A mudança do sistema de colheita da cana-de-açúcar com o uso de fogo para a colheita mecanizada, chamada de cana verde ou cana crua, é um processo irreversível, gradativo porém contínuo, previsto na legislação estadual paulista. Um dos pontos críticos no processo produtivo da cana-de-açúcar é a interferência imposta pelas plantas daninhas. A tiririca (Cyperus rotundus L.) é uma das plantas daninhas mais prejudiciais à cultura da cana-de-açúcar entretanto, com a implementação da colheita mecanizada, o desenvolvimento desta planta poderá ser afetado. O objetivo do experimento foi verificar se a adição de palha de cana-de-açúcar poderia afetar o desenvolvimento de plantas de tiririca provenientes de tubérculos de tamanho pequeno (0,22 a 0,34 g) e grande (1,01 a 1,14 g), plantados em diferentes épocas do ano. O experimento foi instalado em casa-de-vegetação, em Campinas, SP e disposto em blocos ao acaso com quatro repetições. Tubérculos dormentes de tiririca de tamanho pequeno e grande foram plantados em maio, julho e setembro e adicionou-se sobre o solo palha de cana-de-açúcar RB 855156, nas quantidades correspondentes a 0,0, 5,0, 10,0 e 15,0 t/ha. Em cada época de instalação do experimento, a cada 28 dias até 84 dias, as plantas de tiririca foram avaliadas quanto à altura média, cortadas ao nível do solo. As estruturas subterrâneas e aéreas foram separadas nas diferentes estruturas e avaliou-se suas biomassas frescas e secas e a área foliar. De modo geral, o tamanho maior dos tubérculos favoreceu o desenvolvimento da parte subterrânea. O número de brotações emergidas não foi afetado pelo tamanho de tubérculos mas, a altura média, área foliar e as biomassas das folhas e da parte aérea foram maiores quando originadas de tubérculos de tamanho grande. A adição de palha de cana-de-açúcar ao solo afetou mais as plantas originadas de tubérculos pequenos que de grandes. A adição de quantidades crescentes de palha de cana-de-açúcar causou redução no desenvolvimento nas diferentes estruturas subterrâneas, seguindo para todas as variáveis uma equação do segundo grau. Aplicações de quantidades crescentes de palha de cana-de-açúcar causaram diminuição no número de brotações, área foliar e as biomassas frescas e secas das folhas e da parte aérea total. A formação e o desenvolvimento dos rizomas e de tubérculos + bulbos basais, assim como das biomassas fresca e seca de rizomas e fresca de tubérculos + bulbos basais foram maiores no plantio realizados em setembro e menores nos de julho. Verificou-se que, exceto para altura média, o plantio de setembro proporcionou plantas com maior número de brotações, área foliar e biomassas fresca e seca de folhas e da parte aérea total. Para altura média, os melhores resultados foram observados no plantio de maio. Para todas as variáveis analisadas, o plantio de julho apresentou sempre os menores valores. Quanto ao efeito de época de avaliação, verificou-se que para todas as variáveis analisadas foram observados aumentos lineares em função do tempo. / The change in harvest systems for sugar cane from use of fire to mechanical harvest, is an irreversible process, gradual although continuous, foreseen in the São Paulo State Legislation. One of the critical points in the productive process of sugar cane is the interference imposed by weeds. Purple nutsedge (Cyperus rotundus L.) is one of the most sugar cane crop-damaging weeds, nevertheless with implementation of mechanical harvest technology, which leaves a thick layer straw superior to 20 ton/ha, the development of this plant could be affected. This experiment aimed to verify if the addition of sugar cane straw could affect the development of purple nutsedge plants deriving from tubers of small (0,20-0,34g) and large (1,01-1,14g) sizes, planted at different times of the year. The experiment was carrIED out in glass house, in Campinas, São Paulo, in randomized blocks with four replicates. Tubers of small and large sizes of purple nutsedge were planted in May, July and September, and RB 855156 sugar cane straw was added, in quantities corresponding to 0, 5,0, 10,0 and 15,0 ton/ha. Every 28 days until 84 days after each planting period, the purple nutsedge plants were evaluated as to their average plant height, cut to soil level, and the aerial part was separated from the subterranean. The aerial and subterranean structures were separated, and evaluated as to their fresh and dry weights and foliar area. Generally, the larger sized tubers were more favorable to the development of subterranean parts. The number of emerged sprouts was not affected by tuber size; but plant height, foliar area and aerial part weights were larger when originated from large-sized tubers. The addition of sugar cane straw to the soil affected plants derivated from small tuber more than those originated from large one. The addition of growing quantities of straw caused reduction in the development of different kinds of subterranean structures, following for all variables one second-order equation. Application of growing quantities of straw caused a decrease in the sprouts number, area foliar and fresh and dry leaf and total aerial part weights. The formation and development of rhizomes and tubers + basal bulbs, similarly to the fresh and dry rhizome weights of tubers + basal bulbs were larger in September planting and the smallest in July. It was verified that, with exception of average plant height, the September planting generated a larger number of sprouts, foliar area and fresh and dry leaf and total aerial part weights. As for average plant height, the best results were observed at the May planting. For all analyzed variables, the July plantation always presented the smallest values. As to the time of evaluation, it was verified that all variables increased linearly in function of time.

