Resumo

PEREZ, Andreína; TRUJILLO, Iselen; VIDAL, María del Carmen  e  DE LIMA, Norka. Propagación in vitro de Stylosanthes Capitata Vogel : una especie de gran potencial forrajero . Acta Bot. Venez. [online]. 2006, vol.29, n.2, pp.335-346. ISSN 0084-5906.

ABSTRACT Stylosanthes capitata (Leguminosae) is a species of great importance in the vegetation of savannas of Venezuela. This perennial species which extends its range of distribution toward the subtropical area of South America (10°N-22°S), has been reported only in Brazil and Venezuela. It is resistant to drought, being able to extend its growing period to nine months in climates where droughts are well defined. Due to the ecological and economic importance of this forage legume, and the use of in vitro propagation as a tool of utility for the conservation of phytogenetic resources and its presence according to seasonal periods, it is of importance to develop an optimum process of in vitro propagation for this species that allows its availability all year around. For testing purposes floral buds as ex-plants, and Murashige & Skoog (1962) salts as base medium supplemented with vitamins as thiamine (5 mg/l), myoinositol (100 mg/l) and nicotinic acid (1 mg/l) were used. Addi-tionally sucrose (30 g/l) as source of carbohydrates and agar (8 g/l) as gelling medium were added. Two concentrations of BA (Bencilaminopurine) were employed as source of cytokinin (0.25 and 0.50 mg/l) as the initiation phase. The first morphogenetic changes ap-peared after 60 days of the explants initiation at the concentration of 0.50 mg/l. In the mul-tiplication phase two concentrations of cytokinins were used (0.50 mg/l and 1 mg/l), at higher concentration of this hormone (1 mg/l of BA) the evolution of the explants is pa-ralyzed and the number of buds by explant is reduced. In the rooting phase when 0.50 mg/l of IBA (indolbutiric acid ) were used and no cytokinin in the medium an adequate develop-ment of the radical system was obtained. The obtained seedlings were then acclimated and transferred with success to greenhouse conditions.

Palavras-chave : In vitro propagation; Leguminosae; Stylosanthes capitata.