OBPC Symposium: maize 2004 &; beyond—Can agricultural biotechnology contribute to global food security?

Summary Bioengineering approaches provide unprecedented opportunities for reducing poverty, food insecurity, child malnutrition, and natural resource degradation. Genetic engineering offers outstanding potential to increase the efficiency of crop improvement. Thus agricultural biotechnology could enhance global food production and availability in a sustainable way. Small farmers in developing countries are faced with many problems and constraints which biotechnology may assist. Yet, there are varying levels of opposition to the use of this technology in most countries and it is especially intense in Europe. While there is certain public apprehension with the use of bioengineering in food improvement, the primary hurdles facing this technology are the stringent and burdensome regulatory requirements for commercialization, opposition from the special interest groups, apprehension by the food industry especially with the whole foods, and trade barriers including rigid policies on traceability and labeling. Bioengineered crops such as soybean, maize, cotton, and canola with a few traits have already made a remarkable impaet on food production and environmental quality. But, in the developing world, bioengineering of crops such as bananas, cassava, yams, sweet potatoes, sorghum, rice, maize, wheat, millet, and legumes, along with livestock, can elearly contribute to global food security. However, the integration of biotechnology into agricultural research in developing countries faces many challenges which must be addressed: financial, technical, political, environmental, activism, intellectual-property, biosafety, and trade-related issues. To ensure that developing countries can harness the benefit of this technology with minimal problems, concerted efforts must be pursued to create an awareness of its potential benefits and to address the concerns related to its use through dialog among the various stakeholders: policy makers, scientists, trade groups, food industry, consumer organizations, farmer groups, media, and non-governmental organizations. Biotechnology holds great promise as a new tool in the scientific toolkit for generating applied agricultural technologies; however, per se it is not a panacea for the worlds problems of hunger and poverty.     

Commercializing genetically modified crops under EU regulations: objectives and barriers

Agriculture faces serious problems in feeding 9 billion people by 2050: production must be increased and ecosystem services maintained under conditions for growing crops that are predicted to worsen in many parts of the world. A proposed solution is sustainable intensification of agriculture, whereby yields are increased on land that is currently cultivated, so sparing land to deliver other ecosystem services. Genetically modified (GM) crops are already contributing to sustainable intensification through higher yields and lower environmental impacts, and have potential to deliver further significant improvements. Despite their widespread successful use elsewhere, the European Union (EU) has been slow to introduce GM crops: decisions on applications to import GM commodities are lengthy, and decision-making on applications to cultivate GM crops has virtually ceased. Delayed import approvals result in economic losses, particularly in the EU itself as a result of higher commodity prices. Failure to grant cultivation approvals costs EU farmers opportunities to reduce inputs, and results in loss of agricultural research and development from the EU to countries such as the United States and China. Delayed decision-making in the EU ostensibly results from scientific uncertainty about the effects of using GM crops; however, scientific uncertainty may be a means to justify a political decision to restrict cultivation of GM crops in the EU. The problems associated with delayed decision-making will not improve until there is clarity about the EU's agricultural policy objectives, and whether the use of GM crops will be permitted to contribute to achieving those objectives.     

Is there a role for arbuscular mycorrhizal fungi in production agriculture?

This review presents the point of view that arbuscular mycorrhizal fungi (AMF) do not play a vital role in the nutrition and growth of plants in many production-orientated agricultural systems. Highly available soil P often limits AM colonisation and causes the C-costs to the host to outweigh any benefits from colonisation. Even when P availability is low and AM colonisation levels are high, as may occur in organic and biodynamic agricultural systems, AMF may not always contribute to plant growth for reasons not yet understood. AM fungal activity may also be greatly limited by soil fumigation, non-responsive plant varieties, or rotations based primarily on non-mycorrhizal crops or crops of low AM dependency. Thus, profitability may sometimes be enhanced by management practices, such as tillage and P-fertilisation, which limit AM colonisation. Manipulation of agricultural systems to favour AMF must occur only if there is clear evidence that AMF make a positive contribution to yield or are vital for maintenance of ecosystem health and sustainability. A crucial role for AMF in soil structural stability or in enhancing micronutrient concentrations in produce may be sufficient evidence and may eventually compel consideration of AMF responsiveness when breeding new crop varieties.     

