74 resultados para Insecticides, Botanical


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In the 1960s Taxon published articles aimed at improving botanical Seed Lists. We compared suggestions made then with the situation in 2007. Sadly the majority of problems raised in the original manuscripts were still evident today. Botanic gardens must improve if this practice is to survive.

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Landscape narrative, combining landscape and narrative, has been employed to create storytelling layouts and interpretive information in some famous botanic gardens. In order to assess the educational effectiveness of using "landscape narrative" in landscape design, the Heng-Chun Tropical Botanical Garden in Taiwan was chosen as research target for an empirical study. Based on cognitive theory and the affective responses of environmental psychology, computer simulations and video recordings were used to create five themed display areas with landscape narrative elements. Two groups of pupils watched simulated films. The pupils were then given an evaluation test and questionnaire, to determine the effectiveness of the landscape narrative. When the content was well associated and matched with the narrative landscape, the comprehension and retention of content was increased significantly. The results also indicated that visual preference of narrative landscape scenes was increased. This empirical study can be regarded as a successful model of integrating landscape narrative and interpretation practice that can be applied to the design of new theme displays in botanic gardens to improve both the effectiveness of interpretation plans and the visual preference of visitors. (c) 2008 Elsevier B.V. All rights reserved.

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A flavonoid survey was carried out on 45 taxa from the genera Shorea, Hopea, Parashorea, Neobalanocarpus, and Dryobalanops of the tribe Shoreae in the Dipterocarpaceae. The study showed significant chemotaxonomic differences in leaf flavonoid aglycone patterns and the presence of tannins in these taxa. The flavonoid patterns are useful in the delimitation of some taxa. For example, the genus Parashorea is distinguished by the universal presence of kaempferol 3-methyl ether, and the monotypic genus Neobalanocarpus is unique in not producing ellagic and gallo tannins. The presence of chalcones and flavone C-glycosides supports the separation of the genus Hopea into two sections, section Dryobalanoides and section Hopea in Ashton's classification, which is based on the type of venation. The flavonoid distributions in this study show that they can be very useful for differentiating between the Balau group in the genus Shorea, and some scaly barked Hopea species, particularly H. helferi (lintah bukit), H. nutans (giam), and H. ferrea (malut). (C) 2008 The Linnean Society of London.

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Amplified fragment length polymorphism (AFLP) genetic fingerprinting of 14 accessions of Chara curta and Chara aspera Willd., sampled across a range of habitats and morphologies in Britain, suggests that these taxa are part of the variation within a single species complex. Two primer combinations generating 397 fragments (97% of which were polymorphic), analysed by Jaccard's similarity coefficient and principal co-ordinate analysis, did not recover groups which reflect the current taxonomy. By contrast with the genetic study, a Gower general similarity coefficient and principal co-ordinate analysis of 52 morphological characters recovered the currently recognized species groups. A Mantel test showed no significant correlation between the genetic data and the morphological data, supporting the hypothesis that phenotypic variability in Chara L. is either to some extent environmentally induced or represents developmental stages. Implications for the conservation status of C. curta in Britain are discussed. (c) 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 155, 467-476.

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This study clarifies the taxonomic status of Anemone coronaria and segregates the species and A. coronaria infraspecific variants using morphological and morphometric analyses. Principal component analysis of the coronaria group was performed on 25 quantitative and qualitative characters, and morphometric analysis of the A. coronaria infraspecific variants was performed on 21 quantitative and qualitative characters. The results showed that the A. coronaria group clustered into four major groups: A. coronaria L., A. biflora DC, A. bucharica (Regel) Juz.ex Komarov, and a final group including A. eranthioides Regel and A. tschernjaewii Regel. The data on the A. coronaria infraspecific variants clustered into six groups: A. coronaria L. var. coronaria L., var. cyanea Ard., var. albiflora Rouy & Fouc., var. parviflora Regel, var. ventreana Ard., and var. rissoana Ard. © 2007 The Linnean Society of London

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Borassus akeassii Bayton, Ouedraogo & Guinko sp. nov. (Arecaceae) is described as a new species from western Burkina Faso in West Africa. It has been confused with the widely distributed African species B. aethiopum and more recently with the Asian B. flabellifer. However, it is distinguished by its glaucous, green leaves with weakly armed petioles and a characteristic pattern of lamina venation. The fruits have a pointed apex and are greenish when ripe, and the flowers of the pistillate inflorescence are arranged in three spirals. The pollen has a reticulate tectum and distinctive ornamentation. The distribution of B. akeassii is discussed and the status of the varieties of Borassus aethiopum (var. bagamojensis and var. senegalensis) is examined. (c) 2006 The Linnean Society of London.

