Spelling suggestions: "subject:"odorants"" "subject:"odorant""
31 |
Implicações ecológicas da dormência de sementes em Butia odorata (ARECACEAE)Schlindwein, Gilson January 2012 (has links)
Butia odorata (butiazeiro) é uma palmeira que ocorre em regiões subtropicais da América do Sul, onde constitui formações savânicas em áreas associadas com o manejo pecuário. Após a dispersão, suas sementes apresentam dormência, que pode ser superada por tratamentos de calor úmido. Esta tese visou avaliar como esta dormência responde a variáveis térmicas e de umidade do ambiente e de que forma ela influencia o sucesso de recrutamento de suas plântulas. Para isto foram feitos três estudos: no primeiro, os efeitos de diferentes tratamentos de temperatura, secagem e armazenamento dos diásporos sobre o sucesso germinativo da espécie foram avaliados em laboratório; no segundo, foram investigados os efeitos sazonais e de micro-hábitat (área aberta e mancha florestal) sobre a emergência de plântulas a partir de diásporos semeados no campo, relacionando as respostas às variáveis ambientais, à dormência e à viabilidade das sementes; no terceiro, foram igualmente avaliados os efeitos sazonal e de micro-hábitat, porém sobre o sobre o recrutamento de plântulas, através da semeadura em duas épocas distintas do ano (antes e após o verão), de diásporos previamente tratados para superação da dormência. Os resultados destes estudos mostraram que períodos de préaquecimento úmido (40ºC) após secagem dos diásporos atuam no alívio da dormência das sementes de B. odorata. Estes fatores também foram relacionados com a liberação da dormência das sementes em condições de campo, agindo de forma cíclica sobre este processo ao longo do ano. Esta estratégia concentrou a emergência de plântulas após o verão, quando as condições térmicas e hídricas foram mais favoráveis. Esta resposta foi potencializada pela presença de manchas florestais, que prolongaram a viabilidade das sementes e aumentaram o recrutamento de plântulas. / Butia odorata (pindo palm) is a palm tree that occurs in the subtropical regions of South America, where it composes a savanna-like vegetation in areas associated with livestock. After dispersal, seeds exhibit dormancy, which can be overcome by moist heat treatments. This thesis aimed to evaluate how such dormancy responds to thermal and moisture variables of the environment and how it influences the success of seedlings recruitment. To accomplish this, three studies were conducted: in the first, the effects of different temperature, drying and storage treatments imposed to the diaspores on the germination success of the species were evaluated in the laboratory; in the second, we investigated the effects the seasonal and microhabitat (open area vs. forest patch) on seedling emergence from diaspores sown in the field, and related the responses to environmental variables, dormancy and seed viability; in the third, the seasonal and microhabitat effects were also evaluated, but now on seedling recruitment, by doing the sowing at two different times of the year (before and after the summer) of seeds which had been previously treated for overcoming dormancy. The results of these studies showed that periods of wet preheating (40 °C) after seed drying act on relieving seed dormancy of B. odorata. These factors were also related to the release of seed dormancy under field conditions, acting in a cyclical way along the year. This strategy concentrated seedling emergence after the summer, when temperature and water conditions were more favorable. This response was enhanced by the presence of forest patches, which extended seed viability and increased seedling recruitment.
|
32 |
Impact of spatio-temporal availability of myrmecochorous seeds on the dispersal activity of Myrmica rubra ants (Hymenoptera, Formicidae)Bologna, Audrey 11 January 2017 (has links)
Une interaction mutualiste peut être définie comme un échange de services, qu’ils soient trophiques ou non, entre individus d’espèces différentes. La myrmécochorie est un mutualisme dans lequel les fourmis récoltent des graines portant un appendice charnu appelé élaïosome (le tout formant une diaspore), les ramènent jusqu’au nid où l’élaïosome est détaché et consommé. La graine, restée intacte, est alors rejetée du nid où elle pourra rester ou être re-dispersée par un autre vecteur avant de germer. Dans ce contexte, le comportement de récolte des fourmis envers les diaspores est décisif pour leur dispersion. Divers traits tels que la morphologie, la composition chimique et la phénologie des graines myrmécochores influencent l’efficacité de leur dispersion par les fourmis. Néanmoins, la disponibilité spatio-temporelle de ces graines est un trait dont l’influence sur le comportement des fourmis reste peu connue.Dans cette thèse, nous nous sommes intéressés à l’influence de la disponibilité spatiale − en termes d’abondance − des diaspores de Chelidonium majus sur leur récolte et leur dispersion par les fourmis Myrmica rubra. Alors que les ouvrières exploitent la totalité d’un petit agrégat de diaspores, seule la moitié d’un large agrégat est exploité. Ceci suggère que la myrmécochorie stricte est efficace pour des plantes produisant peu de graines tandis qu’une libération massive de diaspores nécessite des modes de dispersion complémentaires. Concernant la