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Anthropogenic climate change has significant consequences for the sustainability and productivity of agroforestry ecosystems upon which millions of smallholders in the tropics depend and that provide valuable global services. We here consider the current state of knowledge of the impacts of climate change on tree genetic resources and implications for action in a smallholder setting. Required measures to respond to change include: (1) the facilitated translocation of environmentally-matched germplasm across appropriate geographic scales, (2) the elevation of effective population sizes of tree stands through the promotion of pollinators and other farm management interventions; and (3) the use of a wider range of ??plastic?? species and populations for planting. Key bottlenecks to response that are discussed here include limitations in the international exchange of tree seed and seedlings, and the absence of well-functioning delivery systems to provide smallholders with better-adapted planting material. Greater research on population-level environmental responses in indigenous tree species is important, and more studies of animal pollinators in farm landscapes are required. The development of well-functioning markets for new products that farmers can grow in order to mitigate and adapt to anthropogenic climate change must also consider genetic resource issues, as we describe.  相似文献   
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An increasing trend towards mechanisation of agriculture from the beginning of the 20th century has facilitated the deployment of efficient and powerful machines by fruit farmers of the Lower Elbe region. The transition from a muscle-driven one-horsepower traction and work machine to motorised vehicles falls into that period. Since fruit farmers were engaged also in cattle and dairy production in these early days, some aspects of the latter are also covered here. With a few exceptions, the Technical Section has been a one-man unit since 1947. Seed production, planting, soli cultivation, tree treatment, pest control, harvest, storage and packaging have been the important tasks. The most prominent of all challenges is crop protection technology. Additional aspects of work in the Technical Section are the organisation of the regional annual exhibition of machines and equipment for fruit producers, and recommendations in the course of seminars and articles in the regional journal Mitteilungen des OVR.  相似文献   
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Shortage of fodder is a major constraint to livestock production in Nepal. The genetic variation in canopy biomass production of Bauhinia purpurea L, a very important fodder species in Nepal, was estimated in a Breeding Seed Orchard in order to examine the potential of simple, low input breeding. Substantial genetic variation could be observed suggesting that low input breeding based on simple phenotypic selection can provide biomass gain in the order of 2–5% per year. Very high correlation was observed between stem diameter (cross section area) and total biomass, making farmer based selection relevant. Jointly, these results suggest that low input domestication is a promising option for improving fodder production in Nepal and thereby help to improve rural livelihood and development. A multiple population approach is recommended.  相似文献   
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The outcome of experimental intestinal infections with enterotoxigenic Escherichia coli (ETEC) is dependent on several factors. An important factor is adhesion of the challenge strain to the intestinal mucosa. The test for susceptibility towards ETEC adhesion has so far been made by an intestinal adhesion test made after slaughter of piglets. However, in an experimental infection study with the purpose to obtain diarrhoeic piglets, it would be an advantage to test for susceptibility prior to experimentation. The Mucin 4 gene on porcine chromosome 13 has been proposed as a candidate gene for the production of the specific ETEC F4ab/ac receptor, and a DNA marker-based test has been developed to allow genotyping for ETEC F4ab/ac resistance/susceptibility [J?rgensen, C.B., Cirera, S., Archibald, A.L., Anderson, L., Fredholm, M., Edfors-Lilja, I., 2004. Porcine polymorphisms and methods for detecting them. International application published under the patent cooperation treaty (PCT). PCT/DK2003/000807 or WO2004/048606-A2]. The aim of this study was to test an experimental model for ETEC O149:F4ac-induced diarrhoea in piglets, selected for susceptibility towards ETEC O149:F4ac adhesion prior to experimentation using a DNA marker-based test. Sixty-two healthy 25-32 days old recently weaned Danish crossbred piglets were used. All piglets were tested prior to experimentation for susceptibility or resistance towards ETEC O149:F4ac adhesion. Thirty-nine piglets, both susceptible and resistant, were oro-gastric intubated with 10(9)CFU of ETEC O149:F4ac and 23 age-matched piglets, both susceptible and resistant, were used as non-infected controls. Of susceptible piglets, challenged with ETEC O149:F4ac, 74% had ETEC O149:F4ac-associated diarrhoea first day after first challenge, which were significantly higher relatively to the resistant and challenged piglets where 20% had diarrhoea (p=0.04). This study suggests a model for experimental ETEC induced diarrhoea.  相似文献   
5.
In this study, a methodological approach for an effective and reliable quality control of Chinese star anise (Illicium verum Hook. F.) is developed and validated. A combined method of TLC and HPLC-MS/MS was used for differentiation of various Illicium species, especially Chinese and Japanese star anise. Species can be distinguished by their TLC flavonoid pattern. A sensitive and selective HPLC/ESI-MS/MS method was developed for the detection and quantification of lower admixtures of I. anisatum and of further toxic Illicium species at a low concentration range using the sesquiterpene lactone anisatin as a marker. The proposed assay includes a solid-phase extraction cleanup procedure with a high recovery (>90%). Chromatographic separation of anisatin was carried out on a C18 column, followed by MS detection using ESI in negative mode. The precursor/product ion transitions m/z 327 --> 127 (quantifier) and m/z 327 --> 297 (qualifier) were monitored. Statistical evaluation of this multireaction-monitoring procedure reveals good linearity and intra- and interday precision. The limits of detection and quantification are 1.2 and 3.9 microg/kg, respectively.  相似文献   
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