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1.
Genetic transformation is a useful technique to complement conventional breeding in crop improvement. Although carrot has been a model organism for in vitro embryogenesis study, genetic transformation of carrot is still lengthy and labor intensive. An efficient transformation and detection system is desirable. Direct infection of Agrobacterium to carrot calli has provided an easy way for carrot genetic transformation. To improve the efficiency of antibiotic selection in this method, we report the combined use of an improved green-fluorescent protein, referred to as smGFP, to establish a versatile selection method for carrot callus transformation system. By combining antibiotic selection with the bright fluorescence observed in the callus tissue, we were able to easily identify stable transformants in early stage of the transformation process. In addition to the GFP expression of the callus cells, the transgenic nature of callus cells was confirmed with Southern and Western analysis. We found we can link the simplicity of carrot-callus-cell transformation, early detection of stable transformants with antibiotic selection, visualization of GFP fluorescence, and molecular analysis （Southern and Western） of callus tissue （non-photosynthetic tissue） to provide a more efficient way in identifying stable transformants at early stage of carrot transformation.  相似文献   

2.
Besides the natural selection, the crops cultivated today have experienced two episodes of strong artificial selection, domestic and modern breeding. Domestication led to giant genetic structure differentiation between cultivars and their wild species, while modern breeding made further genetic structure differentiation between the modern varieties and the landraces. In a population, diversity of the loci under strong selection is significantly lower than that of other loci. At the same time, diversity in the genomic regions flanking these selected loci also declines in the process of selection. This phenomenon is called hitchhiking effects or selection sweep in genetics. Genomic regions with selection sweep （haplotype block） could be detected after draft genome scanning （genome typing） with molecular markers in a number of released varieties or natural populations. Marker/trait association analysis in these regions would detect the loci （or QTLs） even the favored alleles （genes） in breeding or natural adaptation. Fine scanning of these genomic regions would help to determine the sizes of haplotype blocks and to discover the key genes, thereby providing very valuable information for isolation of the key genes and molecular design of new varieties. Establishment of high density genetic linkage maps in the major crops and availability of high throughput genotyping platform make it possible to discover agronomic important genes through marker/trait association analysis. On the basis of available publications, we give a brief introduction of the hitchhiking effect mapping approach in this paper using plant height, 1 000-grain weight, and phosphorus-deficiency tolerance as examples in wheat.  相似文献   

3.
Wide adoption of a few kinds of homogeneous germplasm would reduce crop genetic diversity, increase crop vulnerability to stresses, and reduce the stability of crop production. The introduction and utilization of foreign germplasm is a sustainable solution for broadening the genetic diversity and promoting periodical replacement of varieties. The genetic contribution and economic impact of foreign germplasm, particularly those of US and CGIAR （Consultative Group on International Agricultural Research, referred to as the CG system） materials, on China＇s maize production are evaluated on the basis of an analysis of variety pedigree information from 20 major maize-producing provinces in China from 1982 to 1997. The results indicated that the contribution of US and CG germplasm to Chinese maize production continues to increase, particularly CG germplasm, which has shown a rapid increasing trend since the 1990s. If the genetic contribution of US germplasm is increased by 1%, maize yield will gain by 0.2% （0.01 t ha^-1）. If contribution of CG germplasm, which has greater production potential, is increased by 1%, maize yield will gain by 0.025 t ha^-1. A policy should be implicated by the government in this direction to encourage breeders to focus more on the use and improvement of CG germplasm. The US germplasm has been utilized extensively in China so that it can offer germplasm resources for maize breeding efforts.  相似文献   