disponibilité temporelle, des expositions successives à une même espèce de graines (V. odorata ou C. majus) conduisent à une diminution de l’intensité de leur récolte voire à une complète extinction de ce processus dans le cas de V. odorata. En effet, face à ces dernières, l’extinction de la réponse des fourmis persiste pendant au moins deux mois. Elle apparait également plus rapidement que pour les graines de C. majus et concerne toutes les étapes du processus de myrmécochorie puisque un ratio croissant de graines de V. odorata sont rejetées encore pourvues de leur élaiosome. Cette différence dans le comportement de récolte et dans son évolution temporelle ne semble pas liée à un bénéfice différentiel retiré de la consommation des élaïosomes provenant de ces deux espèces de graines myrmécochores. Par ailleurs, les larves semblent jouer un rôle de régulateurs de la récolte des diaspores de V. odorata et donc dans le phénomène d’extinction. L’ensemble des résultats présentés dans cette thèse met en évidence le caractère dynamique de cette interaction plante-fourmis, dont l’issue et la stabilité varie selon l’espèce considérée et la disponibilité spatio-temporelle des diaspores. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
|
33 |
\"Estudo do desenvolvimento floral em espécies arbóreas da família Meliaceae\" / Floral development in woody species of the Meliaceae familyGouvêa, Cantidio Fernando 25 August 2005 (has links)
A família Meliaceae compreende cerca de 51 gêneros e 550 espécies distribuídas principalmente na região Neotropical. Incluídas nesta família, estão espécies de elevado interesse comercial para a produção de madeiras nobres. Há carência de informações quanto à biologia floral dessas espécies, que aliada a problemas silviculturas dificulta a elaboração de programas efetivos de melhoramento genético das espécies de interesse econômico da família. O presente trabalho visa contribuir para o entendimento do desenvolvimento floral na família Meliaceae, com destaque para sete espécies de interesse econômico e/ou ecológico: Cedrela fissilis L., Cedrela odorata L., Swietenia macrophylla R. A. King, Trichilia claussenii C. DC., Guarea guidonea (L.) Sleumer, Toona ciliata M. J. Roem e Melia azedarach L. Para os estudos morfo-anatômicos utilizaram-se técnicas de microscopia óptica e microscopia eletrônica de varredura. Analisou-se igualmente o padrão de expressão de genes do modelo ABC, relacionados ao desenvolvimento floral, via hibridização in situ. Os estudos morfo-anatômicos permitiram caracterizar o desenvolvimento dos primórdios dos órgãos florais e o estabelecimento de estágios arbitrários de desenvolvimento, auxiliando na caracterização da expressão gênica. Estes resultados permitiram ainda a identificação de flores funcionalmente femininas ou masculinas em S. macrophylla C. fissilis, C. odorata e T. ciliata, as quais apresentam dimorfismo sexual. O padrão de expressão dos homólogos dos genes: APETALA1 (AP1), APETALA3 (AP3) e AGAMOUS (AG) foram diferentes daqueles previstos pelo modelo ABC. A expressão dos homólogos de AP1 foi verificada em todo o meristema floral nos estágios iniciais de desenvolvimento, em todas as espécies estudadas. O sinal de expressão concentrou-se nos primórdios das sépalas e pétalas em estágios mais avançados do desenvolvimento, porém um fraco sinal de hibridização de AP1 foi verificado em todos os verticilos. A expressão dos homólogos de AP3 foi verificada nas regiões previstas pelo modelo ABC, correspondentes ao segundo e terceiro verticilos. Porém um fraco sinal de AP3 foi também observado no quarto verticilo, o que não é previsto pelo modelo teórico. A expressão dos homólogos de AG foi restrita à região central do meristema floral, correspondente ao terceiro e quarto verticilos, em todos os estágios do desenvolvimento floral de todas as espécies estudadas. Entretanto, sinais adicionais de hibridização dos homólogos de AG foram visualizados na região abaxial dos primórdios de sépalas e pétalas em C. fissilis, C. odorata e T. ciliata. Os estudos da expressão dos genes do modelo ABC em Meliaceae revelaram padrões de expressão que não concordam com o modelo teórico vigente do controle molecular da determinação da identidade dos órgãos florais. / The Meliaceae family comprises approximately 51 genus and 550 species mainly distributed in the Neotropical region. In this family there are many species of commercial interest for the production of noble wood. The lack of information on the floral biology associated with silvicultural problems limits the elaboration of effective breeding programs with species of economic interest. The present work aims to contribute with the understanding of floral development in Meliaceae, focusing in seven species of economical or ecological interest: Cedrela fissilis L., Cedrela odorata L., Swietenia macrophylla R. A. King, Trichilia claussenii C. DC., Guarea guidonea (L.) Sleumer, Toona ciliata M. J. Roem e Melia azedarach L. Morpho-anatomical analyses were done by light and scannning electron microscopy. The expression pattern of the ABC model genes, which are related to floral development, was analyzed by in situ hybridization. The characterization of the development of floral organ primordia and the establishment of arbitrary stages of floral development was done and was important for the