A mudança do sistema de colheita da cana-de-açúcar com o uso de fogo para a colheita mecanizada, chamada de cana verde ou cana crua, é um processo irreversível, gradativo porém contínuo, previsto na legislação estadual paulista. Um dos pontos críticos no processo produtivo da cana-de-açúcar é a interferência imposta pelas plantas daninhas. A tiririca (Cyperus rotundus L.) é uma das plantas daninhas mais prejudiciais à cultura da cana-de-açúcar entretanto, com a implementação da colheita mecanizada, o desenvolvimento desta planta poderá ser afetado. O objetivo do experimento foi verificar se a adição de palha de cana-de-açúcar poderia afetar o desenvolvimento de plantas de tiririca provenientes de tubérculos de tamanho pequeno (0,22 a 0,34 g) e grande (1,01 a 1,14 g), plantados em diferentes épocas do ano. O experimento foi instalado em casa-de-vegetação, em Campinas, SP e disposto em blocos ao acaso com quatro repetições. Tubérculos dormentes de tiririca de tamanho pequeno e grande foram plantados em maio, julho e setembro e adicionou-se sobre o solo palha de cana-de-açúcar RB 855156, nas quantidades correspondentes a 0,0, 5,0, 10,0 e 15,0 t/ha. Em cada época de instalação do experimento, a cada 28 dias até 84 dias, as plantas de tiririca foram avaliadas quanto à altura média, cortadas ao nível do solo. As estruturas subterrâneas e aéreas foram separadas nas diferentes estruturas e avaliou-se suas biomassas frescas e secas e a área foliar. De modo geral, o tamanho maior dos tubérculos favoreceu o desenvolvimento da parte subterrânea. O número de brotações emergidas não foi afetado pelo tamanho de tubérculos mas, a altura média, área foliar e as biomassas das folhas e da parte aérea foram maiores quando originadas de tubérculos de tamanho grande. A adição de palha de cana-de-açúcar ao solo afetou mais as plantas originadas de tubérculos pequenos que de grandes. A adição de quantidades crescentes de palha de cana-de-açúcar causou redução no desenvolvimento nas diferentes estruturas subterrâneas, seguindo para todas as variáveis uma equação do segundo grau. Aplicações de quantidades crescentes de palha de cana-de-açúcar causaram diminuição no número de brotações, área foliar e as biomassas frescas e secas das folhas e da parte aérea total. A formação e o desenvolvimento dos rizomas e de tubérculos + bulbos basais, assim como das biomassas fresca e seca de rizomas e fresca de tubérculos + bulbos basais foram maiores no plantio realizados em setembro e menores nos de julho. Verificou-se que, exceto para altura média, o plantio de setembro proporcionou plantas com maior número de brotações, área foliar e biomassas fresca e seca de folhas e da parte aérea total. Para altura média, os melhores resultados foram observados no plantio de maio. Para todas as variáveis analisadas, o plantio de julho apresentou sempre os menores valores. Quanto ao efeito de época de avaliação, verificou-se que para todas as variáveis analisadas foram observados aumentos lineares em função do tempo. / The change in harvest systems for sugar cane from use of fire to mechanical harvest, is an irreversible process, gradual although continuous, foreseen in the São Paulo State Legislation. One of the critical points in the productive process of sugar cane is the interference imposed by weeds. Purple nutsedge (Cyperus rotundus L.) is one of the most sugar cane crop-damaging weeds, nevertheless with implementation of mechanical harvest technology, which leaves a thick layer straw superior to 20 ton/ha, the development of this plant could be affected. This experiment aimed to verify if the addition of sugar cane straw could affect the development of purple nutsedge plants deriving from tubers of small (0,20-0,34g) and large (1,01-1,14g) sizes, planted at different times of the year. The experiment was carrIED out in glass house, in Campinas, São Paulo, in randomized blocks with four replicates. Tubers of small and large sizes of purple nutsedge were planted in May, July and September, and RB 855156 sugar cane straw was added, in quantities corresponding to 0, 5,0, 10,0 and 15,0 ton/ha. Every 28 days until 84 days after each planting period, the purple nutsedge plants were evaluated as to their average plant height, cut to soil level, and the aerial part was separated from the subterranean. The aerial and subterranean structures were separated, and evaluated as to their fresh and dry weights and foliar area. Generally, the larger sized tubers were more favorable to the development of subterranean parts. The number of emerged sprouts was not