4.
The objectives of this study were to set up a new genetic evaluation procedure to predict the breeding values of Holstein herds in Heilongjiang Province of China for milk and fat production by utilizing Canadian pedigree and genetic evaluation information and to compare the breeding values of the sires from different countries. The data used for evaluating young sires for the Chinese Holstein population consisted of records selected from 21 herds in Heilongjiang Province. The first lactation records of 2 496 daughters collected in 1989 and 2000 were analyzed. A single-trait animal model including a fixed herd-year effect, random animal and residual effects was used by utilizing Canadian pedigree and genetic evaluation information of 5126 sires released from the Canadian Dairy Network in August 2000. The BLUP procedure was used to evaluate all cattle in this study and the Estimated Breeding Values (EBV) for milk and fat production of 6697 cattle (including 673 sires and 6024 cows) were predicted. The genetic levels of the top 100 sires originated from different countries were compared. Unlike the BLUP procedure that is being used in conjunction with the single-trait sire model in Heilongjiang Province of China now, the genetic evaluation procedure used in this study not only can be used simultaneously to evaluate sires and cows but also increase the accuracy of evaluation due to using the relationships and genetic values of the Canadian evaluated sires with more daughters. The results showed that the new procedure was useful for genetic evaluation of dairy herds and the comparison of the breeding values of these sires imported from different countries showed that a significant genetic improvement has been achieved for milk production of the Heilongjiang Holstein dairy population by importing sires from foreign countries, especially from the United States due to the higher breeding values.  相似文献   

5.
The objectives of this study were to estimate the genetic parameters and the breeding progress in a Landrace herd in China, and to predict the potential benefits by applying new breeding technology. Hereby, the performance records from a Landrace swine herd in China, composing over 33 000 pigs born between 2001 and 2013, were collected on six economically important traits, i.e., average daily gain between 30–100 kg(ADG), adjusted backfat thickness at 100 kg(BF), adjusted days to 30 kg(D30), adjusted days to 100 kg(D100), number born alive(NBA), and total number born(TNB). The genetic parameters were estimated by restricted maximum likelihood via DMU, and realized genetic trends were analyzed. Based on the real population structure and genetic parameters obtained from this herd, the potential genetic trends by applying genomic selection(GS) were predicted via a computer simulation study. Results showed that the heritability estimates in this Landrace herd were 0.55(0.02), 0.42(0.01), and 0.12(0.01), for BF, D100, and TNB, respectively. Favorable genetic trends were obtained for D100, BF, and TNB due to direct selection, for ADG and NBA due to indirect selection. Long-term selection against D100 did not improve D30, though they are highly genetically correlated(0.64). Appling GS in such a swine herd, the genetic gain can be increased by 25%, or even larger for traits with low heritability or individuals without phenotypes before selection. It can be concluded that conventional breeding strategy was effective in the herd studied, while applying GS is promising and hence the road ahead in swine breeding.  相似文献   

6.
The amount of molecular marker information has considerable impact on the results of studies of crop germplasm genetic relationships in crop. The number of alleles required to reveal genetic relationship in maize inbred lines is a theoretical issue that needs to be addressed. In this study, 112 pairs of SSR （simple sequence repeat） primers and 97 maize inbred lines were selected to study the relationship between the number of inbred lines and the number of SSR primers and alleles required for a stable cluster. The results showed that the number of SSR primers is not tightly associated with the stability of the cluster analysis results, while an increase in the number of alleles can significantly improve the stability of cluster analysis results. The number of inbred lines （X） is significantly associated with the number of alleles required for stable cluster analysis （Y）, and the regression equation is Y- 600.8xe（-15.9/x）. This equation can be used to calculate the number of SSR alleles required for a genetic relationship study of maize inbred lines. These results provide a reference for determining of SSR alleles number in genetic relationship analysis of maize inbred line and other crop germplasm.  相似文献   

7.
The objective of this study was to develop a method to assess and analyze the total allelopathic potential of crop germplasm and to test this method on four winter wheat accessions commonly planted in the Loess Plateau. A systems engineering model was developed and used to evaluate the total allelopathic potential of crop cultivars. In addition, a method for quantifying the total allelopathic potential in crop accessions was presented. Total allelopathic potential of four winter wheat accessions from the Loess Plateau was estimated and compared using a systems theory approach. The model assessed allelopathic potential in different parts of the plants from the time wheat turned green in spring until maturity. Results from these models indicated that the four wheat accessions had very weak allelopathic potential. Allelopathic potential declined in the order Xiaoyan 22 〉 Ningdong 1 〉 Fengchan 3 〉 Bima 1. This system engineering evaluation method allows for the assessment of allelopathic potential among crop varieties. It will help plant breeders to select and develop allelopathic crop accessions that combine weed suppression properties with agronomic traits related to yield and quality.  相似文献   