characterization of gene expression. These results allowed for the identification of functionally female and male flowers in Swietenia macrophylla, Cedrela fissilis, Cedrela odorata and Toona ciliata, characterizing sexual dimorphism. The patterns of gene expression of the homologous of APETALA 1, APETALA 3 and AGAMOUS were different from those predicted by the ABC model. AP1 expression was observed in the entire floral meristem in the initial stages of development, in all seven species. The expression signal was more concentrated in sepal and petal primordia in further stages of development, although a weak hybridization signal of AP1 was verified in all four whorls. The expression of AP3 homologs was observed in the second and third whorls, as predicted by the ABC model. However, a weak signal of AP3 was also observed in the forth whorl, which was not predicted by the ABC model. AG homolog expression was restricted to the central region of the floral meristem, corresponding to the third and forth whorls, in all stages of development of all seven species. However, additional hybridization signal of AG homologs were seen in the abaxial region of sepal and petal primordia in Cedrela fissilis, Cedrela odorata and Toona ciliata. The analyses of the ABC model genes in Meliaceae revealed that the expression patterns do not agree with the theoretical currently accepted model that determines the molecular control of the identity of the floral organs.
|
34 |
Etude phytochimique de deux Dipterocarpaceae de la forêt thaïlandaise : Hopea odorata Roxb. et Dipterocarpus costatus Gaertn.f. / Phytochemical screening of two Thai tropical rainforest Dipterocarps : Hopea odorata Roxb. and Dipterocarpus costatus Gaertn.f.Satiraphan, Malaï 27 September 2012 (has links)
Les extraits n-hexaniques respectivement des feuilles d’Hopea odorata Roxb. et du bois de Dipterocarpus costatus Gaertn.f. ont été sélectionnés sur la base d’un criblage biologique préliminaire. Ces extraits présentent des activités cytotoxiques significatives sur les lignées MCF-7 (cancer du sein) et NCI-H187 (cancer du poumon non à petite cellule). De plus, l’extrait du bois de D. costatus inhibe la croissance de la souche K1 de Plasmodium falciparum. L’étude phytochimique de l’extrait n-hexanique des feuilles d’Hopea odorata a permis d’isoler 19 composés terpéniques dont 16 triterpènes des séries lupane (n=8), (3,4-seco)cycloartane (n=4), friedélane (n=2) et oléanane (n=2). Parmi les lupanes, l’acide 3,30-dioxolup-20(29)-èn-28-oïque a été isolé pour la première fois d’une source naturelle. L’évaluation de l’effet de ces lupanes sur la croissance de quatre lignées cancéreuses humaines (PC3, MDA-MB-231, HT-29 and HCT116) a permis d’identifier des composés actifs et d’apporter des éléments de relations structure-activité tels que l’influence du degré d’oxydation des positions C-3, C-28 et C-30 sur la cytotoxicité. Parmi les cycloartanes, deux nouveaux 3,4-secocycloartanes ont été identifiés. Il s’agit de deux esters d’acide gras saturés et de l’acide (24S, 25S, 26)-trihydroxy-3,4-secocycloart-4(29)-èn-3-oïque. Par ailleurs, l’étude phytochimique de l’extrait n-hexanique du bois de Dipterocarpus costatus a permis d’isoler 31 terpènes dont 12 nouveaux triterpènes, parmi lesquels 5 norlupanes, 3 dammaranes, 2 nordammaranes et 2 secodammaranes. Les activités biologiques de l’ensemble des composés isolés, ont été évaluées sur la croissance des lignées cancéreuses humaines précédemment citées et de muscle squelettique de rat L-6, ainsi que sur la croissance de la souche K1 du Plasmodium falciparum. En particulier, le norlupane 36 possédant une fonction endoperoxyde, montre une forte activité antiplasmodiale associée à une faible cytotoxicité. / Preliminary study of the extracts from Hopea odorata leaves and Dipterocarpus costatus wood showed that the hexane extracts of both plants exhibited cytotoxicity against breast cancer (MCF-7) and small cell lung cancer (NCI-H187), in conjunction with potent antimalarial (against Plasmodium falciparum K1 strain) activity of D.costatus wood hexane extract. Phytochemical studies of H. odorata leaves hexane extract led to the isolation of 16 terpenoids in the series lupane (n = 8), (3,4-seco) cycloartane (n = 4), friedelane (n = 2) and oleanane (n = 2). Among lupanes, 3,30-dioxolup-20(29)-en-28-oic acid was isolated for the first time from a natural source. Cytotoxicity of lupanes triterpenes against four human cancer cell lines (PC3, MDA-MB-231, HT-29 and HCT116) was evaluated and showed the structure activity relationship related to the oxidation degree at position 3, 28 and 30. Among cycloartanes two new 3,4-seco-cycloartanes were identified. They are saturated fatty acid esters of (24S,25S,26)-trihydroxy-3,4-seco-cycloart-4(29)-en-3-oic acid. Isolation of D. costatus wood hexane extract discovered 31 terpenoids of which 12 triterpenes are new, including 5 norlupanes, 3 dammaranes, 2 nordammaranes and 2 secodammaranes. The biological activities of all isolated compounds were evaluated through cytotoxicity against human cancer cell lines mentioned above and rat myoblast-derived cells L-6, as well as antimalarial activity against Plasmodium falciparum K1 strain. Interestingly, the norlupane 36, possessing an endoperoxide group, showed a strong antiplasmodial activity associated with low cytotoxicity.