affected by tuber size; but plant height, foliar area and aerial part weights were larger when originated from large-sized tubers. The addition of sugar cane straw to the soil affected plants derivated from small tuber more than those originated from large one. The addition of growing quantities of straw caused reduction in the development of different kinds of subterranean structures, following for all variables one second-order equation. Application of growing quantities of straw caused a decrease in the sprouts number, area foliar and fresh and dry leaf and total aerial part weights. The formation and development of rhizomes and tubers + basal bulbs, similarly to the fresh and dry rhizome weights of tubers + basal bulbs were larger in September planting and the smallest in July. It was verified that, with exception of average plant height, the September planting generated a larger number of sprouts, foliar area and fresh and dry leaf and total aerial part weights. As for average plant height, the best results were observed at the May planting. For all analyzed variables, the July plantation always presented the smallest values. As to the time of evaluation, it was verified that all variables increased linearly in function of time.

En Nouvelle-Calédonie, les sols développés sur roches ultramafiques (5.500 km2) sont constitués à plus de 65% d'oxy-hydroxyde de fer, ils présentent des teneurs très faibles en azote et en phosphore (1/10 à 1/100 des teneurs moyennes), de surcroît ils sont déséquilibrés pour le rapport Ca/Mg et contiennent des concentrations très élevées en métaux lourds (nickel, manganèse, cobalt, chrome). L'exploitation à ciel ouvert du nickel sur ces sols associés à des écosystèmes particulièrement originaux et diversifiés doit prendre en considération à la fois les intérêts économiques et les préoccupations écologiques. Des espèces endémiques pionnières des sols ultramafiques ou cicatricielles des sites miniers dégradés ont été identifiées. Parmi ces espèces, plusieurs espèces de Costularia (Cyperaceae) sont préconisées pour la revégétalisation des sites miniers après exploitation. Les itinéraires techniques de restauration écologique des sites miniers requièrent une approche pluridisciplinaire intégrant des données pédologiques, physiologiques et microbiologiques des écosystèmes des maquis miniers. L'analyse des relations sols/plantes sur une toposéquence comprenant différents types de maquis a permis de mettre en évidence une relation directe entre les concentrations du sol en éléments disponibles et la diversité et l'organisation des espèces, notamment pour ce qui concerne la structuration de la strate herbacée. Ce travail couplé à la mise en place par la société SIRAS Pacifique d'un champ semencier expérimental de Cyperaceae a permis de montrer que la croissance de Costularia comosa répond positivement à la fertilisation azotée et phosphatée. L'expérimentation a permis également de souligner que la vigueur, la vitesse de développement, le taux de mycorhization et la fructification des plants sont stimulés par des doses modérées de ces éléments. D'autres travaux réalisés ont apporté un approfondissement de nos connaissances sur le rôle des microorganismes associés aux racines des Costularia. Ainsi, nous avons montré que neuf espèces pionnières de Cyperaceae étudiées in situ, développent des symbioses mycorhiziennes arbusculaires. Une expérience de mycorhization contrôlée de Costularia comosa a permis de montrer que la mycorhization par Glomus etunicatum est fonctionnelle, avec une augmentation de la biomasse des plants 2,8 fois supérieure au témoin. De plus, la mycorhization réduit la concentration en nickel dans la plante, suggérant un rôle barrière du champignon mycorhizien vis-à-vis du nickel. Dans cette étude, nous présentons également une description des populations bactériennes aérobies, hétérotrophes et résistantes au nickel, isolées des racines de deux espèces de Costularia inféodées aux maquis. Ces populations bactériennes sont de faible densité et dominées par les Protéobactéries. Certaines des souches isolées présentent une tolérance à 15 mM de nickel soluble et la capacité de solubiliser les phosphates. L'avancement apporté dans les connaissances concernant la nutrition minérale des Cyperaceae et le rôle des microorganismes qui leur sont associés permet d'envisager la mise en place en routine de champs semenciers productifs et l'utilisation des microorganismes associés aux Costularia dans les itinéraires techniques de restauration écologique pour en améliorer la réussite.

