Morphological features of proembryogenic masses in relation to the ability of somatic embryo formation in conifers.

摘要

In order to investigate the ability of somatic embryo formation, morphological features of proembryogenic masses (PEMs) of Picea glehnii and Cryptomeria japonica, which differed in the ability of somatic embryo formation, were observed. PEMs of P. glehnii were composed of three kinds of cell, namely round or oval cells, elongated cells and protean cells. The embryo was composed of round or oval cells with dense cytoplasm. In suspensor, elongated cells with large vacuoles were arranged tightly and regularly beneath the embryo and protean cells were arranged at the bottom. By contrast, in PEMs of C. japonica, suspensor was composed of elongated cells with large vacuoles but protean cells were not observed. Arrangement of cells of suspensor in PEMs of C. japonica was sparse compared with that of P. glehnii. Such morphological features in suspensor would be contributed to the difference in the ability to form somatic embryos.