Anatomy, ultrastructure and secretion of Hibiscus pernambucensis Arruda (Malvaceae) extrafloral nectary

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

Seleção de clones de batata para microclimas de altitude no Planalto Central

Iniciou-se em 1986, em Anápolis, um programa de desenvolvimento de cultivares de batata adaptadas ao clima de altitude do Brasil Central, partindo-se de 15.000 genótipos, resultantes de 200 famílias obtidas pela Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Hortaliças em 1985 e 1986. No primeiro ciclo, em 1986, foram selecionados 5.000 genótipos, considerando-se aspectos fenológicos, incidência de doenças, qualidade dos tubérculos e potencial de produção. Esses mesmos critérios foram adotados nas gerações posteriores, selecionando-se, anualmente, 15-20% de genótipos superiores. em 1990 avaliaram-se 52 destes clones, tendo como testemunhas as cultivares Achat e Bintje; Destes foram selecionados 28 clones promissores que foram submetidos à cultura de ápices caulinares e à indexação para os vírus PLRV, PVY e PVX na Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Hortaliças. No período de 1995 a 1997 foram avaliados em Goiás, nos municípios de Anápolis, Morrinhos, Pirenópolis e Urutaí, e em Jaboticabal. Os dados foram submetidos à análise de variância, e aqueles referentes a 14 genótipos em 7 ambientes, à regressão pelo método de Eberhart & Russell. Os clones BAT 2, BAT 3, BAT 4, BAT 19, BAT 27 e BAT 28 destacaram-se entre os mais produtivos, considerando-se, também, as características de tubérculos para o consumo. Os genótipos responderam proporcionalmente à melhoria do ambiente. O clone BAT 19 foi o mais estável.

Ontogênese, anatomia e ultra-estrutura dos nectários extraflorais de Hymenaea stigonocarpa Mart. ex Hayne (Fabaceae - Caesalpinioideae)

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

Enraizamento de estacas de azaléia tratadas com concentrações de ANA em diferentes substratos

De acordo com a necessidade de aumentar a produção de mudas de azaléia por meio da propagação vegetativa, em menor intervalo de tempo, foi proposto estudar os efeitos de diferentes substratos e concentrações de ANA (ácido naftalenoacético). O experimento foi conduzido em esquema fatorial 3X4 com três substratos (areia grossa lavada, casca de arroz carbonizada e húmus) e quatro concentrações de ANA na forma de pó (0; 2,5; 5,0 e 7,5%). Utilizaram-se estacas de 100 mm de comprimento retiradas da porção apical do ramo, sem gema apical e com corte em bisel na parte superior, deixando um par de folhas cortadas ao meio. Essas foram colocadas para enraizar em bandejas de isopor de 128 células, por um período de 90 dias, nas quais avaliaram-se: comprimento, superficie, volume e diâmetro radicular e a porcentagem de estacas enraizadas, sobreviventes, mortas e número de brotos. Pode-se concluir que a maior porcentagem de enraizamento foi obtida no substrato de casca de arroz carbonizada e com ANA na concentração de 5%.

Chromosomal polymorphism in 12 populations of Mikania micrantha (Compositae)

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

Development of Intra- and Interxylary Secondary Phloem in Coccinia indica (Cucurbitaceae)

Stern anatomy and the development of intraxylary phloem were investigated in six to eight years old Coccinia indica L. (Cucurbitaceae). Secondary growth in the stems was achieved by the normal cambial activity. In the innermost part of the thicker stems, xylem parenchyma and pith cells dedifferentiated into meristematic cells at several points. In some of the wider rays, ray cells dedifferentiate and produce secondary xylem and phloem with different orientations and sometimes a complete bicollateral vascular bundle. The inner cambial segments of the bicollateral vascular bundle (of primary growth) maintained radial arrangement even in the mature stems but in most places the cambia were either inactive or showed very few cell divisions. Concomitant with the obliteration and collapse of inner phloem (of bicollateral vascular bundles), parenchyma cells encircling the phloem became meristematic forming a circular sheath of internal cambia. These internal cambia produce only intraxylary secondary phloem centripetally and do not produce any secondary xylem. In the stem, secondary xylem consisted mainly of axial parenchyma, small strands of thick-walled xylem derivatives, i.e. vessel elements and fibres embedded in parenchymatous ground mass, wide and tall rays along with exceptionally wide vessels characteristic of lianas. In thick stems, the axial parenchyma de-differentiated into meristem, which later re-differentiated into interxylary phloem. Fibre dimorphism and pseudo-vestured pits in the vessels are also reported.

