Indução de brotações in vitro de Heliconia latispatha em função do fotoperíodo e reguladores de crescimento

Abstract

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 ...

Global vision of heliconias research as cut flower: a review

“…Regarding propagation, the studies were oriented to the use of growth regulators (BAP and NAA) in culture medium as this favors an increase in sprouts and it is possible to obtain satisfactory levels of propagation in heliconia cultivars (Raizer et al, 2015;Rodrigues et al, 2016). Tillering was also evaluated in relation to the efficiency of water use, harvested flower stems, relationship of harvested stems and number of tillers, among other variables (Coelho et al, 2019).…”