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Capercaillie (Tetrao urogallus) populations are declining in western parts of their range, including Scotland. It has been proposed that their numbers, and the extent of their range in Scotland be increased to reduce the risk of a second extinction in the UK. The feasibility of a reintroduction of capercaillie to coniferous plantations in southern Scotland was assessed by undertaking a population viability analysis. Following a review of capercaillie ecology and habitat requirements, VORTEX population simulation software was used to identify a minimum viable population (MVP). From this the minimum dynamic area of suitable habitat required in order to support such a MVP was then calculated. It was estimated that a minimum of 60 individuals would be required in approximately 5000ha of habitat in order for the population to have a >0.95 probability of surviving for 50 years. Supplementation of populations with two unrelated individuals every five years reduced the MVP to ten individuals. Further simulations were run in order to establish the sensitivity of the model to changes in three key parameters. Assessment of areas of suitable habitat identified two potential release sites, Wauchope and Newcastleton forests, in southern Scotland. Some practical considerations relating to management of a release population are outlined. It was concluded that an appropriately planned and resourced reintroduction was feasible.  相似文献   
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The taxonomic affinity of Halosphaeria cucullata to Halosphaeria is reassessed based on a recent collection of this fungus. Halosphaeria cucullata is characterized by immersed, darkly coloured ascomata, clavate asci which deliquesce very early in development, and cylindrical ascospores with or without a polar cap-like appendage at one end. In a phylogenetic analysis of the LSU rDNA sequences from members of the Halosphaeriaceae, H. cucullata did not form a monophyletic clade with H. appendiculata , the type species of the genus. These results suggest that H. cucullata should not be included in Halosphaeria . Okeanomyces gen. nov. is proposed to accommodate this fungus.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 223–229.  相似文献   
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Previous studies have indicated that the common European pipistrelle bat ( Pipistrellus pipistrellus ) comprises two cryptic species, P. pipistrellus and Pipistrellus pygmaeus , which differ in echolocation call frequency and mitochondrial DNA sequence. However, levels of divergence based on nuclear markers have not been examined, and hence the potential for male-mediated gene flow between the species cannot be discounted. Moreover, little is known about population structure and migration patterns in either species. Here, we describe the use of microsatellites to investigate nuclear DNA differentiation between, and the pattern of population genetic structure within, the two cryptic pipistrelle species. In total, 1300 individuals from 82 maternity colonies were sampled across the British Isles and Continental Europe. We show, using multivariate analyses, that colonies of the same species are generally genetically more similar to each other than to those from the other species regardless of geographical location. Our findings support the hypothesis that the species are reproductively isolated. Significant patterns of genetic isolation by distance were identified in both species, indicating that mating may occur before any long-distance autumnal migration. The presence of a sea channel does not confer higher levels of genetic differentiation among colonies over and above distance alone in either species. Differences in genetic population structure were identified between the species, with P. pipistrellus showing a wider range of levels of genetic differentiation among colonies and a stronger relationship between genetic and geographical distance than P. pygmaeus . Differences in dispersal, mating behaviour, colony size and/or postglacial colonization patterns could contribute to the differences observed.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 90 , 539–550.  相似文献   
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It has been suggested that plants that are good colonizers will generally have either an ability to self‐fertilize or a generalist pollination system. This prediction is based on the idea that these reproductive traits should confer resistance to Allee effects in founder populations and was tested using Gomphocarpus physocarpus (Asclepiadoideae: Apocynaceae), a species native to South Africa that is invasive in other parts of the world. We found no significant relationships between the size of G. physocarpus populations and various measures of pollination success (pollen deposition, pollen removal and pollen transfer efficiency) and fruit set. A breeding system experiment showed that plants in a South African population are genetically self‐incompatible and thus obligate outcrossers. Outcrossing is further enhanced by mechanical reconfiguration of removed pollinaria before the pollinia can be deposited. Self‐pollination is reduced when such reconfiguration exceeds the average duration of pollinator visits to a plant. Observations suggest that a wide variety of wasp species in the genera Belonogaster and Polistes (Vespidae) are the primary pollinators. We conclude that efficient pollination of plants in small founding populations, resulting from their generalist wasp‐pollination system, contributes in part to the colonizing success of G. physocarpus. The presence of similar wasps in other parts of the world has evidently facilitated the expansion of the range of this milkweed.  相似文献   
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The intermediate leaf-nosed bat ( Hipposideros larvatus ) is a medium-sized bat distributed throughout the Indo-Malay region. In north-east India, bats identified as H. larvatus captured at a single cave emitted echolocation calls with a bimodal distribution of peak frequencies, around either 85 kHz or 98 kHz. Individuals echolocating at 85 kHz had larger ears and longer forearms than those echolocating at 98 kHz, although no differences were detected in either wing morphology or diet, suggesting limited resource partitioning. A comparison of mitochondrial control region haplotypes of the two phonic types with individuals sampled from across the Indo-Malay range supports the hypothesis that, in India, two cryptic species are present. The Indian 98-kHz phonic bats formed a monophyletic clade with bats from all other regional populations sampled, to the exclusion of the Indian 85-kHz bats. In India, the two forms showed 12–13% sequence divergence and we propose that the name Hipposideros khasiana for bats of the 85-kHz phonic type. Bats of the 98-kHz phonic type formed a monophyletic group with bats from Myanmar, and corresponded to Hipposideros grandis , which is suggested to be a species distinct from Hipposideros larvatus . Differences in echolocation call frequency among populations did not reflect phylogenetic relationships, indicating that call frequency is a poor indicator of evolutionary history. Instead, divergence in call frequency probably occurs in allopatry, possibly augmented by character displacement on secondary contact to facilitate intraspecific communication.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 88 , 119–130.  相似文献   
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Effect of Exogenous Glycinebetaine on Na+ Transport in Barley Roots   总被引:5,自引:0,他引:5  
Ahmad, N., Wyn Jones, R. G. and Jeschke, W. D. 1987. Effectof exogenous glycinebetaine on Na+ transport in barley roots.—J.exp. Bot. 38: 913–921. A comparison has been made of the kinetics of 22Na+ uptake intoexcised barley roots and roots pre-loaded with glycinebetaine.The elevated intracellular glycinebetaine or a metabolic consequencethereof increased the Na+ influx, and the effect was relatedto the level of internal glycinebetaine and or Na+ [Cl].The quasi-steady-state Na+ influx at the tonoplast rather thanthe plasmalemma influx was apparently influenced by glycinebetaineloading. The tonoplast fluxes and vacuolar Na+ content wereconsistently higher in glycinebetaine-loaded roots than unloadedroots. A membrane-modifying role of glycinebetaine in relationto ion compartmentation is discussed. Key words: Excised roots, glycinebetaine, Na+, ion fluxes, barley  相似文献   
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The accompanying papers and posters at this conference provide ample testimony that there is much potential in the exploitation of micro-organisms. The classical use of microorganisms in fermentation processes is well established and will not be discussed here but, in an age when research without a molecular input is likely to be judged as unfashionable, it is well worth emphasising that the microbiological aspects of brewing, dairy products and many industrial processes have been widely exploited, in many instances from before the earliest written histories.  相似文献   
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