著多于耐盐性,表明抗旱"隐蔽基因"更广泛分布在不同籼粳水稻品种中,而且抗旱性可能比耐盐性具有更广泛的适应机制。研究表明,培育回交导入系加以适当的选择压是发掘耐盐和抗旱"隐蔽基因"的有效方法。 相似文献
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花药培养在水稻籼粳交恢复系选育上的应用 总被引：7，自引：0，他引：7
对6个籼粳单(复)交组合进行花药培养,所获花培后代株系用“三系”不育系与之测交,以鉴定各株系的恢复度及杂种优势。结果表明:120个单交花培株系中有27.50％的株系,35个复交花培株系中有44.00％的株系能使野败型不育系的育性恢复正常;在149个株系配制的“三系”组合的优势鉴定中,有12.08％的组合比对照汕优63增产10-38％;在130个“二系”组合的优势鉴定中,有4％左右的组合比对照汕优63增产18—41％。经与籼梗测验种及“三系”不育系的测交鉴定证实:通过花药培养可以在较短时间内(3-4年)获得性状稳定的新广亲和系和广亲和恢复系。讨论了花药培养技术在水稻籼粳交恢复系选育上的可利用性,及由此而展现了在“三系”或“二系”上逐步实现籼粳亚种间杂种优势利用的前景。 相似文献
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水稻亚种间、品种间杂交揭示杂草稻的起源和进化 总被引：1，自引：0，他引：1
杂草稻是在稻田或可耕地周边生长的类似杂草并兼有野生稻和栽培稻特性的稻属植株或群体。迄今对杂草稻的发生和进化尚有很多的争论和假说,本研究通过水稻亚种间和品种间的杂交试验以及亲本与杂交后代籼粳分化分子标记的遗传分析,对杂草稻起源和进化途径进行了探讨并提出了相应的防控策略。研究结果显示:亚种间和品种间特定亲本杂交组合(7个籼/粳,4个籼/籼)的后代中均可分离出类似杂草稻的植株,其频率为籼/粳>籼/籼;籼粳交或籼籼交F2-F4代群体中产生类似杂草稻植株的频率随世代增加呈现递增趋势(F2最低为1.26%,F4最高为15.35%),这与双亲的遗传背景有密切关系,即籼、粳亚种的遗传背景差距越大,其杂交组合后代中产生杂草稻的机率越高;籼/粳交组合安山稻/9311F3代分离群体中类似杂草稻的植株以籼型为主(占52.8%);韩国粳稻品种安山稻在籼粳组合中不论作母本或父本,杂交后代都易产生类似杂草稻单株,这可能与其籼粳组分遗传异质性较高有关;粳/粳组合后代中未鉴定出类似杂草稻的植株,预示粳稻品种间杂交可能不易产生杂草稻。本研究为杂草稻的防控和利用研究提供参考依据。 相似文献
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利用SNP标记进行水稻品种籼粳鉴定 总被引：2，自引：0，他引：2
亚洲栽培稻(Oryza sativa L.)分为籼、粳2个亚种,随着杂交水稻的发展、种间杂种优势的利用,籼粳之间的界限变得越来越模糊。本研究利用3000份水稻种质资源信息,通过计算约2000万个单核苷酸多态性(single nucleotide polymorphism, SNP)位点的SNP-index值,进行籼粳特异SNP位点筛选,最终得到4084个籼粳特异SNP位点(4k-SNP);同时确定以籼粳指数作为水稻品种籼粳鉴定的指标。研究进一步采用大规模简单随机取样等统计分析方法对籼粳特异位点进行数据降维处理,将4k-SNP精简至40个SNP位点(40-SNP),用于水稻籼粳鉴定。为了验证40-SNP的籼粳鉴定效果,本研究一方面利用水稻生产上推广的82份选育品种,对40-SNP籼粳鉴定结果与4k-SNP鉴定结果进行比较,结果发现40-SNP与4k-SNP得出的粳型指数非常接近,相关系数为0.99;另一方面利用全球6类型(indica、aus、rayada、aromatic、tropicaljaponica、temperatejaponica)水稻品种共49份材料,对40-SNP籼粳鉴定... 相似文献
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Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts 总被引：7，自引：0，他引：7
Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed. 相似文献
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C. J. Spurr D. A. Fulton P. H. Brown R. J. Clark 《Journal of Agronomy and Crop Science》2002,188(4):275-280
Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality. 相似文献
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Jens Jensen 《Euphytica》1979,28(1):47-56
Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans. 相似文献
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G. H. Kroon 《Euphytica》1994,76(1-2):125-125
Summary
K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes. 相似文献
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Hongyan WEI Jian ZHOU Jinguang LU Jingzheng SONG Qiongxi YU Zhihong JIANG 《Medicinal Plant》2019,(6):27-29
[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol... 相似文献
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Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed. 相似文献
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Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes. 相似文献
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W. Erskine M. Tufail A. Russell M. C. Tyagi M. M. Rahman M. C. Saxena 《Euphytica》1993,73(1-2):127-135
Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed. 相似文献
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Herbage yield trials are necessary to test if candidate varieties are well suited for organic conditions. In order to elucidate
a particular suitability for organic conditions, we run such trials in parallel under both organic and conventional conditions.
Here, we report on second and third year results of the sowings 2004 and 2005. These trials are part of a targeted breeding
programme for organic conditions. Irregular colonisation of pure grass plots with adventitious plants, in particular white
clover, was recognized as a major constraint to the quality of the results obtained under organic conditions. The coefficients
of variance in dry matter yield almost doubled when compared to conventional trials, and significant differences in annual
yield among varieties were rare. However, when herbage yield was corrected for the estimated fraction of adventitious plant
colonization at each cut, the number of instances with statistically significant differences for annual yield among varieties
increased more than fourfold. Dry matter yields under organic and conventional conditions were significantly and positively
correlated. However, analysis of variance showed a significant culture type by variety interaction for annual dry matter yield
in 12 out of 24 trials. When diploid and tetraploid varieties of the same Lolium species were tested in one common trial, only tetraploid varieties were identified as being particularly well suited for organic
conditions, while in these trials, the great majority of apparently poorly suited varieties were diploid. This suggests that
breeding tetraploid Lolium varieties is promising when aiming at a favourable response to organic agriculture. 相似文献
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Summary Six pear and five apple trials were carried out to ascertain the outcome of combinations of compatible pollen (C) with self (S) or incongruous pollen (I) as to the pollination index (PI=seeds/pollinated flower). The PI of the mixture C+I (1:5) was consistently depressed as compared to that of the control C. The results of the double pollinations S/C and I/C were affected by the temperature at pollination; their PI's at <15°C were twice as high as those at >15°C, being well above and below the PI of C in the former and latter case respectively. The opposite was true for the C/S combination, the PI of which increased with the pollination temperature; the PI of C/I did not differ much from the PI of C, irrespective of temperature. The conclusion was reached that the interaction previously and presently found between compatible and self-incompatible pollen also exists to a fair extent between compatible and incongruous pollen. However, in pear neither the mentor nor the pioneer pollen technique proved to aid its hybridization with apple, the formation of self seed was not observed either. In apple the production of apple × pear hybrids was likewise doubtful, but the double pollinations S/C and C/S formed 4–10% self seed. 相似文献