CHARACTERIZATION OF COMPETENCE DURING INDUCTION OF SOMATIC EMBRYOGENESIS IN ALFALFA TISSUE-CULTURE

Systematic manipulations of the culture protocol leading to somatic embryogenesis in alfalfa petiole-derived callus were performed to study the competence phase during somatic embryogenesis in alfalfa. These demonstrated a requirement for the acquisition of competence prior to the induction of the embryogenesis pathway. Induction was triggered by a number of synthetic auxins including 2,4-dichlorophenoxyacetic acid (2,4-D). Competence could be acquired in the presence of these auxins as well as phenylacetic acid (PAA), an auxin that did not induce embryogenesis. Different degrees of competence were apparently acquired by exposure to 2,4-D and PAA. Some degree of competence was acquired in the absence of auxin treatment. The current understanding of the concept of competence is discussed.