8.
Genetic transformation is an important technique for functional genomics study and genetic improvement of plants. Until now, Agrobacterium-mediated transformation methods using cotyledon as explants has been the major approach for cucumber, and its frequency has been up to 23%. For example, significantly enhancement of the transformation efficiency of this plant species was achieved from the cotyledon explants of the cultivar Poinsett 76 infected by Agrobacterium strains EHA105 with efficient positive selection system in lots of experiments. This review is to summarize some key factors influencing cucumber regeneration and genetic transformation, including target genes, selection systems and the ways of transgene introduction, and then to put forward some strategies for the increasing of cucumber transformation efficiency. In the future, it is high possible for cucumber to be potential bioreactor to produce vaccine and biomaterials for human beings.  相似文献   

9.
Indoor microclimate is important for crop production and quality in greenhouse cultivation.This paper focuses on microclimate study based on a computational fluid dynamics(CFD) model of a typical plastic greenhouse(with a sector shape vertical cross-section) popularly used in central China.A radiation model is added into the CFD model so as to simulate coupling of convective transfers and radiative exchanges at the cover and the roof,instead of using the usual coupling approach based on energy balance.In addition,a fractal permeability model is innovatively adopted in the modeling of the crop canopy.Compared the numerical results with measured experimental data,the model simulation is proved with success.This model then is used to explore the microclimate variable distributions in the greenhouse.It shows that the airflow pattern,temperature and humidity profiles are different from those in a sawtooth Mediterraneantype greenhouse.The study suggests that this deliberately developed CFD model can be served as a useful tool in macroclimate research and greenhouse design investigating.  相似文献   

10.
Molecular genetic maps of crop species can be used in a variety of ways in breeding and genomic research such as identification and mapping of genes and quantitative trait loci （QTLs） for morphological, physiological and economic traits of crop species. However, a comprehensive genetic linkage map for cultivated peanut has not yet been developed due to the extremely low frequency of DNA polymorphism in cultivated peanut. In this study, 142 recombinant inbred lines （RILs） derived from a cross between Yueyou 13 and Zhenzhuhei were used as mapping population in peanut （Arachis hypogaea L.）. A total 652 pairs of genomic-SSR primer and 392 pairs of EST-SSR primer were used to detect the polymorphisms between the two parents. 141 SSR primer pairs, 127 genomic-SSR and 14 EST-SSR ones, which can be used to detect polymorphisms between the two parents, were selected to analyze the RILs population. Thus, a linkage genetic map which consists of 131 SSR loci in 20 linkage groups, with a coverage of 679 cM and an average of 6.12 cM of inter-maker distance was constructed. The putative functions of 12 EST-SSR markers located on the map were analyzed. Eleven showed homology to gene sequences deposited in GenBank. This is the first report of construction of a comprehensive genetic map with SSR markers in peanut （Arachis hypogaea L.）. The map presented here will provide a genetic framework for mapping the qualitative and quantitative trait in peanut.  相似文献   

11.
植物育种模拟的原理和应用   总被引：1，自引：0，他引：1  
传统植物育种很大程度上依赖于表型选择和育种家的经验，分子生物学积累的大量遗传数据使得在基因水平上进行目标性状的选择成为可能，但是由于缺乏必要的工具，大量的遗传信息尚未在育种中得以有效利用。模拟方法可以利用各类遗传信息，在育种家进行田间试验之前，对杂交组合的表现、后代选择效果以及整个育种过程进行模拟，提出最佳的亲本选配、杂交和后代选择策略，从而提高常规育种的预见性和效率。本文介绍育种模拟的一些基本原理，包括遗传模型的构建、杂交类型和选择方法的定义等，概述育种模拟工具QuLine的基本功能及其在育种方法的比较、利用已知基因信息的亲本选配和设计育种等方面的应用。模拟方法通过定义复杂的遗传模型和育种方法实现对育种过程的模拟，在更真实的情形下比较不同育种方法的优劣、预测不同亲本杂交后代的表现，从而为育种家有效利用大量的分子信息和遗传数据提供了手段。  相似文献   