|
35 |
Substratos e fertirrigação na produção de mudas de Anadenanthera macrocarpa (Benth.) Brenan e Cedrela odorata L. / Substrate and frequency of the production of and seedlings of Anadenanthera macrocarpa (Benth.) Brenan; Cedrela odorata L .Uliana, Marcelo Bortoli 08 August 2009 (has links)
Made available in DSpace on 2017-07-10T17:37:35Z (GMT). No. of bitstreams: 1
Marcelo_Bortoli_Uliana.pdf: 321238 bytes, checksum: 83cb6d5a28541de9251afb4cf5cbfc14 (MD5)
Previous issue date: 2009-08-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The growing demand for seedlings of forest native sorts has been demanding inquiries made a list to the use of substrates and fertirrigação, able to provide seedlings that present elevated rates of initial growth and of survival after the planting to the least possible cost. In this context, this work intended to contribute to identify the best frequency of fertirrigação, better substrate as well as the time of permanence of the seedlings of the sorts of angico and cedro rosa. The study was carried out in the Experimental Station of the UNIOESTE, Campus of Marechal Candido Rondon, PR. The experimental used delineation was in blocks at random, in arrangement of subdivided pieces, taking four frequencies as a principal piece of fertirrigação (0; 7; 14 and 21 days) and in the subpieces four types of substrates (commercial Substrate, Mixture of BCD H (7:3 v:v); Mixture of BCD V TO, (7:2:1 v:v:v); and Mixture of BCD V (7:3 v:v)), with four repetitions. They were valued the height of plant, diameter of I collect, foliaceous area, dry mass of the air part, root and total, relation breaks air / root, quality rate of DICKSON, rate of absolute growth and condutividade of the substrate. These parameters were valued to 50, 80, 110, 140 and 170 days after emergence of the plantules. Through the analysis of the obtained results, it was ended that for the best development of seedlings of angico and pink cedar recommends to itself to do the fertirrigação to each 14 days, as soon as the interval presented better results in several parameters. The seedlings of angico can go for the field after 140 days while the seedlings of cedar can go to 110 days. The mixture of pulp of cane when more humus (7:3 was analysed; v:v) it provided the best development of the seedlings Anadenanthera macrocarpa (Benth.) Brenan; (angico vermelho) and of Cedrela odorata L (cedro rosa) / A crescente demanda por mudas de espécies florestais nativas tem exigido pesquisas relacionadas ao uso de substratos e fertirrigação, capazes de proporcionar mudas que apresentem elevadas taxas de crescimento inicial e de sobrevivência após o plantio ao menor custo possível. Neste contexto, este trabalho pretendeu contribuir para identificar a melhor freqüência de fertirrigação, melhor substrato bem como o tempo de permanência das mudas das espécies de angico e cedro rosa. O estudo foi realizado na Estação Experimental da UNIOESTE, Campus de Marechal Cândido Rondon, PR. O delineamento experimental utilizado foi em blocos ao acaso, em arranjo de parcelas subdivididas, tendo como parcela principal as quatro freqüências de fertirrigação (0; 7; 14 e 21 dias) e nas subparcelas os quatro tipos de substratos (Substrato comercial, Mistura de BCD+H (7:3 v:v); Mistura de BCD+V+A, (7:2:1 v:v:v); e Mistura de BCD+V (7:3 v:v)), com quatro repetições. Foram avaliadas a altura de planta, diâmetro do coleto, área foliar, massa seca da parte aérea, raiz e total, relação parte aérea/raiz, índice de qualidade de DICKSON, taxa de crescimento absoluto e condutividade do substrato. Estes parâmetros foram avaliados aos 50, 80, 110, 140 e 170 dias após emergência das plântulas. Através da análise dos resultados obtidos, concluiu-se que para o melhor desenvolvimento de mudas de angico e cedro rosa recomenda-se fazer a fertirrigação a cada 14 dias, uma vez que o intervalo apresentou melhores resultados em vários parâmetros. As mudas de angico podem ir para o campo após os 140 dias enquanto as mudas de cedro podem ir aos 110 dias.A mistura de bagaço de cana decomposto mais húmus (7:3; v:v) proporcionou o melhor desenvolvimento das mudas de A. macrocarpa (angico vermelho) e de C. odorata (cedro rosa)
|
36 |
The role of fire and mechanical clearing in the management of Chromolaena odorata.Wessels, Mathias Fittschen. January 2006 (has links)
The effects of fire and mechanical clearing were investigated for their potential in assisting with
the eradication of Chromolaena odorata (previously Eupatorium odoratum). The study was
divided into two focus areas, the first focused on mechanical clearing of dense stands of C.