Glandular dots of Caesalpinia echinata Lam. (Leguminosae): Distribution, structure and ultrastructure

The structure and ultrastructure of immature to fully mature glandular dots in the leaf, floral organs and fruit, and their secretion components were described in Caesalpinia echinata Lam. (Leguminosae) for the first time. Data showed that glandular dots were groups of idioblasts with contents that reacted positively for both lipophilic and hydrophilic substances. Idioblasts originated from successive divisions of the ground meristem cells or mesophyll cells of an ovary of a fertilized flower. Following division, cells enlarged, the cytoplasm became denser and its content became full. No idioblasts were observed after fruit sclerification. Besides these mixed-content idioblasts, some cells in the sepals, petals and mesocarp were found to contain phenolic compounds, which probably represent a kind of constitutive defense mechanism, once the flowers and fruits become highly fitness-valued parts of the plant and can be commonly attacked. The contents of the idioblasts are released as the growth rate of the embryo increases, indicating that the plant probably diverts the precursors of secondary metabolites into the primary metabolism, at this critical time of embryo development.

Micropropagação de babosa (Aloe vera L.)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The use of the carbon-13 in the partitioning of photosynthate in vegetative and reproductive twigs of 'Sweet' passion fruit

This study's objective is to evaluate the photosynthates partitioning and source-sink relationships, in vegetative and reproductive twigs of sweet passion fruit, using the carbon-13, stable isotope of carbon. The leaves of vegetative and reproductive twigs were placed in a sealed chamber and 13CO 2 were injected for 30 minutes. After six hours, the different organs of the twig were collected and immersed in liquid nitrogen (-196°C). All plant samples were oven-dried, powdered and combusted in an elemental analyzer. The results showed that the methodology was efficient to evaluate the partitioning of photosynthates. In the vegetative twigs, the new open leaves, the closed leaves and growth meristem were the principal sink for the source leaves enriched with 13CO 2. In the reproductive twigs with only flowers buds, the source-sink relationship was changed and the flowers buds turn to be the principal sink and the growing leaves were secondary sinks. The presence of young fruits changed again the source-sink relationship of the twig, and they were the principal sinks. The apical leaves, with 60% of final leaf area were also a sink for photosynthates.

Alocação de fotoassimilados marcados e relação fonte-dreno em figueiras cv. Roxo de Valinhos. 1. Relação fonte e dreno

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Alocação de fotoassimilados marcados e relação fonte-dreno em figueiras cv. Roxo de Valinhos. 2. Tempo de alocação

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Stem anatomy and development of successive cambia in Hebanthe eriantha (Poir.) Pedersen: A neotropical climbing species of the Amaranthaceae

Hebanthe eriantha (Poir.) Pedersen, a climbing species of the Amaranthaceae increases in stem thickness by forming successive cambia. The family is dominated by herbaceous species and is constantly under discussion due to its disputed nature of the meristem. In the young stem small alternate segments of vascular cambium cease to divide and new arc of cambium initiates outside to it. The newly formed arcs connect with pre-existing alternate segments of cambium to complete the ring. On the contrary, in thick stems, instead of small segments, complete ring of cambium is replaced by new one. These new alternate segments/cambia originate from the parenchyma cells located outside to the phloem produced by previous cambium. Cambium is storied and exclusively composed of fusiform initials while ray cells remain absent at least in the early part of the secondary growth. However, large heterocellular rays are observed in 15-mm diameter stems but their frequency is much lower. In some of the rays, ray cells become meristematic and differentiate into radially arranged xylem and phloem elements. In fully grown plants, stems are composed of several successive rings of secondary xylem alternating with secondary phloem. Secondary xylem is diffuse-porous and composed of vessels, fibres, axial parenchyma while exceptionally large rays are observed only in the outermost regions of thick stems. Vessel diameter increases progressively from the centre towards the periphery of stems. Although the origin of successive cambia and composition of secondary xylem of H. eriantha remains similar to other herbaceous members of Amaranthaceae, the occurrence of relatively wider and thick-walled vessels and large rays in fully grown plants is characteristic to climbing habit. © 2013 Springer-Verlag Wien.

Frutos, sementes e plântulas de três espécies de Mimosa Linnaeus(Fabaceae: Mimosoideae): aspectos morfoanatômicos e considerações ecológico-filogenéticas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Identificação de genes candidatos para resistência ao mosaico da cana-de-açúcar a partir da técnica de cDNA-AFLP

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV