ABSTRACTStudies that evaluate the physiological and biochemical mechanisms of germination within forest species are needed in order to improve our understanding of such processes. Mercury and dithiothreitol are indicated as important tools in studies that assess the activity of aquaporins during imbibition and germination of seeds. To investigate the alterations caused by mercury inPlathymenia reticulata seedsdifferent doses of mercury were used in the presence and absence of dithiothreitol. Mercury had a dose-dependent effect on the seeds; in the most dilute solutions mercury partially inhibited the imbibition process, whereas in the most concentrated solutions it caused the death of the embryos. A delay in the hydration of the seeds may have caused decreased germination as a result of the reduced functionality of the aquaporins that were oxidized by mercury. In the presence of the reducing agent dithiothreitol, the activity of these proteins was restored and the germination process was re-established. These findings indicate the importance of aquaporins in the imbibition and germination stages of P. reticulataseeds, and they provide a better understanding of these important developmental events in plants.

Resumo: A sacha inchi (Plukenetia volubilis L.) é uma espécie amazônica de elevado potencial agroindustrial devido ao alto teor de ômega-3 e ômega-6 em suas sementes. Apesar disto, pouca informação acerca de sua propagação seminífera é encontrada. Dessa forma, o objetivo do trabalho foi avaliar a germinação das sementes, sobrevivência e crescimento das plântulas da espécie em diferentes condições de substrato (sobre papel, entre papel e em rolos de papel), luz (escuro contínuo, fotoperíodo de 12 horas e luz contínua) e temperatura (constante nas temperaturas de 20, 25, 30, 35 e 40 °C). A germinação é estimulada por substratos que possuam maior superfície de contato com a semente, pela presença de luz e por temperaturas entre 25 e 35 °C. A sobrevivência e o crescimento inicial das plântulas são favorecidos pela vermiculita, luz contínua e temperatura de 30 °C. Estas condições permitem uma germinação rápida e uniforme e um bom estabelecimento e desenvolvimento das plântulas. Nós encorajamos a propagação seminífera de sacha inchi, uma vez que ela se mostra uma técnica viável.

Abstract: Sacha inchi (Plukenetia volubilis L.) is an Amazon species of elevated agro-industrial potential due the high content of omega-3 and omega-6 in its seeds. Despite of it, little information about its propagation by seeds is currently available. Thus, the aim of this study was to assess seed germination, seedling survival and growth of this species under different conditions of substrate (on paper, between papers and paper roll), light (continuous darkness, 12-h photoperiod and continuous light) and temperature (continuous temperature at 20, 25, 30, 35 and 40 °C). Germination is stimulated by substrates with increased surface contact with the seeds, presence of light and temperatures between 25 and 35 °C. Survival and initial growth of seedlings are favored by vermiculite, continuous light and 30 °C temperature. These conditions allow rapid and uniform germination of seeds and better establishment and development of seedlings. We encourage the propagation of sacha inchi by seeds, since we consider it a feasible technique.

This study aimed to establish and propagate in vitro plants of Bouchea fluminensis, a medicinal species known in Brazil as gervão-falso ("false verbena"), evaluating the influences of different growth regulators on in vitro multiplication and rooting stages, as well as examining ex vitro acclimatization of rooted plants. Explants were established on Murashige and Skoog medium at half strength of salts and vitamins without growth regulators. For multiplication, the explants were subjected to combinations of 6-benzyladenine (BA; 0, 2.5, 5.0 and 7.5 µM) and α-naphthalene-acetic acid (NAA; 0, 0.2, 0.4 and 0.6 µM). The medium found to induce the greatest number of shoot was that containing 5 µM of BA (NAA-free). For rooting, we evaluated three auxins (NAA, indole-3-acetic acid and indole-3-butyric acid; 0.1, 0.2, 0.3 and 0.4 µM), as well as a control. No differences were observed between the control and the other treatments. The auxin-free medium was deemed the most suitable, because it ensures the lowest cost in the micropropagation procedures. We obtained 100% survival of the acclimatized seedlings, and the plants showed normal vegetative and reproductive development, suggesting that the micropropagation did not alter the biological cycle of this species. The results show the importance and potential of micropropagation for biodiversity conservation of Bouchea fluminensis.