This thesis examines the introduction and importation of numerous exotic food plants into north-western and western Europe during the Roman and medieval periods. It constitutes the first part of a wider, ongoing research project directed by Prof. Van der Veen on “Long-Distance Trade and Agricultural Development”. The aim is to establish the dispersal histories of these exotics and highlight the active role of food in processes of socio-economic change in past societies. Relevant data were collected from all available archaeobotanical records in the area and period under study, and brought together in a uniform database format. Information was gathered on the species presence, mode of preservation and accuracy of identification. Sites are classified by period (Roman/early medieval/medieval), type (urban/rural/military), status (elite/non-elite) and context (secular/ceremonial/religious). Two types of analyses are employed to identify the chronological, social and geographical dispersal of the most common (forty-two) species: a species-specific, and a multivariate technique (Correspondence Analysis). Results indicate the emergence of very distinct dispersal patterns for each period and for the various species. In the Roman period numerous new food plants become available in different contexts. Many species that could be locally cultivated become incorporated into local diet, particularly near the Rhine frontier, while rarer species are limited to military, major urban and elite sites. In the following period most exotics disappear, indicating a turn towards more local dietary and agricultural regimes and highlighting the disjointed socio-economic context of the early medieval world. A shift in activities northwards is observed during the medieval period when the diversity of species increases again. Different food plants become prominent but most are associated with towns and the urban elite, marking socio-economic divisions. This study advances understanding of the changing nature of the exotic status of many species, and reveals these as crucial guides to charting human and economic impacts and movements.

A comparison was made between the physiological ecology of Daucus carota subsp. carota and D. carota subsp. gummifer, the first a widespread weed, the latter restricted to exposed coastal cliffs in the south-west. Experiments were carried out on germination, growth and flowering both in the field and in the laboratory. These included studies on reciprocal transplants in the field, growth on different soils, culture experiments on the effect of salinity, pH and nutrient concentration. Experiments on the effect of temperature, shade and wind were also conducted. Germination in the field was found to take place mainly in the spring for subsp. carota as the seeds need to be after-ripened over winter, whereas there is no requirement for after-ripening in most of the seeds of subsp. gummifer, so that a large percentage of them can germinate immediately on maturation in the autumn. The optimum temperature for germination of subsp. carota is 20°C, but for subsp. gummifer it is between 200 and 25°C. Weak acids inhibited the germination of both subspecies, whereas alkaline solutions and KNO3 were stimulators, and NaCl stimulated the germination of subsp. gummifer in the dark. Transplanted D. carota subsp. carota grew better inland than subsp. gummifer, whereas transplanted subsp. gummifer grew better at an exposed site at Portland Bill. Wind at Portland Bill broke and killed plants of subsp. carota, whereas those of subsp. gummifer survived and were undamaged. Sodium chloride had a beneficial effect on the growth of subsp. gummifer even at a concentration of 1 g/l, which inhibited the growth of subsp. carota. The highest wind speed produced in a wind tunnel (3 m/sec), decreased the growth of subsp. carota, whereas growth of subsp. gummifer increased with increasing wind speed. The main conclusion of this study is that air temperature, wind speed and the salinity of the soil are the most important factors determining the distribution of the two subspecies.

