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1.
观赏植物种类繁多,在这些植物的育种、销售及栽培过程中,与植物病害相关的各种病原物也被广泛传播。因此,培育抗病品种一直是园艺育种工作者的重要目标性状之一。在粮食作物中,抗病育种方面已经投入了很大的人力物力,新的生物技术不断被用于作物新品种的培育。但对于观赏植物而言,这些新技术应用范围还极为有限。本综述对园艺植物抗病育种现状进行了总结,并对育种前景进行了预测。 相似文献
2.
玉米株型与冠层光合作用的数学模拟研究 总被引：4，自引：0，他引：4
用数值方法，分析了直立和平伸两种株型结构在冠层光分布，光合作用分布，冠层光合作用速度、光合作用日变化和光合日总量等方面的差异。指出叶面积指数越大，太阳辐射越强、太阳高度角越大（在纬度越低的地区或赤纬越高的季节），把一般株型改造成直立株型的增产潜力增大。对于叶片光合效能较高的区域，季节或品种，直立株型的增产潜力也较大。植株由一组具有各种倾斜角的叶片组成。理想株型的叶片分布函数随上述环境的和生理的因素 相似文献
3.
Modern plant breeding is highly dependent on new technologies to master future problems. More traits have to be combined, frequently originating from wild species. Traditional breeding is connected with linkage drag problems. The crop plant itself and its crossable species represent the traditional breeders gene pool. GM-breeding is a new way of improving existing varieties. Transgenes originate from non-crossable species and are representing a new gene pool. For release of GM-plants into the environment and onto the market in Europe Directive 2001/18/EC has been developed, primarily based on GM-technology and not on gene source. In society, opposition against GM crops is complicating the implementation of GM crops. In this paper, it is shown that not only transgenes, representing a new gene pool but also cisgenes and intragenes are available, representing the breeders gene pool. Cisgenes are natural genes and intragenes are composed of functional parts of natural genes from the crop plant itself or from crossable species. Cisgenesis is the combined use of only cisgenes with marker-free transformation, mimicking linkage drag free introgression breeding in one step. Therefore, cisgenesis is a new sub-invention in the traditional breeding field and indicates the need for reconsideration of GM Directives. Inventions are frequently containing not only hardware elements, but also software and orgware elements. For cisgenesis it is foreseen that the technical (hardware) and bioinformatic (software) elements will develop smoothly, but that implementation in society is highly dependent on acceptance and regulations (orgware). It could be made in a step by step approach by specific crop-gene derogations from the Directive, followed by adding cisgenesis to annex 1b of Directive 2001/18/EC for exemption. At present GM crops can only be introduced by large companies. An open innovation approach for cisgenesis by public private partnership including traditional SMEs has been discussed. Cisgenesis has been exemplified for resistance breeding of potato to Phytophthtora infestans. 相似文献
4.
The importance of reduced tillage in sustainable agriculture is well recognized. Reduced-tillage practices (which may or may
not involve retention of crop residues) and their effects differ from those of conventional tillage in several ways: soil
physical properties; shifts in host–weed competition; soil moisture availability (especially when sowing deeply or under stubble);
and the emergence of pathogen populations that survive on crop residues. There may be a need for genotypes suited to special
forms of mechanization (e.g. direct seeding into residues) and to agronomic conditions such as allelopathy, as well as specific
issues relating to problem soils. This article examines issues and breeding targets for researchers who seek to improve crops
for reduced-tillage systems. Most of the examples used pertain to wheat, but we also refer to other crops. Our primary claim
is that new breeding initiatives are needed to introgress favourable traits into wheat and other crops in areas where reduced
or zero-tillage is being adopted. Key traits include faster emergence, faster decomposition, and the ability to germinate
when deep seeded (so that crops compete with weeds and use available moisture more efficiently). Enhancement of resistance
to new pathogens and insect pests surviving on crop residues must also be given attention. In addition to focusing on new
traits, breeders need to assess germplasm and breeding populations under reduced tillage. Farmer participatory approaches
can also enhance the effectiveness of cultivar development and selection in environments where farmers’ links with technology
providers are weak. Finally, modern breeding tools may also play a substantial role in future efforts to develop adapted crop
genotypes for reduced tillage. 相似文献
5.
