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Micropropagation of banana by means of different morphogenetic routes is an important source of genetically uniform, pest-and disease-free planting materials of Musa spp. Morphogenesis of in vitro grown plants are affected by light quality, light quantity and photoperiod. Light-emitting diode (LED) lighting systems have several unique advantages, including their peak spectral output, which closely coincides with the red absorption peak of chlorophyll and the reported wavelengths for maximum photosynthetic efficiency. The present study was aimed to investigate the effect of two LED lighting treatments (white LED and deep red/white LED) compared to conventional fluorescent lamps on the stomata formation and chlorophyll (Chl) levels in micropropagated banana plantlets through organogenesis. Both LED lighting evaluated increased the levels of total Chl, Chl-a and Chl-b in banana in vitro plantlets, indicating no statistical difference between them, but being higher then plantlets subjected to fluorescent lamps. The number of stomata was also increased equally by both LED lighting treatments, indicating increased formation of stomata in both abaxial and adaxial leaf surfaces when compared to fluorescent lamps. Although all treatments presented 100 % survival in the acclimatization phase, LED lighting show promising for micropropagation of banana due to its known superior light quality, low energy consumed, little heat generated and long operating lifetime.

Varronia curassavica, a subshrubby medicinal species associated with restinga in the Atlantic Forest, has been exploited by local people and the pharmaceutical industry. Indeed, restingas have experienced a continuous process of degradation, and thus, with species and ecosystem both at risk, efforts to support conservation actions are required. The present study aimed to evaluate aspects of V. curassavica reproductive biology. To accomplish this, morphological characterization was performed by monitoring flowering events. The availability of nectar and pollen, as well as the frequency and behavior of floral visitors and dispersers, was also evaluated. This species exhibits both heterostyly and protogyny. Anthesis is diurnal, and flowers last less than a day. The high number of flower and fruit abortions suggests that mechanisms, such as self-incompatibility intra-morphs and easily detached flowers, contribute to reduced fruit production. The high diversity of floral visitors indicate a generalist pollination syndrome. Diptera, Hymenoptera and Lepidoptera were the main pollinators, and nectar was the main resource sought by these insects. Fruits were dispersed by birds and ants. It can be concluded that the interaction of V. curassavica with several species is a key factor in its own survival and for maintaining the biological diversity of restinga.

Here we propose a protocol for embryogenic cultures induction, proliferation and maturation for the Brazilian conifer Podocarpus lambertii, and investigated the effect of abscisic acid (ABA) and glutathione (GSH) supplementation on the maturation phase. ABA, zeatin (Z) and salicylic acid (SA) endogenous levels were quantified. Number of somatic embryos obtained in ABA-supplemented treatment was significant higher than in ABA-free treatment, showing the relevance of ABA supplementation during somatic embryos maturation. Histological analysis showed the stereotyped sequence of developmental stages in conifer somatic embryos, reaching the late torpedo-staged embryo. GSH supplementation in maturation culture medium improved the somatic embryos number and morphological features. GSH 0mM and GSH 0.1mM treatments correlated with a decreased ABA endogenous level during maturation, while GSH 0.5mM treatment showed constant levels. All treatments resulted in decreased Z endogenous levels, supporting the concept that cytokinins are important during the initial cell division but not for the later stages of embryo development. The lowest SA levels found in GSH 0.5mM treatment were coincident with early embryonic development, and this treatment resulted in the highest development of somatic embryos. Thus, a correlation between lower SA levels and improved somatic embryo formation can be hypothesized.

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