Screening of ethnomedicinal plants for antimicrobial activity among plants used in Ghanaian folklore medicine to treat infectious conditions was conducted on Alstonia boonei (Apocynaceae), Balanites aegyptiaca (Balatinaceae), Bidens pilosa (Compositae), Distemonanthus benthamianus (Leguminosae), Funtumia elastica (Apocynaceae), Kigelia africana (Bignonaceae), Mitracarpus villosus (Rubiaceae), Parquetina nigrescens (Asclepiadaceae) and Penianthus zenkeri (Menispermaceae). The selection of the plants was based on ethnomedicinal use and literature search and the aim was to investigate the scientific basis of their use in treating infectious diseases. It was, in addition, aimed at selecting the plant with the most potent activity for detailed bioactivity and phytochemical studies. The methanolic extracts of the plants showed antimicrobial activity with an MIC range of 0.5 - 2.0mg/ml against at least three of the test bacteria (Gram-positives and Gram-negatives) and the yeast-like fungi, Candida albicans, used. F. elastica leaf was selected for further bioactivity studies based on its relatively more potent antimicrobial activity. Bioactivity-guided phytochemical investigation of F. elastica, used to treat infections (including dysentery and gonorrhoea), wound and whooping cough, lead to isolation of eight compounds designated as C2RPA, C2RP1, C2RP2, C2RP3, C2RP4, C2RP5, C2RP6 and C2RP7. Three of them were characterized as (-)epicatechin [C2RP1], taxifolin-3ß-O-glucopyranoside [C2RP2] and the rare A-type proanthocyanidin, epicatechin-(4->8; 2-ºO--'7)-epicatechin (4-+8)-epicatechin (proanthocyanidin trimer) [C2RPA] using spectroscopic methods. This is the first report on isolation and characterization of these compounds from F. elastica. In addition, other compounds obtained as mixtures, and characterized to comprise hydrocarbons including hexadecane, octadecane, eicosane, heneicosane, tetracosane, octacosane, nonacosane and heptacosanew ere also identified. Epicatechin, the proanthocyanidin trimer, C2RP4 and C2RP5, showed antimicrobial activity against the Gram-positive bacteria and C. albicans with MIC range of 31- 500gg/m1; C2RP5 exhibiting the highest antimicrobial activity with an MIC of 31 μg/ml against Stapylococcus aureus. These compounds also exhibited an ability to destroy biofilm formed by MRSA using the standard Calgary MBECTM HTP Assay. Fractions of the crude extract and two isolates containing mainly taxifolin-3ß-Oglucopyranoside and proanthocyanidin trimer each exhibited anti-quorum sensing activity by inhibiting the QS controlled phenotypic purple violacein production by Chromobacterium violaceum. Furthermore, the extracts and the compounds isolated also showed an excellent antioxidant activity with ECso values ranging from 3.88μg (for proanthocyanidin trimer) to 24.59μg (for C2RP7). Also, taxifolin-3Q-Oglucopyranoside stimulated proliferation of fibroblast by 19.5% at a concentration of 4μg/ml. The study on F. elastica leaf has shown that in addition to its ability to arrest the growth of micro-organisms, the plant may have other novel mechanisms of attenuating bacterial pathogenicity by way of interfering with quorum sensing signals and formation of biofilm. Furthermore, the anti-oxidant activity and the ability to stimulate growth of fibroblast, coupled with the antimicrobial activity, may suggest that F. elastica may be useful in wound management. The study therefore shows that plants such as F. elastica may be useful in the management of infectious diseases and wound as purported in folklore medicine.

No description available.

No description available.

The National Institute of Agricultural Botany, founded in 1919 and still operating today from its same Cambridge headquarters, is one of Britain’s oldest agricultural science institutes. Using the extensive and hitherto unexamined archive materials held by NIAB, this thesis offers both a new history of the Institute from 1919 to 1969, and an analysis of that history in the light of wider historiographies of science. It is well known that state patronage of science in Britain entered a new phase towards the end of the nineteenth century. The number of national laboratories, organisations, and institutions dedicated to scientific work grew rapidly, as did the number of professional scientists. The agricultural sciences and their institution’s benefited as much, if not more, from the state’s newfound interest in science, and yet hardly anything at all is known about them. This historiographical oversight is all the more troubling when one considers the changes that took place within British agriculture and the global food industry at this time. The thesis makes three important new points in particular. Firstly, that scientific regulatory bodies (often marginalized in preference for basic research centres) offer a valuable new perspective for historians interested in relations between science and the state. Secondly, that the techniques used during regulation and assessment (which draw upon the latest scientific developments and theories), can reveal a great deal about an institution’s social location. Finally, appreciating the perspective on variation and heredity held by agricultural scientists and plant breeders, one which will be shown to be quite different from more general biologists, offers solutions and problems for contemporary historiography on issues ranging from the impact of Mendelism on plant breeding to the history of plant patenting.

