-Key words: Orchidaceae. Tissue culture. Photoperiod. 6-benzylaminupurine. Naphthaleneacetic acid.RESUMO -A técnica do estiolamento é muito utilizada na micropropagação de várias espécies de plantas. Este trabalho teve como objetivo avaliar o crescimento e desenvolvimento de brotos de Cattleya labiata in vitro em função de reguladores de crescimento e da presença e ausência de luz. Segmentos caulinares, com aproximadamente + 1,0 cm de altura, foram inoculados em tubos de ensaio contendo 15,0 mL de meio de cultura MS, acrescido de diferentes concentrações de BAP (0,0; 2,0 e 4,0 mg L -1 ), ANA (0,0; 1,0 e 2,0 mg L -1 ) e ambientes de cultivo (sala de crescimento no escuro e com fotoperíodo 16 horas) em delineamento inteiramente casualizado. Aos 150 dias, avaliou-se: a) número de brotos estiolados; b) número de nós por broto estiolado; c) comprimento do segmento caulinar (cm); d) número de raízes; e, e) massa seca total da plântula (g). As maiores médias foram obtidas com a utilização de 4,0 mg L -1 de BAP e 1,0 mg L -1 de ANA para número de brotos estiolados e de 2,0 mg L -1 de ANA para número de nós por broto estiolado, em ausência de luz. O comprimento do segmento caulinar foi superior em ambiente sob ausência de luz; em contraste, o número de raízes e a massa seca total da plântula foram superiores em ambiente luminoso, independente do regulador de crescimento adicionado ao meio de cultivo. O estiolamento de segmentos caulinares é uma técnica viável, visto que proporcionou características vantajosas para a fase de multiplicação in vitro da referida espécie.Palavras-chave: Orchidaceae. Cultura de tecidos. Fotoperíodo. 6-benzilaminupurina. Ácido naftaleno acético.

The large ornamental potential of tropical flowers has stimulated the commercial cultivation of various species. Micropropagation is a viable alternate method of propagation, since it enables obtaining a higher number of seedlings with uniformity and pathogens free. The objective was to evaluate the in vitro multiplication rate of Etlingera elatior cv. Porcelana, using explants obtained from in vitro established seedling shoots, obtained from the 2nd subcultive. The explants were inoculated in MS culture medium containing different concentrations of BAP (0.0; 2.22; 4.44; 6.66; 8.88; and 11,10 μM), and the cultures maintained in a growth room with temperature 25.0 ± 2.0 °C under a photoperiod of 12 hours of light and light intensity of 30 μmol.m-2 s-1. The multiplication rate was monthly, according to the four subcultives, totaling 120 days. The experimental design was completely randomized, with four replications, analyzed in a factorial 4 x 6. The data were submitted to analysis of variance and regression. There were significant differences in subcultives and made for BAP concentrations used. For the first subcultive, the concentration of 2.22 μM of BAP afforded a rate of 4.06 sprouts per explant, already in the second and fourth subcultives, with the addition of cytokinin concentration was increased amount of sprouts reaching at a rate of 4.05 and 4.96 shoots/explant in the highest concentration of BAP. The results of the treatments evaluated indicate that the presence of BAP favored sprout emission. The concentrations of 2.22, 8.88 and 11.10 μM this cytokinin promoted the highest multiplication rates in the first, second and fourth subcultives, respectively.

Considering the growing economic importance of tropical flowers and the advantages of techniques applied to the in vitro cultivation of these plants, it is necessary to carry out studies to evaluate growth in species such as Heliconia latispatha. The aim of this study therefore, was to evaluate in vitro shoot induction for different concentrations of BAP and NAA and as a function of the photoperiod. Explants from zygotic embryos were inoculated in MS medium containing different concentrations of BAP (0.0, 0.5, 1.0, 1.5, 2.0 or 2.5 mg L -1 ), with the cultures kept in a growth room at a temperature of 24.0 ± 2.0° C, under a photoperiod of 12 and 16 hours of light and a light intensity of 30 μmol m -2 s -1 . At 21, 28, 35, 42 and 49 days after inoculation, the number of shoots per explant was evaluated. The treatment at the BAP concentration that gave the best multiplication rate (2.5 mg L -1 ) was set, and was tested in a further trial with different concentrations of NAA (0.0, 0.2, 0.4, 0 6, 0.8 or 1.0 mg L -1 ) under the same conditions as the previous experiment. The experimental designs were completely randomised, with five replications, and analysed in a 6 x 2 factorial. The data were submitted to analysis of variance and regression. No significant differences were seen in relation to the photoperiod or its interaction with the cytokinin and auxin under test. Multiplication was greater in the presence of 2.5 mg L -1 BAP, which gave a rate of 1.25 shoots/explant at 49 days of in vitro culture. The association of this BAP dosage with 1.0 mg L -1 NAA was even more efficient, producing 1.83 shoots per explant at 30 days of growth. The use of BAP together with NAA is beneficial to the induction of shoots in H. latispatha. Keywords: Heliconiaceae, 6-benzylaminopurine, naphthaleneacetic acid, tissue culture. RESUMO Indução de brotações in vitro de Heliconia latispatha em função do fotoperíodo e reguladores de crescimentoConsiderando a crescente importância econômica das flores tropicais e as vantagens das técnicas aplicadas ao cultivo in vitro para estas plantas, torna-se necessária a realização de estudos que avaliem a propagação de espécies como a Heliconia latispatha. Diante do exposto, o objetivo do trabalho foi avaliar a indução de brotações in vitro em função de diferentes concentrações de BAP e ANA em função de fotoperíodos. Os explantes, oriundos de embriões zigóticos, foram inoculados em meio MS contendo diferentes concentrações de BAP (0,0; 0,5; 1,0; 1,5; 2,0 ou 2,5 mg L -1 ), mantendo-se as culturas em sala de crescimento com temperatura de 24,0 ± 2,0 ºC sob fotoperíodo de 12 e 16 horas de luz e intensidade luminosa de 30 μmol m -2 s -1 . Aos 21, 28, 35, 42 e 49 dias após a inoculação, foi avaliado o número de brotos obtidos por explante. O tratamento com a concentração de BAP que proporcionou melhor taxa de multiplicação (2,5 mg L -1 ) foi fixado e, em outro ensaio foi testado com diferentes concentrações de ANA (0,0; 0,2; 0,4; 0,6; 0,8 ou 1,0 mg L -1 ) nas mesmas condições do experimento ...

Potted plants have wide appeal among ornamental plants and one of the most produced for the market belong to the genus Kalanchoe. One aspect to be observed in potted plants is their durability post-production when maintained in indoors conditions as offices and homes. This study aimed to evaluate the durability of the pot post-production life of three species of Kalanchoe (K. marmorata, K. thyrsiflora and K. tubiflora) on different substrates. The experiment was arranged in a completely randomized design with 40 replicates per treatment in factorial 3 x 2 (three species of Kalanchoe x two substrates - washed sand and coconut fiber). After 30 days, it was evaluated the general aspects as changes in color, leaf abscission and shading of the stem apex. It was found significant differences between species and also between the substrates tested, but only in relation to the general aspects. The species Kalanchoe marmorata and K. tubiflora stood out by receiving top grades in most of the evaluated characteristics. The best substrate that provided plants the maintenance of the most of their ornamental characteristics over the 30 days was the coconut fiber.