Micropropagação de gloxínia em diferentes concentrações de nitrato de amônio e uréia

Abstract

The high cost allied to the difficulty in the acquisition of the ammonium nitrate has been taking the accomplishment of works looking for an alternative for the substitution of this source of nitrogen. It was aimed at to study the technical viability of the substitution of the ammonium nitrate for urea, as source of nitrogen in the medium of culture for the culture in gloxinia "vitro". Gloxinia plantlets nodal segments were used, already established "in vitro", were inoculated in medium of culture MS 50%, added of 1 mg.L-1 of BAP, solidified with 7 g.L-1 of agar, pH was adjusted for 5,8 and sterilized to 121ºC and 1 atm for 20 minutes. The treatments consisted of the substitution of 0, 20, 40, 60, 80 and 100% of NH4NO3 for urea, and the swinging of nitrogen supplied by the medium MS it was not altered. The explantes were maintained by 120 days in growth room with temperature of 27 ± 1ºC, photoperiod of 16 hours and luminous intensity of 32 μM.m-2.s-1. From the obtained results it can be concluded that the urea doesn’t substitute NH4NO3 in MS culture medium as nitrogen source in the culture of gloxinia (Gloxinia speciosa Lodd.).