In order to study the intrinsic allergenicity of the plant-based storage 2S albumins Ber e I, the major allergen from Brazil nut seeds (Bertholletia excelsa) and the related but weak allergenic SFA8 from sunflower seeds (Helianthus anniuis), were used as model proteins. Previous studies showed that stimulation of bmDCs with Ber e 1 and SFA8 resulted in polarised DC programming that affect DC maturation state and Thl/Th2 responses. The recombinant Ber e 1 (rBer e 1) and SFA8 (rSFA8) produced in P. pastoris expression system were shown to retain the tertiary structure, biochemical properties and immunoreactivity of their native counterparts. However, previous findings indicate that rBer e 1 is glycosylated whereas native Ber e 1 (nBer e 1) is not. Glycosylation of proteins has been shown to increase immunogenicity of antigens and characterised as allergenic Th2 adjuvant in other systems. Thus amongst other objectives, the main aim of this study was to determine whether glycosylation plays a role as an antigenic determinant for Ber e 1 and its effects on the immunogenicity of the protein. Furthermore, we questioned whether the differences in intrinsic properties of the 2S albumin model allergens affect the modulation of gene expression in dendritic cells that may result in the polarisation of Thl/Th2 response. The glycosylation patterns of rBer e 1 and nBer e 1 extracted from Brazil nut were detected and profiled by periodic acid Schiff’s (PAS)-SDS-PAGE and mass spectrometry (MS). MS analysis confirmed that mannose residues are present in rBer e 1.

The increased movement of plants around the world is a serious and impactful environmental consequence of increased human dominance globally. Some of these plants will become established in new areas, some will proliferate, and some will become invasive causing environmental and socio-economic damage. Environmental processes contribute to plants becoming introduced, established and invasive. However, humans have an increasingly important role in all stages of the invasion process. In particular, the social processes that shape decision making, such as knowledge, risk perceptions, values and attitudes, can influence people’s behaviour that might lead to increased or decreased spread of invasive non-native plants (INNP). The social processes contributing to individual decision-making can be particularly influential in domestic gardens as it is the individual(s) responsible for that garden that decides how it is managed. Furthermore, the socio-economic impacts of INNP can be particularly acute in domestic gardens. In addition to the direct impacts of INNP in domestic gardens, an increase of their abundance therein could be detrimental to the health and well-being benefits gardens can provide, such as increased connectedness to nature. Invasion ecology is a rapidly growing area of research, however, key gaps in knowledge remain. In particular, little research has been done on INNP in domestic gardens and the perceptions of risk people have about the impacts they can have therein. This thesis applies an interdisciplinary approach to address these gaps. Japanese knotweed Fallopia japonica, is used as a case study throughout as it exemplifies many of the environmental and socio-economic impacts of INNP, many of which are particularly acute in domestic gardens. Identifying the processes contributing to the spread of INNP will help develop mitigation strategies to reduce their spread and therefore impact - this is the focus of chapters two to six. Chapter two explores the predictors of presence and abundance of Japanese knotweed at a 1km resolution within Cornwall, UK, finding that building density is the strongest predictor, followed by biophysical variables (minimum and maximum monthly temperature), and then socio-economic status of the residents within the 1km grid-cell. Chapter three considers one social process that might be contributing to the spread of INNP - the movement of propagules within soil. One of the key results of this chapter is that the abundance of invasive and naturalised species was significantly higher in garden than in housing development samples. This suggests that informal movement of soil between gardens poses a greater risk of spreading invasive plants than do commercial sources. Chapter three highlights the importance of high levels of identification skills of INNP to reduce their spread, however no previous research has tested INNP identification levels amongst the public. Chapter four