New insecticidal natural products are required to find compounds with higher intrinsic activities to lower field application rates, and with novel modes of action to combat insect pest species which have developed resistance to current commercial insecticides. Using a taxonomic approach, studies on plants of the Myrtaceae family led to the isolation and characterisation of a range of insecticidal natural products 1 - 9 (figure 1). These compounds are all structurally related as they contain a tetramethylcyclohexenedione group, attached to either a terpene or a phloroglucinol moiety. Seven of the nine compounds (1 - 6, 9) are novel. For compounds 7 and 8, no synthesis had been previously reported. The compounds are active against a range of insect species, although in general they are less active than commercial natural products. Further tests show some of the compounds are potent antifeedants. Synthesis of seven of the nine natural products (1 - 5, 7, 8) by short, convergent, stereospecific and high yielding routes was achieved. The synthetic routes were devised to mimic the postulated biosynthesis of the compounds. Reaction of syncarpic acid, an aldehyde and pyrrollidine formed a Mannich base, which on elimination gave a key alkylidene intennediate. This key intermediate was reacted, with either terpenes in Diels-Alder reactions or with phloroglucinols in aromatic alkylation reactions, to synthesise seven of the natural products.

Thesis (MSc)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Two key attributes of biodiversity, species richness and endemism are documented, analysed and mapped for the indigenous spermatophyte plant taxa of Namibia. A provisional diversity map is presented and transitional zones were shown to be the most significant for species richness. Distribution maps of the majority of endemic species in Namibia are shown together for the first time. Combinations of these data were used to map the overall distribution of endemic taxa, localities where significant numbers of local endemics occur, as well as the species that can be found in taxon phytogeographic centres. Recurring patterns are evident and areas of high species concentrations are catalogued. This thesis has contributed to the knowledge of the large number of plant taxa for .which Namibia is solely responsible, i.e. endemics restricted to within the political borders of Namibia. The mapping used an updateable, but permanent dataset on which future applications can be based. Examples of the uses of phytogeographic information proposed, include not only the traditional role in the identification of species in the herbarium, but also in creating a better basis for future policy especially in the development of land management strategies and conservation of Namibia's plant wealth / AFRIKAANSE OPSOMMING: Twee sleutelkenmerke van biodiversiteit, naamlik spesiesrykheid en endemisme word dokumenteer, ontleed, en karteer vir die inheemse saadplante van Namibië. 'n Voorlopige kaart van diversiteit word voorsien waaruit blyk dat oorgangsgebiede die belangrikste is vir spesiesrykheid. Verspreidingskaarte van meeste van die endemiese spesies in Namibië is word vir die eerste keer gesamentlik aangebied. Kombinasies van hierdie gegewens is gebruik om die algehele verspreiding van endemiese taksa, plekke waar betekenisvolle aantalle plaaslike endemiese taksa voorkom, sowel as die spesies wat voorkom in takson-geografiese sentrums, te karteer. Herhalende patrone is sigbaar, en gebiede met hoë specieskonsentrasies is gelys. Hierdie tesis het bygedra tot die kennis van 'n groot aantal plantsoorte waarvoor Namibië alleen verantwoordelik is, synde endemiese soorte wat beperk is tot binne die polieke grense van Namibië. Die kartering het 'n opdateerbare, maar permanente, databasis gebruik waarop toekomstige aanwendings baseer kan word. Voorbeelde van die gebruike van plantgeografiese inligting wat voorgestel is, sluit in tradisionele gebruik in die identifikasie van species in die herbarium, sowel as die skepping van 'n beter fondament vir toeskomstige beleid in veral die ontwikkeling van bestuurstrategië en bewaring van Namibia se planterykdom

Flower initiation and development to anthesis in Dutch iris were investigated using three cultivars, 'Wedgwood', 'Ideal' and 'Professor Blaauw'. In particular, environmental effects on flower initiation and on flower abortion were studied. With the aid of a thermal-time model, the rate of initiation (the reciprocal of time to initiation) was shown to be linearly related to the temperature used to store dry bulbs, provided that this was constant. When bulbs were transferred from one temperature to another, however, the rates of initiation differed from those expected. It was concluded that the sequence of temperatures was important and a possible mechanism for flower induction was discussed. Following the start of flower initiation per se, a different optimum temperature for flower-organ differentiation was observed. The effect of both pre-planting and post-planting temperatures on the growth and development of the flower were investigated. The proportion of bulbs with successful flower development to anthesis increased with mean flower and stem dry weight. The heaviest flower and stems were produced by those bulbs with the greatest leaf weight. This was attributed to the increased availability of current photosynthates in plants with the largest foliage frames. Flower development was affected by an interaction between time of planting, bulb size and glasshouse temperature for a given light integral. With