Calla lily in vitro multiplication: spectrum of light and sucrose/Multiplicacao in vitro de copo-de-leite: espectros de luz e sacarose

Light spectrum can modify plant morphogenesis through a number of processes mediated by light receptors, mainly in the red and blue region. The aim of this work was to determine a possible light type more active than the white light, and an optimized sucrose concentration, in order to increase the efficiency of the calla lily in vitro multiplication . To that end, the treatments consisted of four different light types (white, red, blue and green), under which the explants grew, supplied by colored T8 20W Ecolume 05/1 fluorescent lamps and various sucrose concentrations (0; 15; 30; 45 and 60g [L.sup.-1]). The culture medium contained MS salts and vitamins, added of 5mg [L.sup.-1] BAP and 5.5g [L.sup.-1] agar. The light type did not influence in vitro propagation of calla lily and there were a higher number of sprouts (2.0) in 45g [L.sup.-1] of sucrose. There was higher number of leaves in white (3.8) and in blue light (2.9) with 15 and 60g [L.sup.-1] of sucrose, respectively. Higher length of sprouts (3.7cm) was observed in 60g [L.sup.-1] of sucrose and higher fresh weight of the aerial part (1.07g) in 60g [L.sup.-1] of sucrose.