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Hunting foxes with hounds has been a countryside pursuit in Britain since the 17th Century, but its effect nationally on habitat management is little understood by the general public. A survey questionnaire was distributed to 163 mounted fox hunts of England and Wales to quantify their management practices in woodland and other habitat. Ninety-two hunts (56%), covering 75,514 km(2), returned details on woodland management motivated by the improvement of their sport. The management details were verified via on-site visits for a sample of 200 woodlands. Following verification, the area of woodlands containing the management was conservatively estimated at 24,053 (+/- 2241) ha, comprising 5.9% of woodland area within the whole of the area hunted by the 92 hunts. Management techniques included: tree planting, coppicing, felling, ride and perimeter management. A case study in five hunt countries in southern England examined, through the use of botanical survey and butterfly counts, the consequences of the hunt management on woodland ground flora and butterflies. Managed areas had, within the last 5 years, been coppiced and rides had been cleared. Vegetation cover in managed and unmanaged sites averaged 86% and 64%, respectively, and managed areas held on average 4 more plant species and a higher plant diversity than unmanaged areas (Shannon index of diversity: 2.25 vs. 1.95). Both the average number of butterfly species (2.2 vs. 0.3) and individuals counted (4.6 vs. 0.3) were higher in the managed than unmanaged sites.

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We have identified two mutations in the ace1 gene of Aphis gossypii that are associated with insensitivity of acetylcholinesterase (AChE) to carbamate and organophosphate insecticides. The first of these, S431F (equivalent to F331 in Torpedo californica), is associated with insensitivity to the carbamate insecticide pirimicarb in a range of A. gossypii clones. The S431F mutation is also found in the peach-potato aphid, Myzus persicae (Sulzer), and a rapid RFLP diagnostic allows the identification of individuals of both aphid species with a resistant genotype. This diagnostic further revealed the presence of S431 in several other pirimicarb-susceptible aphid species. The serine at this position in the wild-type enzyme has only been reported for aphids and provides a molecular explanation of why pirimicarb has a specific aphicidal action. A less specific insensitivity to a wide range of carbamates and organophosphates is associated with a second mutation, A302S (A201 in T. californica).

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Nine different classifications have been produced in the last 70 years for the horticulturally valuable genus Cyclamen, a small genus with fewer than 30 species. These classifications, generated by intuitive methods and cladistic analyses, incorporated a total of four infrageneric ranks above that of species and were based on data from morphology, cytology and DNA sequencing. Our results, based on cladistic analyses of three independent data sources − nrDNA ITS, cpDNA trnL intron and morphological data − reveal good resolution only in nrDNA sequence data. However, when these three data sources are combined they provide stronger resolution and support for three major clades, only one of which, subgenus Psilanthum, has been consistently supported in previous classifications. The differing infrageneric classifications produced in Cyclamen result from varying taxon sampling, differing interpretation of morphological data, changes in the sources and analysis of data, and inconsistent application of names. Extensive subdivision of small genera in the absence of adequate data that could provide evidence for consistent patterns of relationship is premature and leads to a proliferation of names.© 2004 The Linnean Society of London, Botanical Journal of the Linnean Society, 2004, 146, 339-349.

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In terms of their land area, many islands contain a disproportionate number of taxa for certain groups of organisms. Thus the IUCN/WWF Centres of Plant Diversity project, which identifies 234 first order sites that are globally most important from a botanical point of view, includes a considerable proportion of islands, and in Conservation International’s Hotspot programme, Madagascar and the Indian Ocean Islands, the Philippines, and the Caribbean are identified as three of the five “hottest of the hotspots”. Priority for conservation action is often assumed for islands because of the often dramatic losses already suffered and the serious level of threats to which plant or animal populations are subjected, largely as a result of direct or indirect human action. The practicalities of conservation are not, however, straightforward in many cases. In the conservation of island hotspots of biodiversity, in addition to the many scientific and technical issues involved, political, financial and socio-economic factors also have to be addressed. The priorities for conservation will be examined in the light of targets set by the recently approved CBD Global Strategy for Plant Conservation and in the wider context of sustainable development of island ecosystems and the needs and aspirations of the people who inhabit them. Particular attention will be given to the threats from invasive species and the resultant increasing homogenization of floras and faunas, leading to the ‘deinsularization’ of islands.