Jaime Prohens Pietro Gramazio Mariola Plazas Hannes Dempewolf Benjamin Kilian María J. Díez Ana Fita Francisco J. Herraiz Adrián Rodríguez-Burruezo Salvador Soler Sandra Knapp Santiago Vilanova 《Euphytica》2017,213(7):158
The need to boost agricultural production in the coming decades in a climate change scenario requires new approaches for the development of new crop varieties that are more resilient and more efficient in the use of resources. Crop wild relatives (CWRs) are a source of variation for many traits of interest in breeding, in particular tolerance to abiotic and biotic stresses. However, their potential in plant breeding has largely remained unexploited. CWRs can make an effective contribution to broadening the genetic base of crops and to introgressing traits of interest, but their direct use by breeders in breeding programs is usually not feasible due to the presence of undesirable traits in CWRs (linkage drag) and frequent breeding barriers with the crop. Here we call for a new approach, which we tentatively call ‘introgressiomics’, which consists of mass scale development of plant materials and populations with introgressions from CWRs into the genetic background of crops. Introgressiomics is a form of pre-emptive breeding and can be focused, when looking for specific phenotypes, or un-focused, when it is aimed at creating highly diverse introgressed populations. Exploring germplasm collections and identifying adequate species and accessions from different genepools encompassing a high diversity, using different strategies like the creation of germplasm diversity sets, Focused identification of germplasm strategy (FIGS) or gap analysis, is a first step in introgressiomics. Interspecific hybridization and backcrossing is often a major barrier for introgressiomics, but a number of techniques can be used to potentially overcome these and produce introgression populations. The generation of chromosome substitution lines (CSLs), introgression lines (ILs), or multi-parent advanced inter-cross (MAGIC) populations by means of marker-assisted selection allows not only the genetic analysis of traits present in CWRs, but also developing genetically characterized elite materials that can be easily incorporated in breeding programs. Genomic tools, in particular high-throughput molecular markers, facilitate the characterization and development of introgressiomics populations, while new plant breeding techniques (NPBTs) can enhance the introgression and use of genes from CWRs in the genetic background of crops. An efficient use of introgressiomics populations requires moving the materials into breeding pipelines. In this respect public–private partnerships (PPPs) can contribute to an increased use of introgressed materials by breeders. We hope that the introgressiomics approach will contribute to the development of a new generation of cultivars with dramatically improved yield and performance that may allow coping with the environmental changes caused by climate change while at the same time contributing to a more efficient and sustainable agriculture. 相似文献
6.
The evaluation and use of the vast diversity contained in plant genetic resources (PGR) is a main challenge for today’s plant breeding. The use of molecular markers has hugely increased the knowledge about genetic diversity and great hopes are raised about the potential of marker assisted selection [MAS; sometimes also termed SMART breeding (Selection with Markers and Advanced Reproductive Technologies)] to help increasing the use of PGR and maintaining crop genetic diversity. Another approach growing attention has been paid to over the past two decades and which also aims to increase variation in crops is evolutionary and participatory breeding (EPB). In this paper we discuss both the potential of marker-assisted breeding strategies and the potential of EPB breeding to contribute to the maintenance, increase and development of agrobiodiversity. The potentials of molecular markers in the evaluation and use of PGR and their documented contribution to agrobiodiversity are reviewed and results from guided interviews with scientists and breeders are given. Despite tremendous research efforts involving molecular markers, it is still difficult to obtain a clear picture how molecular markers contribute to the use of PGR in plant breeding. Minor and major crops do not benefit to the same degree from recent developments in marker technology. It therefore depends at least in part on economic considerations whether SMART breeding or EPB strategies or both are implemented in the breeding process of a crop. A general decision in favor or against MAS or EPB when breeding for diversity would not yield optimum results. 相似文献
7.
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
8.