later bulb plantings, between January and March, higher light integrals were required for the same flower development at moderately high temperatures (16-18°C). This higher light requirement was detected with the largest bulbs first and not until the last planting date with smaller bulbs. At higher temperatures (20°C) flower development was poor regardless of the light integral. At lower temperatures (14°C) the same flower development achieved regardless of the light integral within the range tested. Further investigation in controlled environments enabled the detection of a photoperiodic effect at the moderately high temperatures. Daughter-bulb growth was promoted by long photoperiods and high temperatures increasing sink strength there for assimilates with a corresponding decrease in flower development. The partitioning of assimilates under high and low light was examined by determining the distribution of 14C-labelled assimilates during growth in the glasshouse. Daughter bulbs under low light had a higher relative specific activity than those under high light, at the time when the flower was most prone to abortion. Application of cytokinin to the flower bud resulted in a reduced daughter bulb weight, but heavier flower buds. It was concluded that flower development was affected by the total current assimilate available and the partitioning of these assimilates between daughter bulbs and flower bud.

Mt. Tamalpais, 2571 feet in elevation, is found eighteen miles north of San Francisco in southern Marin County (see Plate 1). Despite its close proximity to a world port and metropolis, its slopes still display a wildness and natural beauty that have remained relatively unaltered as compared with other areas of the Bay Region and demonstrates ready accessibility to detailed ecological study. The study began during the spring of 1963 when plant specimens were first collected. After a period of reconnaissance and mapping of the vegetation, quantitative samples were taken in the study area in hopes that relationships could be established between plant communities and environmental factors.

This study had for its aim the collection, identification, and listing of the spermatophytes growing upon the Austin Chalk formation of Collin County, Texas.

In this thesis, the distribution and state of Posidonia oceanica meadows along the Turkish coast of the north eastern Mediterranean was investigated. The study area was a unique site due to the presence of eastern geographical limit of Posidonia oceanica meadows in Mediterranean Sea. It was aimed to assess the possible reasons of the absence and/or regression in relation to environmental changes. The study was conducted from September 2004 to January 2007 in 5 main regions between Anamur/Mersin and Samandag/Hatay. The regions were determined according to the presence/absence of Posidonia oceanica meadows / 1 region including the boundary meadow at the geographical distribution limit, 1 region western and 3 regions eastern to that boundary meadow. To describe the hydrological characteristics of the study area temperature, salinity and light were measured as abiotic descriptors. Additionally sedimentological analysis was carried out to check the suitability of the substrate type for Posidonia oceanica colonization. The main differences between the regions were found in temperature and light conditions. Both, the recordings of temperature loggers at 10 and 15 meter depths and the sea surface temperature retrieved from satellite (NOAA-AVHRR) showed that the eastern stations with no Posidonia oceanica meadows were warmer than the western stations. Consequently in this study the maximum tolerable temperature limit for Posidonia oceanica growth was determined as 28.4&deg / C from the data collected by the temperature loggers placed to natural meadows near to the boundary meadow. Generally, the whole study area had a limiting light condition for seagrass growth due to low penetration depths of the 10% of surface irradiation. This was a generalized minimum light requirement for growth of seagrasses. Especially in Mersin and Iskenderun bays the minimum required light level did not reached deeper than 10 meter depths in coastal stations. The biological parameters of the Posidonia oceanica meadows were investigated under 3 complementary methods in the first two regions. The structural descriptors were measured in-situ. The lowest shoot density and leaf lengths were found to be in boundary meadow. This meadow had also the lowest depth limit among other stations. The functional descriptors were examined by the lepidochronological and phenological analysis in laboratory. Most of the measurements varied either with respect to depth or among stations according to the abiotic factors of the stations. The lepidochronological cycles obtained from sheath thicknesses were further correlated with abiotic descriptors via a mathematical model. Finally, the first transplantation experiment of Posidonia oceanica along Turkish coasts has been conducted in 2 regions where presently no meadows exist. The survival of cuttings in one station indicated the success of the methodology, while the failure in other stations provided information on the possible reasons of absence/degradation of natural meadows in the area. These included the destructive impact of bottom trawling, the high pressure of grazing (the potential causes of Lessepsian migration) and the long term changes in climate resulting in alterations of environmental conditions such as increasing temperature and reduced light penetration.