odorata on three sites and the second focused on the long term influences of a single burn on C.
odorata plants in the different size categories. For mechanical clearing, two key issues were
investigated; namely whether this type of clearing procedure was effective in dense C. odorata
stands and whether rehabilitation was necessary in these cleared areas. The study was conducted
from July 2002 to June 2004. The area was subject to a severe drought throughout the duration
of the study. The severe drought had a large influence on the result in both focus areas. A
bulldozer was found to be a very effective at clearing dense C. odorata stands. Results from the
mechanical clearing study showed that there was still a large viable grass seed population in the
areas that had been covered by a dense stand of C. odorata plants for over three years. Thus,
indigenous plants were able to re-colonize the area after removal of C. odorata without human
intervention, even thought the area was experiencing a severe drought. The density of C. odorata
seedlings emerging in the cleared areas was far lower than expected. The C. odorata density in
the permanent plots, for seedlings that germinated in the first season after clearing (SeptemberOctober
2002), was only 0.25,0.03 and 0.72 per 5 m2 in the three sites respectively by the end of
the study in June 2004. For the C. odorata seedlings that germinated in the second season
(September-October 2003) the density was, 0.5, 0.56 and 1.06 per 5 m2 in the three sites
respectively by the end of the study in June 2004. It was suspected that the drought influenced
seed germination. Unfortunately the number of C. odorata seedlings was so low, that no
significant relationship could be found between grass and C. odorata seedling density. By the
end of the study the grass fuel mass in all the rehabilitated sites was already over 3000 kg ha-1,
even though the area was experiencing a severe drought. This grass fuel load, when burnt, will
assist land managers in controlling C. odorata plants, especially seedlings. Very few other alien
invasive plant species emerged in the cleared areas. At the Mhlosinga site, Senna pendula made
up less than one percent of the herbaceous species composition and only a single Ricinus
communis plant was recorded. No alien plant species were recorded on the other two sites.
Results from the burning trials revealed that plants in all the size categories were affected by fire.
Greater fuel masses and fire intensities were required to kill larger C. odorata plants relative to
smaller ones. Fire was found to be very effective at eliminating small and medium size C.
odorata plants. Fire applied as a once off treatment had a significant long-term effect on the C.
odorata population. The following fuel loads were required to achieve 80% mortality in this
11
study: for small plants a fuel load of over 4000 kg ha-I, for medium plants a fuel load over 4200
kg ha-I and for large plants a fuel load over 4600 kg ha-I. Little difference could be detected
between a head or a back burn, as both fire types had their own advantages and disadvantages.
Although some of the C. odorata plants in the burnt plots had not perished by the time of the
first investigation, following the burn (February 2003), by the time of the second investigation
(June 2004), many of these plants had eventually succumbed. These results highlighted the fact
that plants which are damaged by fire were more likely to persish during an extended droughts
period, than plants which were not subjected to fire. Results from the control plots, in the
burning trials, for medium and large plants showed dramatic increases in density over time.
