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Culture collections conserve the living tools for biotechnology. Without them there would be no reference organisms, and no stocks of crucial or rare microorganisms that are so valuable for biotechnology and biomedical research. The expertise that drives these collections is under threat, but the collections themselves may survive by pooling their knowledge. 相似文献
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Marker-assisted selection: an approach for precision plant breeding in the twenty-first century 总被引:3,自引:0,他引:3
Collard BC Mackill DJ 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2008,363(1491):557-572
DNA markers have enormous potential to improve the efficiency and precision of conventional plant breeding via marker-assisted selection (MAS). The large number of quantitative trait loci (QTLs) mapping studies for diverse crops species have provided an abundance of DNA marker-trait associations. In this review, we present an overview of the advantages of MAS and its most widely used applications in plant breeding, providing examples from cereal crops. We also consider reasons why MAS has had only a small impact on plant breeding so far and suggest ways in which the potential of MAS can be realized. Finally, we discuss reasons why the greater adoption of MAS in the future is inevitable, although the extent of its use will depend on available resources, especially for orphan crops, and may be delayed in less-developed countries. Achieving a substantial impact on crop improvement by MAS represents the great challenge for agricultural scientists in the next few decades. 相似文献
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Varro E. Tyler 《Economic botany》1986,40(3):279-288
Lack of effective cooperation among researchers in the applicable biological, physical, and clinical sciences has accounted, in large measure, for the lack of successful development in the United States of any significant number of new plant drugs during the latter part of the 20th century. Unrealistic federal regulations that tend to render unprofitable such research have also played an important role in hindering the development of new plant drugs. It is likely that both of these factors will change in the future as health-conscious consumers demand more accurate information and wider availability of natural drug products. Several anticipated developments will greatly facilitate research and production in this previously difficult area. These include the development of new, simplified bioassay procedures; improved, easily applied analytical methods; and innovative plant-cell-culture methodologies, possibly involving genetic manipulation. The kinds of drugs that need to be developed using such techniques are discussed. It is concluded that significant new plant drugs and new methods of producing them will be developed to serve mankind during the 21st century. 相似文献
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Question: How does climate change influence plant species population dynamics, their time to extinction, and proportion of occupied habitats in a fragmented landscape? Location: Germany and Central European lowland. Methods: We apply a mechanistic general simulation model to test the response of plant functional types to direct and indirect effects of climate change. Three functional types were chosen to represent a set of well‐studied perennial plant species: Juncus atratus, Gentiana pneumonanthe and Primula veris. We link local population dynamics within a heterogeneous, fragmented landscape context. “Species spheres”, i.e. multi‐dimensional parameter ranges rather than single parameter realizations, based on field and literature data served as proxy for life stage transition parameters. Four climatic scenarios summarizing different cumulative weather effects on demographic rates and different local disturbance frequencies were run. The model predicts “time to extinction” (TE) and “proportion of occupied habitat” (POH) as regional indicators for species extinction risk. Results: TE decreased for all species when weather conditions worsened, and even more so when the frequency of local destructive events additionally increased. However, management towards fewer disturbance events could buffer the negative effect of climate to some extent. The magnitude of these responses varied with species type. POH declined with an increase in bad weather as well as with increasing disturbance frequency. The better the climatic conditions, the less severe were disturbances on population performance. Conclusions: The “species spheres” proved to be a valuable approach for predictive trends. As climate change usually also implies destructive events such as land‐use change, flooding or fire, our model on local and regional extinction risks can support conservation issues and management actions. 相似文献
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Wetlands Ecology and Management - This synthesis is a short introduction to the Wetlands and Mosquito Control special issue of Wetlands Ecology and Management. The geographic extent of the articles... 相似文献
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Plants and human health in the twenty-first century 总被引:14,自引:0,他引:14