Approaches to prevention, removal and killing of biofilms

Biofilms contribute to hygiene problems in the food industry and in the medical field. Biofilms are diverse and due to the development of special phenotypes, biofilm organisms are not as susceptible to biocides as planktonic microorganisms. Biofilms may be prevented by regular disinfection. Since the attachment of microbes to surfaces and the development of biofilm phenotypes is a very fast process, it is, however, almost impossible, to prevent biofilm formation completely. The removal and killing of established biofilms requires harsh treatments, mostly using oxidising biocides. Depending on the nature of the biofilms, different biocides may be useful and the best biocide for a specific biofilm still has to be determined under practical conditions. Another approach is the prevention of biofilm formation by selection of materials that do not support the attachment of microorganisms. Some materials like glass and stainless steel show less biofilm formation than others. The ranking of materials, however, depends on the conditions, under which they are tested. A novel approach is biofilm inhibition by supplementation of systems with nutrients, to inhibit attachment. First results on inhibition of biofouling in reversed osmosis systems are presented.     

Transgenic farm animals - A critical analysis

The notion of directly introducing new genes or otherwise manipulating the genotype of an animal is conceptually straightforward and appealing from the standpoints of both speed and precision with which phenotypic changes can be made. Thus, it is little wonder that the imagination of many animal scientists has been captivated by the success others have achieved in introducing foreign genes into mice. Transgenic mice not only exhibit unique phenotypes, but they also pass those traits on to their progeny. However, before transgenic farm animals become a common component of the livestock industry, a number of formidable obstacles must be overcome. In this review we attempt to identify the critical issues that should be considered by both those currently working in the field and those scientists considering the feasibility of initiating a transgenic livestock project. The inefficiency of producing transgenic animals has been well documented. This does not constrain investigators using laboratory animal models, but it has a major impact on applying transgenic technology to farm animals. The molecular mechanisms of transgene integration have not been elucidated, and as a consequence it is difficult to design strategies to improve the efficiency of the process. In addition to the problems associated with integration of new genes, there are inefficiencies associated with collecting and culturing fertilized eggs as well as embryo transfer in farm animals. Transgenic farm animal studies are major logistical undertakings. Even in the face of these practical hindrances, some may be pressured by administrators to embrace this new technology. As powerful as the transgenic animal model system is, currently there are limits to the kinds of agricultural questions that can be addressed. Some uses are so appealing, however, that several commercial organizations have explored this technology. Within the next decade or two, it is likely that many of the technical hurdles will be overcome. Combining new techniques with a better understanding of the genetic control of physiological systems will make it possible to improve the characteristics of farm animals in highly imaginative ways.     

The Relative Decline in Women's Contribution to Agriculture with Intensification

This paper suggests why the intensification of agriculture is associated with a relative decline in women's participation in agriculture. The statistical evidence described here is consistent with the theory that women contribute relatively less to agriculture when it becomes intensive because their domestic work and fertility have increased. It is also argued that most men may be able to contribute more to agriculture in societies cultivating intensively because hunting, warfare, and trade are not so likely to pull them away from crop production [women's contribution to subsistence, agricultural intensification, time allocation, fertility, cross-cultural]     

Habitat selection of the Black-shouldered Kite Elanus caeruleus in agroecosystems of Swaziland

A decline in many African raptor populations may contribute to loss of ecosystem services such as pest control. The Black-shouldered Kite Elanus caeruleus stands out as an exception, experiencing range expansions due to its proclivity for agricultural landscapes. We surveyed roads throughout agroecosystems in Swaziland for Black-shouldered Kites and looked at habitat selection in a used versus available framework. We found that kites selected for savannas and tall herbaceous vegetation but did not show preferences for or against land-use types. We also found a significant relationship with kite presence and low tree densities in the immediate vicinity of a perch site. Singles, pairs and fledgling kites were observed in agricultural landscapes, suggesting that although they are not selecting for these areas in proportion to their availability, they are foraging in it. This may be a boon for farmers who implement ecologically based rodent management programs.     