Tagged individuals from the control plots did reveal that some of the medium and large plants
did die during the drought, although the amount was negligible when compared to the number of
new plants growing into the new size categories. A large proportion of the small plants in the
control plots also survived the drought with many of them even growing into the medium
category. The difference between the control plots and the burnt plots was obvious and
significant, especially once the fuel mass exceeded 3783 kg ha-I. Results from this study show
that fire can be used as a very effective tool in assisting land managers to control C. odorata in
open savanna bushveld. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
|
37 |
Investigation of the biology and cross-breeding of populations of Pareuchaetes insulata (Lepidoptera : Arctiidae) and the implications for the biological control of Chromolaena odorata (Asteraceae) in South Africa.Dube, Nontembeko. 27 May 2014 (has links)
Larvae of Pareuchaetes insulata were released in South Africa for the biological control of the invasive weed Chromolaena odorata. Pareuchaetes insulata has proved to be a difficult agent to establish in the field in South Africa, for various possible reasons. Populations collected from Florida and Jamaica (their aboriginal home) were released separately at several sites each in South Africa, but only one population (Florida) was definitely established. It is possible that adults from this established population interbred with adults from the Jamaican population released at nearby sites.
The aims of this study were to determine whether there were any differences in biology between the two populations and whether hybridization affected the fitness of either. Trials involved: (i) pure-breeding of both Florida (F) and Jamaica (J) populations; (ii) cross-breeding of the two populations and; (iii) back-crossing of the hybrids with the parent populations. The fitness of these populations was determined by measuring adult longevity and fecundity, egg viability, and larval development and survival rates.
The F population was superior to the J population in most of parameters measured, including fecundity. Hybridization of these populations reduced the fitness of the F population. It is unknown whether these differences in fitness reflect differences in their native regions, laboratory cultures or response to South African C. odorata. It appears that different populations of P. insulata have different levels of fitness, and that hybridization negatively affects the fitness of stronger populations. The lower fitness of the J population may have reduced its likelihood of establishing successfully, and even reduced the fitness of the established F population where the populations came into contact. These results caution that the possible consequences of mixing different genotypes of a biocontrol agent species should be properly investigated prior to their release in the same country. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.
|
38 |
\"Estudo do desenvolvimento floral em espécies arbóreas da família Meliaceae\" / Floral development in woody species of the Meliaceae familyCantidio Fernando Gouvêa 25 August 2005 (has links)
A família Meliaceae compreende cerca de 51 gêneros e 550 espécies distribuídas principalmente na região Neotropical. Incluídas nesta família, estão espécies de elevado interesse comercial para a produção de madeiras nobres. Há carência de informações quanto à biologia floral dessas espécies, que aliada a problemas silviculturas dificulta a elaboração de programas efetivos de melhoramento genético das espécies de interesse econômico da família. O presente trabalho visa contribuir para o entendimento do desenvolvimento floral na família Meliaceae, com destaque para sete espécies de interesse econômico e/ou ecológico: Cedrela fissilis L., Cedrela odorata L., Swietenia macrophylla R. A. King, Trichilia claussenii C. DC., Guarea guidonea (L.) Sleumer, Toona ciliata M. J. Roem e Melia azedarach L. Para os estudos morfo-anatômicos utilizaram-se técnicas de microscopia óptica e microscopia eletrônica de varredura. Analisou-se igualmente o padrão de expressão de genes do modelo ABC, relacionados ao desenvolvimento floral, via hibridização in situ. Os estudos morfo-anatômicos permitiram caracterizar o desenvolvimento dos primórdios dos órgãos florais e o estabelecimento de estágios arbitrários de desenvolvimento, auxiliando na caracterização da expressão gênica. Estes resultados permitiram ainda a identificação de flores funcionalmente femininas ou masculinas em S. macrophylla C. fissilis, C. odorata e T. ciliata, as quais apresentam dimorfismo sexual. O padrão de expressão dos homólogos dos genes: APETALA1 (AP1), APETALA3 (AP3) e AGAMOUS (AG) foram diferentes daqueles previstos pelo modelo ABC. A expressão dos homólogos de AP1 foi verificada em todo o meristema floral nos estágios iniciais de desenvolvimento, em todas as espécies estudadas. O sinal de expressão concentrou-se nos primórdios das sépalas e pétalas em estágios mais avançados do desenvolvimento, porém um fraco sinal de hibridização de AP1 foi verificado em todos os verticilos. A expressão dos homólogos de AP3 foi verificada nas regiões previstas pelo modelo ABC, correspondentes ao segundo e terceiro verticilos. Porém um fraco sinal de AP3 foi também observado no quarto verticilo, o que não é previsto pelo modelo teórico. A expressão dos homólogos de AG foi restrita à região central do meristema floral, correspondente ao terceiro e quarto verticilos, em todos os estágios do desenvolvimento floral de todas as espécies estudadas. Entretanto, sinais adicionais de hibridização dos homólogos de AG foram visualizados na região abaxial dos primórdios de sépalas e pétalas em C. fissilis, C. odorata e T. ciliata. Os estudos da expressão dos genes do modelo ABC em Meliaceae revelaram padrões de expressão que não concordam com o modelo teórico vigente do controle molecular da determinação da identidade dos órgãos florais. / The Meliaceae family comprises approximately 51 genus and 