Bundle sheath ontogeny in Kranz and non-Kranz species of Cyperaceae (Poales)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Do leaves in Cyperoideae (Cyperaceae) have a multiple epidermis or a hypodermis?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Karyotypic diversification and its contribution to the taxonomy of Eleocharis (Cyperaceae) from Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Developmental anatomy of Cyperus laxus (non-Nranz) and Fimbristylis dichotoma (Kranz) (Cyperaceae, Poales) and tissue continuity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Anatomia e ultra-estrutura foliar de Cyperus maritimus Poir. (Cyperaceae): estratégias adaptativas ao ambiente de dunas litorâneas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Distribution of 45S and 5S rDNA sites in 23 species of Eleocharis (Cyperaceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Phylogenetic Relationships in Eleocharis (Cyperaceae): C-4 Photosynthesis Origins and Patterns of Diversification in the Spikerushes

Eleocharis (Cyperaceae) is a morphologically and physiologically diverse lineage of 250 + species with a cosmopolitan distribution. We here explore phylogenetic relationships in this lineage using maximum parsimony and Bayesian inference analyses of nrDNA ITS and cpDNA trnC-ycf6 and ycf6-psbM sequence data with the goals of comparing our phylogenetic hypotheses to previous classifications, morphological variation, and photosynthetic pathway variation. Our results suggest that in Eleocharis C, photosynthesis has been derived at least three times, with several cases of possible reversion to C-3-like or intermediate pathways and several additional origins of C-3-C-4 intermediate photosynthetic pathways, as inferred by carbon isotope ratio measurements. Many classification units currently recognized in Eleocharis are not monophyletic, however, E. subgenus Limnochloa and E. subgenus Scirpidium are monophyletic. Other classification units largely corresponding to clades include E. subgenus Zinserlingia, E. subseries Chaetariae, and E. series Maculosae. Problems with species circumscription and morphological variation in several groups are discussed in light of the phylogeny, particularly in the context of species membership of seven focal clades found in the analyses.

Cytogenetical and cytotaxonomical analysis of some Brazilian species of Eleocharis (Cyperaceae)

Karyotype analysis of 21 samples of 11 species of Eleocharis ( Cyperaceae) from 10 localities in Brazil, showed the presence of chromosomes without primary constrictions and parallel movement of chromatids at metaphase-anaphase transition. Only the terminal nucleolar constrictions ( satellites) were visualised. The chromosome numbers varied from 2n=6 in E. subarticulata to 2n=54 in E. acutangula, but the chromosome basic number x=5 was confirmed. Generally, C-CMA(3)(+) bands appear mostly in the extremities of the chromosomes, associated to NOR, and interstitial C-CMA(3) bands were found only in E. geniculata and E. acutangula. C-DAPI(+) bands were not found. Fluorescence in situ hybridisation ( FISH) with the 45S rDNA probe was performed in five species. The results showed from four to eight hybridisation signals, always terminal. The analysed species include representatives of the following three subgenera of Eleocharis that occur in Brazil: Limnochloa, Scirpidium and Eleocharis. Species from the subgenus Limnochloa have small and numerous chromosomes. The remaining species, belonging to subgenera Eleocharis and Scirpidium, possess fewer and larger chromosomes. In subgenus Eleocharis, karyotypes of the section Eleocharis were differentiated by symploidy, agmatoploidy and polyploidy, whereas species of the section Eleogenus were all polyploids. Polyploidy seems to be the most frequent event in the karyotype differentiation in Eleocharis, but changes in the chromosome size and repetitive DNA sites were also observed.

Comparative study of ovule and fruit development in species of Hypolytrum and Rhynchospora (Cyperaceae, Poales)

The development of the ovule and of the fruit of Hypolytrum bullatum and H. schraderianum (Mapanioideae) and of Rhynchospora consanguinea and R. rugosa (Cyperoideae) are described. All species share anatropous, bitegmic and crassinucellate ovules, funicular obturator, megagametophyte of the Polygonum type, presence of starch grains in the mature megagametophyte, free-nuclear endosperm, Onagrad-type embryogeny, testal-tegmic seed, and a simple fruit of the achene type. Rhynchospora species have characters typical of the family: micropyle formed by the inner integument alone; 3-4-layered parietal tissue; and hard achene. Hypolytrum species differ in those characters by presenting a slightly zigzag micropyle formed by both integuments connected with the funicular obturator, 5-8-layered parietal tissue, and fibrous-spongy achene. The peculiar formation of the micropyle in Hypolytrum is a feature reported here for the first time in the family. The ontogeny provides evidence for a better understanding of the dispersal unit in Hypolytrum supporting the classification as a true achene, like that of Rhynchospora, which is characteristic of the family.

Anatomical features of species of Cyperaceae from northeastern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Chromosome reduction in Eleocharis maculosa (Cyperaceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudos anatômicos de Cyperaceae (Poales) com ênfase na anatomia Kranz

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Embriologia e desenvolvimento de frutos e sementes de Eriocaulaceae e Cyperaceae (Poales)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo citogenético e evolutivo em espécies brasileiras de Eleocharis (Cyperaceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Anatomia de órgãos foliares de Mapania Aubl. (Mapanioideae, Cyperaceae)

Estudou-se a anatomia dos órgãos foliares (folhas basais, ou catafilos, no caso de folhas ausentes, e brácteas involucrais) de três espécies de Mapania Aubl. Os espécimes de Mapania macrophylla (Boeck) H.Pfeiff. e M. pycnostachya (Benth.) T.Koyama, pertencentes à seção Pycnocephala, e M. sylvatica Aubl., pertencente à seção Mapania, foram coletados durante expedições científicas na Reserva Florestal Ducke em Manaus, AM, e constituem representantes de um mesmo gênero que ocupam três ambientes distintos da Floresta Amazônica. Em todos os órgãos, as espécies apresentam epiderme uniestratificada, com células de paredes delgadas, e estômatos paracíticos na face abaxial, no mesmo nível ou um pouco acima das demais células epidérmicas. O mesofilo é homogêneo e apresenta dois padrões distintos nos órgãos foliares: o primeiro com feixes vasculares em um único nível, sem extensão de bainha, idioblastos fenólicos abundantes e aerênquima não conspícuo; e o segundo padrão com feixes vasculares maiores e menores intercalados, com extensão de bainha do feixe e interrompidos por aerênquima conspícuo com células translúcidas. O primeiro padrão foi encontrado em brácteas involucrais de M. sylvatica e o segundo em todos os órgãos foliares das demais espécies. Essa diferença corrobora com as seções estabelecidas e é importante na diferenciação de espécies dentro do gênero. No pseudopecíolo de M. pycnostachya foi observada a presença de hipoderme, caráter importante na diferenciação de Mapania e Hypolytrum e que, portanto, necessita ser melhor estudado no gênero. Ainda, a presença de aerênquima, células epidérmicas com parede delgada e posição dos estômatos refletem a adaptação dessas espécies a ambientes úmidos de várzea e igapó onde são encontradas