INDUÇÃO DE CALOS EM EXPLANTES FOLIARES DE LISIANTHUS (Eustoma grandiflorum SHINN)

Abstract

The lisianthus (Eustoma grandiflorum SHINN.) belongs to the Gentianaceae family, is a native North American plant, native northern Mexico and southern United States. The current interest of this species occurs primarily by the wide variety of colors of your flowers, high productivity and a long post-harvest period. Induction of callus is a basic step for the development of plant mass propagation systems. 2,4-D is the most used in auxin induction of somatic embryogenesis of many species. Inadequate concentrations of growth regulator may limit the formation of embryogenic callus and therefore embryos. This study aimed to test the influence of different concentrations of 2,4-D, the callus induction in leaf explants of Eustoma grandiflorum, to obtain somatic embryogenesis. Lisianthus leaf segments were fragmented on a cm² explants which were inoculated individually in test tubes on MS medium plus 2,4-dichlorophenoxy acetic acid (2,4-D) at the concentrations (0,0; 1,0; 2,0; 3,0; 4,0 and 5,0 mg.L-1) and benzylaminopurine (BAP) at a concentration of (0,05 mg L-1) under all treatments a total of 6 treatments with 15 repetitions. The percentage of callus from explants was assessed after 35 days, inoculated and after 42 days were evaluated for callus morphogenesis as consistency, color, median longitudinal length of the callus mass and percentage of embryogenic callus. The higher callus formation in explants of Eustoma grandiflorum occurs at concentrations of 1.0 to 3.0 mg l-1 in the presence of 2,4-D associated with the BAP; The MS medium supplemented with 1.0 and 2.0 mg L-1 2,4-D is effective in the formation of embryogenic callus from explants on Eustoma grandiflorum; All concentrations of 2,4-D associated to 0.05 mg.L-1 BAP caused a greater number of callus and friable with cream yellow color; There is considerable presence of endogenous auxin in Eustoma grandiflorum.