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排序方式: 共有1325条查询结果,搜索用时 31 毫秒
1.
Genetic analysis of rice grain quality   总被引:67,自引:0,他引:67  
 The inheritance of grain quality is more complicated than that of other agronomic traits in cereals due to epistasis, maternal and cytoplasmic effects, and the triploid nature of endosperm. In the present study, an established rice DH population derived from anther culture of an indica/japonica hybrid was used for genetic analysis of rice grain quality. A total of five parameters, amylose content (AC), alkali-spreading score (ASS), gel consistency (GC), percentage of grain with a white core (PGWC) and the square of the white core (SWC), were estimated for the DH lines and the parent varieties. For each parent, the value of each parameter was relatively stable in three locations, Beijing, Hangzhou and Chengdu, while the differences between the parents were significant for all five parameters. AC showed a bimodal distribution, and the distribution of ASS was skewed toward the value of JX17, while the other three parameters displayed continuous distributions among the DH lines with partially transgressive segregations. For AC, a minor and a major gene were found on chromosomes 5 and 6 respectively. The major gene, which should be an allele of wx, explained 91.9% of the total variation. For GC, two QTLs were identified on chromosomes 2 and 7 respectively. For ASS, a minor and a major gene were both located on chromosome 6. The major gene should be the same locus as the alkali degeneration gene (alk). Genetic linkage between alk and wx was found in QTL mapping. For PGWC, two QTLs were located on chromosomes 8 and 12. Only a minor QTL was found for SWC on chromosome 3. The results and the molecular markers presented here may be useful in rice breeding for grain quality improvement. Received: 24 April 1998 / Accepted: 13 August 1998  相似文献
2.
Genetic and molecular dissection of quantitative traits in rice   总被引:54,自引:0,他引:54  
Recent progress in the generation of a molecular genetic map and markers for rice has made possible a new phase of mapping individual genes associated with complex traits. This type of analysis is often referred to as quantitative trait locus (QTL) analysis. Increasing numbers of QTL analyses are providing enormous amounts of information about QTLs, such as the numbers of loci involved, their chromosomal locations and gene effects. Clarification of genetic bases of complex traits has a big impact not only on fundamental research on rice plant development, but it also has practical benefits for rice breeding. In this review, we summarize recent progress of QTL analysis of several complex traits in rice. A strategy for positional cloning of genes at QTLs is also discussed.  相似文献
3.
大豆重要农艺性状的QTL分析   总被引:53,自引:0,他引:53  
应用栽培大豆科丰1号(♀)和南农1138-2(♂)杂交得到的F9代重组自交系(RILs)群体(201个家系),构建了含302遗传标记、覆盖2363.8cM、由22个连锁群组成的遗传连锁图谱。采用区间作图法,对该群体的主要农艺性状的调查数据进行QTL分析,表明与开花期、成熟期、株高、主茎节数、每节荚数、倒状性、种子重、产量、蛋白质和含油量等10个重要农艺性状连锁的QTL位点34个,每个数量性状的遗传变异是由多个QTL位点决定的。与产量有关的农艺性状的一些QTL集中在几个连锁群上。  相似文献
4.
During the last two decades, DNA-based molecular markers have been extensively utilized for a variety of studies in both plant and animal systems. One of the major uses of these markers is the construction of genome-wide molecular maps and the genetic analysis of simple and complex traits. However, these studies are generally based on linkage analysis in mapping populations, thus placing serious limitations in using molecular markers for genetic analysis in a variety of plant systems. Therefore, alternative approaches have been suggested, and one of these approaches makes use of linkage disequilibrium (LD)-based association analysis. Although this approach of association analysis has already been used for studies on genetics of complex traits (including different diseases) in humans, its use in plants has just started. In the present review, we first define and distinguish between LD and association mapping, and then briefly describe various measures of LD and the two methods of its depiction. We then give a list of different factors that affect LD without discussing them, and also discuss the current issues of LD research in plants. Later, we also describe the various uses of LD in plant genomics research and summarize the present status of LD research in different plant genomes. In the end, we discuss briefly the future prospects of LD research in plants, and give a list of softwares that are useful in LD research, which is available as electronic supplementary material (ESM) Electronic supplementary material Electronic supplementary material is available for this article at and accessible for authorised users.  相似文献
5.
 Quantitative trait locus (QTL) analysis has been carried out to identify genes conferring heading date in rice. One hundred and eighty six F2 plants derived from a cross between a japonica variety, Nipponbare, and an indica variety, Kasalath, were used as a segregating population for QTL mapping and more than 850 markers were employed to identify QTLs. Scan-analysis revealed the existence of two QTLs with large effects, Hd-1 and Hd-2, one in the middle of chromosome 6 and one at the end of chromosome 7, respectively. For both loci, the Kasalath alleles reduced days-to-heading. In addition, three QTLs with minor effects, Hd-3, Hd-4 and Hd-5, were found to be located on chromosomes 6, 7 and 8 based on a secondary scan analysis which was carried out by removing the phenotypic effects of Hd-1 and Hd-2. For the three secondary loci, the Nipponbare alleles reduced days-to-heading. The five QTLs explained 84% of the total phenotypic variation in the F2 population based on a multiple-QTL model. The presence of a digenic interaction between Hd-1 and Hd-2 was clearly suggested. Received: 18 March 1997 / Accepted: 24 June 1997  相似文献
6.