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1. The UK Biodiversity Action Plan (UKBAP) identifies invertebrate species in danger of national extinction. For many of these species, targets for recovery specify the number of populations that should exist by a specific future date but offer no procedure to plan strategically to achieve the target for any species. 2. Here we describe techniques based upon geographic information systems (GIS) that produce conservation strategy maps (CSM) to assist with achieving recovery targets based on all available and relevant information. 3. The heath fritillary Mellicta athalia is a UKBAP species used here to illustrate the use of CSM. A phase 1 habitat survey was used to identify habitat polygons across the county of Kent, UK. These were systematically filtered using relevant habitat, botanical and autecological data to identify seven types of polygon, including those with extant colonies or in the vicinity of extant colonies, areas managed for conservation but without colonies, and polygons that had the appropriate habitat structure and may therefore be suitable for reintroduction. 4. Five clusters of polygons of interest were found across the study area. The CSM of two of them are illustrated here: the Blean Wood complex, which contains the existing colonies of heath fritillary in Kent, and the Orlestone Forest complex, which offers opportunities for reintroduction. 5. Synthesis and applications. Although the CSM concept is illustrated here for the UK, we suggest that CSM could be part of species conservation programmes throughout the world. CSM are dynamic and should be stored in electronic format, preferably on the world-wide web, so that they can be easily viewed and updated. CSM can be used to illustrate opportunities and to develop strategies with scientists and non-scientists, enabling the engagement of all communities in a conservation programme. CSM for different years can be presented to illustrate the progress of a plan or to provide continuous feedback on how a field scenario develops.

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The Entodontaceae is characterised by erect capsules with inset and substantially reduced peristomes. Differences in peristome morphology and ornamentation delimit both genera and species within the family. The Entodontaceae, as presently recognised, consists of four genera, Entodon, Erythrodontium, Mesonodon and Pylaisiobryum, which show a variety of peristome ornamentation patterns, and exhibit differing levels of peristome reduction. This variation encompasses an unusual combination of structurally reduced peristomes, which retain massive exostome ornamentation, and residual peristome function. As part of a taxonomic revision of the family in Africa, generic patterns of peristome reduction and ornamentation are described. Inter- and intra-specific variation patterns of both the exostome and endostome have been investigated using detailed SEM studies of material from Africa and beyond. Structural reduction of the peristome is associated with high levels of intra-specific variation in peristome ornamentation patterns. Common trends in these patterns of variation are identified within the family. Putative hybrid sporophytes have been identified in Entodon, and the taxonomic implications of these observations are considered for a family where species delimitation has in the past often depended on minor variation in peristome structure or ornamentation patterns. (author abst.)

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Observations on clumps of Phascum cuspidatum during the summer and autumn indicated that this species is at least a short-lived perennial, as young shoots develop from old, brown shoots persisting from the previous winter. No young shoots arising by vegetative propagation were recorded in Pottia truncata. Rhizoid tubers were observed in this species, but only in one of the many clumps examined. Spores of both species germinated freely in culture, but when spores were planted in the field young gametophytes developed inconsistently in P. truncata and never in P. cuspidatum. An investigation of spore deposition around an isolated clump of P. truncata suggested that 67% of the spores released were deposited within the clump, and 70% within 2m. Electrophoretic studies indicated limited genetic variation within two populations of each species, with no genotypes in common between the populations. No genetic variation was recorded between gametophytes within individual clumps of either species, nor between sporophytes and their maternal gametophytes, suggesting a high incidence of inbreeding in these monoecious mosses. (author abst.)

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In the absence of equivalent research on genetically modified (GM) pest-resistant crops, their impact in pest management can be predicted from experience with traditionally bred varieties which share with GM crops the characteristic that the resistance is based on high expression of a single toxin. Such varieties lead to the rapid selection of tolerant pest strains, damage biological control and induce tolerance to synthetic pesticides. By contrast, polygenic and more broadly based resistant varieties will maintain their resistance for longer, and often synergise beneficially with biological control. The pests also become more susceptible to insecticides, giving the opportunity for applications which are selective in favour of natural enemies. However, although GM crops compare badly with traditional pest-resistant varieties, they compare favourably with insecticides, the technology they are most likely to replace.