Abstract

The micropropagation of zygotic material collected from adult trees constitutes an important alternative in massive propagation of select phenotypes, appropriate for cloning programs implemented by forest companies. Using this technique, embryonic axes extracted from lignified cones located at different heights in the trees (basal, medial and apical zones) where in vitro introduced, with the objective of analyzing the possible relation between the physiological state of the forming tissue and the response obtained in the micropropagation of mature Pinus radiata embryos. Embryos obtained from cones located in the basal zone of the donor tree, demonstrated the best results in regards to germination (95%), survival (100%), microshoot proliferation (1.7 buds/microstems) and microshoot elongation (25 mm), which allowed to establish a relation between the development states of the explants and their response in artificial in vitro conditions, supplying background information for the implementation of a classification criteria of the collected material to be used in tissue cultures, due to the variable responses obtained according to the origin of the embryos from donor trees.