DNA分子标记、基因组作图及其在植物遗传育种上的应用   总被引:44,自引:0,他引:44  
本文总结了现代分子生物学所发展的各类分子标记及其在遗传图谱构建中的作用,还综述了遗传图谱与物理图谱的构建、数量与质量性状定位及分子标记在作物育种中的应用。  相似文献
7.
Quantitative trait locus analysis for rice panicle and grain characteristics   总被引:40,自引:0,他引:40  
 The development of molecular genetic maps has accelerated the identification and mapping of genomic regions controlling quantitative characters, referred to as quantitative trait loci or QTLs. A molecular map derived from an F2 population of a tropical japonica×indica cross (Labelle/Black Gora) consisted of 116 restriction fragment length polymorphism (RFLP) markers. Composite interval mapping was used to identify the QTLs controlling six panicle and grain characteristics. Two QTLs were identified for panicle size at LOD>3.0, with one on chromosome 3 accounting for 16% of the phenotypic variation. Four loci controlling spikelet fertility accounted for 23% of the phenotypic variation. Seven, four, three and two QTLs were detected for grain length, breadth, shape and weight, respectively, with the most prominent QTLs being on chromosomes 3, 4, and 7. Grain shape, measured as the ratio of length to breadth, was mostly controlled by loci on chromosomes 3 and 7 that coincided with the most important QTLs identified for length and breadth, respectively. A model including three loci accounted for 45% of the phenotypic variation for this trait. The identification of economically important QTLs will be useful in breeding for improved grain characteristics. Received: 18 July 1997 / Accepted: 9 December 1997  相似文献
8.
Linkage between RFLP markers and genes affecting kernel hardness in wheat   总被引:39,自引:6,他引:33  
A molecular-marker linkage map of wheat (Triticum aestivum L. em. Thell) provides a powerful tool for identifying genomic regions influencing breadmaking quality. A variance analysis for kernel hardness was conducted using 114 recombinant inbred lines (F7) from a cross between a synthetic and a cultivated wheat. The major gene involved in kernel hardness, ha (hard), known to be on chromosome arm 5DS, was found to be closely linked with the locus Xmta9 corresponding to the gene of puroindoline-a. This locus explained around 63% of the phenotypic variability but there was no evidence that puroindoline-a is the product of Ha (soft). Four additional regions located on chromosomes 2A, 2D, 5B, and 6D were shown to have single-factor effects on hardness, while three others situated on chromosomes 5A, 6D and 7A had interaction effects. Positive alleles were contributed by both parents. A three-marker model explains about 75% of the variation for this trait.  相似文献
9.
Genomic regions affecting seed shattering and seed dormancy in rice   总被引:39,自引:0,他引:39  
Non-shattering of the seeds and reduced seed dormancy were selected consciously and unconsciously during the domestication of rice, as in other cereals. Both traits are quantitative and their genetic bases are not fully elucidated, though several genes with relatively large effects have been identified. In the present study, we attempted to detect genomic regions associated with shattering and dormancy using 125 recombinant inbred lines obtained from a cross between cultivated and wild rice strains. A total of 147 markers were mapped on 12 rice chromosomes, and QTL analysis was performed by simple interval mapping and composite interval mapping. For seed shattering, two methods revealed the same four QTLs. On the other hand, for seed dormancy a number of QTLs were estimated by the two methods. Based on the results obtained with the intact and de-hulled seeds, QTLs affecting hull-imposed dormancy and kernel dormancy, respectively, were estimated. Some QTLs detected by simple interval mapping were not significant by composite interval mapping, which reduces the effects of residual variation due to the genetic background. Several chromosomal regions where shattering QTLs and dormancy QTLs are linked with each other were found. This redundancy of QTL associations was explained by ”multifactorial linkages” followed by natural selection favoring these two co-adapted traits. Received: 23 November 1998 / Accepted: 27 August 1999  相似文献
10.
水稻纹枯病抗性QTL分析   总被引:35,自引:4,他引:31  
对灿稻窄叶青8号(ZYQ8)和粳稻京系17(JX17)以及由它们构建的加倍单倍体(DH)群体,分别在杭州和海南岛,采用注射器接种法进行纹枯病抗性鉴定,并使用该群体的分子链锁图谱进行数量性状座位(QTL)分析。共检测到4个抗纹枯病的QTL(qSBR-2、qSBR-3、qSBR-7和qSBR-11),分别位于第2、第3、第7和第11染色体。其中qSBR-2、qSBR-3、qSBR-7的抗性基因由抗病亲本ZYQ8贡献,而qSBR-11的抗性基因来自感病亲本JX17。qSBR-2、qSBR-3、qSBR-7在杭州和海南岛都能检测到,而qSBR-11只在杭州检测到。在杭州的实验中,纹枯病病级与秆长和抽穗期呈显著负相关;在控制秆长和抽穗期的QTL中,控制秆长的qCL-3与qSBR-3位于同一染色体区域,其余QTL与抗纹枯病的QTL之间无连锁关系。  相似文献
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