The Carex nardina complex is a group of one to three species (C. nardina, C. hepburnii, C. stantonensis) and six taxa of unispicate sedges (Cyperaceae), the taxonomy of which has been controversial since the 1800s. As initial DNA phylogenies suggested that the complex was nested within Carex section Filifoliae and sister to C. elynoides, a species often confused with C. nardina and sympatric with it in the western North American Cordillera, analyses were conducted to determine whether C. hepburnii, C. stantonensis and other infraspecific taxa could be the result of hybridization. Morphometric and molecular analyses found no substantial evidence for hybridization and supported the recognition of no taxon beyond C. nardina. Consequently, this study concludes that the complex comprises a single variable species, Carex nardina, distributed throughout arctic North America south through the western Cordillera to New Mexico with a minor portion of its range in northeastern Russia, northwestern Scandinavia and Iceland.

For over a century, the origins and mechanisms underlying the diversification of the enormous cosmopolitan genus Carex (>2,100 species; Cariceae, Cyperaceae or sedge family) have remained largely speculative. Although its unique morphology (e.g., unisexual flowers, perigynia) clearly indicated it was a natural group, it obscured its relationships to all other Cyperaceae because the morphological gap between it and the rest of the family was so wide. Consequently, no plausible sister group to Carex has ever been proposed. Early molecular analyses narrowed the problem by placing Carex within a strongly-supported clade with the enigmatic monospecific genus Khaosokia, and tribes Dulichieae and Scirpeae (hereafter CDS), a group consisting of 2,250 species, or approximately 41% of all Cyperaceae. However, poor taxonomic sampling and the limited number of molecular markers used in these studies meant that the sister group to Carex remained a mystery. The goals of this thesis were to resolve evolutionary relationships within the CDS clade, to identify the sister group to Carex, and to develop a new natural tribal classification of CDS that could be used in future biogeographic and comparative analyses of Carex and its relatives. Initial phylogenetic analyses using two plastid markers (matK, ndhF) identified seven major CDS lineages, and suggested that Carex could be nested within a paraphyletic Scirpeae. However, backbone support for these relationships was low due to an ancient rapid radiation (~10 million years) followed by long divergence of the seven major lineages (~40 million years). The addition of conventional sequence-based markers from the plastid genome (rps16) and nuclear ribosomal region (ETS-1f, ITS) indicated that a traditional molecular approach would not resolve these key backbone nodes. Consequently, a recently developed flowering-plant-specific anchored enrichment probe kit targeting hundreds of conserved nuclear genes combined with next generation sequencing was used to resolve the CDS backbone. Although the resulting phylogenomic dataset was able to resolve the CDS backbone with high support, the topology and branch lengths only reaffirmed the isolated position of Carex. However, comparative morphological analyses of specimens at key herbaria not only suggested that Sumatroscirpus, a rare genus thought to be endemic to Sumatra, could be sister to Carex, but they also provided an easily accessible site to collect DNA in Northern Vietnam. Subsequent phylogenetic analyses of plastid (matK, ndhF, rps16) and nuclear ribosomal (ETS-1f, ITS) markers strongly supported Sumatroscirpus as the sister to Carex, and molecular dating estimates suggested they shared a common ancestor in the late Eocene (~36 million years ago). Comparative studies and ancestral state estimates of key morphological characters were congruent with this hypothesis, suggesting that the perigynium is not unique to Carex, but in fact a synapomorphy shared with Sumatroscirpus. This means that the initial key innovation in the remarkable diversification of Carex is not the perigynium, but could be the release of mechanical constraints that permitted the evolution of the remarkable morphological diversity of Carex perigynia seen today. A taxonomic revision of Sumatroscirpus revealed that this purportedly monospecific genus actually consisted of four species, and it extended its range over 2,400 km to the north into Northern Vietnam, Myanmar, and Southwestern China. The phylogenetic framework provided by the previous studies enabled a new tribal and generic classification of CDS to be proposed. Seven monophyletic tribes are recognised including four new tribes (Calliscirpeae, Khaosokieae, Sumatroscirpeae, Trichophoreae), and a new genus (Rhodoscirpus). Morphological synapomorphies are identified for all recognized tribes, and a worldwide treatment, including identification keys, is provided for Sumatroscirpus species, CDS genera, and Cyperaceae tribes.