550 species mainly distributed in the Neotropical region. In this family there are many species of commercial interest for the production of noble wood. The lack of information on the floral biology associated with silvicultural problems limits the elaboration of effective breeding programs with species of economic interest. The present work aims to contribute with the understanding of floral development in Meliaceae, focusing in seven species of economical or ecological interest: Cedrela fissilis L., Cedrela odorata L., Swietenia macrophylla R. A. King, Trichilia claussenii C. DC., Guarea guidonea (L.) Sleumer, Toona ciliata M. J. Roem e Melia azedarach L. Morpho-anatomical analyses were done by light and scannning electron microscopy. The expression pattern of the ABC model genes, which are related to floral development, was analyzed by in situ hybridization. The characterization of the development of floral organ primordia and the establishment of arbitrary stages of floral development was done and was important for the characterization of gene expression. These results allowed for the identification of functionally female and male flowers in Swietenia macrophylla, Cedrela fissilis, Cedrela odorata and Toona ciliata, characterizing sexual dimorphism. The patterns of gene expression of the homologous of APETALA 1, APETALA 3 and AGAMOUS were different from those predicted by the ABC model. AP1 expression was observed in the entire floral meristem in the initial stages of development, in all seven species. The expression signal was more concentrated in sepal and petal primordia in further stages of development, although a weak hybridization signal of AP1 was verified in all four whorls. The expression of AP3 homologs was observed in the second and third whorls, as predicted by the ABC model. However, a weak signal of AP3 was also observed in the forth whorl, which was not predicted by the ABC model. AG homolog expression was restricted to the central region of the floral meristem, corresponding to the third and forth whorls, in all stages of development of all seven species. However, additional hybridization signal of AG homologs were seen in the abaxial region of sepal and petal primordia in Cedrela fissilis, Cedrela odorata and Toona ciliata. The analyses of the ABC model genes in Meliaceae revealed that the expression patterns do not agree with the theoretical currently accepted model that determines the molecular control of the identity of the floral organs.
|
39 |
Évaluation de l’approche métabolomique pour l’authentification des extraits naturels utilisés dans le secteur arômes et parfums / Metabolomics for the authentication of natural extracts used in flavour and fragrancesSaint-Lary, Laure 10 June 2015 (has links)
Certains extraits naturels sont très rares et onéreux. La tentation est alors forte pour les producteurs de matières premières ou intermédiaires d’avoir recours à des adultérations. Le mélange avec des extraits issus d’origines botaniques apparentées, d’origines géographiques différentes, l’ajout d’un composé synthétique présent dans l’extrait naturel ou d’un autre extrait végétal, l’utilisation de produits phytosanitaires réglementés, la mise en place de procédés d’extractions non standardisés, en sont quelques exemples. Ces différences de qualité sont de plus en plus difficilement décelables. Cette thèse a pour objet de mettre au point une méthodologie rapide, efficace et non ciblée. Une approche métabolomique en UHPLC-HRMS est développée pour identifier ces défauts ou pratiques frauduleuses pour les absolues destinées au secteur arômes et parfums. Cette mise en évidence est réalisée par la détection de métabolites marqueurs. Les absolues présentent un défi particulier : entre 50 et 95 % de l’extrait peut être constitué de composés non volatils, rarement décrits dans la littérature. La recherche d’authenticité de ces extraits est alors plus complexe que dans le cas d’un extrait volatil tel qu’une huile essentielle, dont la composition peut être plus facilement déterminée par des techniques analytiques éprouvées et l’utilisation de bases de données. Deux plantes emblématiques de la parfumerie ont été étudiées : la violette (Viola odorata) et la rose (Rosa damascena et Rosa centifolia). Des marqueurs d’origine géographique ont été identifiés dans le cas de la violette, et des marqueurs d’origine botanique dans le cas de la rose. / Some natural extracts are very scarce and expensive. The temptation is therefore very high for producers or brokers to resort to adulterations. Mixing of extracts from related botanical origins, from different geographical origins, addition of synthetic compounds with natural occurrence in the extract, or addition of another vegetal extract, use of phytosanitary products, non-standardized extraction processes, are some examples. The quality differences are more and more difficult to detect. The objective of this PhD study was to develop a fast, efficient and non-targeted methodology. Metabolomics approach in UHPLC-HRMS was developped to identify defects or fraudulent practices in absolutes used in flavour and fragrances. These identifications are realized by the detection of chemical markers. Absolutes are a great challenge: between 50 and 95 % of the extracts consist of non-volatile compounds; moreover these products are seldom described in literature. The quest for validation for authenticity is then much more complex than in cases of volatile extracts such as essential oils, whose composition can be more easily determined by robust analytical instruments and numerous databases. Two symbolic plants used in perfumery were studied: viola (Viola odorata) and rose (Rosa damascena and Rosa centifolia). Markers of French origin were identified for viola, and markers of R. centifolia were identified for rose. Their characterizations were nevertheless the fundamental limit for this technique being at trace level in the extract. This work demonstrated the performance and limitation of the non-targeted metabolomics approach on absolutes, which are specialties of perfumery.