Raskin I Ribnicky DM Komarnytsky S Ilic N Poulev A Borisjuk N Brinker A Moreno DA Ripoll C Yakoby N O'Neal JM Cornwell T Pastor I Fridlender B 《Trends in biotechnology》2002,20(12):522-531
The concept of growing crops for health rather than for food or fiber is slowly changing plant biotechnology and medicine. Rediscovery of the connection between plants and health is responsible for launching a new generation of botanical therapeutics that include plant-derived pharmaceuticals, multicomponent botanical drugs, dietary supplements, functional foods and plant-produced recombinant proteins. Many of these products will soon complement conventional pharmaceuticals in the treatment, prevention and diagnosis of diseases, while at the same time adding value to agriculture. Such complementation can be accelerated by developing better tools for the efficient exploration of diverse and mutually interacting arrays of phytochemicals and for the manipulation of the plant's ability to synthesize natural products and complex proteins. This review discusses the history, future, scientific background and regulatory issues related to botanical therapeutics. 相似文献
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David Fowler Mhairi Coyle Ute Skiba Mark A. Sutton J. Neil Cape Stefan Reis Lucy J. Sheppard Alan Jenkins Bruna Grizzetti James N. Galloway Peter Vitousek Allison Leach Alexander F. Bouwman Klaus Butterbach-Bahl Frank Dentener David Stevenson Marcus Amann Maren Voss 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2013,368(1621)
Global nitrogen fixation contributes 413 Tg of reactive nitrogen (Nr) to terrestrial and marine ecosystems annually of which anthropogenic activities are responsible for half, 210 Tg N. The majority of the transformations of anthropogenic Nr are on land (240 Tg N yr−1) within soils and vegetation where reduced Nr contributes most of the input through the use of fertilizer nitrogen in agriculture. Leakages from the use of fertilizer Nr contribute to nitrate (NO3−) in drainage waters from agricultural land and emissions of trace Nr compounds to the atmosphere. Emissions, mainly of ammonia (NH3) from land together with combustion related emissions of nitrogen oxides (NOx), contribute 100 Tg N yr−1 to the atmosphere, which are transported between countries and processed within the atmosphere, generating secondary pollutants, including ozone and other photochemical oxidants and aerosols, especially ammonium nitrate (NH4NO3) and ammonium sulfate (NH4)2SO4. Leaching and riverine transport of NO3 contribute 40–70 Tg N yr−1 to coastal waters and the open ocean, which together with the 30 Tg input to oceans from atmospheric deposition combine with marine biological nitrogen fixation (140 Tg N yr−1) to double the ocean processing of Nr. Some of the marine Nr is buried in sediments, the remainder being denitrified back to the atmosphere as N2 or N2O. The marine processing is of a similar magnitude to that in terrestrial soils and vegetation, but has a larger fraction of natural origin. The lifetime of Nr in the atmosphere, with the exception of N2O, is only a few weeks, while in terrestrial ecosystems, with the exception of peatlands (where it can be 102–103 years), the lifetime is a few decades. In the ocean, the lifetime of Nr is less well known but seems to be longer than in terrestrial ecosystems and may represent an important long-term source of N2O that will respond very slowly to control measures on the sources of Nr from which it is produced. 相似文献
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CATRINA M. MARTIN 《Ibis》1995,137(S1):S198-S203
The Endangered Species Act of 1973, as amended, is one of the most significant pieces of conservation legislation ever passed in the United States. The passage of this act spawned the creation of the Endangered Species Program of the US. Fish and Wildlife Service (USFWS). Under the Act, the USFWS has responsibility for implementing many provisions of the Act: listings, consultations, enforcement of prohibitions and recovery planning. Recovering threatened and endangered species, as well as other declining species yet to be listed, is accomplished through many of the activities that occur under the auspices of the Act, not only through the formal recovery planning process. The Act is fundamentally an instrument for ecosystem conservation, although this aspect of the Act is often over-looked. Planning and implementing an ecosystem approach to conservation activities is a priority for the USFWS, not only for threatened and endangered species but for all wildlife. The recent emphasis on regional habitat conservation planning and the development of regional and multi-species recovery plans are indicative of the priority placed on sound ecosystem conservation planning. All of these processes are implemented with the participation of the potentially affected communities and state wildlife management agencies through a public review process. State conservation agencies are part of the process through a special grant programme. 相似文献
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Immunology: improving on nature in the twenty-first century 总被引:4,自引:0,他引:4