Este estudo trata da estrutura e diversidade genética de uma espécie típica do Cerrado brasileiro, Qualea grandiflora Mart (Vochysiaceae), presente nas diversas fisionomias do bioma. Foram desenvolvidos oito locos microssatélites para analisar 420 amostras de indivíduos adultos pertencentes a quatro populações distribuídas no estado de São Paulo, sendo três delas em unidades administradas pelo Instituto Florestal de São Paulo (Assis, Itirapina e Pedregulho) e uma em propriedade particular (Brotas) além de 300 progênies coletadas de 25 matrizes na área de estudo em Assis. Os resultados mostraram a ocorrência média de 12,9 alelos por loco, sendo que o número médio de alelos efetivos foi seis, além de terem sido encontrados 26 alelos exclusivos nas populações. A média dos valores de Heterozigosidade esperada foi de 0,803 enquanto de Heterozigosidade observada foi de 0,512. O Conteúdo de Informação Polimórfica (PIC) variou de 0,708 a 0,801 nos locos estudados. A média dos valores de fixação foi de 0,349 indicando a presença de endogamia nas populações. Não há presença de clones em nenhuma população. O teste de adesão ao Equilíbrio de Hardy Weinberg confirma o desvio de equilíbrio em todas as populações. Há formação de estrutura populacional nas primeiras classes de distância em todas as populações estudadas, variando de 30 a 40 metros e há uma formação de 3 possíveis grupos de genótipos. A influência do efeito Wahlund foi variável nas populações (de 8,5% até 53,3%). As estimativas de tamanho efetivo populacional foram baixas (menos de 10 indivíduos) e a área mínima viável foi estimada de 4 a 184 hectares, considerando estimativas de curto, médio e longo prazos. Com relação ao sistema reprodutivo, os resultados indicam que Q. grandiflora Mart se reproduz por cruzamentos entre indivíduos parentes e não parentes (0,913). A taxa uniloco foi de 0,632, indicando que há mais cruzamentos entre não aparentados do que aparentados. A taxa de autofecundação foi baixa (0,087) indicando que a espécie é alógama, com pouca pré disposição para autofecundação. Aproximadamente 35% das plantas dentro de progênies eram parentes no grau de irmãos-completos e aproximadamente 57% eram meios-irmãos. Além disso, aproximadamente 8% das progênies eram irmãos de autofecundação. O coeficiente de coancestria estimado nas progênies foi de 0,139 enquanto o índice de fixação foi de aproximadamente 27%. A estimativa do tamanho efetivo indicou que a representatividade genética da descendência é inferior à esperada em progênies de cruzamentos aleatórios: as amostras analisadas correspondem a apenas 13,2 indivíduos de uma população panmítica ideal. Os resultados demonstram que a espécie possui potencial para conservação genética in situ embora a coleta de sementes para manter o tamanho efetivo deva utilizar de um número elevado de árvores. Sugere-se que as áreas estudadas sejam tratadas como Unidades Significativas Evolutivas (USE) e como Unidades Independentes para o Manejo (UIM). / This study deals with the structure and genetic diversity of a species typical of the Brazilian Cerrado, Qualea grandiflora Mart (Vochysiaceae), present in different physiognomies of this biome. We developed eight microsatellite loci to analyze 420 samples of adult individuals from four populations distributed in the state of São Paulo, three of them in units managed by the Forestry Institute of Sao Paulo (Assis, Itirapina and Pedregulho) and one in a private property (Brotas). We also analyzed 300 progeny collected from 25 matrix in Assis. The results showed an average occurrence of 12.9 alleles per locus. The average number of effective alleles was six, and 26 exclusive alleles were found in the populations. The average expected heterozygosity was 0.803 while the observed heterozygosity was 0.512. The polymorphic information content ranged from 0.708 to 0.801 at the loci studied. The mean fixation was 0.349, therefore indicating the presence of inbreeding within populations. There is no presence of clones in the populations. The test of adherence to the Hardy Weinberg Equilibrium confirms the deviation from equilibrium in all populations. There is formation of population structure in the first distance classes in all populations studied, ranging from 30 to 40 meters, and there is a formation of three possible genotype groups. The influence of the Wahlund effect varied among populations (from 8.5% to 53.3%). The effective population size estimates were low (less than 10 individuals) and the minimum viable area was estimated between 4 to 184 hectares, taking into account