Summary The crop domestication process is examined from plant collection to product release for various junctures at which deliberate
breeding, selection, and crop transformation may occur to prevent invasive potential. Four primary juncture opportunities
for research on techniques and development of selection procedures for non-invasiveness include: The Plant Exploration Phase,
Initial Trial Phase, Fast-Tracking Phase, Selection and Improvement Phase. Avoiding the collection of germplasm that appears
weedy during plant exploration is an obvious, yet cost-effective way to reduce invasiveness in a selection program. During
initial trials, comparing genotypic differences in traits related to invasiveness should allow plant breeders to identify
cultivars that pose the least risk before undertaking comprehensive field trials. Genotypes with high commercial value, considered
candidates for “fast-tracking”, should only advance quickly to product release if they exhibit a minimum level of invasive
risk, i.e., species with low dispersal capacity and that have little potential to impact ecosystems. Fast-growing taxa, those
with high seed production, ones likely to be rapidly dispersed by wind, animals, water or people, and others that can significantly
alter nutrient or light levels are examples of species that should not be “fast-tracked”. Field trials that have typically
been used to evaluate performance of genotypes across a broad range of cultivated environmental conditions need to be expanded
to adequately evaluate invasive potential during the selection and improvement phase. Testing in environments that mimic conditions
where introductions could naturalize is crucial, as are evaluations of competition with indigenous species. The time and resource
investment needed to conduct adequate trials at this stage is potentially very high; more research is needed to ensure the
trials conducted are targeting important information gaps for decision-making. Additional research is also needed to develop
modeling approaches that effectively forecast long-term dynamics of introductions and to assist in developing field testing
priorities. Minimizing invasive potential could significantly reduce introductions that cause inadvertent damage to landscapes
and ecosystems. The strategy proposed here will require further development, especially in the context of understanding and
assessing risks of pre- and post-release strategies for minimizing damage from invasive species.
Scientific Paper No. 051210156 of the Department of Horticultural Science. 相似文献
9.
10.
J. C. Dorst 《Euphytica》1954,3(3):212-220
Summary In the Netherlands the home-bred varieties are developed almost entirely by private establishments. The Government institutes (Institute of Agricultural Plant Breeding and Foundation for Agricultural Plant Breeding) at Wageningen give advice to the breeders of field crops.The private plant breeders are informed of the results obtained and the working methods. They receive plant material for their breeding programme.The List of Varieties is the reference guide not only for the farmers but also to the plant breeders and the seedsmen. In the case of field crops it forms the basis for the seed inspection. A close connection exists between the breeding, variety-list and seed inspection. 相似文献
11.
Haizheng Xiong Jun Qin Ainong Shi Beiquan Mou Dianxing Wu Jian Sun Xiaoli Shu Zhixue Wang Weiguo Lu Jianbing Ma Yuejin Weng Wei Yang 《Euphytica》2018,214(1):4
The evolution of species is complex and subtle which always associates with the genetic variation and environment adaption during active/passive spread or migration. In crops, this process is usually driven and influenced by human activities such as domestication, cultivation and immigration. One method to discover this process is to analyze the genetic diversity of those crops in different regions. This research first assessed the similarity and differentiation between genetic diversity of genotype and phenotype in 768 world-wild cowpea germplasm which were collected by USDA and US breeding programs. Totally 1048 genotyping by sequencing (GBS) derived single nucleotide polymorphisms (SNPs) and 17 agronomic traits were used to analyze the genetic diversity, distance, cluster and phylogeny. The group differentiation was analyzed based on both the genotype distances from 1048 SNP markers and the phenotypic (Mahalanobis) distance D2 from 11 traits. A consistent result of diversity in genotype (polymorphism information content, PIC) and phenotype (Shannon and Simpson index) indicated that the East Africa and South Asia sub-continents were the original and secondary regions of cowpea domestication. Both dendrograms built by genetic distance present relationship among different regions, and the Mantel coefficient showed medium correlation level (r = 0.58) between genotype and phenotype. The information of both genotypic and phenotypic differentiations may help us to understand evolution and migration of cowpea more comprehensively and also will inform breeders how to use cowpea germplasm in breeding programs. 相似文献
12.
作物驯化和品种改良所选择的关键基因及其特点 总被引：2，自引：0，他引：2
近15~20年作物基因组学迅速发展,特别是第2代测序技术的普及,显著降低了测序成本,使单核苷酸多态性(SNP)分析和单元型区段(也称单倍型区段)分析渗透到生命科学的各个领域,对系统生物学、遗传学、种质资源学和育种学影响最为深刻,使其进入基因组学的全新时代。一批驯化选择基因的克隆,特别是对一些控制复杂性状形成的遗传基础及其调控机制的解析,更清晰地揭示了作物驯化和品种改良的历史,提升了人们对育种的认知,推动育种方法的改进。驯化和育种既有相似之处,也存在明显的差异。驯化选择常常发生在少数关键基因或位点,对基因的选择几乎是一步到位;而现代作物育种虽然只有100年左右的历史,但其对基因组影响更为强烈,是一些重要代谢途径不断优化的过程。随着生态环境或栽培条件的变化,育种选择目标基因(等位变异)会发生相应的变化或调整,因此对基因(等位变异)的选择是逐步的。此外,强烈的定向选择重塑了多倍体物种的基因组,使其亚基因组与供体种基因组明显不同。在群体水平上,系统分析驯化和育种在作物基因组和基因中留下的踪迹,凝炼其中的规律,将为品种改良和育种提供科学理论和指导,本文也简要介绍了"十三五"国家重点研发计划专项"主要农作物优异种质资源形成与演化规律"的基本研究思路。 相似文献
13.
