Resumo

MATERAN, María Elena et al. Reactivation of elite pinus radiata d. don. plant tissue by in vitro micrografting. INCI [online]. 2008, vol.33, n.1, pp.66-70. ISSN 0378-1844.

The effect of two asepsis protocols, scion type (apical shoot tips and brachyblast), gathering season (autumn and summer) and insertion position of the scion in the ortet (apical and basal) upon the micrograft establishment and consolidation of Pinus radiata D. Don. was evaluated. Scions were obtained from mature nursery cultivated clones. The asepsis consisted on the immersion in sodium hypochlorite to 2.5% v/v i.a for 15min (A1); or for 20min, followed by the immersion in a solution with benomyl+cisteyne 50mg·l^-1 each, until their use (A2). Hypocotyls from seeds germinated in vitro in QL medium without growth regulators were used as rootstock grafting. Micrografting was carried out using the apical wedge technique. The micrografts were kept in tubes with QL medium + 0.1mg·l^-1 AIB and 1mg·l^-1 BAP at 25 ±2°C, light intensity of 80µmol·m^-2·s^-1 and photoperiod of 16h. A completely random design with factorial arrangement (2⁴) was used, with 13 replications. Micrograft establishment showed significant differences in the type of interactions between asepsis/gathering season and type of scion/gathering season, turning out to be the apical shoot-tips gathered during the autumn and the A2 asepsis the best treatments for the micrograft establishment of P. radiata. The consolidation was influenced by the scion type and the time of the year when micrografting was carried out, the apical shoot tips (BA) behaving again as the most reactive material.

Palavras-chave : Asepsia ; Microinjerto ; Micropropagación ; Pinus radiata ; Tipo de Púa .