estimates of short, medium and long terms. Regarding the reproductive system, results indicate that Q. grandiflora Mart reproduces by crosses between relatives and unrelated individuals (0.913). The single locus rate was 0.632, indicating that there are more crosses between unrelated than related individuals. The self-fertilization rate was low (0.087), therefore indicating that the species is allogamous, with little predisposition for self-fertilization. Approximately 35% of the plants within progenies were full-sibs and approximately 57% were half-sibs. In addition, approximately 8% of progenies were self-fertilized brothers. The estimated coefficient of coancestry in progenies was 0.139, while the rate of fixation was about 27%. The estimated effective size indicated that the genetic representativeness of the offspring is lower than the expected in random cross progenies: the samples analyzed account for only 13.2 individuals in a ideal panmitic population. The results show that this species has potential for in situ genetic conservation, although the collection of seeds to maintain the effective size should use a large number of trees. It is suggested that the studied areas be treated as evolutionary significant units and as independent units for management.

Este estudo trata da estrutura e diversidade genética de uma espécie típica do Cerrado brasileiro, Qualea grandiflora Mart (Vochysiaceae), presente nas diversas fisionomias do bioma. Foram desenvolvidos oito locos microssatélites para analisar 420 amostras de indivíduos adultos pertencentes a quatro populações distribuídas no estado de São Paulo, sendo três delas em unidades administradas pelo Instituto Florestal de São Paulo (Assis, Itirapina e Pedregulho) e uma em propriedade particular (Brotas) além de 300 progênies coletadas de 25 matrizes na área de estudo em Assis. Os resultados mostraram a ocorrência média de 12,9 alelos por loco, sendo que o número médio de alelos efetivos foi seis, além de terem sido encontrados 26 alelos exclusivos nas populações. A média dos valores de Heterozigosidade esperada foi de 0,803 enquanto de Heterozigosidade observada foi de 0,512. O Conteúdo de Informação Polimórfica (PIC) variou de 0,708 a 0,801 nos locos estudados. A média dos valores de fixação foi de 0,349 indicando a presença de endogamia nas populações. Não há presença de clones em nenhuma população. O teste de adesão ao Equilíbrio de Hardy Weinberg confirma o desvio de equilíbrio em todas as populações. Há formação de estrutura populacional nas primeiras classes de distância em todas as populações estudadas, variando de 30 a 40 metros e há uma formação de 3 possíveis grupos de genótipos. A influência do efeito Wahlund foi variável nas populações (de 8,5% até 53,3%). As estimativas de tamanho efetivo populacional foram baixas (menos de 10 indivíduos) e a área mínima viável foi estimada de 4 a 184 hectares, considerando estimativas de curto, médio e longo prazos. Com relação ao sistema reprodutivo, os resultados indicam que Q. grandiflora Mart se reproduz por cruzamentos entre indivíduos parentes e não parentes (0,913). A taxa uniloco foi de 0,632, indicando que há mais cruzamentos entre não aparentados do que aparentados. A taxa de autofecundação foi baixa (0,087) indicando que a espécie é alógama, com pouca pré disposição para autofecundação. Aproximadamente 35% das plantas dentro de progênies eram parentes no grau de irmãos-completos e aproximadamente 57% eram meios-irmãos. Além disso, aproximadamente 8% das progênies eram irmãos de autofecundação. O coeficiente de coancestria estimado nas progênies foi de 0,139 enquanto o índice de fixação foi de aproximadamente 27%. A estimativa do tamanho efetivo indicou que a representatividade genética da descendência é inferior à esperada em progênies de cruzamentos aleatórios: as amostras analisadas correspondem a apenas 13,2 indivíduos de uma população panmítica ideal. Os resultados demonstram que a espécie possui potencial para conservação genética in situ embora a coleta de sementes para manter o tamanho efetivo deva utilizar de um número elevado de árvores. Sugere-se que as áreas estudadas sejam tratadas como Unidades Significativas Evolutivas (USE) e como Unidades Independentes para o Manejo (UIM). / This study deals with the structure and genetic diversity of a species typical of the Brazilian Cerrado, Qualea grandiflora Mart (Vochysiaceae), present in different physiognomies of this biome. We developed eight microsatellite loci to analyze 420 samples of adult individuals from four populations distributed