Protocolo para a propagação In Vitro de Cedro (Cedrela Odorata L.).

Abstract

The family Meliaceae stands out for its economic value, medicinal, ecological and its potential for biotechnological exploitation. This study aimed to define a protocol for obtaining of plants of — cedar (Cedrela odorata L.) from explants excised of aseptic seedlings germinated in vitro and cultured in basic MS media supplemented with growth regulators and the addition of sucrose. For seed disinfestation were tested immersion in a solution of sodium hypochlorite at 0; 1,0:.1,5 and 2,0%, for 10, 15 and 20 minutes. The design was completely randomized in a 3x3 factorial (three concentrations and three immersion times) with four replications, with 5 tubes in each repetítion, totaling 200 tubes in the experiment. It was evaluated the percentage of contamination by fungi and bacteria at seven days and 15 days. To the induction of shoots, the study was divided into two tests. Test 1 was used nodal segments and apical in different concentrations of BAP: O; 1,0; 2,0; 3,0 and 4,0 mg.L'". The design was completely randomized in a 5x2 factorial design (five concentrations and two types of explants), with four replicates with five tubes in each repetition, totaling 200 tubes in the experiment. It was Evaluations were made at intervals of 15 days on the number and length of shoots by treatment. In the second test was used stem segments using 0, 10, 20 and 30 g.L"' of sucrose. The design was completely randomized with four replications, with 5 tubes in each repetition, totaling 80 tubes in the experiment. lt was Evaluations were made at intervals of 15 days on the number and length of shoots by treatment. For the rooting of shoots in vitro test was used to O; 1,0; 1,5; 2,0 and 2,5 mg.L' ANA. The design was completely randomized with four replications, with 5 tubes in each repetítion, totaling 100 tubes in the experiment. It was Evaluations were made at intervals of 15 days on the number and root length by treatment. The data obtained in different experiments, were subjected to analysis of variance and means compared by Tukey test at 5% probability. The results showed that use of sodium hypochlorite 2.0% for 15 minutes in the disinfestation of the seeds had the lowest percentage of contamination (10%). The induction of shoots was possible using 1 mg. L" BAP promoting the highest number d, 45 shoots/explant) and length (1,96 cm/explant) of shoots in the segments . apiosl and 2 g.L' of sucrose in inducing shoots on stem segments with the number of 2,05 shoots/explant and length of 1 cm shoots/explant. The rooting was possible with the use of 1 mg. L' of ANA with the highest number (2,5 roots/shoot) and root length (3,4 em/shoot) to obtain complete plant. Seeds are disinfested with success in solution of sodium hypochilorite 2,0%, induction of shójals on MS medium supplemented with 1 mg. L' BAP and sucrose at 2,0%, rooting at 1 mg. L” of ANA.