explores this idea, finding that less than 20% of the public could identify Japanese knotweed. Even if people can identify INNP, if it is present in their garden they may not know how to manage it correctly and details of the impacts it can have therein. Chapter five analyses internet-based information about the management advice and impacts of INNP, determines the authors of this discourse, and considers whether and how this could be confusing to those responsible for managing domestic gardens. Analysis identified extensive variation in document structure, topics discussed, references and links to other sources, and language style; sometimes this variation was between and sometimes within author categories. A key conclusion from chapter five is that some internet-based information sources might potentially contribute to amplification (or attenuation) of risk perceptions, that could in turn lead to inappropriate management actions, resulting in increased spread of INNP. Chapter six uses a survey approach to explore risk perceptions of INNP in domestic gardens further. The results suggest differences in perceived risk of Japanese knotweed depends on people’s occupation, their direct experience of the species in a domestic context, their geographical proximity to the risk, their age and level of education. Greater understanding of the impacts INNP can have within domestic gardens will help assess the level of risk, plan mitigation strategies and design risk communication. This is the focus of chapter seven, which focuses on the economic impacts within domestic gardens. Results indicate that the magnitude and frequency of the risks Japanese knotweed poses in domestic gardens are much lower than anticipated based on media coverage, and compared with public perception. The results of this thesis have several important implications: (1) To mitigate potential inaccurate perceptions of INNP, governmental authorities need to provide clear and accurate communication about the impacts of INNP and how best to manage them. (2) When resources are limited, identifying the areas of society where knowledge is lowest or perceptions most inaccurate can help awareness and educational campaigns to be more impactful, thus reducing spread and impacts of INNP. (3) Implementation of the recommendations to reduce the spread and impacts of INNP within domestic gardens given within this thesis could contribute towards preserving the health and well-being benefits gardens can provide. Overall this thesis demonstrates further evidence of the need to consider the human causes and solutions to INNP and the need for knowledge on this topic to be applied by a diverse range of stakeholders.

La prolifération d’espèces invasives est un problème mondial. Après la pollution et la destruction des habitats, l’introduction d’espèces exogènes est une des principales causes de la disparition de la biodiversité animale et végétale dans le monde. La Corse n’est pas épargnée par le phénomène ; en effet, chaque année nous dénombrons de plus en plus d’espèces végétales introduites, potentiellement envahissantes et dangereuses pour l’écosystème insulaire. Si elles ne sont pas contrôlées, ces plantes peuvent rapidement gagner du terrain et s’installer durablement en raison de leurs facultés d’adaptation à divers écosystèmes.C’est dans ce contexte que nous sommes intéressés à quatre plantes de la famille des Astéracées considérées comme envahissantes : deux espèces du genre Xanthium (Xanthium italicum et X. spinosum) et deux espèces du genre Senecio (Senecio angulatus et S. inaequidens). L’objectif principal était d’initier une possible voie de valorisation de ces espèces par la production d’huile essentielle ; cela permettrait d’une part de limiter la dissémination et d’autre part, de générer un débouché économique.Par ailleurs, nous avons étendu ce travail à Limbarda crithmoides et à six espèces du genre Senecio poussant à l’état spontané en Corse. Une approche chimiotaxonomique réalisée à partir de 180 échantillons d’huiles essentielles du genre Senecio a conduit à différencier les espèces dites halotolérantes (S. aquaticus, S. transiens et S. cineraria) des espèces plus « terrestres » (S. vulgaris, S. angulatus, S. inaequidens, S. serpentinicola et S. lividus). L’étude de la variabilité chimique intraspécifique a permis de mettre en évidence des corrélations entre la composition chimique des huiles essentielles et le polymorphisme des taxons et/ou des facteurs édaphiques. L’étude du genre Senecio a