in the state of São Paulo, three of them in units managed by the Forestry Institute of Sao Paulo (Assis, Itirapina and Pedregulho) and one in a private property (Brotas). We also analyzed 300 progeny collected from 25 matrix in Assis. The results showed an average occurrence of 12.9 alleles per locus. The average number of effective alleles was six, and 26 exclusive alleles were found in the populations. The average expected heterozygosity was 0.803 while the observed heterozygosity was 0.512. The polymorphic information content ranged from 0.708 to 0.801 at the loci studied. The mean fixation was 0.349, therefore indicating the presence of inbreeding within populations. There is no presence of clones in the populations. The test of adherence to the Hardy Weinberg Equilibrium confirms the deviation from equilibrium in all populations. There is formation of population structure in the first distance classes in all populations studied, ranging from 30 to 40 meters, and there is a formation of three possible genotype groups. The influence of the Wahlund effect varied among populations (from 8.5% to 53.3%). The effective population size estimates were low (less than 10 individuals) and the minimum viable area was estimated between 4 to 184 hectares, taking into account estimates of short, medium and long terms. Regarding the reproductive system, results indicate that Q. grandiflora Mart reproduces by crosses between relatives and unrelated individuals (0.913). The single locus rate was 0.632, indicating that there are more crosses between unrelated than related individuals. The self-fertilization rate was low (0.087), therefore indicating that the species is allogamous, with little predisposition for self-fertilization. Approximately 35% of the plants within progenies were full-sibs and approximately 57% were half-sibs. In addition, approximately 8% of progenies were self-fertilized brothers. The estimated coefficient of coancestry in progenies was 0.139, while the rate of fixation was about 27%. The estimated effective size indicated that the genetic representativeness of the offspring is lower than the expected in random cross progenies: the samples analyzed account for only 13.2 individuals in a ideal panmitic population. The results show that this species has potential for in situ genetic conservation, although the collection of seeds to maintain the effective size should use a large number of trees. It is suggested that the studied areas be treated as evolutionary significant units and as independent units for management.

El objetivo de la Tesis es obtener una visión de la situación actual de la laguna costera del Mar Menor en relación con la contaminación por metales pesados procedentes de actividades mineras mediante el empleo de herramientas ecotoxicológicas. Comienza con el estudio de la entrada de residuos mineros en el ecosistema, su distribución en las aguas de la laguna así como los efectos tóxicos asociados. Continua valorando la biodisponibilidad de los metales contenidos en los sedimentos lagunares mediante pruebas de toxicidad y de bioacumulación; sus efectos en praderas de fanerógamas y comunidades de invertebrados asociados, para continuar determinando la potencial transferencia trófica de metales en las redes alimenticias lagunares y su posible biomagnificación. Finalmente, la Tesis concluye determinando la utilidad de indicadores propuestos para su aplicación en la Directiva Europea Marco del Agua cuando son aplicados a dos ecosistemas acuáticos contaminados por contaminación tóxica (metales pesados). / The objective of the Thesis is to determine the present situation of the Mar Menor coastal lagoon in relation with the contamination caused by heavy metals coming from old mining activities through the use of ecotoxicological tools. It begins with the study of the entrance of mining wastes in the lagoon ecosystem, its distribution in the lagoon waters as well as their toxic effects. It continues assessing the bioavailability of metals contained in sediments of the lagoon by means of bioaccumulation studies and toxicity tests; their possible deleterious effects on marine phanerogams and associated invertebrate communities. It also determines the potential trophic transfer of metals in trophic webs of the lagoon studying the possible biomagnification of metals. Finally, the Thesis concludes determining the utility of some indicators proposed for their application in the European Water Framework Directive when they are applied to aquatic ecosystems impacted by toxic contamination (heavy metals).