12.
数码育种新概念   总被引：2，自引：0，他引：2  
根据十几年的育种实践,将作物育种发展的阶段划分为测量育种、模糊育种和数码育种三个阶段。首次提出了数码育种概念,即用不同的数位来代表作物的生物学性状,数位上的数字代表该性状的量。育种者根据要调查的性状及该性状的分级标准,制定一个统一的编码程序,然后对所有的育种材料进行编码,所有的育种材料就都有了自己的身份证。只要看到某一材料的身份证,便可知其所有的遗传性状。利用计算机数据管理系统,对育种材料进行科学管理,分析其遗传规律,科学选配组合,资源信息交流共享,从而使育种工作有明确的目标、清晰的路线、快捷的路径、准确的选择、高效的运作。  相似文献   

13.
基因组选择(Genomic Selection)方法最近已经在奶牛育种中获得革命性突破。美国农业部和加拿大奶牛网络的最新研究发现,基因组育种值和传统育种值合并后对后备公母牛的育种值的可靠性(准确度)平均增加幅度最大(23%),相当于后裔测定11头女儿的可靠性。基因组选择可以允许育种者提前选择那些获得优越染色体片段的种畜,因此可加快和提高遗传改良的速度和效率,降低后裔测定的成本,甚至最终取代整个后裔测定方法。从2009年起,美国和加拿大将在官方颁布的奶牛育种值中合并基因组育种值和传统育种值。及时采用这一新方法,对我国奶牛业的遗传改良发展速度尤其至关重要。  相似文献   

14.
Phosphorus is the second most important macronutrient after nitrogen and it has many vital functions in the life of plants. Most soils have a low available P content, which has become a key limiting factor for increasing crop production. Also, low P use efficiency (PUE) of crops in conjunction with excessive application of P fertilizers has resulted in serious environmental problems. Thus, dissecting the genetic architecture of crop PUE, mining related quantitative trait loci (QTL) and using molecular breeding methods to improve high PUE germplasm are of great significance and serve as an efficient approach for the development of sustainable agriculture. In this review, molecular and phenotypic characteristics of maize inbred lines with high PUE, related QTL and genes as well as low-P responses are summarized. Based on this, a breeding strategy applying genomic selection as the core, and integrating the existing genetic information and molecular breeding techniques is proposed for breeding high PUE maize inbred lines and hybrids.  相似文献   

15.
作物模拟与QTL定位的互补作用及其应用   总被引：2，自引：0，他引：2  
 作物模型正日益用于设计不同环境中的理想株型育种。DNA分子标记可把复杂的数量性状分解成若干个数量性状位点（quantitative trait loci,QTL）的效应,并将QTL转入到栽培品系中去。作物模拟与QTL定位相结合,QTL将去除若干所测定模型输入参数的随机误差。这种基于QTL效应的作物模型,将弥补常规模型忽视其输入性状遗传效应的缺点,并能更准确地预测遗传群体中各个体间的产量差异。另一方面,作物模型能成为解释"基因型与环境互作"的有力工具,也将弥补QTL定位不能将一个环境条件试验分析结果外推到另一环境条件。基于上述分析,提出了一个将标记辅助育种与以模型为基础的理想株型育种的综合方法。  相似文献   