Les stilbènes sont des composés phénoliques issus du métabolisme secondairevégétal, dont la distribution au sein du règne végétal est limitée aux espèces qui ont acquis aucours de l’évolution la capacité à synthétiser ces molécules. Leurs impacts et leurs activitésbiologiques tels que les effets neuroprotecteurs, anticancérigènes, antioxydants ont déjàconcerné plusieurs sujets d’étude. C’est dans ce contexte que l’objectif de notre travail a prisnaissance. Dans un premier temps, nous avons isolé et identifié ces molécules chez quelquesespèces de la famille des Cypéracées. Cette étude phytochimique a été réalisée en utilisant unensemble de stratégies analytiques et préparatives faisant appel à la CLHP analytique etpréparative et la CPC (Chromatographie de Partage Centrifuge) pour l’obtention desmolécules pures et à la LC-Masse et la RMN pour l’identification des composées isolés. Dansun second temps, nous avons étudié les activités biologiques in vitro de ces produits telles queles activités antioxydantes par trois méthodes (ORAC, DPPH et MCA) et l’effet de cesstilbènes sur la cytotoxicité neuronale induite par le peptide β-amyloïde avec des cellulesPC12. Nous avons isolé une nouvelle molécule, le carexinol A, pour la première fois, qui amontré une forte activité anti-amyloïde. La dernière partie de cette thèse fait état de l’analyseet du dosage des stilbènes dans des vins tunisiens dont le vin Sidi Zahia qui a donné lesmeilleurs résultats. / Stilbenes are phenolic compounds of plant secondary metabolism, whosedistribution within the plant kingdom is limited to species that have acquired during theevolution the ability to synthesize these molecules. Their impacts and their biologicalactivities such as neuroprotective, anticarcinogenic, antioxidant effects have already touchedseveral topics. It is in this context that the purpose of our work arose. First, we have isolatedand identified these molecules in some species of the sedge family. Phytochemical studieswere performed using a set of analytical and preparative strategies by means of analytical andpreparative HPLC and CPC (Centrifugal Partition Chromatography) for obtaining puremolecules and LC-Mass and NMR for identification of compound isolated. In a second step,we investigated the in vitro biological properties of these products such as antioxidantactivities by three methods (ORAC, DPPH and MCA) and their effect on neuronalcytotoxicity induced by β-amyloid peptide with PC12 cells. We isolated a new molecule, forthe first time, carexinol A, that showed strong anti-amyloid activity. The last part of this thesisrefers to the analysis and determination of stilbenes in Tunisian wines including Sidi Zahiawine that gave the best results.

Approximately 50 percent of all endangered species in Scandinavia are associated with old agricultural landscapes. During the agricultural industrialization of the past century the traditional practices and methods that created these environments have been phased out. This has brought on a serious decline and fragmentation of biomes that many endangered species depend on. Knowledge of traditional agricultural landscapes and their species dynamics is needed to make well informed decisions regarding their care and restoration. One way to acquire such knowledge is to study fossil plant remnants from old agricultural contexts. In this study sub-fossil Cyperaceae achenes were analyzed in an attempt to identify them. The achenes had been preserved in three Iron Age wells (80-980 AD) at the Gilltuna settlement in central Sweden and were found during an archeological investigation in 2010. The purpose of this study was to identify the achenes to species level, make conclusions about the ecology of the surrounding landscape, and construct simple species identification key as well as evaluate archaeobotany as an ecological tool. The identification attempt resulted in 14 determined species, which were in consistency with previous landscape analyses made using ecological species distribution. The resulting identification key is a suggestion, to be expanded in the future. This method can undoubtedly provide further knowledge of prehistoric and historical biomes, but in order to draw useful conclusions the identification technique further as well as knowledge of present regional ecology must be developed, especially concerning different Cyperaceae species‟ response to different kinds of stress.

Traditional agriculture has played an important role in shaping the landscape for thousands of years. Agriculture and interactions between humans and their surroundings have changed since the beginning of historic time in Sweden, approximately 1000 years ago. Through botanical macrofossil analysis of plant remnants found in an urban ditch in Sigtuna, Sweden, I examine which natural landscapes the town’s inhabitants may have interacted with in terms of resource collection in the beginning of the Medieval period. The results showed indications of predominantly nutritious wet grassland habitats, but also dry grassland and forests, as well as remnants of urban and cultivated species. The species indicate that the resources may have been used as winter fodder for animals, but possibly also as sustenance for humans as well as building material. The results indicated little change over time, regarding which landscape types were interacted with, but there were possible indications of a decrease in grassland resource collection in the youngest sample from 1150 A.D. Further research is needed to understand the indication. The material indicates that the Cyperaceae family will be instrumental in continuing this research.