In vitro germination of babassu: influence of growth regulators in zygotic embryos/Germinacao in vitro de babacu: influencia de reguladores de crescimento em embrioes zigoticos

Babassu is a highly productive oil plant that is propagated from seed. Therefore, tissue culture techniques are of great importance because propagation is accelerated. The objective of this study was to evaluate the effect of growth regulators, NAA, BAP, and KIN, on in vitro germination and on the growth of babassu zygotic embryos. Three trials were conducted. For trial (I), the interaction between NAA (0, 1, and 2 µM) and KIN (0, 1, and 2 µM) were studied; for trial (II), the interactions among NAA (0, 1, and 2 µM), KIN (0, 1, and 2 µM), and BAP (1 µM) were studied; and for trial (III), the interactions among NAA (0, 1, and 2 µM), KIN (0, 1, and 2 µM), and BAP (2 µM) were studied. At 30, 60, 90, and 120 days of culture, we assessed average seedling height, and at 120 days, we assessed germination, the germination speed index, cotyledonary petiole growth, oxidation, and the formation of shoots, roots, and calluses. The best results for cotyledonary petiole formation and average seedling height were obtained when using 1 µM of BAP in the culture medium. We also found that the 2 µM of NAA favored root formation. Keywords: Orbignya oleifera (Burret.), biodiesel, Arecaceae. O babacu e uma palmeira oleaginosa, que se propaga via sementes. A contribuicao das tecnicas de cultura de tecidos e de grande importancia, pois acelera sua propagacao. Objetivou-se com este trabalho avaliar o efeito dos reguladores NAA, BAP e KIN na germinacao e no crescimento in vitro de embrioes zigoticos de babacu. Para isso foram feitos tres ensaios: Ensaio (I) interacao de NAA (0, 1 e 2 µM) e KIN (0, 1 e 2 µM); Ensaio (II) interacao de NAA (0, 1 e 2 µM), KIN (0, 1 e 2 µM) e BAP (1 µM); Ensaio (III) interacao de NAA (0, 1 e 2 µM), KIN (0, 1 e 2 µM) e BAP (2 µM). Aos 30, 60, 90 e 120 dias de cultivo, avaliou-se o comprimento medio das plantulas e aos 120 dias germinacao, indice de velocidade de germinacao, crescimento do peciolo cotiledonar, formacao de parte aerea, raiz, calos e oxidacao. Verificou-se que os melhores resultados para formacao do peciolo cotiledonar e o comprimento medio de plantulas foram obtidos com a utilizacao de 1 µM de BAP no meio de cultivo, e que a concentracao de 2 µM de NAA favoreceu a formacao de raizes. Palavras-chave: Orbignya oleifera (Burret.), biodiesel, Arecaceae.