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Growth and maturation are considered the most reliable indicators of health status. Their progression rates in turn are strongly influenced by nutrition and socio-economic status, a well-documented relationship. The pattern of the so-called positive secular changes, i.e. the increase in size and earlier maturation, fits the populations' historical model of economic development very well. The historical, political and economic changes occurring in this century in Hungary have had a remarkably strong impact. Until World War I Hungary was an agrarian part of the Austro-Hungarian monarchy, its ethnic composition was most variegated. Both World Wars caused fundamental changes, namely in respect of post-war Hungary they were associated with marked territorial losses and considerable population mobility. In interpreting the developmental differences in the data collected before and after these wars one should take account of the important facts that, in addition to the changes in socio-economic conditions, affected the gene pool of the populations in Hungary. Over the past 100 years profound changes have occurred in the mean body size, growth rate and timing of maturation of the country's population. This paper is a brief analytic summary of the tendencies observed in adult stature, maturation and some socio-economic conditions. It also compares the cohorts of sub-populations as reflected by the reviewed reports. In summarizing the change in adult stature estimated by the data on recruits, soldiers and students of higher education, it could be stated that adult mean stature had become markedly taller in Hungary since the end of the fifties. However, any estimation of the absolute increment and the exact rate is severely biased by the variable character of the samples' representativeness. Similar problems arose in dealing with sexual maturation, because the retrospective and status-quo methods of assessment were found incomparable. Nevertheless, menarche was observed to have shifted to an appreciably younger age lately, a trend that by the end of the 20th century seemed to have reached a more or less stable level. 相似文献
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Detecting changes in arctic tundra plant communities in response to warming over decadal time scales 总被引:2,自引:0,他引:2
Howard E. Epstein Monika P. Calef Marilyn D. Walker† F. Stuart Chapin III ‡ Anthony M. Starfield§ 《Global Change Biology》2004,10(8):1325-1334
Detecting the response of vegetation to climate forcing as distinct from spatial and temporal variability may be difficult, if not impossible, over the typical duration of most field studies. We analyzed the spatial and interannual variability of plant functional type biomass from field studies in low arctic tussock tundra and compared these to climate change simulations of plant community composition using a dynamic tundra vegetation model (ArcVeg). Spatial heterogeneity of peak season live aboveground biomass was estimated using field samples taken from low arctic tundra at Ivotuk, Alaska (68.5°N, 155.7°W) in 1999. Coefficients of variation for live aboveground biomass at the 1 m2 scale ranged from 14.6% for deciduous shrubs, 18.5% for graminoids and 25.3% for mosses to over 57% for forbs and lichens. Spatial heterogeneity in the ArcVeg dynamic vegetation model was simulated to be greater than the field data, ranging from 37.1% for deciduous shrubs to 107.9% for forbs. Disturbances in the model, such as caribou grazing and freezing–thawing of soil, as well as demographic stochasticity, led to the greater variability in the simulated results. Temporal variances of aboveground live biomass over a 19-year period using data from Toolik Lake, AK fell within the range of field and simulation spatial variances. However, simulations using ArcVeg suggest that temporal variability can be substantially less than site-scale spatial variability. Field data coupled with ArcVeg simulations of climate change scenarios indicate that some changes in plant community composition may be detectable within two decades following the onset of warming, and shrubs and mosses might be the key indicators of community change. Model simulations also project increasing landscape scale spatial heterogeneity (particularly of shrubs) with increasing temperatures. 相似文献
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Hagelin J 《Alternatives to laboratory animals : ATLA》2005,33(2):111-118
A literature-based survey was conducted on the use of live apes in research between 2000 and 2003. The 599 studies identified and considered were grouped according to area of research, taxonomy and geographic location of the work. The results suggested that behaviour/cognition, conservation and various applications related to virology (most notably, hepatitis and HIV) were the most frequent areas of research. Of the studies, 73% were classified as non-invasive, whereas 27% were classified as invasive. Among the invasive studies, 39% were scored as of mild severity, and 61% were scored as of moderate/substantial severity. Pan species were involved in 65% of the studies, Gorilla species in 15%, Pongo species in 12%, and Hylobates species in 8%. Most of the invasive research was conducted in the USA (60%). The majority of the non-invasive research was conducted in the USA (31%), Japan (13%), or in the animals natural habitats in Africa (35%) and Asia (8%). 相似文献
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