Shoot proliferation, leaf anatomy and pigment content of Eugenia dysenterica growing in conventional and natural ventilation systems 1 Natural ventilation micropropagation systems differ from conventional systems by allowing gas exchange between the internal and external media of the culture flask. The objective of this work was to compare the conventional system of in vitro propagation of Eugenia dysenterica (Mart.) DC. with a natural ventilation system. For shooting, explants were inoculated into test tubes with conventional lids and natural ventilation lids (NV), and WPM medium supplemented with four concentrations levels of 6-benzilaminopurine (BAP). The position of explants in each plant was considered by identifying buds as more proximate to the root, or to the apex, or in an intermediate position. Plant growth in the natural ventilation system was superior to that in the conventional system, with a 448.53% increase in leaf number, 85.64% increase in chlorophyll a levels and 74.90% increase in chlorophyll b levels. Plants with intermediate buds exhibited better results. Foliar anatomical analysis revealed abnormalities in leaves grown in the conventional system such as "giant" stomata, which remain always open. Our results indicate that the use of natural ventilation improves the water loss regulation capacity in micropropagated E. dysenterica plants and may favor plants survival and growth after transference to the natural environment.

Balanced levels of macronutrients and sucrose may ensure the success of micropropagation of the endangered ones. This study aimed to evaluate the effect of levels of salts in the culture medium on in vitro culture of Lomatozona artemisiifolia, as well as to determine the influence of light emitting diode (LED) on the shoot proliferation and rooting of the species. Nodal segments were used to evaluate the different macronutrient concentrations of MS medium (25, 50 and 100%), as well as sucrose concentrations (0.0 mM; 0.34 mM; 0.68 mM and 1.03 mM). Five light conditions were evaluated at shoots proliferation and rooting [100% blue (455 nm); 100% red (630 nm); 30% blue + 70% red; 30% red + 70% blue or fluorescent white]. Low levels of macronutrients in MS (50% and 25%) and sucrose (0.00 mM and 0.34 mM) resulted in plants with higher height, number of shoots and higher production of photosynthetic pigments. The 100% red light promoted rooting of 100% of the plants, and in 100% red or 70% red + 30% blue, higher plants were observed. These results demonstrate that under in vitro conditions, L. artemisiifolia has low nutritional needs, typical of plants that live in rupestrian fields.

Dipteryx alata Vogel é uma espécie nativa do domínio Cerrado, a qual possui potencial econômico de uso madeireiro e alimentício. Objetivou-se estabelecer um protocolo de germinação e proliferação de brotos in vitro desta espécie, visando futuros estudos de enraizamento e aclimatização. Frutos foram coletados em outubro de 2013. Para assepsia e germinação, as sementes foram divididas em dois grupos: no primeiro, o tegumento foi retirado, e no segundo este foi mantido. Os dois grupos foram submetidos à assepsia com detergente e álcool 70%, e em seguida a distintas concentrações de hipoclorito de sódio (NaClO) (2,5% de cloro ativo) (v/v): 00%; 10%; 50%; e 100%. Para proliferação de brotos in vitro, dois experimentos foram conduzidos: tampas convencionais ou ventilação natural.  Segmentos nodais oriundos de plantas germinadas in vitro (dois meses de idade) foram inoculados em diferentes concentrações de 6-Benzilaminopurina (BAP) (0,00 µM; 4,44 µM; e 11,10 µM) combinadas a ácido naftaleno-acético (ANA) (0,00 µM; 2,69 µM; e 5,37 µM). A descontaminação de sementes foi realizada com sucesso, observando-se superioridade de sementes com presença de tegumento e 50% de NaClO. Alta proliferação de brotos foi observada em ventilação natural, com 4,44 µM de BAP (média de 4,03 brotos), um aumento de 101,50% em relação ao controle e 43,93% em relação ao melhor tratamento do sistema convencional. Por outro lado, este último sistema propiciou brotos com maiores alturas em 2,69 e 5,37 µM de ANA (média de 19,42 e 18,18 mm respectivamente), assim como em 2,69 µM de ANA combinado a 4,44 µM de BAP (média de 18,46 mm). Por outro lado, o sistema de ventilação natural mostrou brotos mais altos em 5,37 µM de ANA combinado a 11,10 µM de BAP (média de 12,81 mm).