Abstract: The explants were collected in April and June from the same mother plant. The medium MS+6-BA 1 mg·L^-1+IBA 1 mg·L^-1 supplemented with L-glutamine 1 000 mg·L^-1 and proline 500 mg·L^-1 was used for somatic embryogenesis. The results showed that the better acquisition time is April. The histological study revealed that the cells of embryonic were small in size and dense in cytoplasm, which were significantly different with the cells of non-embryonic callus. The histological origin of somatic embryos was internal callus, subepidermal cells or surface of primary embryogenic complex. Observations by scanning electron microscopy (SEM) showed that the structure differences between embryogenic and non-embryogenic callus were distinct. We found that the cells of embryogenic callus were equal in size and had the shape of ball. There were cell masses consisting of many embrgogenic cells. The cells of non-embryogenic callus had no regular shape. There was interspace between them and cannot form cell masses.

Key words: Quercus acutissima, stem, somatic embryogenesis, histological observation