Formal plant breeders could contribute much to collaboration with farmers for improving crop varieties for local use. To do
so outside researchers must have some understanding of local selection practices and their impact on crop populations in terms
of the genetic theory underlying plant breeding. In this research we integrated methods from social and biological sciences
to better understand selection and its consequences from farmers' perspectives but based on the concepts used by plant breeders.
Among the households we worked with, farmers' selection practices were not always effective yet they understood the reasons
for this and had no expectations for response to selection in some traits given the methods available to them. Farmers' statements,
practices and genetic perceptions regarding selection and the genetic response of their maize populations to their selection
indicate selection objectives different than may be typically assumed, suggesting a role for plant breeder collaboration with
farmers.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
14.
K. B. Saxena R. K. Saxena S. Sharma C. V. Sameer Kumar R. Sultana E. B. von Wettberg R. K. Varshney 《Euphytica》2018,214(12):222
With the exception of Cajanus cajan (L.) Millspaugh (pigeonpea), the remaining species of genus Cajanus have not been domesticated. For millennia these taxa have persisted in natural habitats through self-sown seeds. These wild species are an asset for sustaining future pigeonpea breeding programmes since they contain certain traits (genes) that are necessary for encountering various breeding challenges related to crop improvement and adaptation. In this review we identify the key traits from wild Cajanus species, and discuss various physical and genetic constraints encountered in their utilization in introgression breeding. Some noteworthy achievements recorded from inter-specific breeding programmes in pigeonpea are also discussed. These include the development of (1) high protein (>?28%) genotypes (2) cytoplasmic nuclear male sterility systems (3) highly (>?95%) self-pollinating genotypes, and (4) resistance sources to sterility mosaic disease, nematodes, salinity, photo-insensitivity, pod borers, podfly, bruchids, and Phytophthora blight. To help pigeonpea breeders engaged in inter-specific breeding programmes, we suggest the division of the secondary gene pool germplasm into two sub-group/tiers on the basis of ease in hybridization. 相似文献
15.
Mark E. Sorrells 《Euphytica》2007,157(3):299-306
There have been many changes impacting wheat improvement since the 1996 International Maize and Wheat Improvement Center Wheat
Yield Symposium. This review highlights a few of the technological advances and impacts of new knowledge on wheat improvement
that have occurred in the past 10 years as well as on-going challenges. One of the most dramatic discoveries has been the
revelation that the genomes of graminaceous crops are complex, rapidly evolving, and heterogeneous, even within species. The
use of marker-assisted selection for improving complex traits is one of the challenges facing wheat breeders. Integration
of association analysis into conventional breeding programs is proposed as a crop improvement strategy that has the potential
to improve the efficiency of molecular breeding. 相似文献
16.
作物分子设计育种 总被引：77，自引：4，他引：73
优质、多抗、抗逆和高产作物新品种的选育和推广是实现我国粮食安全的重要途径。目前大多数育种工作仍然建立在表型选择和育种家的经验之上,育种效率低下;另一方面,生物信息数据库积累的数据量极其庞大,由于缺乏必要的数据整合技术,可资育种工作者利用的信息却非常有限。作物分子设计育种将在多层次水平上研究植物体所有成分的网络互作行为和在生长发育过程中对环境反应的动力学行为;继而使用各种“组学”数据,在计算机平台上对植物体的生长、发育和对外界反应行为进行预测;然后根据具体育种目标,构建品种设计的蓝图;最终结合育种实践培育出符合设计要求的农作物新品种。设计育种的核心是建立以分子设计为目标的育种理论和技术体系,通过各种技术的集成与整合,对生物体从基因（分子）到整体（系统）不同层次进行设计和操作,在实验室对育种程序中的各种因素进行模拟、筛选和优化,提出最佳的亲本选配和后代选择策略,实现从传统的“经验育种”到定向、高效的“精确育种”的转化,以大幅度提高育种效率。 相似文献
17.
Strategies employed by dry bean breeders to improve yield include early generation testing, ideotype breeding, selection for
physiological efficiency, and selection based on genotypic performance and combining ability across gene pools of Phaseolus
vulgaris. Ideotype breeding has been successfully deployed to improve yield in navy, pinto and great northern seed types.
