Effects of salinity on the physiology of Salvinia auriculata Aubl. (Salviniales, Pteridophyta)

Salvinia auriculata Aubl. is reported to occur in different zones of the Capibaribe River, Pernambuco State, Brazil. This river varies in salinity in different areas. This study evaluated the growth, photosynthesis and pigment contents of S. auriculata at different salinity levels. Plant sections were collected in the Cursaí Reservoir, located in the municipality of Paudalho, Pernambuco, and were brought to a greenhouse, where they were put in glass flasks filled with 250 mL of liquid, placed on benches. The plants were exposed for 40 h to salinity levels of 0, 17 and 34, obtained with reservoir freshwater, 1:1 freshwater:seawater and pure seawater, respectively. At the end of the experimental period, the plants in salt water showed color changes, with brownish leaves. In addition, plant growth rates decreased. Salinity and time had a negative influence on photosynthetic responses such as Fv/Fm, ETRmax and ETR, which showed reductions under the highest salinity treatment. Response patterns may help to explain S. auriculata occurrence, and its distribution can be regulated by salinity

Ontogenetic study in fruits and seed of Jatropha curcas L. (Euphorbiaceae)

O pinhão-manso (Jatropha curcas L.) é uma espécie lenhosa-arbustiva, pertencente à família Euphorbiaceae que se caracteriza por apresentar uma facilidade de adaptação a ambientes semiáridos, além de um rápido crescimento. Suas sementes oleaginosas despertaram interesse por serem utilizadas como matéria-prima na obtenção, principalmente, de óleo para a produção de biocombustíveis. Sabendo que a fisiologia do amadurecimento dos frutos, de um modo geral, envolve desde a produção de fotoassimilados, para a sua formação e desenvolvimento até o óleo presente na semente, o objetivo deste trabalho foi identificar as estruturas e substâncias produzidas durante a ontogenia de frutos e sementes de J. curcas. O material botânico foi composto por frutos em dez estádios de desenvolvimento, determinados de acordo com os dias após antese; coletados de indivíduos adultos de J. curcas, cultivados em campo aberto em Rio Largo - AL. A partir desse material foram realizadas secções anatômicas seriadas em micrótomo para caracterização e acompanhamento da ontogenia dos frutos e sementes do pinhão-manso. Os frutos atingem seu máximo volume por volta de 47 DAA, mas com significativa redução a partir doa 54 DAA, quando os frutos se tornam secos e escurecidos. Em muitos casos foi possível observar a má formação ou aborto de um ou mesmo de dois óvulos. Há grande presença de laticíferos por todo mesocarpo dos frutos, podendo ser ramificados ou não, articulados ou não. As sementes se tornam completamente maduro já com 13 DAA. O tegumento é composto de testa e tégmen, onde cada um subdividido nitidamente. A camada mais externa da testa apresenta macroesclereídes, fibras e células lignificadas. Entretanto foi possível observar a existência de algumas células sem lignificação ao longo de toda semente. A partir de 18 DAA o endosperma começa a ser consumido, com consequência de um aumento do corpo do embrião, o qual se mostra totalmente desenvolvido aos 40 DAA, com a evidência de um eixo hipocótilo-radicula, além de cotilédones e primórdios caulinar e radicular. As esclereides e fibras presentes no tegumento seminal são responsáveis pela alta rigidez nas sementes de Jatropha curcas, porém essa característica, ao que tudo indica, não compromete o processo germinativo da espécie.Jatropha curcas L. is a woody-shrubby species belonging to the Euphorbiaceae family, which is characterized by having an easy adaptation to semiarid environments, and fast growth. Its oilseeds aroused interest because they are mostly used as raw material to obtain oil for biofuel production. Knowing that the physiology of ripening of Jatropha fruits involves since the production of photoassimilates, to their formation and development, until the oil present in its seed, the aim of this study was to identify the structures and substances produced during ontogeny of their fruits and seeds. Botanical material, composed of fruits in ten stages of development, according with the days after anthesis, were collected from adult individuals of J. curcas, grown in an open field in the State of Alagoas. From this material were performed anatomical sections in serial microtome for characterization and monitoring of the ontogeny of Jatropha fruits and seeds. The fruits reach their maximum volume around 47 DAA, which suffers a reduction from 55 DAA, when they become dried and darkened. It was possible to see in many cases malformation or abortion of one or even two eggs. There is major presence of lactiferous all over fruit mesocarp, which may be branched or not, articulated or not. The seeds become fully ripe 13 DAA. The tegument is composed of testa and tegmen, where each one is clearly subdivided. The testa outermost layer has macrosclereids, fibers and lignified cells. However, it was observed the existence of some cells without lignification along the entire seed. Already from 18 DAA endosperm begins to be consumed, in consequence of an increase in the embryo’s body, which shows fully developed after 40 DAA, with evidence of a hypocotyl-radicle axis, besides cotyledons and primordial stem and root. The sclereids and fibers present in seminal tegument are responsible for the high rigidity in J. curcas seeds; however this characteristic, it seems, does not affect the germination process of the species.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPE

GerminaQuant: a new tool for germination measurements

Abstract:The seed technologies related with germination and seed research has provided unprecedented opportunities for the biologic research community. Researchers require such information to rapidly determine the speed of seedling emergence. However, an immense amount of data must be analyzed to achieve this goal. In this paper, we introduce a computer software designed for broad use to facilitate the understanding of germination processes and their analysis. GerminaQuant 1.0 was written in the C++ programming language and presents a user-friendly interface. The accuracy of the software was tested using fifty different matrices, whose output values were compared with other spreadsheets available on the web. With data analysis, we showed that the GerminaQuant is capable of generating mathematical calculations with extreme accuracy, besides have a good performance and wide ease of use in any kind of computer. In addition, the new software has been tested by at least eighty users, which compared functionality, designer and accuracy of the output data. In all variables, the GerminaQuant was evaluated as superior compared to other spreadsheets available on the web. The full GerminaQuant package (for Windows(r), Macintosh(r) and Linux(r)) is freely available to the scientific community and can be easily downloaded from the website (http://www.ufpe.br/lev)

Effects of salinity on the physiology of Salvinia auriculata Aubl. (Salviniales, Pteridophyta)

A macrófita aquática Salvinia auriculata Aubl. ocorre em diferentes regiões do Rio Capibaribe, no estado de Pernambuco, Brasil. Esse rio desemboca no mar e, consequentemente, apresenta setores com diferentes gradientes de salinidade. Este trabalho avaliou a fotossíntese, o crescimento e o teor de pigmentos fotossintetizantes de S. auriculata frente a um gradiente de salinidade. As plantas foram obtidas em um reservatório no município de Paudalho e foram levadas à casa de vegetação, onde foram mantidas em frascos de vidro contendo 250 mL de volume preenchido, posicionados em bancadas durante 40 h nas seguintes condições de salinidade: 0, 17 e 34, obtidas com água doce, mistura de água doce e salgada e água salgada, respectivamente. Ao final, as folhas das plantas tratadas com água salgada apresentaram mudança na coloração (de verde para marrom) e também as plantas tiveram redução no seu crescimento. A salinidade e o tempo afetaram negativamente as respostas fotossintetizantes das plantas, com diminuição de Fv/Fm, ETRmax e ETR conforme aumentava o conteúdo de sais ao qual as plantas estiveram expostas. Os padrões de respostas obtidos ajudaram a esclarecer a distribuição de S. auriculata, podendo ser regulada pela salinidade. Salvinia auriculata Aubl. is reported to occur in different zones of the Capibaribe River, Pernambuco State, Brazil. This river varies in salinity in different areas. This study evaluated the growth, photosynthesis and pigment contents of S. auriculata at different salinity levels. Plant sections were collected in the Cursaí Reservoir, located in the municipality of Paudalho, Pernambuco, and were brought to a greenhouse, where they were put in glass flasks filled with 250 mL of liquid, placed on benches. The plants were exposed for 40 h to salinity levels of 0, 17 and 34, obtained with reservoir freshwater, 1:1 freshwater:seawater and pure seawater, respectively. At the end of the experimental period, the plants in salt water showed color changes, with brownish leaves. In addition, plant growth rates decreased. Salinity and time had a negative influence on photosynthetic responses such as Fv/Fm, ETRmax and ETR, which showed reductions under the highest salinity treatment. Response patterns may help to explain S. auriculata occurrence, and its distribution can be regulated by salinity.