également conduit à la caractérisation de deux nouvelles molécules, l’oxyde d’acétoxybisabolène et le 8-acétoxybisabolène 1,9-diol, isolées de l’huile essentielle de S. transiens (espèce endémique de Corse).D’un point de vue plus appliqué, les mesures des activités anti-radicalaires et anticorrosives des huiles essentielles ont démontré le potentiel de certaines espèces comme sources d’anti-oxydants naturels (notamment, Xanthium italicum et X. spinosum) mais aussi le pouvoir anticorrosif de la cacalohastine, isolée de l’huile essentielle de S. inaequidens (espèce invasive). / The proliferation of invasive species is a global problem. The introduction of exogenous species is after pollution and habitat destruction a major cause of the disappearance of the worldwide plant and animal biodiversity. Corsica is not spare to the phenomenon and every year there are numerous dangerous species which are introduced to the island ecosystem.In this study, we have studied four invasive species of Asteraceae (X. italicum, X. spinosum, S. angulatus and S. inaequidens) from Corsica. The aim of this study is to initiate a possible valuation pathway of these species by production of their essential oils. For this purpose, we investigated the chemical variability of each essential oil and their antioxidant and anticorrosive activities. Then we have extended our investigations to the others species of Senecio genus and to Limbarda crithmoides, anciently parented taxa.GC and GC/MS analysis allowed the identification of 107 and 74 components which accounted for 98.7 and 93.5% of the X. italicum and X. spinosum essential oils, respectively. Essential oils of X. italicum and X. spinosum were dominated by hydrocarbon monoterpenes (66.2%) and oxygenated sesquiterpenes (41.5%), respectively. The same metabolomic pathways seem occur for both species during the vegetative cycle of the plant: oxygenated sesquiterpene-production was higher during the flowering stage. Moreover the study of 25 sample oils of X. italicum and X. spinosum showed that the chemical variability of both essential oils could be linked to morphological characters.A comprehensive work on the chemical variability of 180 sample oils of Senecio was carried out and 251 components were identified. Among them, using mono and bi-dimensional NMR the structures of 8-acetoxybisabolene-1,9-diol and 8-acetoxy-1,9-oxobisabolene, two new components of S. transiens essential oil were described for the first time. Corsican Senecio species exhibited interspecies chemical variability: the halotolerant Senecio species (S. transiens, S. cineraria and S. aquaticus erraticus) were characterized by essential oils dominated by non-terpenic compounds while the so-called “terrestrial” Senecio species (S. angulatus, S. ineaquidens, S. lividus, S. vulgaris and S. serpentinicola) exhibited terpenic component-rich oils. The study of intra-species chemical variability highlighted direct correlations between the plant-production of secondary metabolites and the nature of soils on which S. lividus, S. vulgaris and S. transiens grows. Hence essential oil compositions and morphological polymorphism are indirectly related. In the same way, the chemical variability of S. cineraria essential oils seems to be linked to the geology of the soils while the oil diversity of the invasive S. angulatus, could be linked to the both spots of introduction on Corsica Island. In addition, an original chiral-gas chromatographic method was improved and applied to the main components of the essential oils in order to complement the chemical composition of the Senecio sample oils.Furthermore the originality of Corsican Limbarda crithmoides essential was highlighted by the occurrence of two p-cymenene derivatives, never reported in the related studies from literature. The investigation of 25 Corsican L. crithmoides focuses on a direct correlation between the water salinities of the plant locations and the chemical compositions of the essential oils.Finally the antioxidant activities, anti-free radical and reducing power, were measured on some essential oils of the studied species. Essential oils of the Xanthium genus appeared to be most effectives. In addition, anticorrosion properties of the essential oils were investigated and the best corrosion inhibiting activity was exhibited by those of S. inaequidens . Anticorrosion activity could be attributed to the cacalohastine, a naphtalofuranic component, isolated form the whole essential oil after column chromatography.