16.
大豆分子育种研究进展   总被引：19，自引：1，他引：19  
 大豆分子育种代表了大豆育种的发展方向，主要包括分子标记育种、转基因育种和品种分子设计育种三个方面。通过综合利用基因组学、生物信息学、计算机模拟与遗传育种学等多个学科的理论和方法，大豆分子育种可对大豆从表型到分子等多个层次进行遗传操作，有助于大幅度提高育种效率，最终实现大豆品种的定向遗传改良。本文介绍了中国大豆分子标记育种、转基因育种和品种分子设计育种三个方面的开创者，将国内的主要研究进展与国外相关的最新研究成果进行了综述和比较，由于知识所限对未提及的做出重要贡献的科学家在此致歉。通过比较发现，中国大豆分子育种与国外相关研究的差距普遍存在，然而，有些分子育种相关研究如基因克隆及功能研究等方面则与国外的差距正在逐渐缩小。笔者认为，大豆分子育种正朝着遗传图谱信息多元化、基因发掘规模化、分子育种技术高效化、分子育种理论系统化的方向发展。  相似文献   

17.
针对鲁西黄牛肉用品系现行的核心群育种方案,以育种最大投资回报率为评估标准,通过活体质量、繁殖、日增质量和胴体性状测定记录作为选择信息,根据使用不同可利用记录作为不同选种的标准设定了4种选择方案(方案1:活体质量信息+日增质量信息;方案2:活体质量信息+繁殖信息;方案3:方案1+方案2;方案4:方案3+胴体性状信息),并采用确定性模型评估了4种选择方案的遗传进展和育种效益.结果表明,4种选择方案的年综合育种进展分别为21.87、34.08、38.09和54.86元;育种效益为147.39、204.44、241.83和309.05元;投入产出比为1∶3.78、1∶4.60、1∶5.14和1∶5.77;平均世代间隔均为5.53年.以上数据表明,随着可利用信息在选择标准中的变化,遗传进展和育种效益也随之变化,选择方案4可获得较好的育种效果,所以,在现行育种方案中,采用方案4可获得理想的育种效果.  相似文献   

18.
染色体重排是一种可能导致DNA片段丢失、重复、易位和倒位的机制,从而改变基因组结构,为创造新的变异性状提供可能。植物染色体重排事件的准确鉴定有助于更深入地理解植物基因组的结构、功能及它们在植物演化和作物育种中的作用。该文深入探讨了植物染色体重排的基本概念,介绍了植物染色体重排的自然发生和人工诱导的技术方法,阐述了植物染色体重排的细胞生物学、分子遗传学和高通量测序鉴定方法。同时,系统总结了植物染色体重排技术在作物遗传育种中的应用,结合具体实践,着重强调了染色体重排技术在提高农作物的遗传多样性、改良农作物的重要性状、增强农作物的环境适应性等方面极具优越性。然而,目前染色体重排的发生概率较低,技术上仍存在挑战,需要更多精准的工具和策略来实现染色体片段的精准定位和重排。通过全面了解染色体重排及其相关技术,研究人员和育种家可以更好地利用植物基因组,为全球粮食安全和环境可持续发展提供创新解决方案。相关研究不仅为深入认识植物基因组提供新途径,也为未来创新作物育种奠定坚实基础。通过挖掘植物基因组的多样性和可塑性,染色体重排技术有望为培育高产、优质、多抗的农作物新品种提供更多可能性,对解决全球日益严峻的...  相似文献   

19.
生物信息学是基因、基因结构、基因产物功能分析必不可少的技术手段。根据生物信息数据库的现状,讨论了生物信息学在农业上的应用,如挖掘新的基因、电子克隆及系统进化分析等。将生物信息学与常规育种技术相结合,对提高育种效率,创新遗传资源,加快作物改良进程都有重要意义。  相似文献   

20.
数字化植物育种是综合利用当代计算机和信息网络技术辅助于现代植物育种的一项标准化的动态系统工程。通过对广泛的动态育种(资源)数据的标准化管理和分析,对育种材料综合属性进行自动数据处理,对育种材料进行遗传距离和类群分析、杂种优势预先判定,按照育种者需要给出适当推荐结果,辅助提高育种的目标性、准确性和育种效率。任何与(玉米)育种有关的环境因素、生物学和遗传学等多个科学领域的研究进展、育种者的不断积累的经验以及田间试验等数据都应该充分考虑到并整合到数字化育种系统中。数字化育种对于整合育种行业资源、提高育种效率将起到积极的作用。数字化育种方兴未艾,期待更多育种者的努力。  相似文献   

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