Initiation of embryogenic callus from mature zygotic embryos in Japanese larch (Larix kaempferi)

Embryogenic callus (EC) was created from mature embryos of Larix kaempferi. With the mature embryos, keeping the culture in dark conditions throughout the experiment (38.2%) seemed to give better results than exposing them to 16 h light (25 μEm -2 S -1 ) for the first week (21.9%). EC was obtained most frequently from Quoirin and Lepoivre (LP) mediums with 1.0 mg/L 4-amino-3,5,6- trichloropicolinic acid (Picloram), plus 1.0 mg/L benzyladenine (BA) (62.8%) or Litvay``s medium (LM) containing 1.0 mg/L p-chlorophenoxyacetic acid (pCPA) plus 1.0 mg/L BA (62.8%) treatment. In both cases, best results were obtained when zygotic embryos were cultured in darkness. As for the effective sucrose concentration on initiation of EC, 29.2 mM sucrose (38.6%) gave the best results.