The ideotype method is based on an ideal plant architecture to which breeders target their selection. Breeding for physiological
efficiency is important in combining increased biomass, high growth rates and efficient partitioning. Genotypic performance
and combining ability are also critical for yield improvement, since crosses between gene pools can exhibit negative combining
ability and problems with lethality, whereas interracial crosses within the same gene pool exhibit the greatest potential.
Breeders must work within specific constraints for growth habit, maturity, seed quality and disease resistance. A three-tiered
pyramidal breeding strategy is proposed to facilitate yield improvement in dry bean. Breeding of elite, agronomically acceptable
germplasm within the same market class is restricted to the apex of the pyramid. The intermediate level has fewer constraints
and greater access to diverse germplasm. Interracial crosses within the same gene pool are utilized to exploit genetic differences
within adapted material. Extracting genetic diversity from unadapted sources, including wild germplasm and other Phaseolus
species, is conducted at the base of the pyramid. The objective of this breeding strategy is the movement of improved germplasm
towards the apex, using different breeding procedures to optimize improvement at each tier of the breeding pyramid.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
18.
Niels P. Louwaars 《Euphytica》2018,214(7):114
Plant breeding collects, induces and rearranges genetic diversity followed by selection. Breeding may contribute to diversity in farmers’ fields or significantly reduce it. History has numerous examples of both. The diversity of many crops have gone through domestication, dispersal and modernization bottlenecks. Between these major decreasing processes, diversity has picked up through different evolutionary processes, and plant breeding affected by policies. Major negative effects of plant breeding on diversity have been recorded following the modernization bottleneck, but alternative breeding strategies have come up as well, both in the formal system and in the interphase between formal and farmers’ seed systems. Multiline breeding and participatory plant breeding are introduced as examples to also analyse effects of current developments in technology and policy. This paper intends to shed some light on the questions: how will current developments in technology and policy affect crop genetic diversity? Are we heading for a new bottleneck—either a molecular or a policy bottleneck, or a combination of both? Or could the future become more diverse? We look at the relationship between breeding, policies, and crop genetic diversity in farming systems with a birds-eye view. Notably because of current policy trends we warn for a new diversity bottleneck. 相似文献
19.
RNAi技术在作物中的应用及安全评价研究 总被引：2，自引：0，他引：2
RNA干扰（RNAi）技术在基因功能研究方面应用广泛。近年来,RNAi被认为是具有应用潜力的育种新方法。具有良好抗虫性状的RNAi转基因作物已研究成功,预示其商业化应用成为可能。RNAi转基因作物如何监管成为人们关注的新问题。本文介绍了RNAi转基因作物的发展现状,分析了RNAi技术与传统育种技术及传统转基因技术之间的不同点,总结了RNAi转基因作物的潜在风险,并以美国和欧盟为代表总结了RNAi转基因作物的监管态度,最后分析了RNAi转基因作物存在的监管问题并提出了相关建议,为我国对RNAi转基因作物的监管提供参考。 相似文献
20.
A. M. Osman C. J. M. Almekinders P. C. Struik E. T. Lammerts van Bueren 《Euphytica》2008,163(3):511-522
Main stream commercial onion breeders do not select varieties for organic farming, but solely for conventional farming. Seed
companies consider the organic market too small to justify investments in breeding for this sector. In order to study if their
varieties also suit organic farmers’ needs we interviewed four Dutch commercial onion breeders on their breeding programme
and selection criteria and compared the outcome with a variety profile composed of the priority traits of Dutch organic farmers.
Breeders gave priority to the same storage and bulb quality traits that are demanded by organic farmers, because organic onions
are exported to conventional supermarkets that apply the same quality standards to organic and conventional onions. However,
organic farmers also need varieties that perform well in the field. Breeders give low priority to field selection. Furthermore,
three of the four seed companies only breed hybrids. The cytoplasmic male sterility system used to produce these hybrids does
not comply with organic principles. We conclude that at present breeders can provide varieties that meet organic farmers’
demands for storability and quality traits, but they should give higher priority to field selection to also improve required
field traits. The latter will only occur, if in future the organic seed market will grow. If the organic sector wants varieties
developed according to its own principles, it should either set up its own onion breeding programme or seek alliances with
breeding companies that are prepared to harmonize their breeding methodology with the organic principles. 相似文献