东北—蒙东经济区绿色植保在实施“一带一路”倡议中面临的挑战与发展

东北—蒙东地区包括辽宁、吉林、黑龙江和内蒙古东部五盟市,是我国东北地区对外经贸、科技和文化交流的重要窗口,也是我国粮食生产最集中的地区之一。该地区农业管理水平和灾变应对能力相对滞后,多种重要入侵性和迁飞性有害生物在东北省区间和与其接壤的国家间重叠或交替发生,导致农产品产量和质量下降,严重影响了我国农产品的国际贸易量。随着我国"一带一路"倡议的实施,上述问题势必日益突出,如何保证东北省区粮食生产安全,促进农产品国际贸易发展是我们共同面临的巨大挑战。本文重点阐述了东北—蒙东地区全链式有害生物预警、智能化监测和绿色防控技术体系,在此基础上,拟整合东北—蒙东地区有害生物综合治理优势力量,重点联合俄罗斯、韩国等周边国家植物保护机构、科研人员及技术推广人员共建东北—蒙东地区国际植保联盟,构建农业安全生产的生态屏障。     

Realizing the promise of IVF in cattle--an overview

The in vitro-produced embryo could play a central role in dairy and beef production systems because of its potential role in genetic selection strategies and crossbreeding schemes, and because it can be integrated into reproductive management strategies for improving pregnancy rates in herds with low fertility. The promise attendant upon use of in vitro-produced embryos is not being fully realized, however. Indeed, there are important technical limitations to their production that reduce the desirability of in vitro-produced embryos because of increased costs, sub-optimal embryonic and fetal survival, and offspring that are occasionally abnormal. Most technical problems associated with in vitro production of embryos can be overcome through research. Among the requirements for a successful research program will be renewed emphasis on conducting embryo transfer trials to determine effects of modifications to embryo production protocols on pregnancy rates and fetal development. Given the promise of in vitro embryo technologies, there is an urgent need for a concerted and sustained investment in research to improve these technologies. Developing a consensus that the study of embryo technology is one of the most important areas of agricultural research should be both an individual and organizational priority.     

Shrub‐based plantings of woody perennial vegetation in temperate Australian agricultural landscapes: What benefits for native biodiversity?

Summary  In the highly fragmented agricultural landscapes of temperate southern Australia, fodder shrubs are being established as part of commercial grazing enterprises to fill the summer-autumn livestock feed gap. These woody perennial plantings have greater structural complexity than conventional grazing systems and may supplement resources for native fauna. However, to date the resources provided by these systems are poorly defined or documented. In this paper, we identify the potential environmental values of fodder shrub plantings by considering natural and planted shrub-based systems, with a particular focus on planted saltbush in non-saline lands. In marginal agricultural areas, shrub-based perennial fodder crops can not only provide economic benefits through improved livestock productivity, but also contribute to reducing soil erosion and offer potential carbon sequestration opportunities. We contend that these systems may also provide resources for a range of native fauna. More information is needed on the biodiversity value of grazing systems based on perennial shrubs so that their potential to contribute to conservation in multifunctional landscapes can be fully realised and appropriate management recommendations provided.     

不同农作区土壤轮耕模式与生态效应研究进展

适时进行不同土壤耕作措施的合理组配,形成与种植制度相适应的旱作土壤轮耕技术体系,以解决长期单一耕作措施所带来的诸多问题,在国内外已备受广泛关注。为深刻理解中国农作区土壤轮耕模式及其生态效应研究进展,就土壤轮耕的概念、轮耕模式及其土壤与作物生态效应进行了详细的阐述;在总结现有研究的基础上,归纳总结了不同农作区土壤轮耕模式的类型、作业效果及其机械选择;科学评价不同轮耕模式下土壤与作物的生态效应;指出了目前土壤轮耕技术研究中所存在的问题,并提出相应的建议。针对我国区域农作制的合理轮耕周期研究比较困难,综合国内外土壤轮耕的研究进展,提出土壤轮耕模式及技术体系今后的重点研究方向:(1)结合各区域主流种植模式,研究轮耕与轮作相结合的轮耕模式;(2)不同区域轮耕周期的确定与完善;(3)从技术上解决轮耕导致的土壤质量下降和作物减产的问题;(4)轮耕对土壤供肥与作物吸肥的影响;(5)加强轮耕模式及体系的技术评价、技术推广与配套技术的研究。     

