Efficient Somatic Embryogenesis from Leaf Explants of Phalaenopsis in Vitro Culture and Histological Observations

The leaves of Phalaenopsis were used as explants and cultured in the 1/2MS basic medium with different kinds of plant growth regulators for somatic embryos induction.The effects of different concentrations of three kinds of plant growth regulators of 6-BA,Ad,NAA and their combinations on somatic embryogenesis were studied in in vitro culture.Meanwhile,the influences of the concentrations of sucrose and coconut water on somatic embryogenesis were studied,too.The results showed that the effects of cytokinins 6-benzyladenine(6-BA)was better than adenine sulphate(Ad)in embryoid induction.The auxin A-naphthalene acetic acid(NAA)combined with given concentrations of 6-BA and Ad could effectively raise the frequency of somatic embryogenesis.The optimum plant growth regulator combination for somatic embryogenesis was 6-BA 4.0 mg/L +Ad 2.0-4.0 mg/L+NAA 1.0-2.0 mg/L.20-40 g/L sucrose and 200 mL/L coconut water added in the medium was of benefit to somatic embryogenesis.The results of histological observations indicated that somatic embryos originated from upper epidermis and mesophyll single cell nearby stoma.The course of somatic embryos development was similar to other plants.Finally,the somatic embryos became protocorm-like body.