Somatic embryogenesis in avocado (Persea americana Mill.) in vitro

A tissue culture procedure was developed for the regeneration of somatic embryos from callus cultures of the avocado,Persea americana. Immature zygotic embryos, 0.6–0.8 mm long, were used as original explants. Addition of 0.1 mg/l picloram (4-amino-3,5,6-trichloropicolinic acid) to culture medium appeared critical for callus initiation. Development of somatic embryos was accomplished in picloram concentrations of 0.01 to 0.1 ml/l. A few well developed embryos produced green shoots. Attempts to induce a higher incidence of germination were unsuccessful.Investigation was supported by funds from the California Avocado Society, the Instituto Nacional de Investigaciones Agrarias, the Fundation Juan March, the Chancellor's Patent Fund, and the Southern California Phi Beta Kappa Alumni Association. Authors thank H. Quick for the photography and J. Lippert for the illustrations.