水土保持技术对农业产业-资源系统的耦合路径分析

水土保持技术通过对农业产业-资源系统的作用过程影响系统的耦合效果,这一过程及效果成为农户选择水土保持技术的关键点。为此,运用结构方程模型,以典型流域—县南沟流域为对象,通过对2017年130户农户调研资料的分析,揭示其作用过程和耦合路径,结果表明:水土保持技术与生态环境、农业资源、农业产业形成了一个新的耦合系统,水土保持技术对生态环境的改良和农业资源量的增加具有促进作用,对农业产业的发展具有抑制作用。但其(现阶段)作用强度较弱,(水土保持技术对三者的路径系数分别为0.13、0.08、-0.02);这是由于县南沟流域基本完成了规模化治理,故水土保持技术对农业产业-资源系统的影响的弱强度是基于水土流失治理及治理措施有效发挥基础之上的弱强度,同时隐含了现有的水土保持技术体系已不能完全满足新时代背景下生态文明建设与经济发展的需求,需要围绕水土保持内涵经营过程,以生态功能的提升为主线,筛选、集成、研发水土保持技术,形成可适化水土保持技术体系。     

Activities in nonpoint pollution control in rural areas of Poland

Agriculture can contribute to water quality deterioration through the release of sediments, pesticides, animal manure, fertilisers and other sources of inorganic and organic matter. Nonpoint pollution control activities in rural areas of Poland are insufficient to meet the demands of the recovering agricultural production. There is still a need for agricultural runoff monitoring programs for identification, quantification and control of nonpoint sources. Special efforts are required to familiarise farmers with environmental friendly agricultural production technologies and ‘good agricultural practices’. This paper describes typical nonpoint sources from Polish agriculture. It presents all these activities and achievement in nonpoint pollution control after 1989, when systemic changes began and environmental problems became more visible.     

Microbial hydrogen cycling in agricultural systems – plant beneficial or detrimental?

Hydrogen-oxidising bacteria play a key role in maintaining the composition of gases within the atmosphere and are ubiquitous in agricultural soils. While studies have shown that hydrogen accumulates in soil surrounding legume nodules and the soil surface, soils as a whole act as a net sink for hydrogen, raising questions about how hydrogen is internally recycled by soils. Can the energy derived from hydrogen oxidation be directly funnelled into plants to promote their growth or does it only act as a booster for other plant-growth promoting bacteria? Moreover, while the fertilisation effect of hydrogen on plants has previously been shown to be beneficial, questions remain about the upper limit of hydrogen uptake by plants before it becomes detrimental. Agricultural practices such as fertilisation may impact the balance of hydrogen-oxidisers and hydrogen-producers in these ecosystems, potentially having detrimental effects on not only agricultural land but also global biogeochemical cycles. In this perspectives piece, we highlight the importance of understanding the contribution of hydrogen to agricultural soils and the effects of agricultural practices on the ability for bacteria to cycle hydrogen in agricultural soils. We propose a framework to gain better insights into microbial hydrogen cycling within agroecosystems, which could contribute to the development of new agricultural biotechnologies.     

Agricultural diversification as an important strategy for achieving food security in Africa

Farmers in Africa have long adapted to climatic and other risks by diversifying their farming activities. Using a multi‐scale approach, we explore the relationship between farming diversity and food security and the diversification potential of African agriculture and its limits on the household and continental scale. On the household scale, we use agricultural surveys from more than 28,000 households located in 18 African countries. In a next step, we use the relationship between rainfall, rainfall variability, and farming diversity to determine the available diversification options for farmers on the continental scale. On the household scale, we show that households with greater farming diversity are more successful in meeting their consumption needs, but only up to a certain level of diversity per ha cropland and more often if food can be purchased from off‐farm income or income from farm sales. More diverse farming systems can contribute to household food security; however, the relationship is influenced by other factors, for example, the market orientation of a household, livestock ownership, nonagricultural employment opportunities, and available land resources. On the continental scale, the greatest opportunities for diversification of food crops, cash crops, and livestock are located in areas with 500–1,000 mm annual rainfall and 17%–22% rainfall variability. Forty‐three percent of the African cropland lacks these opportunities at present which may hamper the ability of agricultural systems to respond to climate change. While sustainable intensification practices that increase yields have received most attention to date, our study suggests that a shift in the research and policy paradigm toward agricultural diversification options may be necessary.     

