Effect of reinvigoration in the in vitro establishment of apexes and nodal segments of Cedrela Odorata L.

Abstract

The current research was developed with the objective to decrease the microbial contamination and to increase the survival in vitro of cedar (Cedrela odorata L.). Reinvigoration of mother plants was carried. Sticks of 1-2 cm of diameter and 25 cm of lenth collected in different periods of time were planted in a greenhouse. Growth regulator solutions were applied to evaluate sprouting, and growing of shoots and rootening. New shoots, sprayed with fungicide to eliminate in vitro contamination, were compared with apexes and nodal segments, without fungicide treatment, that were collected directly from field and the green house. Explants were disinfected with sodium hipoclorite (NaClO)to avoid contamination and placed in culture medium with 6-BAP 0.25 mg.l^-1 and AIA 0.125 mg.l^-1. The use of growth stimulating sustances increased sprouting and growing of axillary buds, and rooting of sticks. A n 84% of survival and 10% of contamination were achieved with disinfection by immersion of explants during 10 minutes in NaClO 1.5%. The necessity of reinvigoration of starting material to achieve in vitro establishment of cedar nodal segments was demonstrated.

Key words: nodals segments, axillary buds, disinfection, explants, contamination