|
40 |
Einfluss von Lichtspektren auf wertgebende Inhaltsstoffe und Qualität asiatischer Gemüsepflanzen, am Beispiel von Persicaria odorata (Lour.) SojakPaschko, Kerstin 22 February 2021 (has links)
In der vorliegenden Arbeit wurde der Einfluss von Lichtbedingungen auf den Ertrag und die nutritive Qualität der Versuchspflanze Persicaria odorata untersucht. Die Experimente wurden unter praxisnahen Bedingungen im Gewächshaus (Sonnenlicht) und Klimakammern (Dreiband-Leuchtstoffröhren) unter Berücksichtigung eines breiten Inhaltsstoffspektrums, mehreren Versuchsreihen, Lichtmodifizierungen anhand von Zusatzbestrahlungen mit LEDs und Überdeckungen mit photoselektiven Folien sowie dem Anwenden verschiedener statistischer Auswertungsverfahren durchgeführt. Die Tageslichtsumme beeinflusste das Pflanzenwachstum positiv. Beispielsweise wurde die Frischmasse bei einem Anstieg der Tageslichtsumme um 1% mit gleichbleibender spektralen Lichtzusammensetzung um 0,96% (Gewächshaus) bzw. 0,64% (Klimakammer) erhöht. Versuche mit monochromatischen LEDs zeigten, dass spektralbereichsabhängige Erhöhungen der Tageslichtsumme die Biomassesteigerungen verstärkten. Den deutlichsten Effekt im Hinblick auf die Frischmassebildung hatte das kurzwellige Blaulicht (443 nm). Bezüglich der Inhaltsstoffe zeigte insbesondere das kurzwellige Grünlicht (515 nm) einen positiven Effekt. Dieser Spektralbereich wird jedoch durch die traditionell in Gewächshäusern eingesetzten Natriumhochdrucklampen kaum emittiert. Auch sind die bisher häufig eingesetzten Bestrahlungen mit Blau- und Rotlicht in kontrollierten Anbausystemen zwar wichtig für den Aufbau von Biomasse, jedoch nicht optimal im Hinblick auf den Nährwert.
Die Ergebnisse zeigen, dass die Belichtung im Gartenbau sorgfältig ausgewählt werden sollte, jedoch während strahlungsschwachen Monaten eine effektive Möglichkeit ist, den Ertrag und die nutritive Qualität von P. odorata deutlich erhöhten. Durch Modifikationen der Lichtbedingungen ist es möglich den Ertrag und Nährwert pflanzlicher Erzeugnisse zu steigern und dadurch die Versorgungslage mit gesundheitsfördernden bzw. essentiellen pflanzlichen Inhaltsstoffen zu verbessern. / This thesis examined the impact of light conditions on the nutritive quality of the test plant Persicaria odorata. Experiments took place in a greenhouse (sunlight) and climate chamber (fluorescent tube) and under consideration of a wide range of nutritive compounds, several test series, different light modifications and the use of various statistically evaluation procedures. This thesis demonstrates that varying light conditions increase nutritive value and yield under realistic conditions. Increasing the day light integral by 1% improved the fresh mass of 0,96% (greenhouse) and 0,64% (climate chamber). Experiments with monochromatic LEDs proved a high increase of biomass by spectral range dependent enhancements of the day light integral. For example, in the greenhouse, fresh mass was mostly affected by short wave blue radiation (443 nm). Additionally, the day light integral influenced the accumulation of nutrients. Higher contents of polyphenols and flavonoids in the climate chamber and the reactions on additional monochromatic LEDs proved again that it is more effective to increase day light integral by a specific enhancement of certain spectral ranges. The highest increases were achieved by supplementing spectral ranges that are not included in the emission spectrum of commonly used high pressure sodium lamps. Results also indicate that controlled agriculture’s frequently used lighting systems which emit blue and red light can improve plant growth, but it is not optimal regarding the nutritive quality. Adding short wave green light (515 nm) could increase biomass and improve the nutritive quality considerably. This thesis demonstrates that additional lighting in horticulture is an effective method to improve yield and nutritive quality of herbal vegetables in light deprived northern regions. By altering the emission spectrum of traditional artificial lighting systems, it is possible to increase yield and simultaneously improve the nutritive value of vegetables.
|
Page generated in 0.0722 seconds