An emerging paradigm of colony health: microbial balance of the honey bee and hive (<Emphasis Type="Italic">Apis mellifera</Emphasis>)

Across the globe, honey bee populations have been declining at an unprecedented rate. Managed honey bees are highly social, frequent a multitude of environmental niches, and continually share food, conditions that promote the transmission of parasites and pathogens. Additionally, commercial honey bees used in agriculture are stressed by crowding and frequent transport, and exposed to a plethora of agricultural chemicals and their associated byproducts. When considering this problem, the hive of the honey bee may be best characterized as an extended organism that not only houses developing young and nutrient rich food stores, but also serves as a niche for symbiotic microbial communities that aid in nutrition and defend against pathogens. The niche requirements and maintenance of beneficial honey bee symbionts are largely unknown, as are the ways in which such communities contribute to honey bee nutrition, immunity, and overall health. In this review, we argue that the honey bee should be viewed as a model system to examine the effect of microbial communities on host nutrition and pathogen defense. A systems view focused on the interaction of the honey bee with its associated microbial community is needed to understand the growing agricultural challenges faced by this economically important organism. The road to sustainable honey bee pollination may eventually require the detoxification of agricultural systems, and in the short term, the integrated management of honey bee microbial systems.     

Wildflower areas within revitalized agricultural matrices boost small mammal populations but not breeding Barn Owls

Agro-ecosystems have recently experienced dramatic losses of biodiversity due to more intensive production methods. In order to increase species diversity, agri-environment schemes provide subsidies to farmers who devote a fraction of their land to ecological compensation areas (ECAs). Several studies have shown that invertebrate biodiversity is actually higher in ECAs than in nearby intensively cultivated farmland. It remains poorly understood, however, to what extent ECAs also favour vertebrates, such as small mammals and their predators, which would contribute to restoring functional food chains within revitalised agricultural matrices. We studied small mammal populations among eight habitat types—including wildflower areas, a specific ECA in Switzerland—and habitat selection (radiotracking) by the Barn Owl Tyto alba, one of their principal predators. Our prediction was that habitats with higher abundances of small mammals would be more visited by foraging Barn Owls during the period of chicks’ provisioning. Small mammal abundance tended to be higher in wildflower areas than in any other habitat type. Barn Owls, however, preferred to forage in cereal fields and grassland. They avoided all types of crops other than cereals, as well as wildflower areas, which suggests that they do not select their hunting habitat primarily with respect to prey density. Instead of prey abundance, prey accessibility may play a more crucial role: wildflower areas have a dense vegetation cover, which may impede access to prey for foraging owls. The exploitation of wildflower areas by the owls might be enhanced by creating open foraging corridors within or around wildflower areas. Wildflower areas managed in that way might contribute to restore functional links in food webs within agro-ecosystems.     

Modelling the origins of legume domestication and cultivation

Ladizinsky’s (1987) mathematical model of the domestication of lentils and other Near Eastern legumes is invalid. Ladizinsky believed that the model predicts that high rates of seed harvesting would lead to fixation, in wild populations, of genes conferring lack of seed dormancy (a domesticated trait). In fact, however, the model gives rapid fixation of alleles for non-dormancy underall circumstances; gathering by humans has no effect on allelic frequencies. It appears that in these species cultivation must have preceded the morphological changes that distinguish domesticated from wild plants. The addition of more realistic assumptions to the model does not alter this conclusion. I suggest several scenarios that could explain Near Eastern legume domestication: the most plausible of these postulates that cultivation of cereals led to scheduling conflicts which necessitated the abandonment of harvesting of wild legumes, and hence the initiation of their cultivation. Mathematical modelling may be able to contribute to our understanding of agricultural origins, but it must be carried out with greater rigor and closer attention to the theoretical literature.     

Histone H1

Linker histones of which histone H1 is a representative are a diverse family of architectural proteins within the eukaryotic nucleus. These proteins have a variety of structures, but invariably contain a region enriched in lysine, serine, alanine and profine. All metazoan histone His also include a structured domain that binds to DNA through a helix-turn-helix motif. By binding to the linker DNA flanking the nucleosome core they contribute to the assembly of higher-order chromatin structures. Surprisingly, the use of “knockout” technology to eliminate histone H1 in isolated cells and Xenopus does not prevent the assembly of chromosomes or nuclei, however specific genes are activated or repressed indicative of targeted regulatory functions. A dual role for histone HI in chromatin structure and gene regulation might contribute to epigenetic phenomena in which heritable states of gene activity are maintained through mechanisms independent of gene sequence. This may have important implications for biotechnological and medical research.